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# Morteza (Mory) Gharib

### Hans W. Liepmann Professor of Aeronautics and Bioinspired Engineering

By David Zierler, Director of the Caltech Heritage Project

September 20th and 27th and October 4th and 11th, 2021

DAVID ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Monday, September 20, 2021. I'm delighted to be here with Professor Morteza Gharib. Mory, it's great to see you. Thank you so much for joining me today.

MORTEZA GHARIB: You're welcome. Thank you for inviting me.

ZIERLER: First things first, with your name. Does the nickname Mory, by which you're universally known, trace all the way back to Iran? Or did you take that on when you came to the United States because it was a little easier for people to pronounce?

GHARIB: No, actually, in Iran, all the Mortezas, for some reason, are called Mory, and all the Mostafas are called Mosy. My brother, Mostafa, is called Mosy, and I'm called Mory, so it's something that I inherited from when I was a kid. People called me that.

GHARIB: Yeah. Unless they're serious, and they wanted to punish me. Then, they use my full name. [laugh]

ZIERLER: Of course. That's universal. [laugh] On a more official level, would you tell me your titles and institutional affiliation? And you'll note that I pluralize title because I know you have many.

GHARIB: I'll tell a joke about all those titles. They ask a Russian general, "How come you have so many medals?" The guy says, "The first one was a mistake. The rest followed." [laugh] So all these titles kind of follow that. My official title is Hans W. Liepmann, Professor of Aeronautics and Bio-Inspired Engineering.

ZIERLER: Do you also maintain the Booth-Kresa Leadership Chair?

GHARIB: That's right. It's like a long train. Then, it's Booth-Kresa Directorship Chair. I'm not sure if the Autonomous Systems and Technologies comes after that or not, or just the Leadership Chair.

ZIERLER: And what about the Graduate Aerospace Laboratories? Do you maintain directorship of that?

GHARIB: That's right. Usually, we don't use it as an official title, even though it's my official title. But also, Director of Graduate Aerospace Laboratories. Another title is Executive Officer of the Aerospace Department. When they say Graduate Aerospace Laboratories, it refers to both the aerospace department as well as the Center.

ZIERLER: We'll take these back one by one. So let's start, first, with Hans Liepmann. Do you see any particular intellectual lineage between your work and what Liepmann did?

GHARIB: In many ways, yes. I am the academic grandson of Hans Liepmann. My graduate mentor professor was Professor Anatol Roshko, and his professor was Hans Liepmann. Hans Liepmann made a significant change, and I would say the second paradigm for GALCIT. We went from applied sciences to, a kind of twilight zone of basic research with engineering in mind. That was Liepmann's introduction, the transformation of GALCIT into a new area. We started to, put fundamental changes in the way we teach and how we do our research. It brought more fundamental basic research to the department. In research areas such as high-speed gas dynamics. He started, to a certain extent, encouraging us to search for a new environment to teach science

And also, some of the other areas, looking at turbulence not from what he called past, boring, where everything was mixed up so much that researchers couldn't find any character, to the point that he and his students, especially Roshko, discovered that turbulence is not featureless. And the reason we couldn't see those features is that we didn't have the right tools. So a trend that started under Liepmann was the development of diagnostic tools that were never seen or used before in aerospace, aeronautics, and fluid mechanics.

ZIERLER: So you're saying that Liepmann's influence was clear that at Caltech, he made these changes, but more broadly in fluid dynamics and aeronautics, he had this impact just in the way that basic science was approached in these fields?

GHARIB: That's right. And the reason was, he was a physicist by training when he came from Switzerland to work with Kármán. von Kármán was a true engineer scientist, and he invented the field of applied sciences. That's different from just engineering and more on how to apply science to engineering. Hans Liepmann said, "OK, let's take applied science, but let's now look at the fundamental constituent of this whole thing that builds up to that." Basically, he stepped back a little bit and said, "Let's bring physics into this." So that's what his contribution was.

ZIERLER: Would Liepmann have considered himself an engineer as well?

GHARIB: Well, we never found out. Engineers always claim that they can do "anything." But I think Hans Liepmann gave us the tools of fundamental concepts and principles to be able to do that "anything" much better. [laugh] Because he always told us that our education should allow us to basically delve into any field of science

ZIERLER: And this concept of not being bound by academic department or discipline really is emblematic of Caltech's entire approach to science and engineering.

GHARIB: Absolutely. That's in our fabric. And that's what distinguishes us and the type of education we provide to our students from other places.

ZIERLER: What does the Booth-Kresa Leadership Chair allow you to do in terms of the resources and the prestige? How does it fit into your overall research plan?

GHARIB: The Booth-Kresa Leadership Chair is a kind of magic wand, I would say. Because it allows people like me--I'm the first recipient of this honor--to not be restricted by conditions that some sponsors put around you. You can do projects or help projects with support freely different from the normal conventional avenues. It's really empowering because it allows you to be creative and pick up projects that other people say, "Hey, it's too difficult for us." But for us, too difficult is the right condition. If it's too difficult, we take it. And that's the luxury that this leadership chair provides: the ability to pick up projects that have high risk but high payoff.

ZIERLER: Does Booth-Kresa involve support for your graduate students and post-docs as well?

GHARIB: Well, it's a valuable discretionary fund. I use it in order to make sure that the whole Center for Autonomous Systems and Technologies (CAST) always benefits from it. It can be graduate students, it can be engineers who help us in various projects, or it can allow me to start a new project that I feel requires some new attention or new breakthroughs.

ZIERLER: Beyond Booth-Kresa, you operate in a world where the research can get expensive. You're not a theoretician who only needs a pen and a pad. What are the institutes, individual benefactors, or government funding agencies that are most important to you from a funding perspective?

GHARIB: Well, I'll start with me as a researcher. You're right. Doing experiments is costly. It also requires infrastructure. We're lucky at Caltech, especially GALCIT, that we have invested so much in the platform and the infrastructure that for us, doing some of the experiments or trying ideas that perhaps other people would have difficulty even to start is already here. We just need to direct it towards the research we want to do. Over the years, I've benefitted from the support of the Office of Naval Research, from DARPA, from NSF especially. Other colleagues note the Office of Air Force Research, the Army's Research Office, and different foundations that I have to acknowledge, like the Moore Foundation and other philanthropy-supported projects toward particular specific research.

So these are all well-known. But what's interesting about what we have done is, we've created such trust, and I would say a bastion of good science, especially at Caltech and in GALCIT, that some of those agencies, when they want new ideas, they come to us. I also have to mention the industry. My efforts and many of my colleagues are supported by companies like Boeing. I would say it's almost unconditional love because they know the role of having a place like Caltech and GALCIT to be in their sight when they have big problems.

If you recall that TWA flight that exploded and crashed, one of our faculty, Professor Joe Shepherd, who [was collaborating with] Boeing, he came to and asked for help to find the source of the problem. So GALCIT has that kind of reputation. When there are problems that they need somebody to take as a challenge and solve, they come to us. Over almost 90 years (from the time of von Kármán), we've developed a kind of relationship with aerospace industries. Like Northrup, some of them in Southern California had offices here in the building. They come for consulting. We did't go to them, they came here. Later on, the Rockdynes of the world, TRWs of the world, have all found us to be the ones that could solve problems with their rockets

ZIERLER: On the question of partnering with industry, whether on a consulting basis, just simply by the ideas that you have, or the products you create, what are some of the considerations with regard to intellectual property and patents in terms of where Caltech is in the equation, where you are personally, and where you are in partnership with the industry? How do all of those things work for you?

GHARIB: Well, when I returned to Caltech, as a faculty this time, we had a very old-fashioned system in place. Most of our interactions with our corporate partners were through consulting until we started the Office of Technology Transfer by Larry Gilbert. He did something kind of revolutionary here. He realized that most of our ideas by faculty were disseminated without us getting credit for it. So, after some lengthy discussions, he convinced the faculty and administration that it would be better for us to have these interactions in a structured way. One is a corporate partnership, of course.

And then, when we do consulting, unless there's something quite specific and already established in the industry, we try to develop a structure to protect our IPs. That office eventually evolved into, really, one of the best in the country in terms of how to be generous with industry, and in the meantime, expect that they are generous to us. As part of this new structure, we're protecting ours and their IPs. So those kinds of free-lancing consultations, compared to my time when I came to Caltech in the early 90s, have diminished. In the meantime, our interaction with the industry has become more structured and much more productive.

Then, when it came to protecting our ideas for startups, Larry Gilbert structured it in such a way that Caltech became a partner with startups with a minor role. It didn't become a landlord of the ideas. It was more about how to help you to flourish. In the early stages of any partnership with startups, we are very generous in terms of IPs, equity shares, things that other universities may want some ridiculous numbers. But one thing that Larry pushed was the second bite, which means that, as faculty, if you're successful, without any contract, we give back to campus by supporting graduate students, establishing professorships, scholarships for undergraduates. And that has been successful. Not to the extent that I would like to see, but it's a policy that has been very useful.

GHARIB: Yeah, it's a social contract. It's like the honor system. Put it that way. I'll give you an example. If I started a startup and were at university X, most would want 30% of the company. They'd give you just the rights for those patents. Caltech only asks 7%, 5%. And that gives those companies a good position for being attractive to investors from the outside. So at early stages, they don't die to see the light of day.

ZIERLER: Does this also encourage professors to become involved in these kinds of ventures, this arrangement?

GHARIB: Exactly. Because the world has changed. You don't need to go too far to find examples. Look at Bob Grubbs [Ed. Note: Grubbs passed away shortly after this interview.] Look at Frances Arnold. They both have Nobel Prizes in their pockets, and in the meantime, they have translated their work through very successful companies. It opened up the idea that by being open, sharing, you help both sides. And you don't lose your prestige. In some communities, they look at inventors like, "Oh, he's not doing basic science." But I publish in first-class journals and get the same recognition that those so-called pure scientists get. And in the meantime, we turn around and bring these ideas to a point where they have social impacts. Look at Moderna. It all came from basic research.

I can give you several examples of basic research that turned into something significant like the first DNA sequencer. Polymers that can be as strong as metals. Fundamental, basic research helped us first understand what the polymer is and then change it. There are so many examples that Caltech has pioneered. It shows how the bridge between basic research and something useful–not always immediately useful, sometimes more than ten years out. But some low-hanging fruits can quickly get out. The first DNA sequencer or the first microwave oven was invented at Caltech. Or the Xerox machine. These are all Caltech inventions or invented by people who graduated from Caltech.

ZIERLER: The list goes on.

GHARIB: Or the first robotic surgery, the da Vinci robot. These were all between Caltech and JPL. But they're not well-known in terms of being originated at Caltech. We are famous for our space and chemistry research achievements. But in between stars and Molecules, there's a whole world of amazing and innovative ideas that have come out of Caltech. Mainly because of the environment we have here. We don't distinguish each other as a basic or applied scientists, this or that. There are no castles to keep us from working with each other.

ZIERLER: You say that Caltech is not well-known for many of these things. If I do my job correctly, I'm here to change that perception!

GHARIB: OK, thank you. But I know when I was Vice Provost for Research, I realized that, and I had a presentation that I think my successor and other people have added to. You would be amazed to see how many things have been invented here that people don't know because of the same pre-1980s attitude that, "Anything applied is not good or honorable." But we do it. There are amazing things done. Carver Mead, just an amazing innovative guy who introduced the concept of "very Large Scale Integration" circuits or VLSI that allowed making of small electronic devices such as cell phones possible and other technologies such as CMOS that every camera in your cell phone is based on that technology. The CMOS camera was invented by Eric Fossum at JPL. Nanotechnology was started with Feynman. His famous phrase was, "There's plenty of space down there," about the concept of the nano world. But I think Caltech is very humble, and we do not brag about them. That's one thing that always amazed me when I looked at our professors. They do not like fanfares. That's our character, in a sense.

ZIERLER: It's about the research, it's not about the self-promotion, is what you're saying.

GHARIB: That's right.

ZIERLER: Does your chair as Booth-Kresa Leadership come at the same time as the origins for the Center for Autonomous Systems and Technologies?

GHARIB: No, actually, it came two years after. Because Kent and Lynn realized what was happening at CAST. Because CAST is structured to be different than other centers. We wanted to be a social club of technologies. Our researchers come together and work on ideas that never before were thought of and resolve the showstoppers preventing these ideas from materializing. I believe that Kent and Lin immediately saw the potential. And of course, from day one, they knew what we were doing at CAST. And I think that it didn't take that much convincing for him and Lynn to realize that giving a leadership chair will transform even further the nature of the center that we have.

ZIERLER: The term autonomy as it relates to technology can mean so many different things. How do you understand autonomous systems within the context of the center?

GHARIB: It's an excellent question because there's a difference between autonomy and automatic systems. Let's start with space projects. Think of all the JPL's missions, especially in deep space exploration. Those are basically all automated missions. Somebody wrote down the program. "At this time, you turn this on. At this time, you turn this off." These are OK as long as the time that it takes for the signal to come back and tell you whether you're doing it right or not is within reach of sending another signal that can be read so it can be controlled. If the operator at JPL sees something goes wrong, they can push a button and stop the system. But now, imagine you go to Mars, where it takes many minutes, maybe up to 20 minutes, before you get a signal back.

And now, suppose that something happened that you don't know about. Then, there's no way to react to it. And suppose, now, that the spacecraft had its own brain to solve problems of an unknown nature. Of course, it can say, "OK, if this circuit goes out of control, bypass it and do this." You can do it to a certain limit. But those are all, again, very prescribed kinds of solutions to know possible problems. But even if a well-known problem happens at a time it should not occur, then your spacecraft is hopeless in handling it. It cannot do anything. That's where autonomy comes in, where it can make decisions for the benefit of the system without the intervention of a human operator. And that makes the distinction.

Think of a submarine at the bottom of the ocean. The time delay between what goes and what comes back is not the problem or the limiting factor. At the bottom of the ocean, a machine can't even get a signal. Radio signals cannot penetrate the ocean. You need to have systems that can make decisions and solve problems based on whatever's happening at that time. And this is what the center was trying to do, bring us out of that automatic way of thinking and solving problems to a form of autonomous systems that can think independently and solve problems to the benefit of the systems. That's where the gap was. But for many, many years, when we said automatic, people thought it meant autonomous. But that's the distinction.

ZIERLER: And where is artificial intelligence or deep learning in the overall Center?

GHARIB: For the Center, we benefit from some of the best in the world. People like Anima Anandkumar, Yisong Yue, Houman Owhadi, Adam Wierman. Groups will benefit from working with them. They're taking machine learning to different levels and formats. There's nothing for the machine to learn, really, in practice. It's how the thinker behind it wants the machine to learn and think. And that's what defines the quality of the thinking machines. If you're limiting your thinking, you specify the thinking capabilities of the machine. If you are willing to allow the system to be more independent in coming up with new solutions, then the product is, in a way, ready to take more risk. In this respect, machine learning and AI allow you to take calculated risks to minimize the chance of failure. I hope the center provides that environment to enable our researchers to take bold steps.

Think of atmospheric turbulence. It's unpredictable. Even on a very calm day, if you're flying in downtown LA behind a giant skyscraper, suddenly, you can have turbulence of the scales that can easily crash a helicopter if you're not careful. Imagine that with drones, robots, or submarines that go to areas with unknown environmental factors, you need to have a system that is willing to learn to fly or swim into these unknown conditions, for example. We had projects where these machines are learning that instead of jumping into the whirlwind of a tornado, they can just touch it and learn how to go through it. ML and AI can help find a different path or even use the tornado itself to slingshot to the next destination. So those are the kinds of machines you like to have to bring even aviation into a modern and safer space.

Right now, you can see that. We can sort of autonomously take off and land airplanes. But most of them depend on the pilot to be able to intervene. If there's a sudden downburst, most current systems cannot handle it. But in a system that is willing to learn, using a suitable learning scheme, it can get all the information and make a decision much faster than any operator in the control tower can. So that's where we're going.

ZIERLER: This question might push into the realm of science fiction, but as you describe the Center, one of the goals is to push forward the distance or separation between the system and the operator. To what extent is the long-term goal really to fully decouple the system from the human operator?

GHARIB: Well, it's not just a human operator. We want to decouple the actions of the human operator. But we can't decouple a human operator as the entity that designs the system. At the end of the day, whatever decision that machine makes follows protocols we tell the system to follow. It's not total decoupling. And you don't want that even. You don't want just to throw something in the air and say, "Wherever you come down, it's OK." It's not OK. That's where the protocols become essential. So the decoupling is mainly trying to add [to the] system to avoid disaster.

For CAST, for example, from day one, we said, "We want to have a system that can be a partner with engineers, scientists, and first responders. Partners." That's very important, autonomous partners. You have a group of people where each is capable of making decisions, but there's an agreed-upon protocol. If I have an autonomous robot partner, that means that the robot and I are working under the same protocol. That way, you make it safe. This negative connotation of AI that suddenly wakes up and tries to destroy humanity is null if we put in the AI DNA to follow a human-safe protocol.

You create a safe zone if you define the "fight" for AI as the RED line. And that's where we draw the line for the AI or the robot. We draw the line, and it's helpful because we will have an answer to people who say, "What happens if this AI starts to fight us?" So that's the kind of system protocol that we should pursue to develop.

ZIERLER: On that point, because intellectually, your interests are so wide-ranging, to what extent is the Center for Autonomous Systems and Technologies also a place for people to consider the economic, legal, or even moral implications of autonomous systems?

GHARIB: Well, I would say that's the most important question you've asked. Because that goes to the process of understanding the protocols, and you've heard it a lot, "Should I hit the grandma or the lady with two babies?" First of all, I don't think you're going to have fully autonomous systems unless we have, I would say, instrumented environments. Instrumented environment means that every street in the city should be instrumented with gadgets that observe the field and allow autonomous cars to rely on their AI that comes from the factory but operate according to the local AI's guidance. In this respect, the whole city is alive. You (or your car) know about every other car's action that may affect you.

ZIERLER: Kind of like a train only goes where there are train tracks, you're saying.

GHARIB: That's right. But it can go off the track if it knows that everyone else is also following specific protocols. Then, you can have a safe autonomous system. That's what's important. Is it morally OK for us to allow a robot to decide a fate? The quick answer is no. Because you're asking, "Whose morality?" If you go to New York City, Paris, LA, Glendale, or Westwood, they drive differently. Because for them, it's OK to do specific actions. Because of our bandwidth, undertaking research projects on AI ethics was beyond the center's objectives. But that doesn't mean I did not start working with people like Jean-Laurent Rosenthal. I encouraged him, "Please, you should hire people that look at these problems."

Because it's not an engineering question, it's a social question. We like engineers and scientists who will work at CAST to be exposed to those kinds of questions and issues. And thanks to Jean-Laurent, we are hiring people looking at these social and moral issues with AI and autonomous systems. It's going to be an exciting time because, in the next generation of calls for proposals, we're going to ask for those kinds of proposals from different sectors of campus for funding. It's an issue that lots of our students bring up, that it's not just an intellectual interest; it's more our obligation to make sure students are exposed to important ethical and moral issues in AI, even though we may not have the answers. Like science, we don't have answers to the questions of the future, but we're training people to address those questions.

ZIERLER: Of course, it would make sense that students would be keyed in to these things because they recognize that this is a way of life for their future.

GHARIB: Absolutely. I recently got a Tesla. And the first thing I did was to reject the offer of giving me full autonomy. I said, "Not yet. We'll talk later." But it is really impressive when you look at how they employ sensors to empower me. It gives me a sense of autonomy. I'll tell you how. Because many times when we try to park in some tight places, we ask one of the passengers, "Am I close to the curb or some posts?" Because it allows you to park almost without any help from outside. That means the whole system (sensor-empowered driver) is autonomous. So me and my car, we're more autonomous together than before. It's interesting. It's going in the right direction. It causes fewer accidents, enables more alert drivers. And it's a combination of man and machine that makes it a much better machine in total.

ZIERLER: To go back to this idea of shared protocols, what does it tell you not just about Tesla, but about society in general, that when you buy a Tesla, you're given the option to opt-out of the autonomous package?

GHARIB: Well, I think it's a wise decision to opt-out. Because as an individual, I don't want to be a guinea pig for a large corporation to see if I'm going to have an accident with their system or not. It's a very negative thing for me to say that, but it's true. Am I going to drive that thing with my granddaughter sitting in the back? No. I'm not ready for that kind of risk. But eventually, we're going to be convinced once we have a better-instrumented environment. I will have scratches the first three months in every car I buy, a ding somewhere. This is progress! But fortunately, knock on wood, I haven't had a tiny scratch on this machine.

So for me, that's convincing. The next time they come to me, I may consider something. But that shared protocol, I think, is essential. I strongly recommend making your machine learn about me independently, not as a statistic, to all of these companies. Because when I'm driving, I may enter a situation that I may have only one second to make a decision. Well, why not make your machine or car learn from how you make the decision? And why the common protocol from the instrumented environment should stop me or help me to avert dangerous situations. Then, insurance companies are going to have a much easier time. And first responders will have an easier time because they can quickly check lots of things that they couldn't before. Your machine learns about you and works with the instrumented environment to keep you safe.

One of the projects where I haven't seen any proposal yet, but I'm seriously considering starting, is having some robots that can freelance around the lab. They do nothing except observe and learn by being next to a graduate student, for example, and watch how that student works. Robots' mission would be to help or even try to be part of that project following the researcher's style. But that requires a very creative learning process. If you assign the machine to learn from the graduate student, you're saying, "Learn the protocol of how this graduate student works." Each one of us has our style, correct? That's our protocol in doing things. And it's better to have these machines get used to you and even help you follow the established protocols of the lab.

ZIERLER: Does the name Graduate Aerospace Laboratory suggest that undergraduates are not part of the laboratory?

GHARIB: Yes, and no. Academically, we do not give an undergraduate degree. But we allow students from other disciplines to do an emphasis on aerospace. But it's not a degree in aerospace. The whole idea from Kármán was that we don't want just to bring aerospace engineers to become another aerospace engineers. He considered how smart they were. Now, we get students from all different fields. Mechanical, chemical, electrical. It's a research program that allows students with different abilities and enables talents to come become part of us. And we benefit a lot. If you look at our impact on the invention of new instruments for flow diagnostics, you will see, it comes from all different backgrounds. I, myself, will benefit from having students from materials science or electrical engineering. Not from another aerospace program. That doesn't mean they cannot come here. All I'm saying is, it benefits everybody to have people from other disciplines.

ZIERLER: This whole discussion so far has been about all of your titles and associated work. I'd like, now, to ask some very basic questions as they relate to nomenclature and your overall approach to your research. So at the most fundamental level, we have the words, of course, scientist and engineer. To some degree, these are just words, and to another degree, they have actual distinctions to them. For you, what are those distinctions? When do you have the scientist hat on, and when do you have the engineer hat on?

GHARIB: For me, the science hat is the one we wear when we're struggling with understanding some basic, fundamental questions. And most of it is not necessarily something defined 100 years ago. One of the talents, I would say, that we're given here is how to turn around a practical problem and find out the most fundamental question we can make from it. I'll give you a simple example. I was struggling with the very unusual number some of the prominent researchers had reported on the process of vortex formation. A vortex is a well-known fluid mechanical machine known and studied by Lord Kelvin about 100 years before my advisor, Anatol Roshko. They all worked on different aspects of it.

But something caught my attention, that there was a limit to the size of a vortex ring, like the puff of a cigarette, vortex mushroom from a volcanic eruption, to the vortex rings we can generate with a toy gun. I mean the maximum vortex size formed from the roll-up of the jet column that initiated it. It seemed that the maximum size was reached when the column length was four times the column diameter. If you look at Mount St. Helens eruption pictures, the largest puffs diameter is four times the diameter of the jet that comes out. I wondered where that four-diameter ratio came from. The number is so observed in biological propulsions lik in jellyfish. With every stroke, the jet that comes out is about four times the average diameter of the nozzle. We could not explain it. It was not a practical problem issue. Why is it important to figure out the trick behind the four, or why did nature choose that? I also found that the most optimal heartbeat you have, the flow that goes from the mitral valve into the heart chamber, is four times the diameter of the mitral valve. Just like the jellyfish and Mount St. Helens.

And it bothered me; I couldn't even sleep for nights. And that, for me became the most fundamental basic science question I could imagine I faced that later on turned into some important real discovery. Namely, nature uses a very clever optimization of all parameters involved to not spend too much energy, from jellyfish to the human heart. Then, I went back and started to read the work of Lord Kelvin, Helmholtz, and all those guys who came generations before me. My group explained that nature follows a principle known as Kelvin-Benjamin that shows us how to make the largest vortex with minimum energy available. Then, I could sleep. That was nice. Three or four years later, I got a call from one of the agencies saying, "Can you design a nozzle using the KB rules?" That's an engineering problem.

So with science, I explained something that existed. It didn't rely on me to exist. That number four was the so-called formation number – some of my students wanted to call it "Gharib number," but I refused to accept it. Because I just had explained the reason behind the magical number "FOUR," and why fundamentally it was happening. When it comes to creating a new nozzle that sends a vortex ten times further, or combustion engines, or for jet propulsion, something like that, then I made something that had never existed before. That's the difference between a scientist and an engineer. A scientist tries to understand the meaning of things, as Feynman says. An engineer creates things that had never existed before, as von Kármán said.

That, to me, is the line. Caltech values applied sciences, like how we took that science behind vortex formation and applied it to something useful. But let me say something perhaps you've never heard before. I hope. [laugh] But that is about the meaning of the word engineer, which to me is the wrong word for what we engineers do. Italian or Germans use the proper term, Ingegnere or Ingeniour or Creator. The phrase Engineer refers to somebody who runs locomotives and steam engines in English. And unfortunately, in English, the meaning has been lost in translation. Engineers are not the operators; they're creators.

ZIERLER: I can't help but ask, how does it translate in Farsi?

GHARIB: In Farsi, with some influence from Arabic, has a funny twist to it. It refers to a person who uses geometry to build things. Muhandis. It's more like Ingegnere, a creator rather than an engine operator.

ZIERLER: A very broad question that will ask you to survey your research group, and the way that you build experiments, and the papers that you write. When you are conceptualizing an experiment, does every experiment for you always have a basic science and an applied research component to it? In other words, is everything that's done in your lab about understanding how nature works and then figuring out how to apply it? Or are some experiments that you do strictly basic science or strictly applied research?

GHARIB: Yes, to everything you said. I would say there are areas of research that I'm interested in to understand the fundamental aspects and where I can connect it to more fundamental laws of nature. And there are times that I'm just a naughty scientist who puts things together and says, "Hey, this works this way, too." But what is interesting is that every time we do something more practical, naturally, we want to show that it sounds fundamentally correct, too, as we envisioned it. And it's a very, a very gray area, I would say.

So I've done experiments that had no purpose but just to satisfy my curiosity. Mainly because I either couldn't find the correct equation (as I call them "the laws of men") or could not find a solution to the governing equations. But, once you observe a phenomenon, you know that it exists. In other words, you observed manifestation of the "Laws of Nature" through experimental observation. Naturally, we get motivated to fit one of the laws of men to represent the laws of nature. It's a dangerous way of doing things sometimes. Because you know that a solution exists, you find a way of getting to it. And that's where many scientists get it wrong. They come up with a solution that explains what they saw, but it's not necessarily the correct answer. They impose their laws on it. But in the meantime, there were scientists such as G. I. Taylor who conducted seemingly non-purposed experiments to discover new phenomena and formulate the process correctly.

Unfortunately, the academic climate these days does not allow the freedom in exploration that scientists of previous generations had in choosing to do "useless" basic research. Depending on the stage of your scientific endeavor, the restriction I mentioned before may become even more challenging if you are a tenure track professor. As you get to my age, I think, "Hey, what's going to happen? Let me try things that I wanted to do but was afraid of." And that's kind of an approach that is encouraged at Caltech, in a sense, encouraging professors like us to reinvent ourselves by not just limiting themselves to what they have done before.

Some Aerospace professors here have changed the course and started to work on geological problems. So it's an unlimited place. As one of our previous presidents said, "At Caltech, we don't even have a box to think outside of." So the box is something you create, but you shouldn't. I think it was Jean-Lou Chameau who said that. And I use it all the time. I say, "What box? Why am I thinking within this?" Those kinds of limitations are, I would say, hazardous to a free scientific mind.

ZIERLER: On the point of knowing what the solution or the outcome is and then building a means to get there, that begs the question of the role that theory plays in your research. So on that point, what are the most important theoretical propositions that inform your work?

GHARIB: Well, for me, I think I would be delighted if I could come up with a theoretical basis for my research work. And that's always my compass. Because that's the only way, you can build upon more. Otherwise, you have to be careful to build a 100-story building (metaphorically) based on some empirical findings and without enough basic science or modeling. For most of my empirical research findings, I limit their applications to areas I am sure they work. But if I achieve a theoretical work that can fundamentally define what I've done, then I have no limitations. And a good example I gave you is the formation number. It was the most fundamental theoretical work I could imagine in showing how nature optimizes the process of vortex formation.

Once we established the validity of our understanding based on Kelvin-Benjamin optimum energy theory, then I asked myself, "How could I use the Formation number to find if my heart is sick or not sick based on the strength of the vortex that forms inside of our left ventricles with each heartbeat?" However, in physiology, it becomes more statistical than an exact science. We took the same principle and showed how a healthy heart should work. And then, from there, we applied it to the performance of jet detonation to improve thrust generation. But without the theoretical foundation behind the "Formation" number, I would not have permitted myself to act blindly in expanding its application and just say, "Oh, OK, this is another invention." It's a kind of zig-zag path. You go there, try this, go back, check your theory, then see if you can apply it. Then, you build up the platform. After that, you can fly anywhere you want because you know that that theory is still there when you come back.

ZIERLER: So it sounds like theory prevents you from being an aimless tinkerer.

GHARIB: Well, we have to have the option to tinker. I want to make sure that what I build, I can create something on top of it and that it lasts for some time at least before somebody comes and says it's wrong. But that doesn't mean I don't do tinkering. Because tinkering is healthy. I think tinkering is one of the most impressive features of being human. Some animals have it, too, but not like we do. Just think about it. Thomas Edison tinkered. And I bet he didn't know how to write the equation for any of it. And I have an article about Edison and if he could receive his tenure in today's academic environment. If you're really showing a very distinct way of tinkering, Tinkering by itself is important. Remember that people built the steam engines before knowing about the first law of thermodynamics. They came up with the first and second law after we got a good train ride. So tinkering is fantastic. But as a scientist, if that's the only thing you're satisfied with, you're in trouble. Because you're not a scientist or engineer (Ingegnere ). You need to try to understand the fundamentals.

ZIERLER: To go back to basic science versus applied research, even at an emotional level, how do you compare the satisfaction of solving an equation that has no bearing to daily life versus coming up with a drug delivery system that can actually help people? How do you compare those satisfactions?

GHARIB: They're both equal, personally. From outside, I hear people say that through my work, "Oh, yeah, he saved the eyesight for millions of people." And it is very gratifying. But for scientists, that little moment when you could suddenly explain to yourself that through your science and engineering skills, you saved millions of eye sights, it's like winning a chess game against a computer. [laugh] That kind of satisfaction has no equals. With some of my students, I try to show them how they can explain some of the laws of nature through back-of-the-envelope calculations and guide them through clear thinking and a little imagination to see the unseen. And then, they can solve challenging problems because of enabling education that they received in places like Caltech. I think I mentioned it to you. Even though I have close to 140 patents, I had not invented anything until I came to Caltech.

It was amazing. People ask, "How come you suddenly woke up and started inventing things?" I said, "Because I suddenly felt I could. I fundamentally feel satisfied that everything I invent, I can explain." That was really the turning point for me. Because suddenly, I realized that I was strong enough in terms of my science, and so I should not worry about being judged and just apply what my education at Caltech empowered me with to inventing.

ZIERLER: That probably goes back to the Caltech idea that there's not even a box to think outside of.

GHARIB: Absolutely! Let me give you an example of the "NO BOX" scenario. Sometimes back, I invented (with my smart ophthalmologist Dr. Rick Hill) a tiny shunt that nowadays ophthalmologists implant in the human eye as a viable treatment for glaucoma. It is funny that some people thought a different Mory Gharib invented it. Also, a very famous East
Coast professor tried to convince me that my invention should not work according to all the fluid mechanical laws. But my response was, "Yeah, but you forgot that the fluid mechanics that they used his argument for was fluid mechanics of steady flows." But the flow inside the human eye is pulsating, and my design worked because I took advantage of heart pulsation that transmits through the eye. You stand on top of it and don't move; you can see your heart beating in the needle movement.

When I wrote down the equation, I said, "Yeah, the shape of the tiny shunt doesn't matter and only matters if I pulse the flow-through has, and it will have a different behavior." This is an excellent example of not considering any BOX. And it only happened at Caltech. I could not have done this otherwise. We in the science community are not in the moneymaking business, correct? All we live on are the satisfaction of discovering things and acknowledging our colleagues. But sometimes, it becomes restricting. Sometimes, you don't do certain things because of colleagues around you. But at Caltech, I don't feel like that. My colleagues would be unhappy if I didn't go out and do things that make them proud of me, or if they didn't do things that made me proud of them. That's the difference at Caltech.

ZIERLER: A question about the overall academic disciplines that inform your research. There's mechanical engineering, aerospace engineering, aeronautics, fluid dynamics. Is one of those, or something else, perhaps, something you consider the umbrella that the other disciplines fall under? How do you think about those things?

GHARIB: I consider fluid dynamics as a branch of physics. Everything I've done, all my inventions, all my papers, and all my discoveries, I've thought of flow and its magic. It's such a rich area in terms of the type of challenges that it poses to scientists. Even the governing equation itself has the mystery of being non-solvable in some seemingly straightforward cases. We change a condition, fit things, and find a solution. But we could not solve the whole thing. And it all goes back to the fundamental nature of the phenomenon by itself, that from atmospheric turbulence–isn't it fantastic anything even how flies fly? Every time I look at it, I say, "Why?" But there are still so many fundamental problems in fluid mechanics that we could not answer through its known governing equations. It is impressive that even without having a solution for the flow around an airplane, we can still fly them.

ZIERLER: It's incredible that in fluid dynamics, these existential questions remain. In physics, it makes a lot of sense why we don't understand dark matter, or if there is a component part of quarks. But for something as Newtonian and classical as fluid dynamics, how do you understand that even this discipline, there are such fundamental questions that remain to be answered? What is it?

GHARIB: I think it goes back to the fundamental nature of the equations that govern it. An equation is something that man makes, correct? Maybe we don't have the right equations. But I think we have the correct equation to the best of my knowledge. But then, if you look at the nature of the equation, it's such a nonlinear process that it's hard to come up with solutions for every possible boundary condition in time and space. A slight change may result in a completely different outcome. It's hard or impossible to develop one unified theory to cover everything in fluid mechanics. It's the beautiful nature of the fluid mechanics to be mysteriously providing and sustaining life and nature. If you look at it from blood flow, plasma, radio jets, black holes, they're all, in a sense representing flow dynamics.

So it's a very fundamental nature of life in general. I would say the life of physics and the life of us, too. But it's there. It's everywhere. I would use the phrase, "Life is aquatic." That defines the human body. The creation of the universe is a display of gas dynamics. That's all it is. And then, you can imagine that we are made out of the same dust. It's such a complicated, interwoven thing. That's why I would say fluid mechanics is overarching. It benefits from all aspects of physics challenges.

ZIERLER: As you well know, over the past year and a half, fluid dynamicists have been in the spotlight because of their contributions to understanding COVID, both in the way that we have droplets in saliva to the ways that vaccines move throughout our bodies. I'm curious if you've been involved in any of this research.

GHARIB: Not in the vaccine part. But, I was interested and sort of knowledgeable in sneezing and how particulates spread. That's why I was astonished when, for example, in the beginning, some authorities set the social distance at six feet apart. To me, it didn't make sense. Many of my colleagues at Caltech and other universities, who had researched this area, had pointed to some of the issues of why six feet distancing is not good advice and why we should have masks as a better approach. Particle image velocimetry, a digital version, came out of my group in the 1990s. It was used by other researchers in tracking particles and finding the extent of what should be, for example, the distribution of the number of particulates to be dangerous in terms of when you're exposed to it. So in that respect, I made a little contribution.

ZIERLER: What is the origin story for you intellectually in looking at biology as a source of inspiration for engineering challenges?

GHARIB: Well, like everybody else, I thought nature came up with the most efficient, optimized solutions. That was the initial attraction for me. And I felt that fluid mechanics of nature displays an open book of optimized design. But later on, I realized that actually, what we should do is save time by looking at nature for all its mistakes and triumphs. Because it's already done all the experiments required to be done, all the conditions that you may think of. So any natural design we're looking at already has gone through all of the trial and error. So, we already have hints of the evolutionary solution to a specific objective function. Another problem is that nature's objective is usually different from the objective I(as an engineer) have.

For nature, the objective is not sufficient to be efficient. For nature, the aim is to survive. With the limited time (compared to the millions of years that nature had) that we have in designing any system, we need to develop a different approach. That's where I started to look at the subtle differences and see opportunities in understanding natural systems. That's why bio-inspiration is [something] other than biomimetics. Biomimetics, you copy things. I can grow a heart for you, but it's not going to beat. Even if it does beat, it'll stop after ten cycles. But by studying how the signal transmits and how the biological material works, I should be able to develop a similar pumping function by perhaps using a different morphology with materials available to me. Nature created materials like wood that we still can't make. But it's an excellent material for heat transfer for stress resistance.

So what should I do, not build? No, I don't make a tree. I produce other things and materials that I can design and build for that function. That's why, for me, nature is an excellent open book of design. But the designs that nature comes up with are not necessarily the ones I want. But I learned enough to be inspired by it for my design. I think humans are more intelligent than nature because, in some aspects, we achieve things in much shorter time scales than nature can even think of it. That's how I got interested in the field of bio-inspired engineering because I saw nature's tricks. And I'm not the first one. But I tried some approaches that I thought were exciting and important.

ZIERLER: As you explain it, if you are inspired by a particular fish heart and the way that it works, what you're saying is, it works because of evolution, because of natural selection. But you are interfacing with that fish heart just as a snapshot in time, right? To what extent are you inspired more broadly by the process of evolution itself and not just the biological systems that evolution creates?

GHARIB: Well, I can give you an example. What fascinated me was that every biological system sustained itself like a vertebrate heart. Man-made systems don't do that. If you look at a car company, you have to order all the parts, and at the end, you put them together, and you turn it on. But if you look at the evolution of the human heart from embryonic stages, it was a heart providing the same function. It evolved into different phases. Going through the phases, it sustained its functionality. The snapshot of each step was a fantastic experience. If you learn enough, and you are capable of developing the theory behind it–like the case of the embryonic heart of the zebrafish, we helped us discover the concept of valve-less pumping, also known as impedance pumping.

For the impedance-pumping concept, we can write the equations, and the equations are the same equations we use for wave propagation in gas dynamics. So that's a snapshot of that embryonic pump. Then, you look at how an embryonic fish heart, just an elastic tube, suddenly becomes a four-chambered positive-displacement pump. Then, you face the question of, "Why did you stop here, and why didn't you continue your amazing impedance machine to adulthood?" Then, you say, "There must be some epigenetic factors." Something from outside tells the valveless pump that things are not working correctly. Then, you start to look at shear stress on the walls of the vessels, and you realize that every time you pump the flow, because resistance due to growth of the body, the flow comes back. So there is no net flow forward. Flow just goes back and forth and creates an alternative negative-positive shear. Here, nature becomes smarter. Walls of the embryonic heart are made out of cells that sense shear called endothelial.

Then, endothelial cells started to feel the alternating reversing shear. The location that handles the highest shear sent a signal to the cell, "This is the time to grow a valve." So DNA information was there and decided where the maximum shear should be felt. But the epigenetic factor triggers the timing, and that discovery is impressive and important because then, we could control the trigger. I could make the valve starts earlier or later. And then, we took that concept and said to doctors, "Maybe that's why a pregnant woman should not drink too much coffee. Because the heart rate goes up, you will have negative-positive shear stress, and endothelial starts to react differently, so the valve grows earlier than it should."

Or, if you have alcohol, it delays it and grows too late. This is a very fundamental discovery that a snapshot into nature gave us. And nature has gone through all of this. That's why I'm saying it has done all the experiments at a high cost. Many species do not exist anymore. But what we have right now is an excellent solution to a good problem. We can develop sound scientific concepts based on engineering ideas from nature. And that's what I got interested in and inspired by.

ZIERLER: You said that in many ways, we are smarter than nature. It's a comment, of course, that has deep philosophical connotations. Are you suggesting that the human mind has evolved to a point where it is somehow separate from nature? It's a unique category within nature?

GHARIB: No, I didn't mean that. I meant that the human brain has evolved to the point that it can avoid the lengthy processes and jump to a solution at a much faster pace.

ZIERLER: Than evolution?

GHARIB: Than evolution, yeah. And that's what I meant. If intelligence is defined by being faster, then yes.

ZIERLER: It's well-known that art occupies a very special place in your overall inspiration as an engineer and as a scientist. First, where did that come from? Where did this connection of art and science happen for you?

GHARIB: That's a good question. I loved art only in terms of music before. But my wife was a sketcher, and I started to appreciate art in terms of how your brain sees things and how you express them. But then realized that art and science are two sides of the same thing. Only certain plasticity separates them. In reality, I think that an artist sees the same thing but comes up with a different way of expressing it. And many good scientists are natural artists. I'll tell you why. We sometimes see the unseen. And that's what artists do; they see the unseen. So, talking mainly about painters, they draw what is not seen by the naked eye. It's an impression of the brain that sees something you don't. And scientists do the same thing. The brain deciphers things that we don't see first when we encounter a scientific or engineering problem.

And for me, that was intriguing. I know everybody loves Leonardo da Vinci, but I love Leonardo differently. I never believed that he was only an artist. I thought that he was just a discoverer of nature. But he, to me, was somebody I felt everybody has a little bit of him in them. But scientists can adopt it by just being curious about everything. And as a scientist, you develop that kind of artistic approach. As a scientist, we always get interested in where we can bring science and art together. I don't think you should bring it together. They are already together. I don't need to bring them together. To me, if somebody says, "I'm going to combine art and science," they're in the wrong place. I think you should present your science as a form of art no matter what. An artist should be able to comment on science in different ways. They don't use equations.

Unfortunately, because of our education system, we classify so much that people think artists and scientists are two different species. But in the 12th century, a doctor of philosophy approach entitled you to look at anything you want. For Leonardo, even though he did not see the equation of motion, which came 200 years later, he saw the phenomenon and the equations without seeing them. That's why if you look at some people like him, every painting, everything that they say, they follow specific rules that, in their mind, were supposed to be the governing equations of nature. He uses the same rules, from a curl in a lady's hair to the curls of a vortex in the water. Because he thought those were the rules of nature. And some of them, he comes so close that I felt he would write the term for the curl of a vector on the next page of his books as a scientist. It's unbelievable. Because he had this character where he asked himself questions all the time. When you ask questions all the time, you improve all the time. And I was fascinated by that.

ZIERLER: The question of art and science leads me to think about visualization, and that leads me to think about simulation. I wonder what role computer simulation plays in your overall research.

GHARIB: Computer simulation is, again, a tool. It simulates what you want. You can change the parameters of what you're simulating. I will not count on it more than a painter's tools. It gives you options to try in a much faster fashion. Simulation goes two ways. You simulate a process where you're solving equations based on boundary conditions that we define. Solving equations of fluid dynamics for turbulent flows by just simulations is still a challenge; we're not there yet. If we narrow our expectations to a very narrow range, we may reach a solution. But we can use a simulation with new ways of looking at things. We can use machine learning to use the simulation more intelligently.

For example, if I give you in a painting ten points, and then I say, "These ten points are part of Leonardo's The Last Supper," can you create The Last Supper? It's a good question. You just saw ten points, and you know where they are and what color they are. Well, now you have the power of simulating ten billion different shapes until you find the best match. Which before, I couldn't do. So that's a power that simulation through machine learning gives you. It allows you to try things and see which one matches best. But, still, you are the judge of choosing the best match. That's where the power of simulation is.

ZIERLER: We find ourselves, now, in the middle of a quantum computing revolution, and we're at a stage where we can even think not only in terms of what quantum computing is, but what quantum computing can do. For you, obviously operating in a system of classical computing, do you see a way in which quantum computers might offer a revolutionary perspective in the simulations that are most interesting and important to you?

GHARIB: The answer's definitely yes. Even though I'm not an expert, and I don't understand lots of basic principles of quantum computing, it's a different paradigm from what I've seen. And if it materializes one day, it'll be unbelievable in terms of what we can do. You have to look at the communications with all this computing, too, like 5G or XG. If you have the ability of quantum computing, in a way, it's structurally different than solving the equations. Its approach is fundamentally different. But in the meantime, if I had that and if I had the power to communicate this data that I've produced by quantum computing at the same speed as it's computed, then it means you have unbelievable power under your fingertips. Just imagine what you can do with it? For example, diagnosis of diseases. We can use quantum computing to accelerate that.

To me, it's imperative to think of positive applications. There will be negative ones, too. I don't want to waste our time on that. But just think of how we can accelerate early diagnosis of cancer. Cancer treatment is becoming a patient-specific treatment field. If we can quickly sequence a patient's DNA and design a patient-specific solution, give you an alternative to the lengthy process we are doing today, it would be amazing. So from the outcome, I think it's a glorious future. But it has to happen. We are not even close.

ZIERLER: This has been an incredible tour of your approach to science and engineering at a broad level. My last two questions for our first session today are more on a contemporary basis. First, we talked about your work as a fluid dynamicist with regard to COVID. But more generally, for your scholarship, for your management of the laboratory, for your administrative duties, how has it been for you in this past year and a half of remote work and social isolation?

GHARIB: Well, when the COVID regime started, I would say I was very excited for only one aspect of it, that I would have some quiet time. And it didn't happen. It wasn't like that. And as everybody else acknowledges, we were consumed by "Zoommonia" or whatever it is. It ruined all my dreams of catching up with my neglected projects. Because I had read stories about people like G. I. Taylor during the war who could just isolate themselves and work on some fundamental physics or engineering challenges. But, because of our inventions, Zoom meetings, it just didn't happen for me. I wasted lots of time. We wasted hours discussing how to discuss problems. Not to be disrespectful, but in general, I don't think that half of my meetings were productive or even necessary.

On the other hand, I would say that it brought to my attention the importance of human interaction. Firstly, I feel that I appreciated the other people's roles, including my students, colleagues, assistants, and even the administration. They were essential for me. I missed them. Because it was during discussions with my students, I discovered new things, or I realized things that never came to me. And I don't believe that you come up with new ideas while taking a shower. I think it's human brain communication that triggers that process of creativity. That was missing. With Zoom, it's different.

ZIERLER: There's a physicality to your labs, of course, where there's a need for people to be present. Did your lab stay operational, or did it shut down entirely for a period?

GHARIB: Initially, it was shut down for a couple of months. But later on, I realized that my students started to operate in a vacuum. I saw the students working alone in some of the labs I could visit. And I could see their faces, that they need to be with other human beings, work with them, talk to them, just get input, criticize each other, be friends, and be enemies. I think it took a significant toll on our kind of life. Everybody! But as a scientist, we are isolated to start with. And adding pain to it, it was terrible.

ZIERLER: I wonder if this idea of having robots in the lab was particularly crucial during this period.

GHARIB: [laugh] I don't know. I wish I had them because having somebody that talks back to you is important. [laugh] That's how you get too close to your dog; they do not talk back. You start talking to your dog more often. [laugh]

ZIERLER: Finally, just as a snapshot in time circa September 2021, what are you working on right now?

GHARIB: In terms of projects, I'm working on two and a half projects, I would say. One is really trying to perfect the model that we developed for noninvasive cardiovascular system diagnostics. That's one project. I am developing a physical model that can be used just like listening to radar. Just to learn how to read the pulses and all the signals that the body generates and make sense out of them. There are certain rules of interaction that waves have in the dynamical systems within the human body.

So I've been busy with one of my students. It's a challenging problem, but it's interesting if we can solve it. We try to understand how nature uses these signals to synchronize the human body's operation. Or any animal. The other project that I'm interested in is creating plasma in nonconventional environments. This plasma can be used for many applications. What we're thinking about is how we can generate a nano-CERN. Think of a toroidal plasma to send electrons to go running around and see how much you can accelerate them.

ZIERLER: You mean an accelerator facility for plasma, essentially?

GHARIB: That's right but on a tiny scale. On a scale smaller than a human hair. But, even more exciting, now we've found that through quantum sensing, we should be able to detect the magnetic field of this nano toroidal plasma which is smaller than a human hair.

ZIERLER: Will there be collisions as well in this accelerator facility?

GHARIB: I don't think so. This would be just for electrons. I don't think we'll have other particles. But this plasma that we'd generated has not been seen before, and it's unique in terms of its nature. It's a tiny, tiny, tiny donut of the plasma that we generate when we impact certain crystals with a very high-speed jet of water that goes up to 700 meters per second. Without breaking anything, it creates this plasma. But then, we find that this plasma emits radio waves. And my phone doesn't work around it. It's interesting. One of my former SURF undergraduate students is coming back as a graduate student to continue working on it. It's an interesting physics problem.

The problem that I'm trying to solve is a machine learning problem. The other half project is a wind tunnel with about 2,000 fans. With all those fans working, imagine you put a ping pong ball on top of them, so the ping pong ball floats. Now, suppose I ask my machine learning system that has access to these 2,000 fans, "Behave in such a way that I can take this ball from any corner to another corner." It's like a chess game. Suppose that you want to go from point A to point B. It's really a statistical problem that this software should learn how to turn off and on so this ball can jump from one corner to another, another, and another. So it's a very abstract machine learning problem.

ZIERLER: And that's just for fun?

GHARIB: Just for fun, no application. But if any machine learning can figure out how to do this, there's no other problem that cannot be solved.

ZIERLER: That's great. Well, on that note, we'll pick it up for next time.

[End of Recording]

ZIERLER: OK, this is David Zierler, Director of the Caltech Heritage Project. It's Monday, September 27, 20201. I'm delighted to be back with Professor Morteza Gharib. Mory, it's great to see you again.

GHARIB: Nice to see you again, too.

ZIERLER: Last time, we engaged in a wonderful tour of your overall approach to science and engineering. Today, I want to go all the way back to the beginning for your family and your roots in Iran. So my first question is, where does your family ancestry trace to? Where in Iran, ethnically, culturally, religiously? How do all those things work for your family heritage?

GHARIB: I was born in Tehran, the capital of Iran, during the Shah dynastic period. My father–it's a city called Garakan, but he lived in Tehran. And my mother's ancestry goes back to Azerbaijan. Her parents came to the Iranian side of Azerbaijan after the Bolshevik Revolution. Both my parents were teachers, so they met in a high school that they were both teaching in. And as a result of that, their family formed, two boys, two girls. I'm the youngest one. They lived all along in Tehran, but I am familiar with both the languages, Persian and Azeri, a dialect of the Turkish language.

ZIERLER: Who spoke Azeri in your family?

GHARIB: My mother, grandmother, and everybody from my mother's side of the family.

ZIERLER: What language did your parents speak in?

GHARIB: At home?

ZIERLER: Yeah.

GHARIB: Up to when I was 11, primarily Azeri because my grandmother was the main person in the house. But after she passed away, my father decided, "From today, everybody speaks Farsi." So from the age of 11, I spoke Farsi.

ZIERLER: What are some of the main cultural differences in a Persian background and an Azerbaijani background?

GHARIB: Well, in principle, both are the same people. The only difference is that Northwestern Iran to the Caucasus, in the 11th or 12th centuries, were run by Oghuz Turks from Central Asia. And later on, they moved into Turkey, and it became the country of Turkey. But they also branched around the Caspian Sea. Some of them went to Iran on the Eastern side; some went to the Western side. And they imposed their language. All the Persians spoke two languages. Either Persian or Turkish. But for all the official business, it was Persian. The daily spoken language was Turkish. Different dialects of Turkish are called differently. The one spoken in Iran and the country of Azerbaijan is called Azeri. The one that's spoken in today's Turkey is normal Turkish.

GHARIB: Religiously, the majority of people in that region are Muslim. The majority of the Azeris in Azerbaijan and Iran are Shiites. Turkish Azeris are Sunnis. But the amazing part of it is, the unifying glue is the Persian culture. By Persian culture, I don't mean just the food. I mean the poetry, the language, the fact that I can take a book from 900 years ago and understand it. And to say "Persian" doesn't give the right connotation because the Greeks called the people of Iran Persians. After all, at that time, it was Cyrus the King and all those guys (Persians and Meads); they were part of Central Iran called Pars, and Parsian and Persian later on by the British. In general, they are the same people who have the exact same origin. Like Kurds, all the Caucasians, like the people of Azerbaijan. But today, from a DNA perspective, it's very mixed. From 23 and Me, I'm 45% Mazanderani or Caucasian. People of Caucasus. My mother or part of my father. And then, I have from North Africa, Ashkenazi Jews, and some Central Asian [roots]. So I can imagine that I call myself Persian, but it's a jumble of all those who lived in Iran. I would like to tell you a funny story about this. I was involved in a project called flying pyramids.

ZIERLER: The idea that the Egyptians built the pyramids with kites.

GHARIB: That's right. We were doing this project when one of the project's sponsors came to me and asked, "Where are you from?" I said, "I'm from Iran." "What part of Iran?" I said, "Part of Garakan, south of Tehran." And he says, "Do you know that half of that village was Jewish?" I said, "Well, I didn't know, but thank you for telling me. That's nice. How do I learn more?" He said, "You go to UCLA, the oral history of Jews in Iran." So they were converted by force or by some relationship. I said, "OK, that's why I have that J1N1 DNA, 1% Ashkenazi." [laugh] And it's part of our pride, the gene pool is so rich. And that's why people in Iran are true survivors.

ZIERLER: What is the highest level of education that your parents attained?

GHARIB: My mother got her education in a local city college, a two-year college after high school, and she specialized in French, then taught in high school. My father got a bachelor's degree. This was 1935, maybe. It was a bachelor's degree in communication. They called it telegraph/telephone engineering at that time.

ZIERLER: So he worked as an engineer?

GHARIB: Well, at the beginning. Until the whole country in World War II went bankrupt. And then, he said, "OK, I'm going to start a trade school." He started two or three private trade schools similar to two-year colleges.

ZIERLER: Did he have an interest in education? Or do you know where that came from?

GHARIB: Yeah, he was born as a natural teacher. He was mainly teaching mathematics because of his engineering background. But it's hilarious; he taught himself English because the American soldiers were there during World War II. He practiced a lot. And then, he started to teach English. He was fantastic with grammar, but his accent was horrible. Even today, I don't know many people who are so versed in English grammar. He knew by English method. They call it the English direct method. Maybe he got it from his grand uncle, who is known to develop modern Persian grammar.

ZIERLER: Besides the economic deprivation, was your family directly impacted by World War II?

GHARIB: Yes. Our family was not rich at all. We were perhaps lower-middle class. But because both my parents were teachers, they were OK. They worked hard to sustain the family. And education for us was the top priority. From my mother's side, my grandfather was also a poet and a printer. He had printing shops. He was also well-known for his great Sufi poems. He had a book, and his poems were both in Persian and Azeri Turkish.

ZIERLER: Was religion part of your childhood at all? Would you consider your family as religious or more secular?

GHARIB: Well, we were very secular. My father, perhaps, he was. He was an agnostic in general. They were not members of any religious organization, but they followed all the traditional customs. My mother did not wear a hijab. There was an order by the previous Shah of Iran for a woman to wear a hijab. And she was one of the first women to stop wearing hijab. I have pictures of her teaching all the girl students–oh, by the way, she was also a physical education teacher. She didn't give us any bias in terms of religion. Even today, my kids have never practiced any religions. The only things they practice are common sense and being human.

ZIERLER: Just from the cultural side, what were some of the big festivals or holidays that were important as family get-togethers for you?

GHARIB: There were two. The biggest one was Nowruz, which is on March 21, the start of the equinox. In old Persia, before any established religion in Iran, they picked that date as the beginning of the spring. For two weeks, there are festivities. And that was the best time for kids because you many gifts. And then, there's also one in the fall called Yalda. It's like the fall festival. The last day of the fall. And that ceremony was very festive because they saved all the fruits from summer, watermelon, grapes, all those things. And that night, which is the longest night of the year, I think November 21, they all enjoy the fruits, the dry fruits. It's an end-of-harvest festival.

ZIERLER: What are some of the foods or dishes that might bring you right back to childhood at these family get-togethers?

GHARIB: Of course, everybody has different favorites. But I have two. One is a pomegranate stew, which is fantastic. And the other one is a veggie stew that I like. But if you want to know if anybody's Persian, ask if they like rice. Everything is with rice. My mother once made spaghetti, and my sister jokingly said, "Where's the rice?" [laugh]

ZIERLER: Did your family talk politics around the dinner table?

GHARIB: Yes, and no. Because my mother was very strongly pro-Shah, and my father was a socialist in his past. But later on, because of all the pressure, he kept his ideologies shrouded. But I can see it now because he was very anti-religion and open in terms of our political opinions. My mother always warned me that there was a God and to be careful what I did. As a kid, we always had those two negative things in front of us. But both of them, at the end of the day, said, "As long as you're good students, whatever you're doing is OK." So that was kind of an opening for freedom.

ZIERLER: What kind of school did you go to as a young boy?

GHARIB: Well, my mother stopped teaching, I think, after I was born. She had to take care of everything about her kids. But she was the boss of the whole family. She was the only daughter with five brothers. She was running that side of the family. But I went to public school until 10th grade. Because my father was teaching in a public school, and he believed in public schools. He always tried to make sure we got into good public schools, were taught all the necessary fields, had good teachers. He knew all the good teachers. 11th grade, there was an open contest for entering a private school free if you get high scores, one of Iran's first coed private schools.

But they wanted to choose the best. So they ran an open contest. And without telling my parents, I just enrolled. Then, I was number two or three in the group that got accepted. And my father said, "No, you can't go." Because it was in a different city, it was a beautiful city called Shiraz, like the wine. Imagine that school would start in a week, and I didn't know whether I would go. Three days before school started, my father came to me and said, "Do you want to go to that school? Is this your wish?" And I said yes. He said, "OK, you can go." And my mother said, "But we told them that he's not coming." He said, "No, he can go." So my mother took me, we took a bus to this city to see the school principal. He said, "Ma'am, it's too late because the enrollment period is finished."

Then, he pulled my file and saw I was number two in the rankings. He said, "Oh, we can make an exception for him." So I started at that school. And that was perhaps the best experience I had. Because classes were only a third of the size of the public school I had attended before. And teachers were all university professors who volunteered to teach. And that school environment changed my whole perspective on life and how to do science.

ZIERLER: How old were you when you started at this school?

GHARIB: I think I was 17. I was a little old for that grade because my father didn't let me go to the 2nd grade. He said, "Stay in first grade one more year." And I was distraught at that time. My mother said, "Why are you doing this to your boy?" He said, "I went to his class. He was the shortest and youngest guy. And that's not good." He wanted me to be a little bit more mature. He didn't want me to be bullied. And I think it was the right decision. But the school in Shiraz was a turning point for me.

ZIERLER: What was your neighborhood like in Tehran? Was it a single-family house, an apartment?

GHARIB: It was a single-family house. It was a relatively big house, a traditional house. In Iran, usually, houses are walled. It's not like here. So most of the single-family homes don't have a front yard. The backyard and front yard are like a courtyard in the middle of the house. Our house had two rooms in the back, two rooms in the front, and a guest room. It had a lovely rose garden with a small pond in the middle yard. In Iran, people like to be near water and to hear it flow. And that also had a significant influence on me. I spent lots of time alone in that center yard as a boy. How to organize it and reengineer where the water goes and where it comes from. Our gardner complained about me turning his "masterpiece" into a muddy ruin.

ZIERLER: What was your understanding of the United States when you were a boy? How did you think of the United States regarding its relationship with Iran? How did the Shah have relationships with US presidents?

GHARIB: Well, I was born during the Shah's time. At that time, everything American was unique to us. I cried when, for example, I heard that John F. Kennedy was assassinated. So it was that kind of affection. Anything American was fantastic. At least from the middle to upper-class views, Everything from education to lifestyles was influenced by America. For example, at the high school in Shiraz, all of our books except Persian literature were in English.

I went to high school reading Linus Pauling's chemistry book in my 12th-grade chemistry course or Halliday for my physics course. To that extent, I could discuss how subjects of my interest were taught in the American academic system. Because every day, we were fed by the best parts of America, its science, engineering, achievements in space. I remember vividly the day Apollo was going up and admiring America, and the first thing when I got to school was to ask each other, "can [you] believe that they landed on the moon?" However, about ten years later, things had changed. Iran became very rich from her oil revenue. But, the distance between rich and poor increased.

And that's what, in my opinion, [explains] the root cause of the anger of the have-nots against the Shah. But what we didn't know until I got to university was that America was pursuing its interests in Iran and did not see the flaws of the Shah's regime and the desperation of a large section of the Iranian society in wanting a more democratic society. The US was just focused on building up a frontline defense against the Soviet Union in Iran. At university, I concluded that different US administrations followed that policy [which] either blindly supported the Shah or did not care about having a theocratic anti-communist government in Iran. We know that both policies backfired as history proved to us what the US did not appreciate: that for almost 400 years, Russia, either in the form of the empire or the Soviet Union, always worked against Iran. So there was a natural tendency against them. And all the US needed to do was support a secular democratic movement in Iran.

ZIERLER: So the Soviets were the bad guys.

GHARIB: The Soviets were the bad guys. Because there was a history, the US never attacked Iran. If anything, they forced the Russians to get out of Iran after the end of World War II. Or if you look at the constitutional revolution that happened in 1918 in Iran, where the system changed from a monarchy to a constitutional monarchy, guess who was one of the main leaders of the fight against the monarchy at that time? [Howard] Baskerville, an American teacher in Tabriz. There's a huge monument of him in the middle of that city even today. Americans were always the anti-imperialists. And with the size and technology, everybody wanted to move to the US. Of course, at that time, my father could not afford to send anybody from our family anywhere. My brother got a scholarship to a top medical school in Germany. He later became a very famous pediatric surgeon in Germany. So I was about to go to Germany until I realized that I really wanted to go to an American university.

ZIERLER: Domestically, growing up, were you aware of some of the darker sides of the Shah's rule? The oppression, the tensions with religious people, SAVAK? Did you know any of these things?

GHARIB: Not until I went to college. I went to Tehran University. At that time, it was the top university in Iran. Right now, it's not. There are a couple of other universities that are better. But going to the Technical School of Tehran University was the most challenging thing. You had to be in the top 0.1% to be accepted. And I'll tell you how I got there later on. But it was also a very politically diverse and open college. First thing, you arrive at the university, you see all these political groups handing out leaflets and asking you to join them. You start to learn about democratic movements, socialists, progressive Muslim groups, and of course, fanatic ones or followers of Khomeini. And as a young person, I was curious. "What's going on? What's happening?" And that was an exciting experience for me because you started to build your own opinion.

Then, I started to learn more about the oppression that was going on in the background. But they covered that up by the amount of wealth pumped into society. But towards the end, that pumping stopped because it was diverted to other things that were not necessarily impacting the community. And then, somehow, the Shah's regime couldn't handle criticism and started to oppress. And that oppression was the beginning of everything you see today. And the universities were the center of all opposition to the establishment. Tehran University produced almost 80% of all ministers in the Shah's regime. It's like École Polytechnique in France. Once you get there, you have a good government job. However, the level of oppression turned that whole school against the Shah's regime. And, of course, the outcome by no means was or is what we expected.

ZIERLER: Growing up, in what ways did the Arab-Israeli conflict register for you? How did you learn about these things? Who were the good and bad guys for you in that?

GHARIB: It's interesting because we lived in Tehran, a mixed-religion area. For example, my sister's kids all went to an Armenian school. I shared a playground with a Jewish school next to mine. The conflict between Arabs and Israel was [interesting] to us because we did not have that issue in Iran. At least not in modern Iran. At my high school in Shiraz, for example, I learned about the communes in Israel. I had a Jewish classmate friend. She told about the historical connection between Iranian Jews and Iran dating back to Cyrus. At one time, I encouraged myself to go there one summer to a kibbutz. And of course, I couldn't afford to go. But I started to learn a lot for personal reasons. And I'm glad that I learned about it before I got to the Tehran University. Because by the time you got to the university, you could've been brainwashed by one side or the other, unable to see both sides of the story.

My feeling was that there are always two sides to any problem. And I always thought you need to look at a problem and solve it locally. I saw how issues could be solved when people talked to each other. Later on, when things went wrong, I realized that it's hard to compromise when you get religious or one-sided. I used to go to Israel every year for five years, giving lectures in Technion or Tel Aviv University. Some of the best times I had were talking about politics with my Israeli friends and colleagues.

And I was always taught, "Israel was created, they took this space, and some people were deprived of the whole" – then, I went back and said, "Yeah, 100 years ago, Jewish people were expelled from the same disputed land. So who knows who the original people here were?"

After the Holocaust and all those horrible events that Jewish people of Europe went through, they needed to have a place to feel safe living and raising their children, and protecting their culture. And there was nowhere in the world to provide the type of cultural home they needed. If I were a Palestinian, I would accept them and flourish as both people live together. But unfortunately, that did not happen. Many unfortunate events have occurred that make co-existence hard, if not impossible.

ZIERLER: And in your community in Tehran, there were Jewish people around who lived openly?

GHARIB: Yeah, one of the most prominent Jewish communities in the Middle East existed in Iran.

ZIERLER: Well, it's the only place that they didn't have to flee after 1948. In the whole Muslim world.

GHARIB: Yeah, they flourished very well during the Shah's time. After Israel was formed, the Jewish [community] in Iran grew. If you go to Shiraz, it's just amazing to see how they have assimilated culturally with Persians while keeping all of their traditions. And even true today, not to give credit to the current regime, but I would give credit to the affinity of Jewish people to the Persian culture. They stayed there even after the Revolution. And they are there. This is the most exciting part of this whole area that people can live together. But that doesn't mean that Jews in Iran did not go through rough times. They did. And all because of some religious leaders of the time. But the general population absolutely does not care if you are Jewish or Armenian. We didn't even know that some of my parents' friends were Jewish or Baha'i for many years. Nobody asked that kind of question. Because there was no need to ask, "Are you Jewish? Are you Baha'i? Are you Muslim?" In our middle-class communities, they didn't care.

ZIERLER: Right. And by appearance, you couldn't tell. Everyone looked the same.

GHARIB: Oh, yeah. I'm not joking, but I was in Tel Aviv. At that time, I was a Sackler Scholar at the University of Tel Aviv, and nobody spoke any language but Hebrew to me. And I'd have to correct them, "I'm sorry, I don't know Hebrew." [laugh] They're so interwoven. There are many influential Hebrew Persian poets. It's incredible when you read their poems or the songs in Persian. Even today, if you go to Tel Aviv, there are Persian Jews who moved over there after the Islamic revolution. They have their semi-closed communities. And they are more together than with other people. One of my Israeli friend's wife was a social worker.

And one day, when I was there, she said, "Mory, would you like to come with me to visit one of the Persian communities?" I said, "Oh, sure, yeah." So we went there, there's this beautiful building in Herzliya, north of Tel Aviv by the water. It's a beautiful area. We went there, and then she rings the bell. A voice comes out and said in Persian, "Who is this?" And my friend's wife didn't know Farsi, so she said, "Well, I'm Haseyah, and I'm here to check if you are all ok. It's my first time here." "Do you speak Farsi? Said the other voice" [laugh] And Haseyah said, "Answer Mory, answer." I said, "Well, yeah, we speak Farsi." Then, they let us in. [laugh] But it was so hilarious. This lady cannot go inside the building in the middle of Israel if she doesn't speak Farsi. They were all from a place in Iran called Hamadan. One of the oldest Jewish communities in Iran is in Hamadan. It was hilarious. They hugged me, kissed me, offered Persian lunch, all the nice things.

ZIERLER: [laugh] Going back to the connection that you felt towards President Kennedy, did you follow the space race closely as a kid? Did that capture your imagination?

GHARIB: Oh, absolutely. Do you remember those black and white little TVs? Our family got one; my brother-in-law decided to buy one for us. And we were glued to the TV watching the landing many times. Every two or three hours, it was on the news. That's how I learned about NASA, JPL, and later on, through some newspaper about Caltech.

ZIERLER: Did you understand that connection, even as a kid, between JPL and Caltech?

GHARIB: No, no. There was an evening newspaper in Tehran called Keyhan, and one day, there was a little column about exciting places around the World, And it said, "There's a school in California called the California Institute of Technology." And it continued, "It's the only school in the world that for every three students, there's one teacher." And I said, "I have to go there." Every school I went to, there were 40 students in class. I always had so many questions, but no teacher had time for my questions. So I really had this thirst for somebody to answer my questions. I once challenged one of my teachers for his half-hazard answer, which almost got me kicked out of my elementary school.

The teacher was saying something like, "Suppose an apple is on a table that never moves." Then, I said, "Wait a minute, the apple is on the earth. The earth is moving, so the apple is moving." And the teacher said, "Suppose the earth is not moving. The apple is there." I said, "Well if that apple starts to dry out and shrink, so if you do lapse pictures, it's moving again." And the teacher finally called my father and said, "Look, I don't think I can handle this guy." [laugh] So teachers always tried to shrug me off. That's why, for me, I wanted to come to a school like Caltech, where you can have the attention of your professors.

ZIERLER: Did you tinker when you were a kid? Did you take stuff apart? Did you have chemistry sets, airplane models?

GHARIB: Well, kids at that time, my age, there were not many things like chemistry kits. We made them ourselves. I was very interested in the pond and grass in my backyard. I figured out how to get the water to move around, shoot upward, come back to the pond. Often, my father ended up having a gardener come and fix the damage I made to the Garden. And then, I really in 3rd grade, I accidentally started a fire because we got some old films. We tried to build our own projector with a magnifier and a light source. It got too hot, and the whole thing caught fire. But I think the main tinkering was when I made my own kites and tinker with different shapes and forms. Flying objects have always fascinated me.

And flying kites was a fascination for me. Then, later on, like every teenage kid, it was rockets. I tell some of my students this story. I think it was 8th or 9th grade; before I went to Shiraz, some of my friends and I decided to make a rocket over the summer. In Iran, all the roofs are asphalt. We decided to fire this rocket in the middle of the city. But suppose that this thing comes down? Where does it go? We were teenagers, so we didn't think about this. All we wanted was to fire it off. We put all our money together, got all the chemicals we needed, and made this rocket. And we had some small ones that flew nicely, but we decided to make it ten times more powerful. I think there's a picture of it somewhere in my old boxes. We fired it, but it was so heavy that it didn't go up. But it was so hot that it melted the roof. And this was right on top of my room on the second floor of our house.

So it made a hole to my room. All the plaster and everything fell. Fortunately, it turned off after that. And we didn't know what to do. We had a handyman, so we asked him to help fix the hole ASAP. When the handyman arrived and saw the hole asked, "How did you make this hole? This is impossible." We didn't tell him how we did it because he did not see the rocket's remains. He fixed it by covering it with plywood and putting some plaster on it and said, "I'm going to come back and fix it more permanently." Tell your mom I'm coming back later." Of course, you never tell your mom, right? So it was just plaster, which was OK until the winter came with heavy snow. And my whole roof came down. I came home from school, and my mother said, "It's bizarre; half of the ceiling in your room is down. I have to find out what happened."

I didn't know what to say. I could've been in deep, deep trouble. I didn't tell her anything. We fixed it, and everything went well 20 years later; when I was a professor in San Diego, we were sitting around, and we had a drink one night. I told my mom, "Mom, I want to confess something." This was in front of my wife and child. And she said, "about what?" I said, "Do you remember that room with the hole?" And before I finished, she said, "I knew it was you. I knew it." [laugh] Because before that, she knew that she was working with chemistry for this rocket and knew that it exploded and a small piece of glass hit my eye. Still, I have a scar in my left eye. So yes, I tinkered.

ZIERLER: Was the high school in Shiraz a technical high school?

GHARIB: No, it was a regular high school, but they only took so-called talented kids. It was a particular university high school.

ZIERLER: When you were starting to think about college, studying abroad, even as an undergraduate, was that a possibility? It was something that you considered?

GHARIB: No, it wasn't an option for me because my father couldn't afford to send me out. By that time, my sister was in Germany, and most of the family resources were used to support her. So he challenged me to enter one of the top universities in Iran. I wanted to study physics because I had a teacher who was educated at Northeastern University. And he was a fantastic teacher. He got me interested in modern physics and physics in general. And then, there was Linus Pauling's chemistry. I was the best in chemistry in my class, even though I didn't touch it later on. But after taking physics with my great physics teacher, I wanted to study physics, nothing else. In Iran, universities work by selecting your first ten choices, such as physics at a certain university or electrical engineering at another university.

Then, the system ranks you, and you get what you desire based on your ranking. I told my father I would study physics. And he, himself, being a math teacher, said, "Son, I appreciate what you want to study, but physics in Iran, you're not going to get a good education that makes you ready for competition later on. The best you can be is a teacher in high school. Why don't you study engineering?" And I didn't like that idea. So when it came to making choices, I just put mechanical engineering at Tehran University as my first choice to make him happy and the nine other options in physics. I prayed that I do not get to my first choice. But, my prayer was not answered.

ZIERLER: When your father was thinking about physics, was he thinking theoretical physics? What about experimental physics?

GHARIB: Physics in general. Nothing experimental. He just said, "Physics is not going to make you money." In Iran, engineering and medicine are the top two choices, respectively. Because if you go to engineering at Tehran University, you'll have a lucrative job waiting for you. However, I chose mechanical engineering at Tehran University because I felt I was not good enough to get there. So the worst day of my life was when I looked at the results and saw I was ranked number ten and going to mechanical engineering at Tehran University or any other field that I want in engineering at Tehran University.

And first, I was tempted not to tell my father so I could just do physics. But I couldn't do that. I told him, "I'm going to do mechanical engineering in Tehran University." And he was so happy. He said, "You made my day." I said, "There's a price. You have to buy me a car." [laugh] He never bought it. Well, he did, but differently, later on. I think his advice was correct. Because I didn't believe with education in physics at that time in Iran, I could get to any good graduate school here because they wouldn't prepare you to a level that you could compete here. But engineering in Iran is pretty good. Even today, because engineering is in their blood. Ancient engineers in Persia had built amazing tools and structures. And my professors were from some of the best universities in the world. MIT, Berkeley, and von Kármán Institute. The one who became a role model for me was a professor from Berkeley teaching heat transfer and fluid mechanics. In Many occasions, he then told me, "If you want to do fluid mechanics, you have to go to Caltech." Even though he was from Berkeley, he felt that way. That's how I got interested. But I didn't come directly to Caltech.

ZIERLER: Right, there's a story. Did you live at home during undergraduate? Or did you live on campus?

GHARIB: I lived at home. The same room with the hole in the ceiling.

ZIERLER: And intellectually, what was the process for you meeting new people, learning different viewpoints, seeing a different side to the Shah, and some of the tensions, perhaps, that would come only a short time later in Iran? What was that process like for you, learning these things?

GHARIB: It was basically through your classmates. There were different clubs. The process, for me, was very depressing. First of all, I was just leaving a high school where I had fun doing physics, leaving my friends, and everything. But coming to Tehran, back to my old house, was very depressing. I escaped into the world of chess. I almost became a professional chess player, to the point that my father practically had to intervene because they saw my first semester grades. "Oh, what are you doing these days?" I said, "Now, I can play chess blindfolded." I claimed that to my father. "That's nice. What's next? Are you going to go to compete? Where are you going to do this?"

And I suddenly realized he was trying to make a point. "You have to choose, either become a chess player or go to college and finish it successfully. But that was my escape from reality, not doing what exactly I wanted to do, which was to study physics. Then, I woke up. I said, "OK, let's give mechanical engineering and engineering in general a chance." And that's when I got into fluids and aeronautics. I suddenly realized there was another way to fly.

ZIERLER: What were some of your most exciting and important laboratory opportunities as an undergraduate?

GHARIB: In Iran, they like engineering, but they always like the theoretical side because of the lack of experimental facilities. They didn't have as many experimental facilities as people do in the US. But one professor from The von Kármán Institute in Belgium, Rohbakhsh, came to Iran and became a professor at my college. He taught a course in hydrodynamics. And that's also where I got interested in how propulsive systems work and how overarching fluid mechanics is in every aspect of life. And I helped him to translate a book on hydrodynamics into Farsi. He also told me about all these fascinating labs at the von Kármán Institute that we never had. And in some respect, part of it was that even though we wanted to build the best labs at the college, he wasn't that nice to Tehran University during the Shah.

Because all the socialists the progressive religious groups were part of this college. And he didn't like that. He started a competing university called Ariamehr University (the name means "the favor of the Shah"). Later on, it was renamed Sharif University. At the end of my time, Tehran University began to demise because the Shah's government didn't care about it. They didn't have any new labs, all these things. And it made me more motivated to seek my graduate studies somewhere else where I could find the best experimenters in the world. For some reason, I always wanted to explore the rules of nature through experimentation, which was very fulfilling for me.

ZIERLER: In many ways, you had physics in the background in your education. You got more than you thought you might have.

GHARIB: Yes. And I took all the physics courses I could take during my undergraduate in Tehran.

ZIERLER: Let's get back to your political consciousness as an undergraduate, your sense of how things were changing in Iran at the time.

GHARIB: Well, in general, I felt that I had been raised in a very privileged environment. Not because of wealth, but because our parents protected us and our education with great sacrifice. They cut things from their own lives to ensure that we had a good life, we could study, and all those things. And you don't realize that until you get to an age where you have to work. And then, suddenly, I realized how much my father was working. He was going from 9 in the morning to 10 at night. Because he had to teach, he had to run his small business class at the college. Lots of work. He never took a vacation. Then, I realized, "Jesus, they work like hell for me not to work."

And I realized, aside from the part of society that received lots of benefits from the new oil-generated wealth, the rest of the community got a little bit that trickled down. That was when I realized there was something not clicking right here. Even though they claimed they were a capitalist society, they didn't give a chance to everybody to make their own [wealth]. It was only suitable for a particular type of people. It wasn't just for the Shah's family, but a certain layer had this privilege, and the rest did not. For me, that was an eye-opener, especially reading some of the literature that taught critical thinking, which was not common in Middle Eastern cultures. It's not supported for two reasons. Religion doesn't like it because you question them. And the government doesn't like it because you ask them, too.

So it was a very narrow band where we had the chance at universities to read about stuff we couldn't read in open literature or outside. And I have to give credit to open-minded people–the Revolution in Iran wasn't a religious revolution at all. It was stolen, in my opinion. The people of Iran never had any arguments or hated the US. Not at all. If there were any, it was with the British and Russians because historically, they were the oppressors in Iran. The British, and then distorted by Russians, ran the politics. The US, except from supporting the Shah against Mosadeq, was practically absent from Iran's history in modern history. You're talking about 15, 20 years compared to hundreds of years of Russians and British trying to get Iran under their imperial power.

So there was no reason to consider the US as an enemy. And that was also helpful because you see that the most radical socialists, when it came to the US, saw, "Look, this is a country that educates its people for democracy to this level" they could not deny the US level of technology helped humanity so much. Just think about it. The critics appreciated that politicians could challenge each other in the US without the fear of retribution. And that was the important part because we realized that there must be something right in the US that other people don't talk about. That's where critical thinking allows you to question those things and learn the facts. I'm not saying everything in the US is right and perfect. I'm saying the portrait of the US in that part of the world at that time was completely distorted.

ZIERLER: To what extent was Tehran, specifically Tehran University, a cosmopolitan bubble? In other words, for those people in more rural parts of Iran, who supported, for whatever reason, aspects of the Revolution, did you appreciate that there was this level of distrust or desire to move beyond the Shah's rulership? Did that occur to you as an undergraduate, three, four years before the Revolution?

GHARIB: Not at all. I'll tell you why. The word you used, bubble, is the right word. For us, it was the question of change, not revolution. It was a question of what we could do for the Shah to understand to let the people who knew how to run the country. It wasn't about toppling it and replacing it with a theocratic regime. It was a second; I would say, constitutional revolution to remind him that, "Hey, you're the king. Stay there, be there. But let the technocrats, the people who believe in social democracy, run the country." The Shah also had changed over the years, struggling to understand why people did not appreciate him. Towards the end, he needed to be praised all the time. Every time you watched a movie, they played the national anthem based on his family's glory, and you had to stand up and listen. Can you imagine the kind of reaction it created for young people?

They said, "What is this? Is this Nazi Germany? It's not. Why does he need this kind of obedience and loyalty if the country is running so nicely?" Those are the kinds of questions the Shah did not like to hear. And he lived in a bubble as we did in universities hoping for a peaceful change. I, personally, could not believe the fanatics that later on came to power could exist next to me. And I picked on those people later on because of the way they compromised their well-intended ideas. The classmate I did homework with later became one of the ministers because of his religious ideologies. And we knew he was not a religious revolutionary because we were drinking together.

So it created an environment that brought the worst dimension of people out when it became the religious [movement] later on. But it was a very planned, strategic approach that the Ayatollah and his group had. And for centuries, they knew precisely the psyche of Persians. Persians do not like oppression. While they don't realize they're being oppressed. That's the irony. We didn't see we were being oppressed, and in the meantime, we hated oppression. So that bubble was there, and it was not very pleasant when it burst.

ZIERLER: Did you have a senior thesis?

GHARIB: Yeah, my senior thesis was the translation of the hydrodynamic notes of my professor.

ZIERLER: And having finished your undergraduate, what had you discovered at that point that you were good at, you liked, you might have wanted to pursue for graduate school?

GHARIB: I wanted to get into aerospace, into understanding better the physics and science of flight. And the physics and science of hydrodynamics. Early on, I appreciated the most difficult, sophisticated kind of research that one can do in engineering. That was what I was thirsty to get at. And by that time, I was married, and my wife was a chemical engineer. She wanted to do environmental science; I wanted to do aerospace. That's how we decided to go through higher education.

ZIERLER: And what were your opportunities in 1976? You graduate. What's available to you at this point? Did you think about pursuing the jobs your father had in mind that he was so excited about?

GHARIB: No. [laugh] Actually, I believe he wanted me to go out and pursue my dreams. I don't think he wanted me to stay and run his business. Because my older sister did that, but I'll tell you the exciting part. The Shah invested heavily in Grumman, Northrop Grumman, to build the F-14. I was one of the students who was given the scholarship to study aerospace, get my master's, come back, and be one of the first people to run the place. And that was very exciting to me because I read a lot about the beautiful things the Israeli Air Force did for the country. I said, "That's the power of flying the best machines that you can." So at that time, the Iranian Air Force was trained by the US. It was glorious to go into the Air Force and run the industrial aerospace complex.

ZIERLER: This is a different time you're talking about here. It's amazing to think of these things now.

GHARIB: Yeah. Even when I was at Caltech, I always wished there was no Revolution, that people like me could go back and build new things, airplanes, helicopters, things like that. There was no talk of it at that time in Iran.

ZIERLER: And was it specifically the United States that you concentrated on for graduate programs?

GHARIB: Yeah. Nothing else. There was no disrespect to other places, but I looked at Germany, France, and England. None of them were attractive to me. I mean, come on. You have JPL at Caltech, and you want to go to the University of Bristol? I don't know, maybe. [laugh] But it was a long-shot goal. I didn't expect to get into Caltech.

ZIERLER: Did you have any family in the United States?

GHARIB: It's interesting; I did not have any. My wife had a cousin who lived in Syracuse.

ZIERLER: So there's the Syracuse connection.

GHARIB: That's right. I got accepted to Caltech, USC, Virginia Tech, and Syracuse when we applied. My wife got into all of them but Caltech. But in the meantime, her cousin was at Syracuse. We agreed we would both go to Syracuse first. We were only married for six months so that we couldn't go to different universities. So I decided to go to Syracuse, take courses, get a master's. I deferred my admission to Caltech. After the harshest winter in '77, or '78, it was so cold in Syracuse; the US Army moved their training camps from Alaska to Schenectady.

[laugh] Can you imagine? For winter training or whatever it was. I remember that. I love Syracuse. The summer and fall were amazing. But the winter–one day, our front door was snowed in, and we couldn't get out. We had to open a window in the back and go through that. And my wife said, "Is there any other place in this country we can go?" [laugh] But it was perfect for me because it just allowed me to learn about the US before I jumped into all study, study, study. Then, that summer, after we graduated, we drove across the country in my Chevy Nova. And we enjoyed it. I paid 1,500 for the car, and it was one of the most joyful trips. ZIERLER: You were headed to Caltech? GHARIB: That's right. From Syracuse, New York, to Los Angeles. ZIERLER: So you had that admission to Caltech, and you simply deferred it to get your master's at Syracuse? GHARIB: That's right. ZIERLER: What was valuable, in retrospect, to be in Syracuse, to have that separate component of your educational trajectory? GHARIB: First of all, it was a large university. And it gave me that flavor. Three friends followed me from Syracuse to Caltech. No, I'm sorry, there was one ahead of me, Dan Nosencheck, a professor at Princeton now, was at Syracuse. And then, after, Dimitri Papamoschou, who was at Syracuse also, followed me to Caltech. So all three of us came to GALCIT. But my experience was, I loved Syracuse because it was nice; it didn't have all the craziness of the other campuses. It was a very elite university with a good football team. It gave me the flavor of how large universities are compared to Caltech. If you come directly to Caltech, you miss a lot of social life. [laugh] ZIERLER: Syracuse, you see America. Caltech, you see Pasadena. [laugh] GHARIB: That's right. ZIERLER: What was your master's thesis on? GHARIB: It was on jet noise. I worked with two excellent professors. Professors Darshan Dosanjh and Salmon Ashkenazi. And they allowed me to work in a unique and advanced jet noise facility. And that was also where I learned about my later professor, Anatol Roshko. When I came to Caltech, I just went to his office and said, "I'm here." It was all experimental. That's why it strengthened my belief that I wanted to be an experimenter, somebody who discovered things. But don't get me wrong, because of my physics interests, I always liked developing mathematical models, which showed up in my later work. ZIERLER: When you got to Caltech, how well-defined was your research plan? What you wanted to do, who you wanted to study with, what your project would be. GHARIB: I decided that I'm not going to decide about any projects before hearing from Anatol. Like a monk. You just bring yourself and say, "I am here as a raw material. Show me the path." That kind of attitude. Because today even, I just saw an email where a student wrote to me and said, "Your research very much aligns with my interests." And that's not a very good thing to say. For me, as a Ph.D. student– if you want to study fluid mechanics, aeronautics, aerospace, you don't want to go to someone like Anatol Roshko and say, "You know what? I want to study vortex shedding from rectangular cylinders at 10-degree yaw angle ." If you know exactly what you want to study and to that degree of specificity, you miss the chance to hear about better ideas for your thesis from Anatol. I think a Ph.D. thesis is where you mindfully jump in the river, and get wet, and try to learn how to swim before you drown. Your advisor is the coach who directs you to reach the other river bank. So for me, it was just wanting to tell Anatol, "Let me enjoy being your student." Being his student was more important for me than studying with him. I wanted to learn about the art of doing scientific research. People like Anatol are not just scientists who work in the lab all the time. No, they are artists creating science. ZIERLER: Meaning the depth at which they think about science makes them philosophers. GHARIB: Exactly. And that's what I was missing. I was getting lots of science and this from technicians of science. But not from people for which the Ph.D. is titled. Philosophy of Science. And that's where I think I was lucky that Anatol took me. He became my guru. Even though sometimes for months, we were not talking, when we saw each other, we knew exactly what we wanted to talk about. That level of enjoyment of being somebody's student and knowing that somebody's enjoying you. And that friendship lasted until the last day of his life. I'll find a little thing he wrote for me, and I'll send you what I wrote for him. I can read it for you later. One day, I asked him, "Anatol, do you remember the first day I came to your office? You gave me a note that said, 'Read about this, then come talk to me again.'" So then, I went to his office a second time and said, "This is amazing. But I like all the five ideas you sent. I want to do all of them." And he said, "Mm-mmm. Just one. Pick out one." So I picked out one, and I did all four later on. And I wrote to him that it was so amazing that I was listening to him, but I wasn't listening to him. I was just enjoying that he was telling me things. How research should be done. His philosophy of research was fascinating. I have his notebooks today and read them frequently to remind myself to be humble and useful. On one page of his notebook he wrote, "I think Mory should start thinking about this." It doesn't say, "Mory should do this." So any discussions with him, even though almost all the ideas came from him, he gave us the feeling that we came up with it by the end of the discussion. He was a guide with a torch, showing the path. But he was not going to pull you into it. ZIERLER: And what was his research when you connected? What was he working on? GHARIB: Well, he was working on what they call large coherent structures. It's something that changed the way we look at turbulence. Turbulence is the most extraordinary scientific challenge I can think of in physics. Even people like Feynman and Heisenberg threw in the towel. They said, "Hey, there are other interesting things you can do." But Anatol and his team, at that time, introduced the concept that there's beauty in turbulence. And that beauty is that these large coherent structures–the vortices that you see in Jupiter, for example, are everywhere in turbulent flows. They're all there, and the fact that you don't see them doesn't mean they're not there. He showed us the way of looking at them and seeing their beauty. And his discovery of large coherent structures with Gary Brown showed how to model turbulence problems realistically. It wasn't anymore the bland isotropic hodgepodge of random processes. Every turbulent flow has its own character in the form of vortices it generates. These swirling actions, and that's the beauty of it. When he started to show the visualized version of his concepts, the whole world stopped and said, "Wait a minute, maybe we should turn the clock back and start to rethink turbulence." And today, most of the discoveries and achievements we've had in turbulence research are because of him and people he influenced by his contributions. He showed the way. ZIERLER: You first came to Caltech in the fall of '78? GHARIB: Yeah. ZIERLER: And so, obviously, you have no idea what's going to happen in Iran. This is a million miles away. GHARIB: Millions of miles away. Yeah. But that summer, I was in Iran to visit family. And they were telling me that things were not good. Mainly, my father-in-law, a former army general, and a professor of military law at Tehran University, told me that the Shah was getting weak and getting more brutal. He told me he wasn't happy with what he was seeing. And that fall, we were here, and the Winter Revolution happened. It was one of the worst years of my life. It wasn't enjoyable between studies, worrying about the family, and everything else. ZIERLER: Did the Revolution change how you saw your trajectory? In other words, when you first came to America at Syracuse, did you always assume that you would study what you would study and then take it back to Iran? GHARIB: Absolutely. Because we had a good life in Iran. A good job is waiting for me. The intention was to go back. Things happened that changed my mind. In the beginning, we were all a little bit happy that a revolution had occurred. "At least maybe this new government will solve some problems, then we'll get back to business." But then, one day, a letter arrived at my house on Chester Avenue. Like I told you, I had this scholarship to finish my master's degree, but then my mother went to—this is funny—the Pahlavi Foundation and said, "Look, my son got his master's degree from Syracuse, and the scholarship was for him to get the master's and go back. Now he got accepted to one of the best universities globally, and he wants to get his Ph.D. and then come back. Can he have his scholarship extended?" Because with Caltech's stipend at that time, I couldn't manage. It was300 a month, something like that. The guy at the Pahlavi Foundation said, "Oh, California Institute of Technology. Is it a two-year college?" I'm not kidding! My mother got embarrassed and told my father, "Where is this place Mory's going? A two-year college? He just got his master's." So my father wrote to me, "Where is this place you're going?" I said, "It is Caltech." He says, "I never heard of Caltech University. It's not a university. There's MIT University." I said, "No, no" [laugh]

So I said, "Look at how many Nobel Laureates we have," blah, blah, blah. And finally, he realized, and he was embarrassed. He said, "How come I didn't know about this place?" I said, "I told you, this was the place I wanted to go." But it never clicked. So they gave me that scholarship to get my Ph.D. here. Now, six months after the Revolution, they sent me a letter and said that because you got a scholarship from the former Iranian government, we do not honor it anymore, and you're on your own. Do whatever you want." Can you imagine that? Fortunately, Caltech was good, and my wife found a job here. And then, three months later, they sent me another letter that, "Oh, we looked at all the people getting this scholarship, about 2,300 students, and 200 of them were merit-based. And you're one of them."

So they established it again. I was so happy. "Good. This government has sense." And then, the first liberal president they had, [Abolhassan] Banisadr, was toppled. And then, they sent me another letter. It said, "Well since you're educated in the US, we consider you corrupted. We don't need you anymore." So again, it was discontinued. So it was such a –

ZIERLER: A rollercoaster.

GHARIB: Yeah, imagine, a student here, "You're in." "You're out." "You're in." "You're out." And then, this is the best part of it. Then, the war started with Iraq, the Ten Year War. And within three months of that, I get another letter. Since you are in aerospace, you can come back and help us in the war efforts. Here's the ticket." And this was my response: "You must be kidding me." Then, I signed an open letter against the war published in the New York Times.

ZIERLER: But your family is in Iran this whole time.

GHARIB: Yeah.

ZIERLER: Were you worried that rejecting the offer to serve and writing this letter would have negative repercussions for your family?

GHARIB: Yes. They went to my father, and they said that they had to pay back all the money they sent us in dollars. And the dollar, a year and a half after the Revolution, became ten times more expensive. Imagine every dollar they paid, and they wanted ten times more in US dollars. Because my father only earned Persian money. They took our house. Imagine that my father, now 75, was told to pay the whole amount. So he put the home as collateral. He said, "One day, I'm going to go back and pay." And that collateral is still there. Eventually, because our house was valued more than what we owed them, they couldn't take it, but they took a piece of land we had by the Caspian Sea.

They punished my parents for me rejecting them. But after that, even today, I'm very vocal, especially about human rights in Iran. I worked with many Senate and Congress committees on the human rights situation in Iran with senators like Pelosi, McCain, who were really against human rights violations worldwide, especially in Iran, and many other senators. I still get invited to talk to them about how university students and faculty are being treated.

They just fired the head of Tehran University last week because he asked for the release of one of the jailed students. My parents aren't there anymore. At one point, they were so aggressive that my father told them, "Look, it's unfair that you're punishing me for the beliefs of my son. It's not fair." And for that, they fined him an extra $5k for insulting an officer. That was a good reason for me to drop the idea of returning to Iran. ZIERLER: Did you try to get your family out as soon as possible? Did you engage them in those kinds of discussions? GHARIB: No, fortunately, they could get out due to the chaos that existed at the time. My mother got out first because she had a valid passport with an exit visa. Because she was sick, she had cancer. And they allowed her to get out. My father, later on, just went to the airport, and one of his former students was in charge of airport security. So he just said, "Oh, yeah, you can go." He just bought a ticket on the spot and got out. The same thing happened with my father-in-law. He got to the airport, and one of his students was in charge of security also. ZIERLER: Where did your parents go? GHARIB: My father went to Germany, where my brother was. Then, they came to visit us. But unfortunately, on the way back, he had a stroke on the airplane. And he passed away in Germany. ZIERLER: When you wrote that response rejecting the offer to serve in the military, did you have a sense that you'd never be going back to Iran? GHARIB: Absolutely, yes. And it's funny, every four or five years after that, I'd get an invitation from the ministry of this and that to give a lecture. They'd pay first class and everything. I always told them, "Please read my first letter." ZIERLER: You'll never go back. GHARIB: I can go, [laugh] but coming back is a different story. It's such a corrupt system regarding how they treat the most educated population in the Middle East. Even today, if you look at all the physics, astronomy, and math Olympiads, they say that at least one is from Iran in the top five. To me, it's such a sad, unfair situation. ZIERLER: As you well know, the Iranian Revolution was a low point for the United States and Iran, their relationship, and sadly, it remains a low point. That was also coupled with many stories of abuse that Iranians in America received in 1979, 1980. Did you ever experience any of that discrimination or hatred, whether on campus or in Pasadena? GHARIB: Not in my case. I'm sure other people did. It was amazing; even in the middle of that hostility, we, as Iranian students, had a program during the Hostage Crisis where at least 500 people showed up. And the whole idea was to say; please do not mix up Iranian people with this government. That was the entire message. But I'll tell you something that made my love affair with Caltech. Imagine you're here, and then there are hostages in Tehran. Every night. "This is day 230." Do you remember ABC News? ZIERLER: Yeah. Ted Koppel. GHARIB: Yeah. My dream was, one night, I'd turn the news on and not see that number. It was to that level. It stressed all of us. I think I was the second Iranian Ph.D. student from Caltech. The first one was a physics graduate in the 1940s. We tried to find him. But I think I was the second Ph.D. degree recipient of Iranian descent. The minute the Hostage Crisis happened, the temperature went up. There was news of the mistreatment of Iranian students or people in different communities happening. We got a letter from the Caltech president, and the letter stated that, "You're part of the family here. Don't worry about anything. If your tuition is dependent on anything from outside, don't worry about that. If you have any financial problems, see us. And this is the name of a lawyer. If anybody comes and insults you, do not answer. Just give your lawyers a call. They'll defend you." ZIERLER: We use the word inclusivity so much in aspirational terms, but that's inclusivity happening in real-time. GHARIB: Name another university that does that. ZIERLER: How much was that about how Caltech regarded you as a student personally, and how much of it was a broader statement, "This is what Caltech stands for. These are our values"? How did you understand those things? GHARIB: To me, it was just what Caltech is. It was a broader statement. They would have done it for any other member of the community. This is why if you look at it, who would have been a better ambassador of the US than me going back to Iran and representing the culture I come from? This is the US that we knew. This is the kind of place Caltech was. ZIERLER: And it's the US that you idolized ever since you were a boy. GHARIB: Yeah, to me, it just materialized. They didn't kick me out. They said, "Look, if you need money, tell me. Don't worry about your tuition. And if you get into trouble, here's a lawyer's name." To me, it was like, "Are these people naive? I'm not part of the enemy or part of you guys?" These are the kinds of questions you ask. Of course, bad things happened. Some people got crazy and did some crazy stuff. But it wasn't a systematic way of treating us. Especially Caltech. I'm not saying this is paradise, but it's close to heaven for the scientific community, rational people, special people. Everybody here is unique. ZIERLER: Was science and engineering as a graduate student – was Caltech a refuge for you, a place where you didn't have to deal with these terrible political realities? Or did those bigger questions actually influence your scientific and engineering interests, particularly because now you know wherever you're headed after Caltech, it's not back to Iran? GHARIB: No, this was a haven. I remember I had an office at JPL because I did most of my thesis at JPL. I was overlooking the mountains. And I said, "Look where I am. I'm both protected by nature and by man." [laugh] I'll show you some of the pictures I took at that time later. I have a picture of myself wearing headphones, listening to the data streaming. Then, I stopped looking at the newspaper and, for a while, even watching the news. I said, "I don't need it. I've had enough." So it was a cocoon. I protected myself with science, engineering challenges, all those kinds of things. And above all, with the friends around. Anatol Roshko and his wife–we realized that the number of invitations to their house increased as the situation worsened in Iran. I am sure that they realized that we were alone with no close family here. There was a welcoming attitude. And, for me, the science I was doing was so narcotic in terms of helping me not think of anything else. It was amazing. ZIERLER: As you said, when you first arrived in Pasadena, there was no plan. It was an opportunity to immerse yourself in all of the science. So last question for today's session. Of all of the things to work on in the wide world of aeronautics, of fluid dynamics, fluid mechanics, what was the intellectual process of narrowing and choosing a topic to focus on for your thesis research? GHARIB: Well, the process was the challenge of unanswered questions. One day, we sat down with Anatol, and I have his drawings to show you later. He said, "Mory, it's interesting that we always think fluid mechanics, when we look at the process, is just happening, and we're just flowing with it. But it's also essential to see if we can deceive the flow to do what you want it to do for you without exerting too much energy. He said that was a big challenge, working with boundary conditions so that you can force the flow to do what you want it to do for you. Reduce the drag, or reduce the noise. He had a message for me beyond fluid mechanics and more about life. But that was a big challenge, to think about the problem. We came up with this problem, what happens when a vortex is shattered as it impinges on some objects? What kind of a signal does it send out? And how does it change the environment around it? That question, "Understanding how vortices interact with objects and how they would generate disturbances around them," became my passion instantly. If you look at every aerodynamic design, every combustor, every rocket, every airplane, why do you have noise in an aircraft when you fly? Because vortices are impinging on something, but you don't see them. Or why does the vortex in the heart behave like it does when it hits on the apex of the heart? Is it good to impinge on the apex of the heart? Or how do you generate vortices when you flap? And how does impingement of the vortex interact and create forces? These eventually defined my thesis, which was about vortices in cavities. And later on, that cavity, which could be part of a missile system, research funded by the US Army, became applicable to the cavity (ventricle) of the heart. The unifying concept is the same. And in a note to myself, "When I get a faculty job, I'm going to look at vortices in the heart." It was just a note, or maybe I wanted to convince myself that I could put my research into work to save people. My work with Anatol on cavity flows received many citations and is recognized as one of the classical works on cavity flows. A unique moment of my life was when on my graduation day, Anatol told me, "Now that you've graduated, the whole world is for you to discover." And that's where I said, "OK, how many more years do I have in my life? Oh, boy. I'm late." So that's why I decided to try my mental muscles on every subject that I could impact. But fluid mechanics is my passion. Everything I do is related to that. Right or wrong, I think I still enjoy it. I have a natural feeling about seeing things [as] fluids when it comes to that. And Anatol once said, "Sometimes, you see equations without them being there. That's good. That means you know where you're going." That's why that little cavity flow became my work on how the cavity works in the heart of the zebrafish, to the human eye, to later to show how vortices make a shape like the boxfish hydrodynamically stable. So that all came from that little moment where he said, "Now, you have all the tools. You have graduated from Caltech. You have the whole world in front of you." ZIERLER: This idea that at Caltech, you were exposed to a depth of science and engineering where there was a philosophy behind it, that you were thinking at that depth, was there either an expectation put upon you or that you had of yourself that even as a graduate student, you should approach the problems not purely just from a technical level, but also from a philosophical level? GHARIB: It depends. I think it depends on who your advisor was. For Anatol, it was very much philosophical. The expectation was very, very painful for me internally. If I don't follow that philosophy, I will embarrass myself, embarrass my teachers, my family, and my own expectations. I think just doing science or engineering blindly, or just for money, or for something that is not really "Caltech-y" was not an option. I'm not saying you shouldn't be successful and making money like that, not at all. But if you just do it for that, it's not good. Anatol, on many occasions, told me, "If somebody's paying for your ideas, that's a good sign. Because the outside world has a different measure than you." So if somebody's supporting your research, that means they think your research is essential. He introduced me to [the concept of] being entrepreneurial. Even though he never had a startup. But he had an invention that he made some money off of. It was a gas flow metering concept that we have today are based on Anatol Roshko's patent, although the patent has expired. He also introduced me to the world of consulting. He believed that consulting helps us to learn about real-world technical issues. He had the talent to extract a fundamental science question from practical consulting projects. In the meantime, he believed that if possible, using basic science and making it something useful that helps people is good–that's why I feel so proud of that philosophy. I'm following that philosophy to make an artificial heart valve that people can afford to buy for$60 rather than $6,000. To me, it's an achievement of basic science because we used our understanding of the flap of the jellyfish to design efficient heart valve leaflets. And we made it out of polymer, so you don't need to kill ten cows to make a valve. This is the kind of thing where not that many people except the Caltech guys would risk even thinking of making such a bioinspired system. ZIERLER: And even at Caltech, and correct me if I'm mistaken, but Anatol was a pathbreaker in his comfort in thinking about business and entrepreneurship. That was not common for professors at that time to think along those lines. GHARIB: No, it wasn't. But we had ones who were doing it, but they were shy about talking about it. ZIERLER: Yeah, because the culture frowned on that to some degree. GHARIB: Yeah. Many inventions and patents have come out of Caltech. Like I was telling you, the technology behind the microwave oven was invented at Caltech. Every time you toast something, remember us. We're here. We invented it. Or the Xerox machine. Or your cell phone camera. We are not just in deep space or down somewhere in the nano world. ZIERLER: Who was on your thesis defense, and was there anything memorable from the oral discussion? GHARIB: My thesis defense had Ed Zukoski, Don Coles, Anatol Roshko, and Roger Blandford. Roger discovered radio jets. And he gave me the hardest time. And later on, he confessed something that made me laugh ten years later. I saw Roger at a conference for APS, American Physical Society, and I told Roger, "You almost flunked me in the exam with that question you asked. 'Show me how the entropy distribution is in the upper ten kilometers of Jupiter's atmosphere.'" Because my minor was in astrophysics. I said, "Where did that question come from? It wasn't part of the course." He said, "You know what? I was sitting in front of Anatol Roshko, Don Coles, and Ed Zukoski. I wanted to show them that I knew my fluid dynamics." [laugh] I was like a sacrifice. [laugh] He said, "But you did OK, Mory, don't worry." I said, "OK, but you could've ruined my future." [laugh] Yeah, it was that kind of approach. ZIERLER: [laugh] And with that, we'll cut it for next time. [End of Recording] ZIERLER: OK, this is David Zierler, Director of the Caltech Heritage Project. It's Monday, October 4, 2021. Once again, it's my great pleasure to be with Professor Morteza Gharib. Mory, it's great to see you. Thanks for joining me again. GHARIB: Thank you for having me. ZIERLER: Today, we're going to pick up at the very beginning of your post-graduate career. You've successfully defended their thesis defense. And so, my first question is, what was available to you at that time institutionally, academically, scientifically? What did you want to work on, and where could you work? GHARIB: Well, I didn't do a post-doc at Caltech because I did most of my Ph.D. work at JPL. So they (JPL) offered me a senior scientist position, which was kind of odd because usually, you start with a junior [position], then senior. But I had the privilege of getting a senior scientist offer. I accepted that, and basically, I had two projects to work on. One was the extension of my thesis on supersonic flows, and I did most of that at NASA Ames. And then, the other part was to develop a new automated image processing technique for velocity tracking of objects. I stayed at JPL for two years, and in the meantime, an opportunity came up at UC San Diego, which was fascinating for me to be close to the water. But then, also, the quality of the place was impressive because the department I joined was established by about 12 faculty coming from Caltech many years before. That was the opportunity I took. And then, I stayed there until I rose from the rank of assistant professor to full professor. ZIERLER: My first question is, with JPL, was it a staff position? Or was it a post-doc with a fancy title? GHARIB: It was a staff position. ZIERLER: So you really could've stayed on if you wanted to. GHARIB: Oh, yes. Yeah, it was a full-time staff job. ZIERLER: What were some of the primary missions going on at JPL for which your research was relevant at that time? GHARIB: I should say that none of the missions were relevant to my work, or my work wasn't relevant to those missions. Because those missions are usually planned eight to ten years before. My work was relevant to the image processing technique that I had developed for particle tracking. And I heard, later on, they used it for some of their missions. But nothing directly relevant. ZIERLER: Was this imaging more basic science, or were there particular applications that you were thinking about? GHARIB: It was mainly application. I was interested in being able to follow thousands of particles automatically. And the technique at that time was to do it manually, go picture by picture and see how much it moved. So I developed an automated digital method for doing it. At that time, it was kind of advanced, using the digital particle imaging technique. ZIERLER: To go back just a little ways, I wonder if you can talk about how you came across Keith Koenig's work on the aerodynamics of tandem bluff bodies. GHARIB: When I became Anatol's student, Keith Koenig was a student senior to me by about two years. Anatol was interested in knowing what happens if we go to a more basic problem than what Keith was working on because they found something they couldn't explain. Anatol's strategy was usually, "Go back to basics." So he asked me to design an experiment that wouldn't suffer from boundary conditions. I came up with this cavity flow concept, that boundary condition's so uniform, we don't need to worry about directionality and all that. But that's how my Ph.D. work started. But that was my third project, not the first. ZIERLER: Tell me about Anatol's enjoyment of the famous Galileo phrase, "We must measure what is measurable and make measurable what cannot be measured." What does that tell us? What insight does that yield into Anatol's approach to science and what you learned from him? GHARIB: Well, he usually looked at the problems and wouldn't jump to develop a huge master plan for dissecting it. He had made a sketch, showing that "In science, we're like a blind person in a zoo trying to identify an elephant by just touching it." For him, the first step was defining the parameters and some of the features that were quite distinctive in any process and then picking up one and trying to zoom in on it. Usually, in fluid mechanics, you would start with flow visualization. That was his primary tool. We did rough kinds of visualization first, and we'd see something and then improve the technique or change the experiment to be more suitable for the methods we had. That's Galileo's approach. And I found that phrase many years after, and I sent it to Anatol. And it's a fantastic thing because it's precisely what he did. He taught us how to design or change in the experiment something that you want to measure to be able to measure it, rather than trying to half-ass the job of doing a measurement of something you didn't understand. That was his philosophy. ZIERLER: Your research at JPL for those two years, what aspects of it did you see as a continuation, an expansion, or even a refining of your thesis research, and what areas were simply new science and engineering for you? GHARIB: I think the significant expansion of my thesis work was to supersonic flows or high-speed flows. However, we didn't have a suitable tunnel at that time at Caltech or JPL. I believe we had one, which was out of commission. But NASA Ames had an appropriate facility. I spent weeks over there using the country's highest Mach number tunnel to study the cavity flow. Same process, but a much higher Mach number. Of course, there are people before me who looked at the same problem, but they did not have the new understanding that Anatol had introduced, the concept of vortex dynamics in cavity flows. ZIERLER: What did these cutting-edge facilities allow you to see that otherwise would not have been possible? GHARIB: I think I was the second person at Caltech/JPL who used a two-color laser to measure velocity fluctuations inside cavities. Or inside anything. And for that time, in the early 80s, this was about half a million dollar machine. I don't think we had anything close to that on campus. And for me, it was like being a kid in a toy store, having this machine given to me to work with. And for most of my thesis, I used that machine. And the results were so unique. I do not think I could have conducted such an experiment anywhere else but at JPL. ZIERLER: One of your very first awards was the Flow Visualization Award from the APS in 1983. Tell me about that. GHARIB: That one was a very interesting story. [laugh] I visualized a kind of pattern of vortices behind a flat plate that was accelerated and created a beautiful vortex pair with miniature satellites of these smaller vortices, like what you have in Jupiter. And then, I put the nomination aside. And I was very excited because everybody looked at it and said, "Oh, this is a winner." But when they announced the winners [laugh], I wasn't there. I was depressed. Then, Anatol came to me and said, "Mory, you were number one, but I disqualified you." I said, "What? Why did you disqualify me?" I wanted to see how honest he was. He said, "Because my wife was one of the judges, so I was afraid even if you won it, people wouldn't think you won it on merit. And I know you may not be happy with the outcome." I accepted that. I said, "It might be unfair, but I accept it." Then, a month later, the head of the judges apparently visited that and decided to reverse it. The prize was a book of flow visualization by Vandyke, and he said, "Congratulations, we looked at it, and we don't think the judges were biased." He added that Anatol's wife recused herself from judging when my entry was discussed. Anatol didn't know. So that was my first prize. [laugh] The rest just followed. ZIERLER: Now, it's out of the chronology, but while we're on the topic for being recognized for visual imaging, tell me about your connection to the Visualization Society of Japan, which honored your work in the mid-1990s. GHARIB: When I was at UCSD, many faculty researched atmospheric and ocean flows. The atmosphere of the earth is very thin compared to the diameter of the earth. In that respect, simulating a dynamic atmospheric flow experimentally was difficult, if not impossible. I got this idea that maybe I could use a thin soap film that could flow like air in a wind tunnel; if possible, then I might be able to simulate large-scale atmospheric flows. Imagine that you make a tunnel where soap film is moving instead of water or air. And so, one day, I was washing the barbecue grill at home and I realized that by shooting water at the end of the grill, I could make the soap film spanning between the rails on the grill move very fast. And I realized that I could control the speed of moving soap film by controlling the speed of the impinging water jet. And I got the idea, "Maybe I should make a frame, and shoot the water at the end of the frame, and put one end in a soap/water reservoir, and see if it moves." Practically, it was a breakthrough because that was the first time we could simulate atmospheric flows by my soap film tunnel. And the images that we produced were fascinating, especially the ones in color. I got my tenure with a$30 investment. It was a coat hanger and a couple of plastic containers, and a bottle of Dow detergent… I used the same laser technique that I learned at JPL to do the measurements in that one, which by itself was a kind of innovation, and nobody thought you could do it. And the images that came out of that won another APS prize, and then the Flow Visualization Society of Japan picked it up. It's the same image, but we got second prize for it.

ZIERLER: Now, why the Society of Japan?

GHARIB: I have no idea. They must've scanned the APS. It's a booklet that they publish every year, and that image was the cover of that booklet.

ZIERLER: I'll note that the award was recognized by both the technical section and the artistic section of the Visualization Society of Japan. I wonder if that planted an early seed in terms of thinking more broadly and pursuing your interests at the intersection of art and science.

GHARIB: Definitely. My interest in art started with my wife's work and Anatol. Last time, I mentioned that because of our situation, Anatol and Idet (his wife) considered us as members of their family, so we traveled and spent time with Anatol and Idet. She was an artist, and her workshop was in their basement, where she created amazing bronze sculptures. From Anatol I learned how to see the beauty of vortices and the dynamics of nature from the atmosphere to the ocean. That's how I started. But you're right; that soap film tunnel allowed me to create flows and patterns that are hard to see in natural flows. And that changed my mind and creativity in terms of artistry.

I saw nature's beautiful art in flowing soap films, and the artist within me saw and tried to comprehend it. I remember that there was a big, huge soap film event in France, they tried to create similar images and invited me to go there as an artist and not a scientist. But in the meantime, I continued understanding and developing proper equations governing the beautiful similarity in earth's atmosphere and something that you can make with $30. I think that shows the plasticity of the human brain, that a different artist, mathematician, or a scientist…can coexist in the same person. ZIERLER: Maybe it's a difficult question to answer, but I wonder if philosophically, psychologically, would you say more that with the soap films, it was the beauty that you saw that inspired you to make these new measurements? Or did you see a possibility to make new measurements, and that's where the beauty really shone out for you? GHARIB: That's a difficult question. We can sit in front of a soap film and watch it for hours and hours. It's incredible and mesmerizing. But the challenge in doing a measurement was what the Japanese Society also appreciated. Because it's something where you can't even touch it. If you sneeze, it pops. But still, it's robust enough that I was able to do laser measurement. So it was, for me, a challenge showing that while nature is making art, I measure to understand. Chandrasekhar, I think, said, "If nature were not beautiful, it would not be worth studying." I would add to it that "If there's beauty, there is science." So I think that's kind of what motivated me. ZIERLER: Chandrasekhar is a good source to go to for something like that! By 1984, '85, were you looking for new opportunities? Were you on the job market? Or were you happy at JPL but were recruited at San Diego? GHARIB: I wasn't on the job market, but San Diego recruited me. Because by then, I had only one paper, which wasn't even on my Ph.D. work; it was from my master's thesis. I think somebody called Anatol and said, "Whom among your students do you suggest we look at?" And he told me about the opportunity. And I did then apply. Purdue and Georgia Tech approached me, but I decided not to pursue them because my wife's family lived in California. At San Diego, I knew the department's quality, and some of our previous alumni were excellent. When I visited, it was beautiful. ZIERLER: Pursuing a professorship was important to you at that point, not being only a staff scientist at JPL. You wanted to be a professor. GHARIB: Well, not to just teach, but to mentor as a professor. For me, teaching does not mean having so many students in your class. It's to find an apprentice, and I would say, in science someone who can walk with you, who you share all of your ideas with and get feedback from. That's what was missing because I had it with Anatol, and I wanted to see if I could be a good mentor. That was the main challenge for me. Also, freedom to do whatever project that I desired to do. Of course, that's not always true because sometimes you need to follow funding sources. But in the meantime, I showed my students that even a$30 budget could get you your tenure if you have a good idea.

ZIERLER: Of course, you have to pursue the best opportunities available to you, but in light of how wonderfully caring and inclusive Caltech was to you as a graduate student, during those difficult years, during the Revolution, the hostage crisis, did you feel a sense of loyalty to Caltech and JPL where leaving was difficult to some degree?

GHARIB: It was more challenging to leave Caltech because of the environment. JPL's a fascinating place, but it's mission oriented. And I was not ready for that kind of responsibility in terms of being mission oriented. Even though I delivered whatever the project required. For example, my image processing project that later on was used for many other applications was mission oriented. But leaving Caltech was difficult, especially leaving my office, which was the tiniest office in the whole building, but it was so unique that I almost cried. But the loyalty at Caltech was always there because of the kind of unconditional support given to me that allowed my family and I to get through many hard times. And that was always there; whether I worked at Caltech or not, it didn't matter at all. It got to the point that my senior colleagues at UCSD were getting a little bit sensitive when I spoke about how academic environments should be like Caltech.

ZIERLER: Tell me about how the program was organized administratively at San Diego. So it's the Department of Applied Mechanics and Engineering Sciences. How did those things work together? How did San Diego organize itself in that way?

GHARIB: It was exciting. I think they organized themselves very much like Caltech. Because I mentioned that there were 25 faculty between the 1960s and 1980s who came from Caltech. And exactly two of them were from GALCIT, this department. If you look at the courses, they even have numbers close to what we have at Caltech. That was great. And I can say that some of the best work I've done; I'm very proud that some of it came from the seven years I was there. I was cautious about how to pick up my students. And that was critical because some of the best image processing and vortex dynamics work that I did came from my students at UCSD in those early years.

ZIERLER: Did you have startup funding internally from San Diego? Did you have external funding? How did you get your lab up and running?

GHARIB: They had startup funds. And one nice thing was that I was [following the] late professor Chuck Van Atta (a GALCIT graduate) who was about to retire, and I inherited some of his facilities. That was a big, big plus. But I'll tell you, what helped me get funding was my experience at JPL. Because even as a student, I wrote three proposals to get funding at JPL. That helped me first learn how to tap into government funding, tap the foundations, and manage the processes and my group. Other starting assistant professors did not have those experiences.

ZIERLER: What did you want to focus on when you arrived? What was most interesting to you?

GHARIB: That's a very interesting question because a senior faculty over there asked me the same question in my interview. And they always used my answer against me. I answered, "I would like to work in contemporary fluid dynamics." [laugh] And his jaw dropped. He said, "What do you mean, contemporary?" I said, "Contemporary is when your ideas are not necessarily accepted in the mainstream. I think that's where you make discoveries." If we just look at what other people did or follow somebody who did something over and over, then anyone can do that. I wanted to do something entirely different. I studied soap films, a risky start, for example. Many colleagues laughed at me until the NSF decided to give me $300,000 to continue in the soap film research. Or another quite controversial work! A big fluid mechanician, not at Caltech but UCSD, claimed he made a big discovery. And that discovery was so significant, according to everybody, that it could result in solving many other challenging unsolved fluid mechanical problems. And then, here comes the little guy, and I showed that he made a mistake in his experiment, and he did not see it because he was so much in love with his made-up theory. Something was vibrating in his experiment. And after Chuck van Atta and I published our work, it made a big bang because it showed you should not follow "hoopla" in science. If you follow trends or what is hot, you can follow other people's mistakes. Because of that experiment I'm not going to name, many people made up unique theories that promised to solve significant challenges in turbulent flows through chaos theory. It created more chaos than solving it. We showed that "one should just look at things from the simple aspects of them and question whether their discoveries pass basic laws of physics or rational design." That's simple. And that's how I discovered that he must've made a mistake. And that comes from the style that Anatol taught us: "look deeply at problems and ask the right questions." Another area I started to work on was around the old question of vortex formation. I noticed that all the papers on the subject matter of vortices and their properties focused on a single clean vortex that their apparatus could generate. Also, I saw a strange occurring number, "four." It represented the ratio of the vortex diameter to the length of the generating jet. Almost all the previous investigators stopped at a ratio of 4 to have the largest clean vortex that they could produce. Even the formation of atomic mushrooms followed this strange number. Why do all these vortices always form or saturate at four times the diameter of the producing intial jet on such different scales? Those are the kinds of core questions that "follower" types of investigators don't ask, but we are not followers at Caltech. We ask the most challenging questions. And nobody asked why. Because everybody tries to go around it and somehow do something that they're comfortable with, no controversy. Still, we conduct challenging research topics that others are uncomfortable with, and that's the essence of seeing "NO BOX. "You take problems that are not just difficult, but very difficult or almost impossible to solve. That's the kind of trend you'll see most of our graduate students work on, and we try hard to keep this tradition. ZIERLER: You mentioned last time that you had this idea about working on heart valves. Was that something that you pursued at San Diego? GHARIB: Actually, it started in San Diego. I remember that day very clearly. I was in the water tunnel with my student, Kathy Williams, and we were setting up to do some flow visualization on a flapping airfoil. And then, somebody knocked at the door, and came in, and said, "I'm David Sahn, I'm the head of the echocardiology department at UCSD." And I said, "OK. I think the medical school is the next building; it's not here." That's what I told him, and I thought he came in by mistake. He said, "No, no, no, I heard about you, that you're working on flapping airfoils." I said, "Yeah." He said, "Look, you guys are designing stuff for 747s or helicopters, but look at this thing." And he had a mechanical heart valve in his hand. He said, "This is the worst insult to nature that is made by engineers." He was wrong; actually, it was designed by a surgeon. He said, "Can you do something better than that? Thousands of people die because this valve fails." And that's how it started. Together, we wrote an NIH grant. I began to study a wide range of mechanical heart valves. And I began to work on different aspects of it, but the real thing happened when I moved to Caltech, and I met another faculty member, Scott Fraser. And I said, "I want to learn how nature makes heart valves. Maybe that's the way we should learn to do it. If you just mimic, that doesn't mean the function will follow. We should not try to mimic the final product. Let's learn from nature how nature actually makes it." And that's how it started. ZIERLER: Why is the function not the same, even if you do an excellent job mimicking nature? GHARIB: Because even today, we don't know how to make materials that nature makes. We cannot grow tissues the way nature grows them. We cannot make even wood, a simple cloth. We don't have artificial wood. There are so many materials that nature creates and mixes and matches to build functional systems. It builds stuff that we are quite incapable of making. And that's why if you produce something that looks like a heart valve, it doesn't mean it will have all the functionalities or material properties. A heart valve beats about two billion times in an average person. Just name a material that can beat two billion times without breaking. As simple as that. ZIERLER: I wonder if you could explain, then, what expertise in fluid dynamics allows to compensate the fact that we don't have the technology simply to create our own heart-like materials? In other words, what do you bring to the table that a cardiologist would not where you can say, "I understand this at the systems level, and I'm going to come up with a solution, even though we don't have the materials to recreate what nature does on its own"? GHARIB: It's a very critical question. That's why in my title it says Professor of Bio-Inspired Engineering. Because the last 20 years, I've been pushing the idea, "Don't bio-mimic. You're going to fail. Because you didn't have 20 million years to evolve these things." There's no evolution in our work. We create things in a much shorter time scale. We should be inspired. Once you accept that fact, you start to think about shortcuts that nature doesn't have. Nature's mission is not really to be efficient. Nature's mission is to survive and reproduce. That's the only mission. As engineers or scientists, we have other options. We do not want to wait for another million years. We want to save somebody's life in the next 10 or 20 years. We have to put our brains together to come up with the physical scientific principles of operation of these natural physiological machines, take these concepts, then see what we can do to deliver that function. It may not look anything like a heart valve or a pump that nature built, but it delivers the same function. But also, nature has shown that sometimes, different designs converge in functionality. So it can be one of the branches that perhaps shortcuts to that function. ZIERLER: What would be an example in evolution of a convergence of functionality? GHARIB: Look at, for example, a tree. It uses osmotic pumping. It delivers fluids from point A to point B. Then, the same thing will happen in an insect, for example. Insects use wetting and diffusion to pump air and liquids. You can see that using the surface tension concept under two different circumstances delivers the material from point A to point B. That's a convergence, two different designs, same functionality at the same scale. For us, if you look at the heart valve, nature grows it. During growth, what happens is, it tries to minimize the surface tension like teardrops or raindrops. The shape is really because surface tension reduces the surface energy. Think about it. I don't have all the growth mechanisms that nature has, all the DNA information, how the cells should be guided. But how about the minimization of the surface energy? So we designed a heart valve that uses the minimization of surface energy as guidance. We formed a new type of synthetic heart valve using polymers that, under gravity flow, minimizes the surface energy. They form into a shape that is very much like a heart valve that nature grows, except we made it out of polymers. Here the basic principle of the inspiration was that nature uses minimization of surface energy. ZIERLER: Which is looking at the issue much more deeply than just shapes and sizes. GHARIB: That's right. Because I could go there, design the shape, and ask the machine shop to cut it for me. Which people did. And those things did not even flap 500 times. Like bending a credit card over and over, it breaks quickly. Now, because it's minimized the surface energy during the shape formation, this polymeric valve can flap a billion times and still not break. This is the concept of bio-inspiration: don't try to mimic the shape. Let the shape form as the principles allow. That's the difference between bioinspired and biomimetics. ZIERLER: When you studied the failure of the mechanical valves that came before your work on this, what did those investigations tell you? GHARIB: I was involved in a significant trial as an expert witness on a valve that broke in so many different ways and killed many people. And they asked me to understand why it broke, then testify. I realized that it's a blind approach to trying to mimic nature. It's wrong. These guys went and took the most robust material you could ever think of, and they made these valves from it. And those valves did something exciting. Every time they closed, they initiated the phenomenon of cavitation. Navy propellers get destroyed when they see cavitation. And imagine they put this valve inside the human heart. Every time it closed, it closed so fast that its tip produced a cavitation. And that cavitation can break even the most robust man-made material. It just cracked it like glass. Cavitation is like kilohertz hammering. They never expected such a phenomenon to happen inside the human heart. So when I saw that, I said, "Yeah, of course." "This is such a strong material," they said. "Yeah, but when they cavitate, even Navy propellers that work at such pressure break." It's just blind mimicking of the concepts, "The stronger, the better." No, it can be softer and better. Those are the things I learned that I have to respect how natural systems are made. If we don't appreciate it, don't expect to make any machines that we expect to work like physiological machines. ZIERLER: Going back to what you learned from Anatol as your adviser, when you started to take on graduate students at San Diego, you mentioned that you were particular in your choices. What were the things that you were looking for, and how did that harken back to your experiences as a graduate student? GHARIB: Well, I had close to 45 students that graduated with me, and every one of them is a gem. One's a diamond, and the other is silver. To polish them, you have to use a different technique. You cannot take the same file to each one. Part of the challenge to select a student is to find if they are inquisitive. They have to be willing to challenge me by asking hard questions. But in the meantime, to be ready to learn. That's very important. Once you have those two character traits, then anything can work. Of course, you have to be smart. And I always looked for students like that. Not students who just do what you say to do. And to me, that was a really successful formula. ZIERLER: You mentioned that one of the issues at JPL was that it was more mission-focused than you were used to. But in your own lab at San Diego, was there a mission? Was there an overall theme or goal that, no matter what experiment or measurement you were running, they had a common theme or thread? GHARIB: One thing we have to remember is that we're educators. Often, you see some group with a professor who only thinks about research, which is OK. But there are National Labs where you can do the same thing if your mission is not to educate. I always believed that I could not solve problems [for them]; I could educate students to solve those problems. Even when I had a problem, I wouldn't say, "If you do this, you're going to solve a problem." I say, "Try to see how you could solve a problem." And in the process, I tried to ensure that they get all the tools and approaches to scientific thinking and problem-solving. Once they attain that, to me, even if they have not solved the problem, they're ready to fly solo. Thanks to some of the agencies that trusted people like me. They never came to me and said, "Hey, we want to solve this problem. Solve it." The Office of Naval Research is a good example. They said, "OK, Mory has a philosophy of how to do research," and they allowed me to educate a trail of students who eventually either went to other faculty jobs or went to the Navy. And after 10, 15 years, they solved many of those challenging problems. I think this is how basic research translates to solving applied problems—some of my former students are right now at the forefront in solving the Navy's challenging issues. I certainly could not solve these problems. But, my students did, students that I trained. ZIERLER: What were some of your key funding sources beyond San Diego for your students, for your lab? GHARIB: Office of Naval Research, National Science Foundation, Navy labs individually, and DARPA. To a lesser extent, the Air Force. But also San Diego, DARPA. ZIERLER: And to go back to that theory versus applied component of the research, given the extent to which military labs were interested in supporting your work, what were some of the big questions that they were after for which your research was relevant? GHARIB: It's interesting because remember the technique I said for particle tracking. Later on, my work on how the vortices form to keep up the propellers. To give you an example of the practical problem they were interested in solving, during the first Iraq War, our Navy ships, instead of navigating the North Atlantic's cold waters, were suddenly in the Persian Gulf, warm waters. And the type of propellers they'd designed for the north didn't work in the south, in warm waters. It created so many bubbles that miles and miles after they left, everybody knew where they came from and where they went to just from satellite imaging. Russians had it, and the Chinese had it; even small countries could see the Navy ships' pathways. So the mission was to reduce the bubble concentration. But to do that, you have to look at the fluid dynamics of the shape of the boats and propellers and the development of techniques to study the bubble generation issues. For example, we developed a method of imaging for three-dimensional particle tracking. We built an extensive system for the Navy and mounted it under one of the Navy's research vessels. I spent about ten days going from San Diego to Honolulu using this camera, searching for the source of bubbles. Using our 3-D camera, which was mounted under the boat, looking at how the ship makes bubbles to identify the source, how it connects to the propeller, all those things. I went to that kind of practical work because it was fascinating to see how abstract ideas can be converted into practice. ZIERLER: I can't help but ask, but in the fight against Saddam Hussein, living in America, did you have more than one reason to be excited about the relevance of this research? GHARIB: Of course! What happened was that Saddam Hussein and the Iraqis bought some very cheap German torpedoes. Maybe$30,000. Very cheap for a torpedo. They just looked for bubble traces. Once they saw the bubbles, they guided the torpedo towards wherever the bubble was. And then, they cut the wire and torpedo just listened to the pinging of the bubbles bursting until they got to the boat. And there were three near misses that could have killed 2,000 or 3,000 Navy members because it was a big carrier. And that was the mission – get rid of the bubbles to get rid of this trap. That was the only mission. Later on, the enemies changed. But this one was saving the lives of those soldiers.

ZIERLER: Tell me about your service work for the APS, serving as an executive committee member. What was that like, and what does that tell us more broadly about your work in mechanical engineering, fluid dynamics, and how it relates to physics as a large umbrella discipline?

GHARIB: Well, it goes back to my interest in becoming a physicist. The American Physical Society is unique. It had different areas, but as a fluid mechanician-scientist, it was desirable to be part of their activities. I was part of the members at large, and I took in different projects in that role. It's a society that is very close to my heart. ASME is, too, the American Society of Mechanical Engineers. But APS more so.

ZIERLER: When you achieved full professorship at San Diego, your title changed from Associate Professor of Mechanical Engineering to Professor of Fluid Mechanics. What is the significance of that change?

GHARIB: Because I wanted to be in fluid mechanics. That was the love of my life. I really wanted to be in fluids. I love mechanical engineering, but it's too general. I think, and especially at Caltech, I wanted it to be those titles because that's one of the places you can pick your title. UCSD also allowed me to pick up the title of fluid mechanics.

ZIERLER: I'll ask the same question when you were at JPL going to San Diego. In the transition back to Caltech, were you looking for a change? Were you on the market? Did Caltech recruit you? How did all of that play out?

GHARIB: Again, I did not apply to Caltech. What happened was Anatol declared he was going to retire. And apparently, they asked him, "Who do you think should come here?" I am not sure what his answer was. Also, several faculty at GALCIT and MCE have followed my work closely over the years. They knew that I got my tenure for $30, and I could get million-dollar grants from DARPA for looking at some abstract theory of nonlinear dynamics and fluid dynamics. But one thing that caught their eyes was, from what I heard, one of the program managers from the Navy said that if Caltech wants to remain relevant in fluid mechanics and aeronautics, they should look at some of them the work I was doing. I guess the dilemma for Caltech was and always is to avoid hiring their students. But this time, a supporting suggestion came from our mechanical engineering, telling GALCIT, "Look at this guy. And Anatol was retiring. And Anatol tried to be neutral. He didn't intervene at all. Then, I was called by John Seinfeld, who was the division chair, about whether I was interested in being considered. And I took my time to make my decision. And the main reason that convinced me that this was the place was the scale and knowing that colleagues from other departments supported my appointment. It was a different, unique opportunity. ZIERLER: As you said previously at Caltech, it's not that you're thinking outside the box. There is no box. GHARIB: That's right. There was no box. And it has proven to be true. Because what I've done here, I would say 75% of what I've done here is different from what I did at UCSD because of the interaction I had with my colleagues in other departments. Mechanical engineering, but mainly biology. That whole concept of Caltech needing to have bioengineering came from that interaction I had with Scott Fraser, Steve Quake, Paul Sternberg, Joel Burdick, all those guys. We met at the old Red Door [café] and figured it out. ZIERLER: Now, back then, in 1993, were the divisions organized as they are now, where you have bioengineering and chemical engineering as part of the divisions within biology and chemistry, respectively? GHARIB: No, no. We did not have a bioengineering department even though some of our people from here went and started the best bioengineering departments in the country, like Bert Fung, the father of biomechanics, a GALCIT graduate, aerospace engineer, student of von Kármán. One day, he gets interested in the mechanics of bones. And from bones to physiological flows, he writes two seminal books in biofluid mechanics and biomechanics. We had people like Fung and others in ChemE and MCE, but we never had an organized structure of departments. When I came here, I discussed that with one of the provosts, and he told me, "Not in my lifetime." I should relax and not start a new department. Fortunately, he's not here anymore. [laugh] But then, the next provost had a very open mind about that. I'm proud that we started the first bioengineering department within DNS EAS at Caltech with Steve Quake and other faculty. And later on, that split into medical engineering, and the bioengineering part went to biology, like chemical engineering. I'm a proud member of both. That's what happened. ZIERLER: How are these changes relevant in terms of what was available to you, who you could talk to, who you could collaborate with when you came back to Caltech? GHARIB: When I came back to Caltech, except for my heart valve project funded by a significant valve company, I didn't have anything bio-related, and that wasn't bio either. It was more the fluid mechanics of mechanical heart valves. Nothing biological. GALCIT was generous enough to have a lab on the subject. We called it the Heart Lab. I built a heart valve simulator, and I got a couple of students who did a great job in helping me to put together the lab. This is precisely what Caltech is. As an aerospace engineer, I could have a heart lab. [laugh] In the middle of all the shock tubes, and wind tunnels, combustion labs, there's a heart lab. And it was the beauty of it. It made it so colorful. Because the equations are the same. You just turn around and apply it to something that can maybe have a faster societal impact. ZIERLER: You mentioned that most of your work on the heart valve came when you went back to Caltech. This is as much a cultural question as anything else. Fifty or sixty years ago, there was a sense in academia and academic science that you did not get involved with industry, that you were involved in pure science and things like that. And of course, today, fast forward to 2021, so many professors are involved in startups and have entrepreneurial interests. Where were those things circa the mid-1990s? When you got back to Caltech, were you encouraged to think about the business side of things? Or was that still not the accepted side of how things worked? GHARIB: No, nothing. Caltech was very dry. On the surface, it was very pure. But many of our faculty were doing consulting. And to me, they gave away ideas for free. They couldn't get money back to research on campus, and Caltech did not see any benefits from their consulting work for the industry. But it wasn't something I would say that Caltech encouraged. But again, thanks to Anatol, I remember that when I was a graduate student, he asked me if I was interested in helping him with a consulting project. I helped him to design curtains for LAX. They were doing construction, and they had these big, huge air pressure tents. But then, as the luggage comes in and goes out, the air escapes. The whole thing deflated. We designed a curtain system where the bags can go through with minimum air going out. And he asked me to help. I remember that was my first$100 made from consulting. I don't know how much he made; I never asked him. But he said, "Mory, for your time, $100." It was so sweet, and I had a fantastic dinner with my wife. That was the best. But this was when I was a graduate student. I have Anatol's books here. These are consulting books that he used. I inherited all of those. And he told me that a great scientist is the one who takes the most practical problem and identifies a fundamental science question out of it. And that's what he did. He became famous for consulting questions that turned into fundamental science questions. He solved challenging technical problems and extracted some basic science ideas from his consulting work. When I came back to Caltech, it was still the same environment where good ideas went out of Caltech without any IP protection or benefit to Caltech. Until we had an amazing gentleman, Larry Gilbert, who started the Office of Technology Transfer at Caltech, who changed the environment here. I was surprised because I was sitting one Friday afternoon in my office, and an old gentleman knocked at my door and said, "I'm Larry Gilbert. What have you invented this week?" I looked at him and said, "Who are you?" He said, "Oh, nobody told you that we have an Office of Technology Transfer? We want to make sure that if you invent things, we can help you to see the light of the day. I said, "OK, that's a new thing." I had never heard of it before. But then, he and I became close friends. Later, I became vice provost and restructured that whole office with his help and Fred Farina's to promote entrepreneurship and help our faculty benefit the most from their inventions. In essence, OTT has become an excellent one-stop shop helping Caltech entrepreneurs to translate their ideas. ZIERLER: It's obvious what's come as a result of that because really, the startup culture at Caltech now, the entrepreneurial streak of so many professors, and how things have changed over the years, is remarkable. GHARIB: Yeah, I agree. It wasn't that easy. And thanks to the Office of Technology Transfer. But one reason I accepted the vice provost job, and at that time, Ed Stolper was the provost, because I said to him, "I'm not interested in that job. I have enough jobs." But, I will take it if you allow me to change the culture and encourage faculty to be creative and support an entrepreneurial environment for them and their students. In that case, I will accept. The entrepreneurial environment is not just for making money. It's about taking challenging problems, and you come up with ideas that can be useful in the short and long term. And he agreed. And that's how I accepted the job. And basically, my whole mission was to make sure that our Office of Technology Transfer was protected and would be the best in the country. Later on, we started the corporate partnership group within OTT to sustain the flow of industry support to our faculty through OTT. So I think I had a significant impact on that part of the culture in a little way. ZIERLER: What about your own experiences bringing the heart valve technology to market? How did you use that experience as a way to regularize and operationalize that generic process across the board at Caltech? GHARIB: It wasn't just the heart valve. Remember that idea at JPL, the particle tracking for astrophysics? I turned it into a device that dentists can make 3-D scans of teeth [images]. It's a Caltech patent based on the same idea that started in my JPL time. What I learned was that every concept like this can have multiple applications. My talent was to find the proper application. I knew that people do not like the impression materials dentists put in their mouths to make crowns. I said, "Why don't we just scan it?" But again, there are other ideas about scanning, too. So, I miniaturized the three-dimensional imaging system that I developed and used for Navy ships, but this time to 3-D scan teeth. We formed a startup with Caltech licensing. And three years, from start to end, we sold the company. The key was learning how to put a good team together, not fall in love with our ideas, be flexible and ready for changes that other people suggest and apply those to make a product. As vice provost, I tried to give the same experience to younger and older faculty who had good ideas and wanted to translate them. Even today, I had a meeting with one of our new faculty who wanted to start a company. I said, "Don't. That's not going to sell, I tell you." I've given wrong advice before, but some of them I know. It's so clear. Because we fall in love with our ideas and think that everybody in the world needs it. Like, you need a new shirt. We don't know. Let me give you a funny example of how wrong I could be about the business side of this whole thing. One of our first bioengineering students came to me near his graduation and started by saying "Mory, thank you for supporting me (I was his academic, but not research advisor). I really had a good time in bioengineering. But I plan not to pursue it." And I said, "Where are you going? Where are you going to work?" And he said, "I cannot tell you." I said, "Why?" He said, "I know you're going to tell me not to do it." [laugh] I said, "Is it a startup?" He said, "Yes." I said, "I support startups. I encourage you to do it." But then, he said, "But you don't know what I'm going to do, which is why I'm afraid of telling you." So he didn't tell me. Three years later, he was one of the founders of Airbnb. ZIERLER: That's amazing. GHARIB: Yeah. But he wanted to tell me he was going to a startup because he knew I liked them, but he didn't want to tell me what. Because me being me, I would say "Go build better medical devices." ZIERLER: Tell me about the NASA New Technology Recognition. You were awarded so many times for this. What was it about NASA and this particular award that was so relevant for your research? GHARIB: It was all about that particle tracking and different versions of it. They realized that I made it much easier for scientists to do this job because every picture they took had about 10,000 particle images. In order to track their movement, they used photographic films. They had to put the shifted images on top of each other and manually measure the shift. I thought, "Well, I bet we can do it automatically with digital cameras instead of using films" And our first paper was rejected because the resolution of digital cameras was not high enough. They completely missed the concept. Then, my answer to the reviewer was, "Well, maybe today, but the Japanese and Koreans are working so hard at getting better resolution cameras that eventually, this will work. But, what we offered was the mathematical foundation to do it digitally." And that's why NASA appreciated it and gave me that recognition. Luckily, a JPL scientist invented the CMOS technology ahead of Japanese and Koreans. ZIERLER: Tell me about your time as a visiting scholar in Tel Aviv. How did that come together? GHARIB: It came from my work on heart valves. What happened was, I recruited a student who was an Israeli Persian. And he had done his master's in Tel Aviv with Professor Shamuel Einav and he came to do his Ph.D. with me while being a student at Technion. Then, I was invited to be his co-advisor. It was funny, they didn't know me at that time. But then, that turned into one of the best friendships over 20 years. And occasionally, I went to Tel Aviv or Technion. Also, they selected me as a Sackler Scholar (it was a prestigious award at that time). [Ed. Note: this is in reference to more recent developments regarding the Sacklers' role in the opioid addiction crisis.] So I became a Sackler Scholar at the University of Tel Aviv in Biomedical Engineering. It was the inaugural award because the building was new, and they gave me a nice office. I spent some time there, giving lectures, and I enjoyed traveling around. It was fun. My wife joined me too. The next one was in Technion. I worked in the Ramat hospital with a close friend, Simcha Milo, one of the best cardiovascular surgeons in Israel. We studied the problem of cavitation in heart valves. And in the meantime, I was jointly hosted by the aerospace department at Technion. So I had that privilege. It was a great opportunity to know Israel and its great people. ZIERLER: Politically, internationally, this was such a difficult time. There was the Intifada, there was 9/11, there's all of the tensions between the US and Iran, Israel and Iran. Did those geopolitical realities weigh heavily on you? Or operating in a world of science with your colleagues who were American, Jewish, Israeli, Iranian, was it sort of like a refuge from all of those problems? GHARIB: Now, retrospectively, when I look at it, it sounds weird that a professor of Iranian descent goes to Israel. But over there, it was such a friendly environment. I never had a doubt, but just going there and seeing how, academically, they are respecting me, the president of the university calls to talk to me, going to lunch here and there, there was just absolutely no hint of, "Oh, he's Iranian." It wasn't that. And that was really the key for me to build my future collaboration with Israeli scientists and, above all, the friendships. Right now, my students over there are professors at Technion and other universities. And they all call me Mory. In Hebrew, it means, "My teacher." ZIERLER: Tell me about how the Bioinspired Project at Caltech got started. There's no box to begin with, but administratively, what was your inspiration? Who were some of the key partners in getting this operation up and running? GHARIB: Well, we had a virtual Center of Bioinspired Engineering, and I managed to get some funding to establish a [physical] lab, the Center for Bioinspired Engineering. And what motivated me was I believed that "This is something important." I saw that the whole biomedical field was going into, "Oh, yeah, let's mimic this, let's mimic that." So we needed to put some sort of science behind this to be educated and spread the gospel. And among the faculty that were helpful were Michael Dickinson, Beverly McKeon, and my former student, John Dabiri, who became famous for being inspired by jellyfish. I'm very proud of starting the field because it distinguishes what Caltech can do from others. It's interesting that MIT and Harvard immediately started a center in bioinspired engineering after having ours at Caltech. They realized this was something important. And I think it's a$100 million center. It's called the Wyss Center for Bioinspired Engineering. The term "Bioinspired Engineering" had not been used before we coined it at Caltech.

ZIERLER: And where is the significance of being named in honor of Hans Liepmann? Where does that come in with the bioinspired engineering title?

GHARIB: No, the Liepmann professorship is not related to the "Bioinspired engineering. But Liepman was responsible for the establishment of one of the best biomedical departments in the country at UCSD. This is the story I have heard. Well, it's a bizarre and distorted story. Hans Liepmann had this professor here, Bert Fung, one of von Kármán's last students. Hans Liepmann's wife was against animal experiments. Bert Fung only got dead animals' bones to put in a machine to conduct material strength testing and he never killed an animal for his experiments. One day, Liepmann's wife went to Bert Fung's lab and challenges Bert on his rationale for researching using animal parts.

That's the rumor I heard. According to these rumors, Bert Fung left Caltech and started the bioengineering department at UCSD. He is known as the father of the field of biomechanics. I got to know him in San Diego. An excellent and generous scientist whom I respect a lot. The strange turn in the story is that somebody knocked at my office door one day, and I opened it. The person looked very familiar. I said, "Who are you?" he replied, "I am Dorian Liepmann." I said, "Are you connected with Hans?" "Yeah, Hans is my father. And Hans told me, 'Go to San Diego and work with Mory.'" So I took him as my student. Dorian Liepmann, later on, started the department of bioengineering at UC Berkeley, doing excellent biomedical work. So being the Hans Liepmann Professor, for me, shows that Hans Liepmann saw the importance of this, and he was such an open-minded, forward-looking scientist.

The Boeing company endowed his chair because one of his students was the CEO of Boeing at that time. Anecdotally, I guess Caltech decided to give me the prestigious Liepmann chair because Anatol was Liepmann's student, and I am Anatol's student, and then Dorian Liepmann was my student. And the weirdest part is that my daughter got her Ph.D. with Dorian at Berkeley.

ZIERLER: Wow. [laugh]

GHARIB: [laugh] It's academic incest. And I would say Hans could've easily won the Nobel Prize if it was the right time.

ZIERLER: Were you interested in becoming Vice Provost for Research in light of the fact that you had these ideas about intellectual property? Was that something that you pursued? Or were you invited into this position?

GHARIB: I was invited because Larry Gilbert approached Ed Stolper and said, "We need somebody in the vice provost's office who understands entrepreneurship, understands the IP, and can help them to change the environment of the provost's office from that angle." Basically, it was a suggestion by Larry Gilbert to the provost to approach me.

ZIERLER: Was this a new position? Or you were brought in because there was recognition that the job needed to be reframed in light of things like entrepreneurship and intellectual property?

GHARIB: Well, before me, David Goodstein was the vice provost. But when Ed approached me, I said, "I will accept it if you change the title to Vice Provost for Research." Because that allowed me to oversee the OTT then and focus on it, I was also not very happy with the way our conflict of interest and research integrity situation was at that time. So I wanted to have an impact on that, too.

ZIERLER: What were some of the issues in terms of research ethics you were dealing with?

GHARIB: Many faculty did not know what was right and what was wrong because it was not clearly defined. So I hired an excellent candidate (Grace Fisher-Adams) to run our research integrity office. She established new, clearer protocols and updated our catalog to [promote] more successful practices outside Caltech. She saved so many who could have gotten into trouble because we didn't know what to do.

ZIERLER: Famously, of course, at Caltech, division chairs have a tremendous amount of power on campus. Where does the vice provost fit in in terms of that hierarchy, in terms of your ability to change things?

GHARIB: Well, there are seven division chairs but only two vice provosts, one for academic, one for research matters. So in that respect, they were reporting to me regarding research ethics and all this. In general, if there's a conflict, I would have asked the division chair to do the first crack on it and see its merit. If they decided yes, they'd send it to me to organize how it should be investigated.

ZIERLER: What was most satisfying to you in this role?

GHARIB: Well, interaction with the Office of Technology Transfer, especially in cases where we had to fight with huge companies for inventions that they had infringed from us without giving us respect or credit. That was one. Also, I had a role that helped the provost's office make sure some of our endowed centers were managed smoothly, like Linde Institute. I stepped in as its director when there were some critical donor issues popped up. It was my responsibility to make sure that donors' wishes were followed. At some point, I became Linde Center director while being vice provost at the same time. I became director of Linde Institute, a huge responsibility for a year and a half. We wanted to make sure that it was structured so that we could then hand it to a person who could run it smoothly. I didn't know those kinds of issues were on the plate, but when the challenge arose, I took it.

ZIERLER: In this role, did you have to do a lot of work with the Office of the General Counsel?

GHARIB: Oh, yeah, we had two offices right across from each other. So I worked directly with Vicki Stratman and Jennifer Lum later on.

ZIERLER: In what ways, besides protecting the intellectual property of individual professors, was this work vital for Caltech at the institutional level?

GHARIB: Just think of how we got the CMOS Infringement issue resolved. It helped us when we were dealing with some serious financial fluctuations. Also, having an effective research integrity office is an essential component of conducting sound research at the Institute. Because our graduate students' benefit, our professors' benefit, and the Institute benefits from it. I would say that it has helped us from protecting our IPs to protecting the Institute from research ethics-related issues over the years.

ZIERLER: Getting back to the science and the idea that, of course, at Caltech, there's no box, in what ways was nanotechnology a sort of connecting topic that would allow you to work with scientists and engineers all throughout Caltech?

GHARIB: Well, I think it started with the Navy again. They had a challenge of reducing the drag coefficient of Navy boats and submarines. They were looking for ideas. And through my connection with the Navy, I told them about these efforts at JPL that they [should] come up with this new way of growing carbon nanotubes so that compliant surfaces could be used as a cover, things like that. And then, it got me interested in how fluids move in narrow confinements and how those can be used as a new way of injecting drugs to make a new generation of batteries to reduce the drag of Navy ships. Again, it all goes back to surface tension and what I learned from soap films. The novel carbon nanotube technology invented here can disrupt the way we do drug delivery systems to the energy storage field.

ZIERLER: And as your research on the heart valve project was continually improving, not just mechanically, I wonder what ways that computationally, using simulations was relevant for this research.

GHARIB: Once you adapt the concept of minimizing the surface energy, it was all computational after that. That means you have the principle to solve the equations. And you use that computational power to do that – I just submitted a paper to the Journal of Biomechanics to describe the principles of how to make heart valves, using computation based on this minimum energy surface principle. In general, we conduct a few experiments to uncover principles and take that experimental knowledge to computation and use it for optimization. Because it's much cheaper than experimentation, we can change parameters quickly and see the outcome. We can always go back to experiments to verify some selected outcomes to check if computation is doing its job right. So experiments act as a compass to guide us to make sure that we've not violated any basic principles

ZIERLER: Tell me about the Linde Institute. How did that come together for you?

GHARIB: Well, the creation of the Linde Institute was, to me, an intriguing process and rewarding. Rewarding mainly because of my relationship with Ron and Maxine Linde. The whole idea behind the Linde Institute of Economics and Management Science was to bring new ideas in economics and management into some of the mainstream research projects in machine learning or AI at Caltech. And it was an excellent bridge between our CMS, (Computational, and Mathematical Sciences Department, and the HSS division (Humanities and Social Sciences). Now, where's Mory Gharib in this? I don't know. There were many issues in the beginning, from donor relation issues to the center structure, which was running like a fund-distribution center rather than promoting the ideas of the center as had been agreed with Ron and Maxine.

For me, becoming director of the Linde Institute was like dropping me in the middle of an island. As Hans Liepmann said, "All I needed was a piece of paper and a pencil," and to apply the principles of common sense and what I knew about the business of managing a diverse group of faculty in terms of their interests. First, I just tried to be a good listener. Next, I tried hard to see how I could streamline involved faculty with that of the Institute and the wishes of Ron and Maxine. Their desire was to be open-minded and look beyond what exists at Caltech and look for new ideas and talents. They wanted us to be mindful of what is going on outside in real-world economics. Confronting some resistance, I tried to be a negotiator rather than a dictator. Thanks to Professors Rosenthal and Cvitanic, we managed to develop a good plan that works nicely and has become an integral part of HSS and EAS. And that was helpful because it built up in Ron and Maxine confidence in the Institute, and they continue to be our big supporters. They send me letters thanking me for saving the Linde Institute. And it turned out also to be a good friendship. On many occasions, they used my expertise (not as the director of their center) but as somebody who knows Persian art to read some of the expensive stuff they bought. "Mory, is this really Persian?" and I usually say, "No, they are just mimicking Persian calligraphy." [laugh] So that was funny.

ZIERLER: You mentioned before that, at the end of the day, even though there's much more freedom as a professor than as a mission scientist at JPL in terms of the kinds of things you worked on, ultimately you can be boxed in, to some degree based on what your funders are funding. I wonder how directorship of the Linde Institute broadened your understanding of how these things work.

GHARIB: I think I knew a bit of the business of science funding by then. But, the position exposed me to great scientists and amazing people – I never thought about how much mathematics was behind the modeling of economic challenges. As an engineer-scientist, I write equations, and everything I do involves natural laws. Everything I did had to do something with nature. But you're talking about complex models that try to predict the market aspects – real world that impacts us every day, but we don't know. But to appreciate how much computation and mathematics are behind everything that the market does, everything stocks do, for me, was really an eye-opener. And that was the best part of it. It didn't help me to make money, of course. But it's just amazing.

ZIERLER: To go all the way back to your inspiration from Leonardo da Vinci on the heart valve project, the deeper you got in, did your appreciation for what he understood deepen as well? Or did you recognize that what he could know was essentially primitive because of the tools and the time in which he lived? How did that work in terms of understanding what da Vinci was capable of knowing?

GHARIB: At the beginning of my Leonardo-related work, I received many oohs and ahhs (mainly for Leonardo and not me!), "Oh, look at this, Leonardo designed the first artificial heart valve." The replica that we built was toured at the Victoria and Albert Museum in London for six months. And then, they returned it, and it currently sits at the entrance of the HSS Library in Dabney Hall. There's a movie about it too. But then, I started to dig in more depth about Leonardo's scientific investigations. I was interested in understanding how he conceived those beautiful vortices behind heart valve leaflets. The point that got me interested was that he shows the vortices in his physiological drawings of heart valve anatomy in his manuscripts. And then, I asked a simple question, "How did he see these vortices? You have to dissect somebody, but then the guy's dead."

Then, I found a different manuscript with the help of Martin Kemp at Oxford. In a random note he writes to himself, "Hey, get a calf heart, put wax in it, take the skin off, then go to this glassblower, ask him to blow a glass model in that shape. Then, go to this guy (he even gives the address, buy some silk, cut it in the shape of the leaflets and put it together in the shape of the calf's heart valve. Next, put the valve inside the glass model" and he continues to say how to visualize the flow inside the glass using grass seeds as particle tracers. Obviously he saw these vortices forming in the glass model by tracing the grass particles. Then, in a different manuscript, he drew a physiological model of the calf heart and put the vortices he observed in his glass model over it. And nobody asked how the hell he knew about the vortices if he didn't have x-ray or MRI. We just put it together in our paper, and we explained how he did the experiments. Leonardo never mentions that he did the experiments separately when he sketched the shape of those forming vortices in his physiological sketches of the human heart. That reminds me of Galileo's approach. Leonardo could not see those vortices in a beating human heart. So, he changed to a beating glass model to run his experiment with what was available to him.

Then, I realized that this guy is clever. He wanted to impress people by reporting things that other people could not see. People believed that Leonardo had X-ray vision! Our work made some big noise, and some establishment art historians tried to challenge it. But with the help from Martin Kemp, we showed that there were two different manuscripts, one found in Spain, the other one in France, and it wasn't part of the same Codex. Like many of our experimenters always like to say, they knew the theory a priori. But in many cases, they experimented first, came up with a theory later, and did not acknowledge it. Einstein was an exception.

In my later studies of Leonardo, I realized that he wasn't really an artist. At least, it wasn't his first passion. He never finished anything in terms of his art commissions. He was busy dissecting, learning, and writing about his findings in his never-published manuscripts. He wasn't even publishing them. He was just writing and hiding them. He was just doing experiments for the sake of discovery: a true scientist. That's how I got interested in him as a private scientist. We just submitted a manuscript to the Journal Leonardo about how he visualized the concept of acceleration. It's an ingenious approach to understanding gravitational acceleration. Leonardo actually designed an experiment to estimate "g," the gravitational constant, fairly accurately. The number that only found in the early 20th century, we measured it to be 9.82 meters per second squared. The number, he came very close to just by his experiments. But he never talked about it. Just some scattered notes! And it's a bad habit, I tell you, because that's why he never got credited for doing many discoveries first during his time. Only 400 years later, somebody like me or Martin Kemp goes and digs, then says, "Oh, no, he was a good scientist, too."

ZIERLER: And of course, in his own day, the distinctions that we now draw between theory and experiment probably would not have made any sense to him.

GHARIB: He was influenced by Greek philosophy that was not supportive of experimentation. But he was a good scientist because he changed the theory every time he did experiments and realized he was wrong. He didn't go back to push his theory too forcefully. So, his manuscripts are full of conflicting views. A good scientist should go back and forth until they find the truth, not just fall in love with an idea.

ZIERLER: A fun question about one of your most famous experiments, it's really a chicken and the egg question about lifting an obelisk using kites. Were you thinking about how the pyramids were built, and you devised this experiment to suggest that was one method? Or did you only get inspired to think about the pyramids once you put this experiment together?

GHARIB: Well, as an aeronautical engineer, I always thought all the theories we have are good for steady forces. But anybody who has flown a kite knows that you get an extra lift when you pull the string on the kite. So for me, it wasn't really to show that the Egyptians did or didn't do it. If it was possible, the point was that using unsteady forces that you generate with a kite can generate enough strength to lift a heavy stone It wasn't like, "Let's go fly a kite and see if it can lift an obelisk." It was to show that ancient engineers could have used this unsteady motion by a kite-like shape.

As you know, sailing is all about gusts and unsteady forces, and Egyptians built some of the best sails to navigate the Mediterranean. And for us to think that they didn't know how to use unsteady force to pull or lift things is a little bit too ignorant. We need to credit ancient engineers for their ingenuity to circumvent hard labor in building structures. We calculated that to build something like a pyramid just by hard labor; you need at least 2,000 workers to work together. How do you manage that? It's not an easy task.

So they had to be creative. The American Physical Society published an article in their journal about 20 years ago, where they show roads in Egypt that were made out of tiles. They found drawings where oil was used to make it easier to slide heavy loads on these tiled roads. Even just two people can pull a ton of rocks from the quarry to the construction site. The human brain hasn't grown much since ancient times. It was the same size as ours is today. And they didn't waste their time on Facebook or watching TV, so they had lots of time to think and tinker. So I believe in humans; our creativity is unlimited when we give it time.

ZIERLER: Why an obelisk? Why not a block, which is what the pyramids are made of?

GHARIB: That's a good one. If you have an obelisk and pull the tip with a rope from the ground trying to lift, there's no way to stop it from accelerating and not tipping to the opposite side. Because the acceleration you have is enormous. Of course, moving a simple square rock was easier. We tackled the more challenging problem. The obelisk was a special challenge: erecting an obelisk from the ground. There are many ideas, like using a sand pile, but you need a mile of sand to get the obelisk up. As part of a SURF project, Caltech students found that it would be easier if you held the obelisk's tip in place, lifted it straight up from the top, and let the base slide to the desired position. That way, you use the friction of the ground to slow down the acceleration of the base. But there's no way to stop the tip the other way around. We used a large commercial kite and step-by-step pulled the tip using extra force generated by the unsteady jump of the kite. So gravity and friction would align it to the desired position, and you just let it drop. And that's why an obelisk is a more challenging project than moving a piece of rock.

ZIERLER: So you actually made it more difficult for yourself to prove this point.

GHARIB: That's right.

ZIERLER: How heavy was the heaviest obelisk, and how big was the kite that you needed to lift it?

GHARIB: I think it was about 28,000 pounds. Something like that.

ZIERLER: Physically, where did this experiment take place?

GHARIB: In Palmdale. The last one we erected is in front of the city hall over there. If you go there, you will see it.

ZIERLER: Now, obviously, as you said, your mission was not to prove or disprove that this was actually the method used by the Egyptians. But surely, you must've pondered the question, "Is there a more plausible way that the Egyptians could've built the pyramids?"

GHARIB: Yeah, but I wasn't interested in really knowing or researching the subject because it's a strange culture around that whole field. I'll tell you this funny story. After the History Channel documentary about our work aired, I visited Egypt with my wife and daughters. In one of the tours, we visited a sight that was a cemetery of broken obelisks. I remember there were about 20 of us in a conference room, and the guide came and said, "Well, there are many theories of how they raised these obelisks. And the craziest one is that somebody from NASA said they used kites." [laugh] My daughter looked at me like, "Daddy, the crazy guy is you." [laugh]. The guide said that he believed that aliens did it. Of course, it was the more attractive theory.

The first time ABC [News] showed us raising the obelisk, a famous Egyptologist from UC Berkeley who was invited to comment said, "Oh, we call these guys "pyramidiots" because Egyptians didn't have pulleys, they didn't have this or that." Within five minutes, a British engineer doing a project in Giza sent a picture from the Cairo Museum of some Pulleys used in Egypt 2,000 years before the first obelisk was raised. And actually, the ABC person said, "Wait a minute, we just got this picture." And the engineer said, "Go to this hall, and look at this corner to find the actual pulleys." In the Cairo Museum, some items were cataloged. They put them on piles. This guy took a picture of the pulleys and sent them to us

He told this Egyptologist from Berkeley, "Don't say things like that. We don't know what they had." And then, the Egyptologist said, "Well, the pulleys we introduced by Archimedes 2,000 years after the first obelisks were raised." And again, the fact is that Archimedes lived In Alexandria, Egypt. So perhaps he saw what everyday construction workers did using pulleys, and he was smart enough to develop a theory for it. This type of argument is why I decided not to get involved in that kind of discussion. It was not something I was interested in.

ZIERLER: One of the many idiosyncrasies of this field, as you suggested, is the idea that it must've been aliens because humans never could've done this on their own. I wonder if one of the benefits, even if you haven't thought about it so much, is to dispel the notion that it was aliens, if only for the simple reason that, as you note, this was technology that was available to them. We don't need aliens to build these structures.

GHARIB: Exactly, and that was the point. People of the ancient world had developed many engineering solutions for their everyday needs. Thanks to an Archimedes-type who documented some of them. Many of them are lost. But the fact that they didn't publish in journals doesn't mean anything.

ZIERLER: The last topic I'd like to engage with you on for today's session is the way in recent years you have been honored with your professional memberships. So I'll take them one-by-one. First, you became a charter fellow in 2012 of the National Academy of Inventors. And I wonder what that meant to you personally to be recognized specifically for your ability to invent stuff.

GHARIB: Well, I think it just shows one facet of the human brain and that plasticity I mentioned to you. I might be writing papers on theories of many exciting things, including mechanics. But in the meantime, human beings always have been inventors. I did not, and I would say, officially invent anything until I came to Caltech, even though I had a few un-patented innovations before at JPL or USCD. But suddenly, I realized that it might be about time I put some of my ideas on the record, even if I may not get rewarded or credited for those inventions. In one discussion with Paul Sanders at Florida State University, we decided to form NAI to recognize our inventors and encourage the scientific and academic communities to recognize our inventors more appropriately.

We have an article in PNAS about whether Thomas Edison would get his tenure today. And we encouraged academics to recognize the clever inventions of their faculty and consider them in their tenure review or promotions.

ZIERLER: In 2015, an amazing year for you, you were elected both to the National Academy of Engineering and to the American Academy of Arts and Science. It must've been just incredible, both on the engineering side, to be recognized with that highest honor, but then with your interest in art, to be also a member of the AAAS. I wonder if you can compare and contrast what each of those honors meant to you.

GHARIB: Those are great honors. There's absolutely no doubt about it. But I don't think I'm different from many other colleagues who perhaps haven't received them. But I think what was important to me is that it seems societies have started to recognize that you don't need to just be a scientist, engineer, or an artist to be recognized by them. It allows us to be more of a hybrid type that can provide values in terms of a combination of art, sciences, and engineering to their communities. I believe separating art from science is wrong to do when it comes to the education of our younger generation. I don't think either is over the other one. And any time you can mix them properly, I think that's where innovation starts. We need more people like Leonardo who can bring new ideas that reflect the art, science, and engineering to humanity.

ZIERLER: Again, to come back to the idea of mission as you understand it, given the importance that you place in a convergence of science and art, and not separating them out, is your membership in these kinds of societies and the eminence that comes with it, have you found that to be even politically useful as a way to demonstrate that these are essential things and that people should look at them not as separate, but two sides of the same coin?

GHARIB: Oh, absolutely. If there's any good use for it, I would say this is exactly what you mentioned, how to promote those factors in all aspects of our students' education. Because I don't think anything is more important than giving our kids from whatever age you can to think of a level of knowledge that can be multifaceted. In the end, it's their choice. Whatever they choose is the right choice for me. But having those options, where they can do that, is very important. You can be good in mathematics, art, and engineering, you don't need to be excellent at everything but have some exposure to it. It's all necessary for us to grow. And that growth is so important to keep people from buying some of the nonsense you see today in the news because we will deprive our kids of seeing the other side.

ZIERLER: I think that's a perfect place to pick up for next time.

[End of Recording]

ZIERLER: OK, this is David Zierler, Director of the Caltech Heritage Project. It's Monday, October 11, 2021. Once again, it's my great pleasure to be back with Professor Morteza Gharib. Mory, great to see you once again.

GHARIB: Nice to see you, too.

ZIERLER: I'd like to pick up on a very important point you have emphasized throughout our discussions, and that is the role of art and the value you place in art in doing science and engineering. So to that point, I'm curious if you have seen Caltech's Performing and Visual Arts Program as an asset for your research, and if you see opportunity for an expanded art program at Caltech that would be more closely integrated in the science and engineering curriculum?

GHARIB: Unfortunately, I have not been directly involved, which I wish I had, and I will. But one of the important, I would say, people who helped me get into the art side is David Kremers. David worked in the biology department as a consultant to help biologists visualize their concepts better. After his faculty supervisor left Caltech, I invited him to join my group as an artist-in-residence. Over the years, he became a close family friend and an excellent mentor to my group. He introduced me to many art historians, including Martin Kemp. But then, to the second part of your question, yes. We need to bring art and science into the education of our students. And as I reduce my other responsibilities, it's a dream to work with that group.

ZIERLER: For your graduate students, many of whom did their undergraduate work elsewhere, have you ever taken on somebody as a graduate student who did have more formal education in art?

GHARIB: Yes. Not at Caltech. But the most serious one was at UCSD when I was working on the theory of chaos in fluid mechanics. I took a joint Ph.D. student from the music department. I mentioned to you that as a non-tenure-track faculty, I stumbled into the mistake of another scientist who did not appreciate that vibration on an element in a complex system could induce chaos or turbulence in another system. Professor John Silber from the music department approached me because they knew I knew something about vibration, chaos, all those things. He said that one of his students studies an instrument from the Middle Ages – it's like a timbale, a small drum. For many centuries musicians who played timbale noticed that the drum acts chaotically when a nearby violin plays. The outcome of any beating on the drum is unpredictable as long the violin plays in the background.

I co-advised Silber's student, who was a professional jazz drummer (he played in bars to support his studies). He played live at night, but he was a Ph.D. researcher in the morning. We studied and explained how two instruments could incite chaotic behavior in each other. At the prime number ratio of the frequencies, the string instrument becomes the master, and the drum goes haywire. And we showed that example in a live concert at UCSD. Believe it or not, I participated in playing the timbale (sort of) in my demonstration part. I poured sand on the drum and showed that created chaotic patterns when the violin started to play some specific notes. They said that I did a good job. I still think that the outcome would have been chaotic no matter what because I did not know how to play. That was fun.

ZIERLER: Some questions more on a technical aspect with your current research. I know that there's a lot of excitement in the materials science world about graphene. Can you tell me about some of your work in graphene and its most promising applications?

GHARIB: I did not work directly on making graphene, but on how to modify it and on a different kind of carbon, which is very close. It's called a nanocarbon tube. Imagine graphene if you wrapped it and made it into a tube. It's like a caged wire in the form of a cylinder. That's the area of graphene I work in. A diamond is also carbon, correct? So Carbon has different facets. And these carbon nanotubes are excellent also. A gram of it has enough surface to cover up a football field. Chemistry is all about the interactions of molecules through surfaces. You provide more surface, and you have more interaction. And that's how it got my attention. We learned how to grow these carbon nanotubes on different materials in my group.

It's like a forest of tiny, tiny, tiny tubes like a carpet. The aspect ratio is so high that if you have an orange in diameter, the tube proportionally is the height of the Empire State Building. Now, I have so much surface to do different things. One is that I put stuff on it that repels water to make it hydrophobic. I was playing with these sorts of things. I think I told you about the idea that we made a movie about bouncing water droplets on a carpet of nano-tubes on YouTube. The first day, we beat Lady Gaga in terms of hits on YouTube. But we lost, eventually. [laugh] All the high school kids around the world watched it. But then, one of my post-docs figured out he could turn it into a high-energy capacitor using a thin layer of this material.

It has a huge capacity for absorbing electrons. It's interesting. We went from making samples for astrophysics guys for the telescopes and microscopes as a black calibration material, using it for capacitors, and eventually, making batteries. Using carbon nanotubes can make future batteries safer while outperforming other batteries in power density.

ZIERLER: Do you see carbon nanotubes as playing an important part in drug delivery?

GHARIB: That, too. That's another exciting aspect of it. We have a couple of patents on how to shape them. Precisely like your barber and how he can shape your hair of whatever you'd like. We could, through chemistry, make cones of these carbon nanotubes. Hundreds of them can come together and make a sharp cone. That's part of the patent we have on how to grow them. Imagine that those can be used for a sub-dermal delivery of drugs. Exactly like when you feel the touch of the cactus spine. You touch some cactus, and you don't even feel the sharp pain. But a moment later, that area starts to get red. Because the puncturing of the surface in microscale is not that painful. However, when the spine releases the chemicals, you start to feel it. We got this idea, which again, I call bioinspired, and we made patches that we could load with whatever medicines or drugs you like. The only difference is that, unlike the regular drug patches, this one immediately delivers it to a sublayer in the skin. It's more effective. We developed it for Sanofi as part of one of our research projects.

ZIERLER: What about diabetes research? In what ways has your lab focused on diabetes?

GHARIB: I didn't work directly on diabetes. But we used these nanotube patches to extract a small amount of interstitial fluid for glucose measurements. Usually, they have to puncture the finger to get the blood. The interstitial fluid contains all the elements you need for glucose level measurements. The idea was to use the patch to absorb a good amount of interstitial fluid. Like when you put a drop of water on a piece of paper, it spreads through osmotic forces. We designed that to extract those fluids, and then the electronic-powered parts take care of the actual measurement. But indirectly, we worked on some of the side effects of being diabetic, namely, glaucoma. We have discussed this early on in our conversation.

ZIERLER: What about cancer? You've focused on so many essential things in the world of health. How has your research been relevant for cancer studies?

GHARIB: I think the directly relevant one is the discovery with my colleagues, Michael Ortiz and Mikhail Shapiro, on using ultrasound to kill cancer cells selectively. Of course, even though it's been going for five years, it's made a lot of noise in the community because they suddenly realized that ultrasound could be used to kill the cancer cells selectively. And each cancer type has a sensitivity bandwidth. And for each cell, it's slightly different. We can use ultrasound to ablate those cancer cells. It has been shown to work on lab cells, and now, with the City of Hope collaboration, we are trying it on the skin of rats.

ZIERLER: And this is noninvasive? This takes place outside of the body?

GHARIB: That's right. It's the same ultrasound they use for imaging. But we've learned how selective frequency bandwidth can kill certain types of cancers.

ZIERLER: We've talked so much about your heart valve work in a historical context. What is the state of the research today? Where is the heart valve in terms of patents, in terms of applications? And have you updated any of this work since you initially started research in this area?

GHARIB: Yeah, it's perhaps one of the most rewarding in terms of feeling good about solving a problem. Currently, the start-up that has licensed the surgical version of the valve conducting clinical studies is all in surgeons' hands. In my group, we have developed a catheter version of the valve that can be implanted without surgery. We have shown the concept and the start-up gearing up for durability testing. The target is 600 million cycles.

ZIERLER: How long does it take to get to 600 million cycles?

GHARIB: At a normal heartbeat of 60 per minute, it is about 20 years. Instead of doing one beat per second, we do about 100 per minute. Almost a year and a half or two years, you can achieve it. However, FDA requires 200 million to allow you to move to first an in-human phase. We have some machines that are running 24 hours a day. Every tissue valve has about 2,000 sutures. Ours is all robotically done because there's no suturing in the polymeric valve.

Because of robots doing the job, the price went from $6,000 to less than$60. That means a heart valve that is no longer only available to people who can afford it. There are many good doctors, but not everybody's insurance will pay $30,000 to buy a valve. Plus, the cost of the implants. That's why the FDA was so excited, mainly because it will bring the cost of healthcare down. After some struggles, the FDA finally approved our surgical polymer valve for humans. Now, we have just finished our initial study with 40 patients. Some of them have been on this valve for two years. And now, we're going through a pivotal study that includes 2,000 people. ZIERLER: What aspects of this technology and research might be helpful to, or extrapolated to other mechanical problems in the human body? GHARIB: I would say that any time you want to replace any organ. Like an aorta patch or small vessels in the legs. The principle is to have a device formed in a way that nature makes it. I mentioned that bioinspired is not looking for the final design. It learns about how you reach the final design. That's, I think, the big difference. Don't just try to mimic this. If you want to make it naturally, let's see if it can grow into that shape. I think that's the biggest lesson, that for 50 years, others tried to make polymer valves, but 100,000 cycles was the maximum they could reach, then it tore apart. ZIERLER: I wonder if the idea of not looking for a final design is itself inspired from evolution, where there is no final design. GHARIB: Good point, we're evolving. In a Ford assembly line, we order all the parts first, then we put it together, and only at the end could we make it functional by starting the car. That's a car. Nature cannot afford that. Nature basically evolves the heart from a small tube into a four-chambered machine. From day one, the circulation has to work. In the meantime, you're alive. If you're a one-month-old fetus in your mother's womb, you have a heart. It's not the same heart you'll have when you're born. In nine months, you go through about a million years of evolution. It's also how animals evolve. It's incredible, the space-time thing. You see how you go from the heart of a worm to different animals that still exist in various stages of their evolution, like a fish that walks out of the ocean. In nine months, we all go through that. By the way, that's an exciting story. We watch this nine-month development in zebrafish under a microscope in four days. If you protect 300 cells, and look how they work together, they made a pulsating tube, wrapped like a spiral, and made a two-chambered heart. And we got the cover of Nature for revealing this process. That discovery was exciting, how epigenetic factors help form a functional shape. And through all this development, nature follows the minimum surface energy principle. The cells don't go places where they would get torn apart. Lots of examples come with a convergence of design, I would say. ZIERLER: With your focus on the wear and tear of a heart valve over a lifetime, I wonder more broadly if you've ever thought about the process or the puzzle of aging from the perspective of fluid dynamics. GHARIB: Let me make a big suggestion. Reduce stress. It's the same with heart valves. People don't see it, but when you're under pressure, your whole body is under tension. It can be your brain, your eye, your heart. By the way, I'm not following that at all. I have a hard time not getting stressed out. But people who are capable of doing it, good for them. I think they're going to live healthily. Not necessarily more prolonged, but a much better quality of life. We are not designed to be stressed out. ZIERLER: Of course, you don't have a medical degree, but when in your research that has medical applications is it important for you to consult with medical doctors? GHARIB: My mother never forgave me for not being a real doctor. [laugh] Because I wanted to be a physicist. But getting back to your question, I always consult with good doctors who are willing to give their opinion without bias. And there are so many of them in my career. I owe a lot to Simcha Milo (Rambam Hospital, Haifa). Ray Matthews at USC, Dr. David Sahn (OHSU), who showed me the first mechanical heart valve., and Drs. Rick Hill, Dan Schwartz (UCSF), and Mark Humayun (USC). Also, many doctors from outside just wrote to me and said, "Look, I have this challenge…to understand." Some of them are challenging, so I got interested in them. My brother as well! I would say the first challenge for medical devices came from my brother. He's retired now. He's a pediatric surgeon in Germany. And he challenged me to come up with a shunt for children with hydrocephalus. Because he wanted to find a better way of doing it so as children grow, they don't need to go in and replace it. I was in 12th grade when he challenged me. It took 25 years for me to get a patent for a new type of shunt. That was for normal pressure hydrocephalus for the brain. My brother and I have a Caltech patent on that invention. ZIERLER: A specific question that relates back to our earlier discussion on your approach to basic versus applied research, specifically in the field of bioinspiration, as it were. For example, when you set about studying a particular aspect of fish anatomy to understand fish propulsion, in what ways are you simply understanding how a fish moves, and in what ways are you looking to apply that knowledge, presumably to improve how humans or instruments can move better in water? GHARIB: One of the biggest problems in fluid dynamics or fluid mechanics of objects that move efficiently, maneuverability, and quietly is that every species of fish is an open book of design for all the aspects I mentioned before. We looked at jelly fish for efficient jet propulsion. Sharks and dolphins for efficient swimming, and boxfish for stability while maneuvering in turbulent flows. Basic research has told us how the art of vortex formation has helped these aquatic animals. To survive and reach where they are now. But the question is, what is the basic science that governs the protocol for this animal to survive? I would say, "Now, let's study these animal examples and find out how they have evolved under survivability protocol." In another example, we discovered that by generating a pair of vortices, boxfish could be very stable around coral reefs and safely pick up food from the reef. It took me two Ph.D. students to discover the ability of boxfish to maneuver in highly turbulent flows efficiently. Can you guess what happened after we studied the boxfish? ZIERLER: You think to yourself, "How can we do things that we don't crash against the coral reef?" GHARIB: If you have high winds, we don't flip. Mercedes-Benz did some research and made a minibus based on the discovery in our lab at Caltech. Every time you see an Amazon truck made by Mercedes-Benz, you recognize a boxfish profile if you look at it from the side. In one of my group pages, we wrote, "We are really grateful to Mercedes-Benz because they took our idea and made a stable van that all the mankind can benefit from." ZIERLER: More generally, your publication list shows a fantastically broad and diverse group of collaborators. That begs the question, how do you decide who to work with for any given project? GHARIB: Well, it's exciting. Within Caltech, of course, my colleagues are generous and help me develop concepts with them. I've usually been approached from outside, and then I vetted them out. Except, when I had to go to another Center of Excellence in a specific field to search for collaborators, I had to say no to so many people because I could not take all the projects. But I accept projects that give me satisfaction in terms of the challenge, and whether they have some societal impact, they help something. But I've done some nominally useless projects, too. But still, I'm proud of them. There's no application, but they tackled some essential areas that no one else wanted to take on because it was either too complicated or they were not low-hanging fruit. There are some projects I've done that have no immediate results. ZIERLER: A chicken and the egg question as it relates to collaboration. Do you generally have a project in mind and then figure out who to collaborate with? Or are the collaborators, in many ways, the source of inspiration for the project to work on? GHARIB: Good question. I would say it's a 70/30 split. 70% was within my group, and 30% came from outside. Like this project where we showed how bumblebees surf. It was a funny project that came from a student who said, "I don't want to work on this, or this, or that." I said, "What would you like to work on?" He said, "I want to know how bumblebees swim." I said, "OK. Let's look at it." It became one of the fascinating theoretical challenges in fluid mechanics. Imagine you were capable of creating a wave in the ocean and surfing on it yourself. That came from outside by my esteemed student, Professor Chris Roh. But I turned it into something that was not expected because I challenged Chris all the time. "No, that's not going to work. No, that's not the right explanation." And finally, he got to the right answer. ZIERLER: I'm curious if JPL has ever been useful for your research. GHARIB: I did my Ph.D. thesis at JPL. So it was advantageous. [laugh] I was kind of kicked out of my water tunnel on campus. Do you want to hear the story? ZIERLER: Of course I do. GHARIB: When I became a graduate student of Anatol Roshko, there was another prominent professor, Hans Liepmann. And he had one student who could not prove a theory that his thesis depended on it. The problem was that the water tunnels he was using were too noisy, and he couldn't obtain the information he was after. In the meantime, there was a dysfunctional water tunnel in the basement of Guggenheim that nobody wanted to use. I went to Anatol and said, "If you give me$1,000. I can fix that tunnel." I came up with an idea of how to fix it. And I fixed it so that it was better than even the most expensive tunnel we had at that time. "I reduced turbulence level in that tunnel from 10% to 0.01%." I was so proud, I gave my presentation to a group of faculty and students when I was a second-year student.

And everybody admired my achievement. However, the next day my advisor called me and said, "Mory, I'm sorry, but I have to tell you, you have to give up on that tunnel." I said, "What? Why should I do that?" "Hans Liepmann wants his student to finish, and that graduate student was more senior to me." I got very depressed. Then, being concerned, Anatol came to me and said, "I have a solution. Since you're so good, you can build another one. But this time, a better one. But you have to build it at JPL." So I was shipped to JPL. I built a water tunnel for them. And for many years, I was kind of upset that Anatol did that. He had his own political reasons, but it really saved my future. First, I gained Liepmann and Roshko's respect by gracefully accepting their decision. And they were impressed that I built a better tunnel at JPL in record time (eight months) and did my experiments while the other graduate student was still trying to get good data. Also, I became known around the country as somebody who could design and build excellent water tunnels. My design which I shared with a company called "Engineering Design," is duplicated, and you can find them in many universities and national labs around the country. That company in return, built my next water tunnel when I returned to Caltech for the cost of material only. The water tunnel that I built was brought to GALCIT by Hans Hornung. It has produced more Ph.D. theses than any other tunnel in the department.

The experience at JPL was precious because I learned how to work with various groups, including shops, outside vendors, and watchful management. So, JPL provided funds to build a new water tunnel over there. Also, there was another state-of-the-art measurement technology that I didn't have on campus. I was privileged. They had a two-color laser Doppler, which was about half a million dollars at that time. It was available to me. Then, later on, when I came back to Caltech, I started to work on different projects with JPL. I can name many of them. The development of carbon nanotubes, for example.

My collaboration with Dr. Flavio Noca, my former joint student with Anatol, resulted in innovations in carbon nanotube technology. That was important. And later on, for making holographic lenses for tiny devices for skin friction measurement on submarines. These are all technologies that are hard to find on campus. To me, it's an unfair advantage that we, by having JPL next to us to compare to other places. We have an 800-pound gorilla in science technology sitting right north of us.

ZIERLER: One aspect of your career we haven't yet covered in detail is your role as a teacher and a mentor to undergraduates and graduate students. First, on the undergraduate side, what have been your favorite courses to teach?

GHARIB: I have to confess, I only taught one undergraduate fluid mechanics course about 15 years ago. I don't consider myself that effective when I teach large classes. I work the best in small settings. For example, every year, I take something like eight SURF students. And that's where, I think, I give them the flavor of doing research and the sense of discovery. Because there are much better teachers than me who can teach physics, chemistry, mechanics to undergraduates, but when it comes to graduate courses, that's where I feel I'm suddenly empowered to give as much as I can, which I couldn't do teaching undergraduates. I'm very proud of all the undergraduates who went through my labs, ended up in the best graduate schools, and are now even professors. I feel that teaching is best when it's a small setting, six to twelve students, so we can have intense discussions about concepts, challenging each other, and critical thinking. You can't have that in large classes.

ZIERLER: With regard to your interactions with undergraduates, for example, when you first arrived at Caltech, most students were interested in physics. That was the big major on campus. And today, that's been supplanted, in many ways, by computer science, which now dominates among the most popular majors. How have you responded to those changes, in what is most interesting to the greatest number of undergraduates?

GHARIB: You're correct about the interest shifting from physics to computer science. But when it came to research, I think the shift went mainly to bioengineering and biomedical engineering. Both are empowering, but I think more computer science than physics. But I think the physics undergraduates do a better job when they do SURF or enter graduate school than bioengineers or biomedical majors. Computer science students do a much better job when it comes to using machine learning, things like that. I think this shift, in general, is natural and welcome.

But again, what we're doing is trying to make sure we don't miss the basic science part of our student's education. Computer science is impressive and empowering. But it cannot create science. It has to be used to study science. Not as if I'm trying to downplay it. It's the other way around. I'm trying to say that the tools provided to us through AI and machine learning enable us to do basic science more effectively. Because I don't need to sit down and – to exaggerate – memorize the logarithmic table. I think it gives you the freedom to embark on more challenging problems. That's because we don't believe that just numbers are science. Numbers are just created by science. I think we need to keep reminding ourselves of this fact.

Even machine learning today, it's not a good choice without good physics. You can't just randomly ask a machine, "Create the universe for me." It's imperative to have that model and understand how physics can work for machine learning to do better education. As Yaser Abu-Mostafa always says, "Machines don't learn. We teach them." That's very important. That teaching comes from physics, chemistry, biology. But the interplay of empowerment by machine learning and vital basic sciences makes AI viable. I think that's where we can be successful.

ZIERLER: You mentioned the SURF program, which actually leads to my next question. How has the SURF program been valuable for your research group?

GHARIB: Well, I cannot imagine Caltech to be that joyful without SURF programs. Every summer, when you're handed these fresh brains that come to our labs, and we throw at them the most challenging problems that we do not dare to give to our graduate students. You can see it in their eyes, the innocence in the beginning when you provide them with a problem, and later on, they come and beat you up. You can see how you build up the inquisitive soul. They're fearless when they tackle problems. That's the best part of it.

ZIERLER: That reminds me of the comment of Caltech trustee Charlie Trimble, who likes to say that it's boot camp for science at Caltech.

GHARIB: Yeah, I heard that, too. [laugh]In the meantime, Caltech is a party school for the faculty.

ZIERLER: [laugh] I like that! As a window into your style for graduate students, first, what have you found to be the ideal number of graduate students to have at any given time?

GHARIB: The ideal number for me is six or seven. But, I always had close to ten. It is hard not to accept students to our groups when a good one comes around. But I try to make up time for all of them. I think the issue or challenge is that every student is different. And some of them flourish later than others. It's our role to make sure that initially, they stay within the parameters we define for their research and don't go haywire. Eventually, you increase the freedom. Let them build. I always tell my students, "This is your Ph.D. thesis, not mine. If I knew the answer, I wouldn't hire you to be a graduate student. I would give you problems that we don't have the answer to. This is not homework." That aspect of doing a Ph.D. thesis is the most critical factor. I don't call it academic freedom, but I would say freedom of thinking and building upon what has been built before.

ZIERLER: I'm sure there are many thoughts to choose from, but if you search your memory, what have been some of the proudest moments you've experienced as a graduate advisor?

GHARIB: Again, it's when I learned that your student solved a problem that I couldn't. Because that's the whole idea of education, you want to build things up for others. One of the proudest moments was when a Nobel Laureate wrote to me. He said, "I went to a hospital for a problem I had. As part of the routine, they took an ultrasound." They took an ultrasound to check him out. "And then, the radiologist looked at it for common sign-off. Then, he saw something else that had nothing to do with the problem I went there for. He said, 'I don't like this.'" And they found that it was a tumor.

And the radiologist happened to be one of my former students who worked on a novel ultrasound imaging technique. The Nobel Laureate wrote to me and said, "Thank you for training students who know how to look at problems. They have such a curious eye and thinking that they can see things that other people cannot." I almost cried, reading the letter. Because it doesn't thank me for inventing things, he thanked me for educating students who see things that other people cannot. That was my proudest moment.

ZIERLER: As a window into the things that your students are interested in and the ways they can apply those to their careers, overall, what is the distribution of your graduate students who go into industry, into government, and into academia?

GHARIB: It's 30/30/40. I have students all over the place, from Stanford to Berkeley, the UCs, MIT, Cornell. Then, I have students who have gone to national labs. And those who have gone into industry, they're just fantastic. And then, I have students who went to Navy labs. These labs are halfway between industry and academia because they do research. Then, two of my students are vice presidents of Samsung. Samsung has only six vice presidents. [laugh] Or in Boeing, or you name it. Companies in the space industry. I also have students who have gone to medical companies. All of them are doing well. Then, I have a student who just left and became an architect. I still am very proud of her. She's a partner at an architecture firm. Three students became bankers—Bank of Canada, some other places, venture funds.

ZIERLER: It sounds like for you, what's most important is to help them learn how to think, not so much about what they're going to do with it.

GHARIB: Exactly. That's what makes me say, "OK, I've done my job." Like to say, you don't give them a fish, and you teach them how to fish. And that fish is whatever makes them feel happy and fulfilled. I have some students who always were unhappy. I tell them, "Use that negative energy to excel. If you're unhappy, do something that makes you happy. Don't complain." And that encouraged them to find their authentic self and do something else. I had a student who was a tenured faculty, and he was very bored and unhappy about what he was doing. I said, "Change your job. Why not start your own startup. You want to be your own master." As long as you give them the tools of critical thinking, they should think like an entrepreneur which means not to be afraid of tackling new exciting problems. And that's the key.

ZIERLER: Now that we've worked up to the present for the historical narrative, for the last part of our talk, I'd like to ask a few broadly retrospective questions that will ask you to think about your career and your path in the broadest possible terms. First is going to be a counterfactual that might be difficult to answer, but it would be very interesting to see if you've ever thought about that. And that is, let's say the Revolution never happened, and that you would have gone back to Iran. Would you be doing the same thing there, essentially, that you have done in the United States?

GHARIB: It's an interesting question. I have thought about it myself. I think if the Revolution had not happened, I perhaps would be now a retired CEO teaching at university.

ZIERLER: What would be the company?

GHARIB: It would be the Iranian aerospace industry. I told you, I had the scholarship to go there. And you stay there forever until you retire. But knowing myself, I couldn't be in one place like that forever, depending on how things went. But I would say I would get into trouble very early on. Perhaps the system would encourage me to tone down my inventiveness and be happy with whatever was available to do my job. If that same system was there, I knew that there would be some problem for me sooner or later. Because I had uncles who had large construction companies, they always had issues with who got the contract. In the end, you have to bribe someone in the palace to get things done. And the aerospace industry was perhaps a little bit immune because anything like that was kind of protected. That's why I said I would've probably retired from that industry and would have been teaching at a technical university. It would have been exciting in the beginning.

ZIERLER: Of all of the sad aspects of what has happened to the US-Iran relationship since the Revolution, from a science and engineering perspective, what has the world lost from a lack of collaboration between Iranian and American scientists and engineers?

GHARIB: I think what's lost is, perhaps somewhat jokingly, lots of good tourism. [laugh] Because Iran is a beautiful place to visit. Like Egypt or Turkey. Lots of rich history, science, culture, dance, music, and poetry. That's what's missing, cultural people-to-people relationships. We don't see that much, unfortunately. I like music, and I've followed how music has changed in Iran over the last 40 years, the type of music people listen to, how poetry influenced it. Every night, I spend at least a half-hour listening to that stuff, even the rappers in Iran, because they are the winds of change, how people express their frustrations through rap music. They take the poetry of 600 years ago and sing it differently.

And then, you can hear the same poetry at different stages and Persian classical music. And it's incredible how creative people become under censorship. To me, that's the plasticity I was talking about, how your brain reacts to the environment. The other thing that's lost, and this is serious, is we had lots of good Iranian students, and we don't have that exchange anymore. For me, it's heartbreaking that there are smart kids in Iran who win medal prizes in physics or math Olympiads, but they can't come to the US. Recently two of them ended up in jail for some anti-regime literature. Where do they go to study? Canada, Germany, and China. Then many smart kids are lured to devote their life to advance crazy ambitions of a mad government. Now, what happens? The same smart kid is designing ballistic missiles and nuclear bombs.

Anyone educated here in any US university is a good ambassador for the US. Even if they don't stay here and return to their respective countries, they become good ambassadors. This is mainly because people see their education level and how important these educated people become in solving their countries' problems. Iran has a strong film industry now because they are constantly censored. They had to be creative to express their art without getting into trouble. They cannot produce junk stuff anymore—lots of good art and good music. Art and poetry are in Iranian blood. In every Iranian person, you see a poet in a sense. These are the kinds of things we're missing.

I'll show you something. This drawing by a scientist/philosopher/poet, Biruni, from the 11th century. He shows the sun and earth, which are phases of the moon around the planet. If you were Greek or European, you would write this and publish it, correct? But look what he did. He did poetry about the sun being a star, earth, and moon rotating around it. And then, what does he say? It says one can find two types of people. People who have their own light, like stars, and people who need to receive light, like planets. So he discovered that earth as a planet gets its brightness from the star (sun), then he extended his discovery to humans. Stuff like this is what we're missing because there's no incentive for anybody to try to get that kind of art out.

And by itself, just the whole painting is so artistic, and I decided to download it from Wikipedia, enlarge it, and put it on my office wall. It's beautiful and factual. This is 200 years before Kepler. For him, poetry was more important. This is what we're missing, good philosophy and art.

ZIERLER: As a graduate student 40 years ago, if somebody were to tell you that the Ayatollahs would still be in charge today, would you ever have believed it?

GHARIB: Not. But this is the dilemma. How could a nation be hostage to these people? How could they survive? Somebody tried to explain it to me, and of course, in my mind, they would have been there for ten years maximum, and then they would be gone. The issue was that even though the Shah was not as brutal as Ayatollahs, he created the environment for these religious groups to rise by oppressing progressive groups. If you look at the Iranian culture, when Mongols reduced the country's population by half, or the Arabs before them, people of Iran pulled back and did not fight back after they lost initially. Still, they changed the aggressors by their cultural influence. You look at 300 years since the Mongols governed Iran, but eventually, they got absorbed into the culture changed even their official language to Persian.

This time, there is nothing to teach to the mullahs, and I believe that social unrest under a more organized opposition will end this regime and social networking [will help].

ZIERLER: What was your emotional response during the so-called Green Revolution in Iran in 2009? Were you hopeful that things would change?

GHARIB: Everybody was hopeful. The saddest part was that – you saw millions of people on the street, and they're still there but invisible now. But the same thing happened, they shrunk because of the brutality that the mullahs showed in oppressing them. It was unfortunate for every Iranian to see a chance to get rid of this brutal regime. They decided not to get to the point of elimination, as it happened in the mass elimination of political prisoners in the 1980s. In a certain sense, too, I was depressed that the US didn't even give verbal support to the Green Movement. I'm not saying send troops over there, but people were there about to take care of these mullahs. But when we witnessed the brutal suppression, and we were silent, people in Iran got discouraged. For example, if you look at the Arab Spring, I think it was successful, regardless of a good or bad result because of the US support. It was successful because it had international support. But they did not support the Green Revolution in Iran.

ZIERLER: Back to the science, first of all, the terms fluid dynamics versus fluid mechanics, in what ways are they unique disciplines, and in what ways can we use the terms interchangeably?

GHARIB: We use these terms interchangeably. I don't see any difference in terms of mechanics and dynamics. Mechanics, perhaps, include, I would say, the static part, which is, of course, very important. I don't see any difference.

ZIERLER: Whether we call it fluid dynamics or fluid mechanics, throughout your career, from the graduate student days until now, what are some of the biggest puzzles in the field that have been solved or are now well-understood, and what remain some of the fundamental puzzles?

GHARIB: Of course, turbulence is still a real unsolved challenge. Still, we cannot predict certain commonly occurring phenomena in turbulent flows. Reducing the turbulence-generated drag of (large or minor) ships or airplanes is still a fundamental challenge for the Boeings and Airbuses of the world. Navies of the world, Air Forces of the world. They're spending billions of dollars to try to improve drag force and its control. The problem is so nonlinear and sensitive to boundary conditions that each little change would differ in space and time. One problem solved doesn't mean all of the issues are solved. But this sensitivity to the boundary conditions is exponentially amplified in turbulent flows. The governing questions are well established. So, everyone outside the field would ask, "OK, why don't you solve them?" No, it's not that easy because even the most powerful computers in the world cannot solve more than a minute of flow around a large containership.

Or the most powerful computers in the world cannot determine the flow of boulders in a substantial flood in an Altadena creek. The problem is that I don't even know how to define the problem. The problem that has been relatively solved is how to control the flow. We can confidently say that we can successfully handle specific flow control at large scales. We have successfully defined and changed the problem to a form we could solve. If I push the turbulent flow into a channel and re-laminarize it, I can control it. Or I can mix it in a certain way instead of letting it happen randomly, where I have no control. Still, as you get to a certain smaller scale, we lose the control again. But in bulk, we can design successful control strategies. So that has been very successful, especially with the real-time control techniques in aviation. Now, our airplanes are much safer.

It's incredible that something like an airliner goes from point A to point B, and we can sleep without hearing much of the noise from outside. Why? Because we have learned how to reduce the noise by controlling the shape of the jet exit, we have learned how to build structures that can handle immense forces and not break. And how to harvest wind energy efficiently. These are all fluid mechanics. And we have solved all those problems through theory, experimentation and computation. But there's no one solution to every problem. That's the beauty of fluid mechanics, and for my colleagues and me, job security [laughs]. But the point is that it's a problem that people like Heisenberg and Feynman gave up on.

We need to attract our best brains to it because in the future, with global warming and all the expected changes, we're going to have lots of fluid mechanical problems, from predicting forces of hurricanes to how to move freshwater from one part of the country to the other side, how to convert sun energy into something you can store, then give it back. These are all going to be significant problems. Fossil fuels are going to disappear. There's no doubt about that. The highest concentration of energy is in ocean waves. If we can harness those, it would be amazing. We could supply the whole world: by wind and hydraulic energy sources. We're many years behind Switzerland in the production of electric power. One of the challenges, I think, for the future of California is to move away from carrying water over the surface. In the Middle East, they take the water from the mountains and deliver it thousands of miles downstream without it being exposed. For example, we can dig horizontal tunnels with the same technology we use for fracking. And it's all fluid mechanics. There are so many good current problems we can solve with fluid mechanics.

ZIERLER: And to clarify, the problems in turbulence are Newtonian problems, essentially.

GHARIB: Well, yes. But believe it or not, one of the biggest problems, and you will laugh, is how to mix and create homogenized chocolate. It's an intriguing non-Newtonian fluid mechanics problem. But Newtonian, you're right. The clouds, air, and water in the ocean are all Newtonian.

ZIERLER: And this amazing idea that even the most powerful computers in the world have trouble understanding the Altadena creek, right? Obviously, you're talking about computers in the classical sense. Have you thought about possible ways that quantum computing, whatever that means, however we get there, might be useful in solving these question marks?

GHARIB: Yes and no. It's not just the power of the computer, it's also how you define the problem. When I put a model in my wind tunnel, practically I am solving the Navier-Stokes equations. Even if I don't know how to solve it computationally, nature is solving it for me to flow the air around my model. Quantum computing will be helpful once we learn how to define problems we want to solve. If you wish to add one plus one, that's a different story. Quantum computing is not efficient at that. But perhaps it would be more efficient in solving Boltzmann equations.

But it's not there yet. It's really in the embryonic stages. I have to tell you that today's computers can solve some of the turbulence problems. The problem is, we don't know how to define the problem correctly. For example, the problem is that in free-surface flows like flow around ships, the input boundary, is part of the solution we seek. The problem worsens as we go to high turbulence situations. For example, I had been approached by a major aerospace company saying, "They have tried to solve the same problem with three different computational schemes. They ended up with three different answers." They asked us to do a wind tunnel study to find which scheme renders the correct answer. I said, "I cannot." Because I don't know if whatever I do has anything to do with what they computed. Perhaps, all three were correct, but for different problems. Unless they come and take exactly my experimental data and use it as their space-time boundary condition, they would not converge on the same answer. Computational schemes right now are not that bad for solving some essential flow problems. But not for the grand turbulence problem. That, we'll leave it to quantum computing.

ZIERLER: On the social side, to go back to this beautiful story of how, when you were a graduate student, professors and administrators were so generous and caring and did whatever they needed to do to make you feel comfortable, and safe, and at home at Caltech. Forty years ago, words like inclusivity or diversity might not have been used in the way they are today. But what might we learn from that one vignette, that one historical episode at Caltech forty years ago as it continuously strives to make those ways of treating its students a priority?

GHARIB: Well, once you have a system that shows that kind of character, it means it's also capable of change. This is how female undergraduates suddenly went from a dismal number to 45% or, hopefully, even a majority. Not that many schools showed that kind of rapid acceptance of the change. Most of the areas we may believe we are ok are not even on par with other colleges because we're small. This isn't a good excuse, but it's hard for us to reach good statistics in some areas. Our statistics change a lot because we are small. If we lose ten or hire ten faculty, proportionally, that's like hundreds of new faculty leaving or added to MIT. For us, doing the statistics is very difficult.

That's why we should be unique in the changes we make. That's why we were successful when we had undergraduates because the numbers were significant. We could have an extensive program and do it in a way we know is effective. For small numbers, it's challenging. We have to be selective. We have very high bars. And in general, I think that the way I see it, it's going to change, and it's going to be successful. I'll tell you this. When I became a graduate student, they hired my wife as a scientist. And half of her group were female scientists, which was unique at that time. This was 1970.

But in some areas, we innocently, I would say, ignored it. But we're catching up. For example, in the department I have the honor of running, we now have a diverse faculty at GALCIT. You sit in on meetings today, and it's different than even ten years ago. It's not all old white men sitting around, deciding other people's futures. We have three females now out of thirteen. And our new additions are all-star scientists whom we are very proud of, like John Dabiri, Beverly McKeon, Jane Bae, Joanna Austin. This has all happened in the last ten years. And it's a significant change for GALCIT, and I believe that there is still a need for improvement.

ZIERLER: And you're saying this is good not just because Caltech should do this because it's the right thing to do, it's because the diversity is good for the science and engineering.

GHARIB: Absolutely! Because I believe that, for example, getting international students of a different race, gender and ethnicity makes this place more vibrant, more exciting, more challenging in terms of bringing education to all corners of a global society. For example, I'm spending lots of resources to make sure that we go out to community colleges to bring students here for our summer research programs. Even if they don't come to Caltech, that's OK. It serves the community. I think that's what's essential for us. Of course, it's the right thing to do. I don't think we should do it because it's in fashion. We should do it because it's good for us, good for Caltech.

ZIERLER: For your own research and during your tenure as Vice Provost for Research, you've done so much to change the culture around academia and entrepreneurship. Where do you see things headed for Caltech as this legacy of increasing these connections between industry and academia continues?

GHARIB: In terms of the future, where things are headed, I hope it moves a little faster because I think we could have served our faculty, students, and post-docs better by giving them a chance to be exposed to the outside world in terms of what is needed. And sending our students to industry provides that. I don't think that every faculty should have a startup. But if they want to, if somebody's willing to pay for good ideas to solve a good problem, we should be the ones to make the bridge. We shouldn't leave it to a random process. And as I mentioned, one reason I accepted the offer to become Vice Provost was to allow me to break those showstoppers, to make sure we went in a direction, like Stanford, MIT, Harvard even, where we have an environment that allows students to work with industry if they want to.

It's not really about making money, and it's more about the mentality. It is good to have a culture of entrepreneurs. Because you can also be an entrepreneur in science. I always say every group at Caltech is like a startup. They live to make sure they make breakthroughs, to achieve their goal of solving a problem. And that's the kind of environment I like to see. The bold students who tackle issues fearlessly. It's OK to fail. Sometimes, failure is more educational than success. Hopefully, I see we'll have our own large incubator in the future, where we can have a nest for some of these creative minds that want to try their hand outside. And we're going to establish a fund that gives away funds that one's idea needs to have to go over the Valley of Death. And during my tenure as vice provost, I worked with philanthropists and others who were willing to give Caltech that chance, like Jim Rothenberg, who sponsored our CI Squared program with Larry Gilbert.

I remember the day we went with Mark Davis and Larry Gilbert to see Jim. He was one of the nicest people I've ever met. And he turned to me and said, "What do you think will be the best way to encourage people to tackle problems that can have results in five years rather than 20, 30, 40." I said, "Don't let them go outside and beg for money to do it. We should provide it here. They should feel that if they have a good idea, they can come to us." He said, "How do you find those projects?" I said, "I ask three questions. First of all, is this idea novel? Second, is it going to have an impact? Third, can you do it in a short time? If answers to these three questions were yes, then I want to be able to give them \$200,000 over two years to show the viability of their approach." And he said, "Good. Let's do it." So we came out very happy. Of course, it took two years before we saw the first funds distributed but Jim was so generous in doing it. And now, CI Squared is a very successful Jim Rothenberg program.

ZIERLER: To that point and the broader idea that there's value in failure, to get back to this amazing idea that you shared with me that at Caltech, it's not thinking outside the box, it's that there's no box, it sounds like what you're saying is that that's an approach that's not just a privilege of tenured faculty, that even students, graduate students, assistant professors, it's a mentality that pervades the whole Institute's approach to science and engineering.

GHARIB: It is. I don't think the privilege of being at Caltech is only for the professors. It's incredible; we all have such pride in being around each other. We don't have stars here. I remember I was a graduate student, and when I worked at JPL, One day towards the end of the day, I was walking towards the exit gate. That was the time that the Voyager spacecraft had its close encounter with Jupiter. JPL had a big party for that occasion. Mayor Bradley, the mayor at the time, was there, the governor, all those important guys. So I was walking down the road, and there was a big party on the left side, and I saw two guys sitting on the curb. One of them was dressed like a custodian. As I got closer to them, I realized that the other person was Richard Feynman sitting on the curb and explaining to the custodian what was happening and why they were having a party. [laugh] I just went up and asked if I could listen. Feynman jokingly said, "No, I stop for you." [laugh] He knew I was a scientist, and I would ruin his session with the custodian. But, I walked away feeling so proud that a Nobel Laureate would care to sit down and explain things to not just one of his colleagues but a person with no knowledge of the planetary mission. That's the Caltech way, science for all.

ZIERLER: Last few questions as we look to the future. We already talked about possible advances in the world of computation. But for you, what are some of the revolutionary advances to be had in materials sciences?

GHARIB: I think that one is 3D printing. It's made life for scientists and engineers doing experiments so much easier. Our ideas materialize in 24 hours rather than three months. To me, it's fascinating. And once we improve it to high-precision parts for different experiments, it's a success for materials science. Also, for fluid mechanics, because we designed those nozzles. But I think that the type of materials that material scientists have come up with for 3D printing, to me, is a revolution. Carbon nanotubes, yes, but they're precise. Memory alloys like nitinol have allowed us to build durable heart valves. I have here a synthetic polymer heart valve. If I put it in cold water, it's going to be as thin as a pencil.

I can send it to all the vessels, and when exposed to warm blood, it expands to precisely the same intended shape. To me, that's a revolution—all due to material scientists who work in things like this. And the new generation of polymers I mentioned earlier.

ZIERLER: Last question, looking to the future. In whatever time span you use that's valuable in defining your research agenda, one year, five years, ten years, what do you want to accomplish next? What haven't you done yet?

GHARIB: I have to finish some of my projects. Let's start with the medical stuff. I want to make sure I finish this device to predict heart attacks—noninvasive cardiovascular diagnostics. The heart valve is another one. It's my dream to finish that project and make it successful. Also, for me, the future is looking at the human body through the human eye. I think your eye is the gateway to your body. There's so much information that we can get it non-invasively through the human eye. But those are short-term goals. In terms of the long term, please don't laugh, but I want to go back and do some physics. That's my goal for retirement.

ZIERLER: What kind of physics?

GHARIB: I'm interested in how fluid mechanics and plasma can work together to solve some of the energy problems we have.

ZIERLER: This would be a purely academic exercise because perhaps, you're happiest as a student learning?

GHARIB: Absolutely. I'm planning for it. I'm cleaning out one of my labs to start this. People don't know, but Thursdays are my day. I spend the time in the lab. And I try not to get involved in any administrative duties or other people's research.