Home  /  Interviews  /  Peter Wizinowich

Peter Wizinowich

Peter Wizinowich

Chief of Technical Development, W. M. Keck Observatory, Hawaii

By David Zierler, Director of the Caltech Heritage Project

August 16, 2023

DAVID ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It's Wednesday, August 16th, 2023. It is great to be here with Dr. Peter Wizinowich. Peter, it's great to be with you. Thank you so much for joining me today.

PETER WIZINOWICH: My pleasure to join you, David.

ZIERLER: Peter, to start, would you please tell me your title and institutional affiliation?

WIZINOWICH: My title is Chief of Technical Development, and I'm at the W. M. Keck Observatory in Hawaii.

ZIERLER: Just to give an overview, what does that mean to be Chief of Technical Development? What are you developing?

WIZINOWICH: It's new technologies, such as adaptive optics, but also responsibility for all the technical developments at the observatory in terms of projects. So we organize our observatory in terms of operations and development. Development could include things like repairing the pier on the Keck I telescope, or upgrading the active control system on a telescope, or integrating a new instrument with the facility, so quite a wide range. But that's at the high level. There's a lot of people taking care of things at lower levels.

ZIERLER: Peter, so many questions about your work, what Keck is like. But I feel like it's just important right now, given what's happened, the tragedy in Maui, has this affected you personally? Has it affected operations at Keck?

WIZINOWICH: It has not affected operations at Keck. We're trying to be there for folks on Maui. Keck is part of the mayor's council for the Big Island of Hawaii to help people on Maui. We've been collecting donations, getting them airlifted over, trying to collect funds, things like that, help with organizing places to stay. I'm not involved with that personally, but Mari-Ela Chock has been heading that up. We all feel really sad for the people on Maui. We've all been over in Lahaina, Hawaii—well, a lot of us at least—and a lot of old memories there, and it's just gone now, and a lot of lives as well.

ZIERLER: Is there a strategic concern in this brave new climate reality that if this could happen in a place as lushly vegetated as Maui, are there now contingency plans that Keck needs to consider, because if it could happen in Maui, it could happen on the Big Island too?

WIZINOWICH: In fact, we did have fires on the Big Island at the same time. They were really wind-driven. The wind was really high, and so fires were along the coast, and they came close to Mauna Kea Beach Hotel, places like that. Luckily no loss of life or property on this island. But we've had events like this in the past. Grass around here is dry, and then something starts a fire. The observatory has emergency plans for various things, earthquakes, hurricanes, but I'm not actually sure what the state is for fires. But on the mountain itself, of course, fire, grass, [laugh] there's nothing up on the summit to burn, other than the observatories themselves.

ZIERLER: Peter, some administrative questions. For you, who do you report to, and then who reports to you?

WIZINOWICH: I report to the Director. That's currently Rich Matsuda, who's interim Director. People that report to me are the AO scientists and postdocs, and a couple of project managers as well. Then we have an engineering group, and people report to a project, so it's a matrix kind of structure.

ZIERLER: Now, because Keck administratively exists in this complex relationship—there's Caltech, there's University of California, there's all of the other telescope projects on the mountain—beyond Keck immediately, who are some of your peers at academic institutions, on the mountain? Who else do you work with beyond your immediate confines at Keck?

WIZINOWICH: Speaking of adaptive optics, we have a lot of collaborators in both the California and UH communities. At Caltech, it would be people like Dimitri Mawet and Richard Dekany. At UC, it is people like Becky Jensen-Clem, Max Millar-Blanchaer, Phil Hinz. I'm speaking more at the technical side. We have a group called the Keck AO Future Study Group, which includes astronomers from Caltech and UC and UH, as well as technical people. That's helped drive our strategic and tactical kinds of things. Really good collaborations with the astronomers in the UC and Caltech systems, and that's really one of our strengths, the fact that we have discussions, and talk about what's limiting their science, and then think about how as a group we address those issues. There's a real sense of ownership in the UC-Caltech communities of the observatory in a very positive sense. These are their telescopes, and they really want them to be successful, and they want us to be successful in helping them out. It's a real nice relationship.

ZIERLER: Peter, between your own educational trajectory, what you've worked on in your career, your current responsibilities, what's the best way to describe you? Is it electrical engineer? Is it astronomer? Is it physicist? What would you call yourself?

WIZINOWICH: My background is more in optics, so optical sciences, but I think of myself as a systems person. What I like to do is work on not just one discipline but think of things as an overall system, from the initial concept through to it's doing science. That's the fun part. At an observatory, you've got optics engineers, you've got electrical engineers, software engineers, mechanical engineers, and then technicians. It takes quite a variety of skills to build these systems, new instruments, or adaptive optic systems.

ZIERLER: What does a given day look like, and is it not different than any other given day? Are you problem solving? Are you able to do research? Are you always thinking about the next big project? What does a composite day look like for you?

WIZINOWICH: [laugh] There may be meetings because I'm also part of the observatory management, so clearly there'll be meetings, both at the council level or management council level, also at the group level or individual meetings. There'll be some time spent probably on—let's think of today. After this oral history, I have a telecon a little later today with a couple of scientists in the California community that are working on a proposal with me. They're doing the science cases. That's Steph Sallum at UC Irvine, and Becky Jensen-Clem at UC Santa Cruz. We're developing the science case for a new capability for the AO system. I'm also interviewing a candidate actually for my position [laugh] later today, who's actually a former postdoc here who's worked elsewhere for about 15—but I shouldn't give this much detail.

ZIERLER: [laugh]

WIZINOWICH: We just had some observing Friday night where we were commissioning this new real-time controller system with the adaptive optic system. Now we're thinking about what we learned during that run, and the ways we're going to make fixes to the problems we encountered. We also are preparing for a science readiness review for one of those systems. We're planning for FY24, so there might be discussions about how we're going to allocate people between the various projects because we have like 30 different projects. We have to decide how we're going to staff those projects and plan them out. Those are some of the activities in a typical day.

ZIERLER: Peter, on the big question of whether or not TMT gets built in Hawaii, will that affect your world, one way or the other?

WIZINOWICH: Yes and no. Hopefully whether TMT comes here or goes to the Canaries or is built at all, we'll still continue to do great science at Keck for at least another decade or two decades or three decades. I think I shared with you at some level our Keck 2035 strategic plan.


WIZINOWICH: We've got lots of initiatives to try to keep Keck scientifically competitive and, we're going to be still the main science tool for the Keck science community for quite a while — the earliest date probably for either TMT or GMT to be doing science is 2035 and that's optimistic. Keck still has a lot to do. Now, of course, we really hope [laugh] from the science perspective that TMT will be developed, and GMT, so there's concerns that way. There's also real technical collaborations at times. For example, I chaired the preliminary design review for both TMT and GMT for the NSF. They've got a lot of great stuff going, except for the funding situation right now. There are collaborations. We turn to them for ideas. They turn to us for ideas. They're on our review panels. We're on their review panels. It's definitely a community. But the future of Keck astronomy doesn't depend on the TMT, hopefully.

ZIERLER: Peter, as you've witnessed some of the tensions with the native community in Hawaii, and some of their opposition to building the TMT, what have been the takeaways from you about improving relations with native communities, and how to better incorporate astronomy in Hawaii with the people who have been there the longest?

WIZINOWICH: I've been getting educated a lot actually by Rich Matsuda who's been involved with this group that, first of all, set up the idea of having the Mauna Kea Stewardship and Oversight Authority, and now is on that authority. He was born in Hawaii, really has an empathy for all those situations, and he's been educating a lot of the rest of us because, frankly, for myself, head down, doing the job for a long time, I didn't realize we had a problem. Now I understand clearly [laugh] that the future of astronomy has a problem. It's sad because I've been in Hawaii since '82, first of all, working for another telescope, and I didn't realize how much pent-up issue there was. I was excited by a renaissance in Hawaiian culture, like with the voyaging canoes, things like that, but I didn't realize how much opposition there was to astronomy on the mountain. Engineer, head down too much, and the people I associated with in the Hawaiian community didn't bring up any issues to me.

Now, I did see it, of course, with the Keck Interferometer, with the Outrigger telescopes. We proceeded according to the law, for the Outrigger telescopes, and just following UH's direction. The whole process got delayed long enough that the Outrigger telescopes ended up not being built. That was the first sign [laugh] of how bad things were. But I'm really grateful to people like Rich and Fengchuan Liu, the TMT project manager, how much they're reaching out to the community, and really trying to, first of all, understand and then try to help find solutions—listen first.

ZIERLER: Peter, the institutional relationships with both UC and Caltech, is that an asset for you on a real basis? Do you draw on the expertise from Caltech and UC in order to do what you do?

WIZINOWICH: Definitely, in different ways, first of all, in terms of the astronomy, because that drives what we do. They're the users, and we really feel like we're the stewards of the observatory. We're in service for that. The astronomers are a real asset. Then the technical people, I've collaborated a lot with folks at both Caltech and Santa Cruz on building systems, and so it's very positive. Of course, places like Caltech and UC build the instruments, for example, that go behind the adaptive optics system, but also our science instruments in general. Those are really key. We wouldn't be doing great science if we didn't have great science instruments.

ZIERLER: Peter, let's go to adaptive optics 101 now. Before we even get to AO as it applies to astronomy, what is adaptive optics, how is it related to optics overall as a discipline, and how far back does this go? What's the history of adaptive optics?

WIZINOWICH: Our problem on the ground is that we have—we appreciate this as individuals—we have a lot of air, and there's turbulence in that air, air of different temperatures. That basically bends light, and so you have a 10-meter telescope or a 10-inch telescope, and you see about the same amount of detail because of atmospheric blurring. Same thing as you look over a hot highway or you look into a swimming pool, things are blurred, and so the same thing happens through the atmosphere. Typically, astronomers have seen—although at a great site like Mauna Kea, you can have half-arcsecond diameter images, most sites maybe it's closer to one arcsecond. But that's the same, no matter what size telescope. I like to go back to Galileo, 400 years ago or so. Since then, astronomers have been building bigger and bigger telescopes to see further, or to see further back in time, collect more light. But they haven't taken advantage of the fact that the larger your telescope, the more spatial frequencies you can gather, and therefore the higher angular resolution you can get. That's why you put a telescope in space. One of the reasons is you don't have turbulence. By using adaptive optics, which are basically having a mirror that changes its shape about 1,000 times a second to take out the turbulence, but then you need some source outside the atmosphere to give you the information. If you know something outside the atmosphere is a point source, like a star, then you can see how its wavefront has become distorted by the atmosphere, and then you can compute what you have to apply to a mirror to change its shape, to take out that distortion in the wavefront. We use either natural guide stars, stars that are up there already, but unfortunately you can't go very far away from that star before it's a different part of the atmosphere.

That's why we ended up producing laser guide stars because we can point them where we want in the sky, and we basically excite—in our case, they're sodium wavelengths, so we excite sodium atoms up in the Earth's mesosphere, which is up about 90 kilometers. The sodium atoms re-emit, and that's our artificial star. We still need a natural star for some things the laser guide star doesn't measure, but it really improves our sky coverage. We're always trying to do better at measuring, and better at correcting. In terms of history, the US Air Force was doing adaptive optics quite a ways back. They had a different mission in mind, looking at satellites, that kind of thing. They opened up right after the Berlin Wall fell in '89. They opened up about what they were doing, and people like Bob Fugate at Starfire Optical Range really opened up things to the astronomy community. We've used him on reviews and things like that. We've had that sort of access to the military since about 1990. But astronomers were doing it themselves, starting in the—well, the concept actually came from Horace Babcock back in the mid-fifties. The technology he outlined was hardware they had at that time, but it wasn't really capable of it. Astronomers started really doing things more in the early '80s, into the '90s, and were even doing laser guide stars on their own, or trying that out. Astronomy, the fact that astronomy was pushing things, and things like the Berlin Wall fell, there wasn't a reason to hide what the military was doing. We've benefited from the military kind of developments, for example, in deformable mirrors. But a lot of it subsequently has been developments in the astronomy community. Often working with industry, of course.

ZIERLER: Peter, I wonder if you can explain the role of adaptive optics in the status of Keck having these two telescopes, Keck I and Keck II. How is adaptive optics serving as a connecting point for both telescopes?

WIZINOWICH: I don't know that it's connecting right now. We do have adaptive optic systems on both telescopes, and they have different instrument capabilities, so maybe that's one way they connect. For example, a group like Andrea Ghez's at UCLA will sometimes use both of them in parallel, and they'll be doing different wavelength observations or a different characterization on the two telescopes. We initially built the second adaptive optic system because of the Keck Interferometer. With the Keck Interferometer, we needed to first of all correct the wavefronts from each of the individual telescopes, and then we had to combine them. That was pretty exciting. To combine the light from both telescopes with an 85-meter baseline, you get that much more resolution versus a 10-meter telescope.

ZIERLER: The history of astronomy, has adaptive optics at Keck really been at the forefront, and then we see other observatory projects around the world recognize the value of adaptive optics?

WIZINOWICH: I think at the same time as we were building for adaptive optics for Keck, groups were building adaptive optics for the Very Large Telescope in Chile run by the European Southern Observatory and for the Gemini Telescope; maybe a little later with Subaru. There already had been an adaptive optic system on Canada-France-Hawaii Telescope, and at a smaller La Silla, ESO telescope in Chile. It's not like we were alone in terms of the endeavor. We were the first on a large telescope to do both natural and laser guides to adaptive optics. That partly is because we were the first large telescope to be built, or large telescopes to be built, so we had some time advantage, and we took advantage of that. All of the observatories are certainly into adaptive optics.

What's exciting to me, or one of the things that's exciting to me, is I remember in the 19…so the US astronomical community or the National Academy of Science has the astronomy community do a Decadal review at the start of each decade. Back in 1990, they actually had—no, 2000 [laugh], they had a couple of pictures from our adaptive optics system in that Decadal review just starting to show the power of adaptive optics, and therefore some interest. There was more interest in the 2010 Decadal. Now I find it very exciting that in the 2020 Decadal that US-ELTs with adaptive optics are just part of the baseline now. That wasn't true 20 years ago. I think we've had a big hand in it at Keck of changing the community, or showing the power of adaptive optics, and bringing the community along. Certainly the UC-Caltech communities and UH are the biggest users of adaptive optics in the US in terms of science.

ZIERLER: Peter, for all of the incredible discovery that's happened at Keck, where can we most easily or powerfully point to adaptive optics making the difference in making that discovery possible?

WIZINOWICH: I think it's Andrea Ghez's Nobel Prize in physics, looking at the Galactic Center. She did start out with basically taking short exposures with a near-infrared camera, something called speckle imaging. But the observations with adaptive optics allowed her to characterize the supermassive black hole at the center of our galaxy, leading to her Nobel Prize in physics. I think that's the biggest one. There are other things that I think at least got public attention. For example, Mike Brown, who's at Caltech, using the Keck adaptive optics systems to look at Kuiper belt objects, and then being able to detect their moons, and therefore determine their size and their diameters and their masses, and realizing that there's a lot of objects out there like Pluto, very similar. He wrote a book, which you may know about, How I Killed Pluto and Why It Had It Coming.

ZIERLER: [laugh] Right.

WIZINOWICH: It was partly based on those Kuiper belt objects using adaptive optics. Another example, I think, people like Tommaso Treu and Christopher Fassnacht in the UC system are using it to look at gravitational lenses, and therefore characterize the dark mass in the foreground galaxy, and try to understand the dark energy from the background galaxy in terms of timing of events. There's a lot of observations of galaxies at redshifts of 2 to 4 using adaptive optics to characterize their kinematics, metallicity, and other properties now too. Everything from solar system to—there's been a lot of exoplanet observations. The first observation of another solar system, the HR 8799 system, was done with Keck adaptive optics. There's been a lot of follow-up observations using now more recently the Keck Planet Imager and Characterizer (KPIC), developed by Dimitri Mawet's group, and implemented with our Keck II adaptive optic system. This a huge range of science overall. I keep track—this is sort of my stamp collection—of all the papers published using adaptive optics, and there's something like 1,400 papers published, refereed science papers published using our adaptive optic systems.

ZIERLER: Is there a world of adaptive optics beyond astronomy? Are there advances that are happening in other subdisciplines of optics that you're keeping track of because they might be relevant, they might be adaptable for astronomical projects?

WIZINOWICH: Not that I'm keeping very good track of, but certainly vision science and adaptive optics has been huge in that, looking into the human eye, being able to characterize properties of the eye. We're actually going to have hopefully a person from the National Institute of Health on a sabbatical here next summer, and we just want to trade ideas about what they're doing in vision science with adaptive optics, what we're doing with astronomy and adaptive optics. A lot of that actually came out of the Center for Adaptive Optics that was at Santa Cruz for about 10 years. They had both vision science and astronomy in the same meetings. A lot of the adaptive optics that was already happening at places like for vision science at places like Rochester, it just became part of the same community for a while, educating the same people. But now we've separated a little bit. There's other fields too, communications, things like that that are using high-power lasers, you know, trying to target them. There's a military side of things as well.

ZIERLER: Peter, so many people are talking today about the possibilities of machine learning and artificial intelligence. Do you see a future where adaptive optics really become supercharged by these new capabilities?

WIZINOWICH: It's a good possibility. I don't think there's too much in the way of real advantages yet. Turns out when I was at University of Arizona, we did actually train a neural network to phase the Multiple Mirror Telescope. The Multiple Mirror Telescope back then was actually six 1.8-meter diameter mirrors. In simulations, we were able to train a neural network to control the tip, tilt, and piston of these six mirrors. Then we did that in a lab with a mirror that I could piston and tip-tilt the mirrors on. We actually successfully trained it in the lab from a focal plane image and an out of focus image, train it because we knew what we applied to the deformable mirror. We were able to train that neural network to get it right every time. Our next step was to go onto the telescope, and there we found that there were new aberrations that it hadn't been trained on. Therefore, from my experience, these are idiot savants. They're really good at what they've been trained for, and not so good at things they weren't. Our next step would've been training it on sky using a truth sensor. But that's the point when I came to Keck.

ZIERLER: Peter, let's go—

WIZINOWICH: Since then, ever since the big language models and things like that, everybody's getting on the bandwagon for machine learning. I know multiple groups working on machine learning for predictive control, or improving the reconstruction of the wavefront, or estimating the point spread function of objects in the field. It's an exciting field now, and we certainly have the compute power, and so it's going to be a case of seeing what machine learning needs to do that we can't do more analytically.

ZIERLER: Peter, let's go back now, develop some personal history. Where did you grow up?

WIZINOWICH: I was born in Winnipeg, Manitoba, Canada, but quickly moved to Southern Ontario. We moved around every two or three years because my dad was initially in the Canadian military, and then after that he was in correctional services. It was moving around mostly Ontario, one year in Sardinia, which was really nice. But that was all the way through, almost all the way through high school. I think my first three years of high school were in four different high schools. That's where I grew up.

ZIERLER: Tell me about University of Toronto. Were you always on a physics and astronomy track? Was that your interest from the beginning?

WIZINOWICH: Astronomy was probably the real interest, I think, since I was maybe 11 or 12. It really intrigued me how much astronomers could learn just by looking at light. I thought they were the coolest detectives [laugh] because they never got to touch this stuff, but they figured so much out from the electromagnetic spectrum. I always thought that was cool, so I went into physics and astronomy at the University of Toronto, and was more partial to the astronomy, although my degree was in both. My interest was in astronomy. I wasn't sure there was a future in it. I went into a master's at University of Toronto Institute for Aerospace Studies, where I worked on laser ionization studies, which turned out to be using sodium gas and dye lasers, which ended up coming back into my life here at Keck. But then I thought I saw this great opportun…well, to me a great opportunity, because I wanted to travel, to take a position. University of Toronto had a 24 inch telescope in Chile on Las Campanas, and so I applied for the resident astronomer position down there, and was able to spend a year and a half down in Chile, which was a really enjoyable experience for me.

ZIERLER: Did you have any access to telescopes as an undergraduate? Does Toronto have its own telescopes?

WIZINOWICH: It has some on the top of the McLennan physics building—I don't know—15th floor or something like that. There was a 16 inch and an eight inch, and I actually used the 16 inch reflector on a very, very cold night. [laugh] It had a photometer, and I used it to observe a Delta Scuti star—this was my senior project—and doing differential photometry. A photometer, I had to write down the numbers. It was—I don't know—minus 20 [laugh] below or something. I was freezing, but I got a good set of observations, which ended up getting published in Publications of the Astronomical Society of the Pacific. I was able to not just take the measurements but then do a least squares fitting of their orbits and determine—sorry, least squares fitting of their oscillations, their intensities, and determine the periods. That was my first refereed science papers. From the roof of the physics building, I don't know if anybody else has gotten [laugh] any science out of that.

ZIERLER: Now the master's, tell me about UT's Institute for Aerospace Studies. What kind of an organization is that?

WIZINOWICH: It's primarily aerospace, but they also do some applied physics. I was really torn actually finishing my bachelor's, whether I wanted to go into physics or—oceanography was quite an interest back then. I actually got accepted at University of British Columbia's oceanography program, and also the Institute for Aerospace Studies. Because I'd spent the summer in Europe, I guess it was easier to come back to Toronto. [laugh] So it wasn't quite really well planned. But one of the professors there reached out to me, so I already had a topic to work on. There they do, again, a lot of aerospace stuff, like the space shuttle arm, that kind of stuff. But I was more on the applied physics side of things.

ZIERLER: Now was it a terminal master's? Could you have stayed on for the doctorate?

WIZINOWICH: I could have stayed on the doctorate. My thesis advisor actually said, "Oh, Peter, it'll only take you another six months." I said, "No I want to take this position in Chile." I didn't really know what I wanted to do after a PhD at that point, so I thought a master's was probably safer. But it was a fun experiment. I built a heat pipe. You basically have a pipe where you heat it up at the center so you get a vapor. You cool it at the end so the vapor recondenses. Then you have some sort of wick that pulls it back in, it was just screening, and so had to heat this up to vaporize the sodium, fire a laser through it, measure the ionization of the sodium. That was the idea to have a rapid way of ionizing a vapor. This is something you could use, potentially. The National Ignition Facility, they fire lasers at a pellet, but they have it in an environment where they have a gas like lithium or sodium. You can fire an initial laser, ionize the path, and then you've got a way to follow that path with either an electrical discharge or something like that. That was the concept. I had a model of the sodium atom, which was a box and a half of computer cards [laugh] back then, and basically modeled the ionization, and published a couple of papers with my supervisor. Then I was off to David Dunlap Observatory for a couple of months of training while I was writing my thesis, and then down to Chile, which was really exciting to hand in your thesis, and then a day or two later be in another country.

ZIERLER: Now you said the David Dunlap Observatory?

WIZINOWICH: Yeah, back then there was actually an observatory in Richmond Hill just north of Toronto. They had, for a period, the world's largest telescope, a very short period back in the—I don't know—late 1800s, a 72-inch refractor telescope.

ZIERLER: This was training for you going down to Chile?

WIZINOWICH: Right, a lot of electronics training but some optics training too, just so I knew how to align the telescope, knew how to fix circuits or install a new radio or whatever. I was basically responsible for the facility down in Chile for the time I was there.

ZIERLER: This is a UT observatory in Chile?

WIZINOWICH: It was. It was really Bob Garrison, who was a professor at University of Toronto. It was basically his baby. But a lot of the graduate students or postdocs, faculty from Toronto came down to observe.

ZIERLER: What were some of the science objectives going on at the observatory then?

WIZINOWICH: A lot of it was characterizing things with a lot of spectroscopy or photometry. It was maybe a lot of classification kind of stuff and the spectroscopy—I'm trying to remember some of the papers that came out of that—globular cluster observations because there were groups at University of Toronto that we're interested in that. It's been a while. [laugh] I remember Wendy Freedman was coming down for galaxy observations. She ended up being the director of Carnegie for a while, and is now at Chicago. Chris Corbally, who was a Jesuit [laugh], I remember him coming down to observe—people like that. I remember the people maybe more than I remember the science personally. I did do my own observations, and published some of that photometry as well.

ZIERLER: Then how did the Hawaii Telescope opportunity become available for you?

WIZINOWICH: Going back to Bob Garrison, he didn't want me to—because I was thinking of coming back to Toronto, look for a job in Toronto. I didn't see necessarily a future in astronomy, but he wanted to keep me in astronomy. He contacted the director of CFHT, René Racine, and said, "You've got to meet this guy." They flew me out to Hawaii, and gave me a job in the optics group. It was basically Bob who got me the job. [laugh]

ZIERLER: What was the administrative relationship? It was called the Canada-France-Hawaii Telescope?

WIZINOWICH: Yes. Canada had a share. When I got there, using the French language, we were called technicians, sort of junior engineers or senior technicians. Most of us were either Canadian or French, and a few Americans—well, quite a few Americans on the staff actually. But there was a strong Canadian and French contingency. It was kind of funny because the French would be trying to learn more English, I'd be trying to practice my French, and our conversations were kind of funny because I'd be speaking in French to them, they'd be speaking back to me in English. But we managed to do that on Mauna Kea. Long hours because we'd spend 60 or 70 hours on the summit back in those days. But it was a really enjoyable group of people. I was young. They took care of me.

ZIERLER: Peter, I wonder between the two titles—as resident astronomy at the Toronto Southern Observatory, and then as an optics technician at the Canada-France-Hawaii Telescope—if this was a bit of a fork in the road situation for you, if you saw your career more going down the optics engineer technical side versus going down more the science astronomy side, and if that influenced going back to graduate school and focusing on what you did.

WIZINOWICH: Yeah, it did. As I went along, I discovered I was more interested in the systems, and maybe had more capabilities in that area. There's a lot of really smart astronomers out there. Where could I most contribute? I became more and more interested in the optical systems.

ZIERLER: What kinds of schools did you apply to? How widely did you apply, based on what was available?

WIZINOWICH: For my PhD, I only applied to the University of Arizona. CFH had sent me on a two-week short course to Optical Sciences. I was just so impressed by the professors there and how much I could learn. I talked to some people while I was there, and applied, and got in. They didn't even make me take a graduate school entrance exam. [laugh]

ZIERLER: What made Arizona stand out? Was it really unique in the kind of program it was offering?

WIZINOWICH: At that point, both Arizona and Rochester had good optics schools. Some others have developed since then. But Arizona had large telescope optics. They were working more on astronomical things, and Steward Observatory's right there as well, so that attracted me. There were people there that I knew had done some past work in adaptive optics, military kind of work. I thought I'd be able to work on adaptive optics when I went there.

ZIERLER: Now, is the Optical Sciences Center a standalone organization? Is it part of physics and astronomy?

WIZINOWICH: No, it's a standalone organization, and it's been a really growing one. It's done very well. It's fostered a lot of industry in the Arizona area and elsewhere. The graduates get snapped up, so I wasn't worried about a job afterwards. It was just a great group of students and a great group of professors. They treated you like a colleague, and so it was a really positive experience.

ZIERLER: What were some of the big exciting initiatives that were going on when you joined in '86?

WIZINOWICH: I ended up becoming part of Roger Angel's group. I don't know if you know Roger Angel.

ZIERLER: Of course.

WIZINOWICH: He's sort of the father of the other approach to large telescopes. The Mirror Lab was an attraction. Although I originally went there, I thought I'd tried to work on adaptive optics. But the people that had worked on adaptive optics in the past, people like Jim Wyant or Roland Shack or Chris Koliopoulos, weren't interested in [laugh] adaptive optics anymore. I think they thought they'd gone as far as they could back then. Roger asked me if I'd be interested in working on large telescopes and I ended up getting involved with polishing and testing of large optics. That was exciting for me. That was one of the exciting things going on. Lots of other things going on at Optical Sciences, but I got blinders on again for what I was working on.

ZIERLER: What was the funding source for the center? Was it mostly NSF-supported?

WIZINOWICH: Optical Sciences? I'm not really sure, and I'm not even sure where Roger's [laugh] funding came from because, as a grad student, you got shielded from that. Some projects ended up paying for the mirrors at the Mirror Lab. Those weren't necessarily NSF things. But I'm not really sure. I know there was some Defense funding there, maybe some industry funding of optical science itself. But I think people bring in grants there, and then of course if you're faculty, you've got some guarantee of your own salary. I know when I was working with Roger, we also applied for grants and things like that, but I was more able to work on the technical stuff there.

ZIERLER: What was Roger's mentorship style like? Was he hands-on? Did you get to know him well?

WIZINOWICH: I got to know him fairly well. He was a very busy person, so you didn't get a lot of time with him. But I just remember each time I'd meet with him, especially early on, I felt like he had all these ideas. He has just tons of ideas. I thought of them as jewels. I would look at a few of those ideas and, say, do a literature search, because these were ideas that were coming out of him, not necessarily from literature. Make sure somebody hadn't already done it, because sometimes they did, and then before picking a topic that I thought was new. The trick with Roger was to solve a problem before he did.

ZIERLER: [laugh]

WIZINOWICH: [laugh] You didn't want to give him too much time where you were stuck on something, because I remember him coming in, he said, "I was having a glass of wine last night, and I was noticing how the bubbles rose on the surface of the glass. That gave me an idea for how we can get the bubbles out." Referencing the bubbles in the honeycomb mirrors You had to come up with a solution before he did.

ZIERLER: Did that race influence what your thesis research ultimately was?

WIZINOWICH: He gave me a lot of freedom to do it as well. I remember one of the people at the Mirror Lab said that he told them, "Just give Peter the resources he needs." He cleared the way but then let you do it, and gave you good ideas, but he wasn't necessarily requiring how it got done.

ZIERLER: What did you work on for your dissertation?

WIZINOWICH: The first thing was doing the reverse of how the Keck mirrors were polished. They were doing stressed-lap polishing at the Mirror Lab. That's the way they polished the mirrors. For Keck, we stressed the mirror, and then polished the mirror. At Arizona they actually stressed the lap that's moving over the glass. He was interested in whether stressed lap polishing could be used for a secondary mirror as well, something that isn't concave. I built a lap, a plate with pitch on one side, and then vertical bars on the other side, where I attached springs. What I wanted to do is automatically change the shape of the lap as it's moving over the surface to produce an aspheric surface, and I ended up producing—on a secondary mirror, the first aberration you're trying to put in is spherical aberration. You're trying to depart from the sphere, and make an asphere. I was able to put about 30 microns of spherical aberration onto this convex surface, the secondary kind of surface, using the stressed mirror polishing.

The second part of my dissertation was developing a new way to do fast interferometry. A problem when you're testing any optic is vibrations, and if those vibrations change the relative position of the reference surface and the surface you're testing during the measurement, you're going to get a bad measurement or you're going to get errors in that measurement. You need at a least three measurements to get the two intensities and the phase difference. Roger had the idea, another Roger idea. He thought, why don't you have the third measurement be just a background measurement, and the first two just be the actual phase shift. It's called the 2+1 algorithm. Then I came up with the approach for how to do the first two very quickly. The approach [laugh] I actually had was to have a rotating prism. Just when it's at the right time, then I had—this is going to get way too complicated.

ZIERLER: No, please.

WIZINOWICH: Video rate CCD's use two interlaced 30 Hertz images shifted by 1/60th of a second. I'd used one image for the one phase, and the other for the other phase, with a fast shutter opened for 2 ms overlapping the end of one interlaced image and the start of the other interlaced image. A Pockels cell was used to switch between two frequency shifted orthogonal polarizations to provide the phase shift. It was a lot of timing in this process. We demonstrated that 2+1 algorithm for fast measurements of optical surfaces. Once I had my PhD, and was working with a grad student, we tried another approach using an acousto-optic modulator to shift the phases, and that worked better. That was part of my thesis.

ZIERLER: What did you see as your contributions? What was adapted or adopted in astronomical observations as a result?

WIZINOWICH: The 2+1 algorithm is a standard approach now, or it's another approach, not necessarily using the technical approach I use but other approaches. It's one of the standard algorithms now in interferometry. I appreciate being mentioned in books like Daniel Malacara's Optical Testing or Selected Milestone papers, that kind of thing. I don't know that the polishing went a lot further than what I was doing at the time, but I never followed up on it. It was not something I pursued.

ZIERLER: Now, did you spend a lot of time at Steward Observatory as a graduate student?

WIZINOWICH: Yeah, I did there or sometimes at the Mirror Lab but mostly at Steward. I actually set up an optics lab at Steward. Roger didn't have the funding necessary for an optical table, so I got something welded up in the machine shop. Machine shops are really good for grad students. You make friends with the machinists, and they help you a lot. I got a long table welded up, put isolation air springs under it, put it up on cinder blocks, made myself a dark room with plastic sheeting and plywood [laugh] within a larger lab, and basically set up a lab there for the testing of both the 2+1 algorithm and testing the polished aspheric blank that I produced.

ZIERLER: Peter with the PhD, did you ever consider going the faculty academic route?

WIZINOWICH: I did because, first of all, Roger asked me would I stay as a postdoc? I said no. [laugh] I didn't want to do the postdoc thing. Then Jim Breckinridge at JPL had invited me out for an interview. I hadn't applied, but he'd been tracking me, and invited me out for talks during my PhD. He invited me out, and said I could work with any of three groups there. There was really exciting stuff going on at JPL. Sorry, I'm giving you lots of stories here.

ZIERLER: That's the point, please.

WIZINOWICH: [laugh] I remember I'd been in Pasadena for like three days. This would've been 1989. I hadn't seen Mount Wilson all day. I flew back into Tucson. Catalina's crystal clear 40 miles away. I just said, "I can't." You get off on the tarmac, or back then on the tarmac, in Tucson. I said, "I can't go to JPL." But Roger had worked his magic, and got me a staff scientist position at Steward Observatory. He had asked me what would it take for me to stay? I said, "I want to work on adaptive optics." He said, "It's about time I got into that." So we started the Adaptive Optics program at Steward together. That was fun. Those couple of years as a staff scientist were a lot of fun. Right away, we had three grad students from Optical Sciences and three from Steward Observatory. Between those different groups, those different talents, we did a lot of fun experiments, mostly on the Multiple Mirror Telescope but also on the 90-inch at Kitt Peak.

ZIERLER: Your appointment at Steward, it was not a soft money position? You could have stayed longer if you wanted to?

WIZINOWICH: Yeah, I think so, and I was intending to because I was having a lot of fun.

ZIERLER: What was your main work there? What were you doing for those couple years?

WIZINOWICH: I'd known that I had a way to kick off our adaptive optics program because at NOAO, which is right across the street from Steward Observatory, I was aware that basically the AO group that they'd set up there had dissipated. They had a really powerful group there. They had Jacques Beckers, François Roddier, Ed Kibblewhite, Larry Goad, and they were all working on adaptive optics sort of independently [laugh], unfortunately. I knew Larry Goad had built up a whole AO bench. I asked Sidney Wolff, who was the director over there at the time, could I have that bench, and she agreed. We started with some experiments with that bench, first in the lab. Then we also tried an experiment at the McMath solar telescope. We started with that. Roger made a connection with Johns Hopkins, who were doing fast tip-tilt kinds of adaptive optics. We collaborated with those folks, David Golimowski, Mark Clampin, those folks, and doing some experiments at the 90-inch and the MMT. Then we built our own AO system, which we called Acme Adaptive Optics, and put it on the MMT, and were doing experiments. Then we got into this neural network stuff as well. We were demonstrating lots of different kinds of techniques, and writing papers on those techniques. Again, we had fun observing missions with all the young folks, and just being able to try things quickly.

ZIERLER: Now, were you following developments at Keck as it was getting built up? Was that something that was on your radar?

WIZINOWICH: Oh, for sure. You'd be hearing about it at each of the conferences. I'd met Jerry Nelson, Terry Mast, those people. I had a connection through Barbara Schaefer, who was working with them back then, who I rented my apartment from in Hawaii. When I arrived to work at Canada-France, she was leaving to work with Jerry and Terry, and so I rented her apartment. [laugh] Yeah, I was aware of what was going on, and would always talk to them at conferences and things like that, so it was exciting.

ZIERLER: What was the point of connection for you? What was the opportunity that got you over to Keck?

WIZINOWICH: When I finished my PhD, I'd sent out some letters, including to Keck. But then I'd taken a position at Steward, so I'd forgotten about that. Then about two years into my staff scientist position, Gerry Smith, who was the project manager for Keck, as you well know, gave me a call, I think on a Friday afternoon. He said, "Would you be interested in an optics engineering position at Keck?" I said, "Oh geez, I know you're doing exciting work there, but I'm having a lot of fun here, and so I don't think so." [laugh] However, I went back into the lab, and my wife came by and saw this note from something in Hawaii. We'd met here in Hawaii, and got married in Hawaii. She said, "What's this about?" when I talked to her later. I said, "I got a call from Keck." She said, "You don't have to take the position, but you do have to go for an interview." A little sheepishly, I called Gerry back on I think Monday, and said, "After all, after I've given it some more thought [laugh], I would be willing to come out for an interview." I came out for an interview, got excited about what was happening here, they made me an offer I couldn't refuse and Roger wasn't able to compete with, and so I ended up at Keck. Now, the hard part for me was leaving adaptive optics. The exciting part was to be able to put the optics together for Keck.

ZIERLER: Now, that means that your hire was signaling that Keck was embracing adaptive optics in real time?

WIZINOWICH: Not at all. Not at all. They hadn't put the optics—well, they had done the first nine segments in the telescope, and demonstrated that, but they needed somebody to basically get the optics in the telescope and aligned. I ended up being responsible for all the Keck II optics as well, and finishing out the Keck I optics, and things like ion figuring. My first job at Keck was taking out the segments that were in, re-surveying the whole sub-cell of the telescope to position it to 100–200 micron level accuracy, and then putting all the primary mirrors segments in, surveying in the secondary, surveying in the instruments, and things like that. It was really a survey task, and then procuring all the optics, getting the ion figuring process more robust at Kodak, things like that.

ZIERLER: Was Keck doing science already or was it still in building mode when you joined?

WIZINOWICH: No, I joined in late '91. Science didn't start till '93. I don't think we had a science instrument yet, other than a prime-focus camera. It was still building the telescopes or building Keck I.

ZIERLER: What was most exciting to you for all the opportunity to build and make Keck what it ultimately would become?

WIZINOWICH: There's a lot of exciting things [laugh], but seeing it come together, and getting the optics in there, and then seeing that the optics were producing good images, and then getting phased images. A particular exciting night for me was—previously, they'd done prime-focus measurements, basically got the light from those first few segments on the prime-focus camera.—after we got the secondary in, we had to get light on a small CCD on the star stacking camera, which was at a bent cassegrain port. I put a plate across the elevation ring, put a piece of graph paper on it with a hole in the center of that plate, surveyed in the graph paper, put an X where I wanted the star to end up. I was on the Nasmyth platform with a hand paddle, and we pointed at the first star. I looked around with my eyes, found the star, focused it, put it on that X on the piece of paper, rotated the tertiary, and it was on the camera. Just that it worked, things worked like that smoothly. Finding the axis of the telescope using the North Star, things like that. Just those nighttime experiences on top of a huge beast, or riding the secondary [laugh], things like that, to check the vacuum system.

ZIERLER: Did you interact with Ed Stone?

WIZINOWICH: Ed Stone was a very—he talked to people. I wasn't in my office next to Gerry Smith's for very long before Ed Stone came for a board meeting or something, and he popped into your office and said, "Hi, I'm Ed Stone," [laugh] and started talking to you. But it was more at that kind of level. I wasn't reporting to him or anything like that. I was reporting to the project manager.

ZIERLER: When did the astronomers start to come, or were they there already when you joined?

WIZINOWICH: We had some staff support astronomers when I joined that were helping with the development and commissioning of the instruments. I don't know if they were here when I came here. But not too long afterwards, we started hiring support astronomers, so I ended up hiring a few of those. I ended up leading that group for a little bit, for about nine months as an interim. We quickly needed support astronomers to help with the instruments. Then astronomers, initially, of course, had to be on the mountain to do their observations.

ZIERLER: Officially, first light had already occurred at Keck before you joined?


ZIERLER: What does that mean exactly because, as you already said, Keck really wasn't doing science for a few years later. If you could just describe what does first light mean, and then how do you contrast that with what does it mean to do science at Keck?

WIZINOWICH: First light can mean a lot of different things. [laugh]

ZIERLER: [laugh]

WIZINOWICH: In Keck I's case, it meant having nine segments in a telescope, and not phased yet, just nine 1.8-meter segments, and collecting the light on a detector at prime focus, which is a milestone because that was the biggest telescope to date. It was pretty exciting. I wasn't part of it, but it was an exciting moment.

ZIERLER: Did the funding structure feel pretty well stable, or were there some dicey moments there where it wasn't clear if the necessary funding was going to come through in those early years?

WIZINOWICH: I'm sure for people like Gerry Smith or Jerry Nelson—I wasn't dealing with the funding, but to me it always seemed stable. I didn't realize it at the time how lucky we were. The Keck Foundation had provided the money. Caltech found the other one-sixth from NASA. The money was there so we could just proceed. Our schedule was limited by what we could do, not by funding at any point. It was technically driven milestones, and so we just carried out our plans. We could plan and carry them out, and you can't do that very often. I found a whole different thing when NASA was building the interferometer. Obviously, we should be very grateful to the Keck Foundation because I think they made it possible, not just with the money but made it possible to be there first, and in so many ways just by that money being there, solid.

ZIERLER: Peter, do you have insight as to the decision-making behind the sequencing of Keck I going up and then Keck II, as opposed to having them going up in tandem?

WIZINOWICH: I don't think the money was there. Again, other people would know it better than I. But I don't think the money was there for Keck II initially. The idea was there, but the money depended on the first one. I think the success with the first telescope is what prompted the Keck Foundation to provide the money for the second telescope.

ZIERLER: But the goal was from the beginning to have the two telescopes. It was never going to be satisfactory for Keck only to have Keck I.

WIZINOWICH: It may depend on whose perspective, [laugh] because Keck I by itself is a powerful capability, and still the biggest telescope. But I know people at JPL and Caltech in particular wanted to see an interferometer, and so you needed a second telescope for the interferometer plus, of course, you get twice the capability. But the money wasn't there initially for the second telescope. I remember we had weekly meetings on the second telescope, basically lessons learned from the first telescope. What are we going to do different on the second one? We were still finishing the first one when we started on the second one, still finishing the second one when we started on the Keck Interferometer, starting AO when we're still working on the second telescope. There was always overlapping, having to do a lot of things.

ZIERLER: Now, when you say that you need Keck II for the interferometer, is that like LIGO needing two facilities where one verifies the other?

WIZINOWICH: No, not in that verification sense. Each LIGO facility is a distance measuring interferometer. Keck is an interferometer because we interfere the light from the two telescopes. We collect the light from each telescope, and phase them just like we're phasing a single mirror. Then the light from the two telescopes can constructively interfere, and you've got the baseline of an 85-meter telescope. You've got the angular resolution of an 85-meter telescope, and the resolution goes linearly with the size of the aperture, or the separation of the interferometer elements.

ZIERLER: How does that work for Keck?

WIZINOWICH: The interferometer consisted of two telescopes, two adaptive optic systems, Coudé Trains taking the light into the basement, long delay lines to roughly match the light, the distance between the two telescopes, fast delay lines that then track the path length between the two telescopes to maintain it identical, then a fringe-tracking camera that looks at the fringes, and basically you're scanning through the fringes to keep the fast delay line on the white light fringe, and then a science camera, and also a tip-tilt camera. It's the most complicated thing I've ever worked on, and it worked. A lot of people think adaptive optics are hard, but interferometry is even way harder. Then some really fantastic capabilities like the Keck Nuller, which is a Smithsonian-worthy exhibit. The whole basement was a Smithsonian-worthy exhibit. The fact that all that worked and, for visibility measurements, we could do six to eight targets an hour. Efficiency was really high. Downtime was really low. We had a really powerful machine, that's thanks to—JPL was a huge player in this. The interferometer expertise came from JPL. We collaborated, I collaborated, and our group collaborated closely with the JPL team, and then also that group at Caltech at the—I keep forgetting what the name is—Michelson, NExScI but the data reduction side of things for the interferometer. At JPL, Mark Colavita was the brains, Mike Shao as well, but Mark really made things work on the interferometer. Then Rachel L. Akeson led the data side of things at Caltech. It was a great team, and some really nice science results while it was there. One of my huge disappointments is that it's no longer there.

ZIERLER: Yeah. Peter, what was what was first light like for Keck I in '93?

WIZINOWICH: Keck first light was exciting. Oh, first science?

ZIERLER: Yeah, I'm sorry, first science.

WIZINOWICH: First science, that was with the near-infrared camera that was built by Keith Matthews and Tom Soifer, which is a forward cassegrain instrument. It's always nice to have that first science. I don't remember the details of it, I'm afraid, but being able to say you had your first science observation. But the first science paper tells me when we've actually got something working.

ZIERLER: Was the general sense that Keck I was obviously successful, and it put Keck on a successful funding path for Keck II, was that obvious from the beginning?

WIZINOWICH: I don't know how obvious it was until the telescope was phased. I'm forgetting when we first phased the telescopes, but it would've been around that time. Presumably, we had it phased for the first light. The brains behind phasing are really people like Gary Chanan at UC Irvine, and Mitch Troy who's now at JPL. But once we had the primary mirror phased, that's when you knew that Keck had achieved what it needed to achieve. It wasn't going to be just a light bucket with 36 segments. It was going to be a 10-meter telescope.

ZIERLER: What does that mean, phased? Does it mean basically taking one smaller mirror and expanding it, so it's as if it's one giant mirror?

WIZINOWICH: It's like it's one giant mirror. People took different approaches to building large telescopes. You notice everyone else besides Jerry Nelson took the approach of making a monolithic mirror. You know that its phased because it's a continuous surface, as long as the quality of that surface is good. But with our segments, they may be perfect on an individual segment—by the way, they're not perfect on an individual segment [laugh] but they're close to that. But if you're not connecting, you know, not phased at the edge with the next segment and the next one, it's not a continuous surface, and you need that continuous surface to actually get the diffraction limit of the telescope.

ZIERLER: Adaptive optics makes all of this possible, right? That's baked in from the beginning?

WIZINOWICH: If you're phased, then you can get a diffraction limited image at a long wavelength with respect to the diameter of the telescope. At 10 microns, say, you're probably phased good enough without adaptive optics to get a diffraction-limited image. But beyond that, you're right, adaptive optics. The problem is the atmosphere is there, and so it's going to blur things. In the infrared, where we started doing science, that's on the order of maybe a half meter, the size of the atmospheric cell that is coherent. It's still coherent over half a meter to a meter, depending on the conditions. Adaptive optics is what allows the whole telescope to take advantage of the phasing of the telescope, because now it takes up the atmospheric effects, fixes up some residual aberrations in the telescope. But without adaptive optics, you wouldn't achieve the diffraction limit of the telescope.

ZIERLER: Once Keck I was up and running, did that affect how much time you spent atop the mountain? Would you go up more frequently?

WIZINOWICH: With Keck I, I was up on the mountain a lot, to survey optics and stuff like that. Keck II, by then I'd hired another optics engineer who was doing a lot of that stuff. But for Keck II, my role was more of procuring all the optics, going from Schott Germany, to Itek and Tinsley for the polishing, back to Itek for cutting and mounting whiffletrees, to Kodak for ion figuring, and also places like UC Santa Cruz for the secondary mirror, or Kodak for the tertiary mirror. I was worried a lot about the optics, the fabrication. Then Mike DiVittorio, who we hired as optics engineer, who was working with me, took responsibility more for the Keck II system.

ZIERLER: When did you get word that Keck II was a go? How did that news come to you?

WIZINOWICH: I don't remember, David. [laugh]

ZIERLER: [laugh]

WIZINOWICH: But it seemed like that it happened pretty soon. We were still working on Keck I when we knew we were going to be building Keck II.

ZIERLER: It's a good sign.

WIZINOWICH: That's the thing about success: success breeds more success.

ZIERLER: Yeah. You mentioned all the vendors that you worked with. Where could you simply hit repeat in building Keck II from what you did for Keck I, and were there any lessons learned where you decided to go with different vendors or go with a different sequencing?

WIZINOWICH: We stuck with the same vendors, but there was a lot of potential process improvements based on what we learned on the first segments. By the way, when I first got here, and Jerry Nelson and Terry Mast were still here, a lot of this was brainstorming with them about how to improve process. It was a pleasure to overlap with them, of course. Learning the importance of measuring the stress birefringence in the blanks at Schott for example, and how we might do that a little bit better, because that stress in the glass affects how they warp, after the stresses are removed from the blank, how they'll warp, and so being able to predict better how they'll warp. Taking advantage of ion figuring, so ion figuring had already been done on two or three of the segments. There were still problems, like there was a trough in one of them where the ion gun had gotten stuck. Ironing out that process with Kodak on the ion figuring, and how to take the test results, and produce well ion-figured segments. Reducing the polishing requirements at Tinsley and Itek because we now had ion figuring, so we did a bunch of experiments with Kodak and the polishers, where we polished pieces of the glass for different periods of time with different grits and things like that, to learn how long it took to really polish out any subsurface damage, because on a couple of the segments for Keck I, we actually opened up some of that subsurface damage, and so they look a little gray as a result of ion figuring. I didn't want that to happen on any more segments. We increased the polishing time, the minimum polishing time requirement, but reduced the figure requirement for the second telescope or the second round because we could ion figure them.

A lot of it was working with the vendors as well, just to make sure the test setups were reliable, that we believed them because as you learn from things like Hubble, testing is very important. If you get ahead on the polishing or the figuring before you really have the testing under control, you can end up with problems, and so working with them to make sure that we were convinced the test setup was good. I don't know if you're aware of the whole process, but we got the blanks from Schott in Mannheim, Germany. We sent them to Tinsley in California or Itek in Boston, and they did the stressed mirror polishing, which is basically taking a circular blank, which had been ground by Schott as well, and hanging weights on the edge to get the desired final aspheric when the weights are removed. When you polish, you rub two pieces together, you'll get two spherical surfaces, one concave, and one convex. But the trick is then that you've warped the segment, the blank, initially the right amount that when it relaxes, it's the desired asphere. That got pretty close, but then to get closer to the final figure—sorry. Then all the polished blanks were sent to Itek, and they cut the edges, the ears off the segments so they became hexagons, and they also bored the mounting holes in the back. They mounted the whiffletrees, and we had a couple of people, our Keck employees at Itek that were monitoring the process, and signing off on things. They had a test facility at Itek, their auto-collimation test facility, where they would measure the segments interferometrically using a Reticon detector back then. Then they would send me the test results for approval. Then we'd have the segments ion-figured at Kodak, and then they'd go back to the test facility, and sometimes we'd have to ion figure a second time. It's a quite a process, using a lot of company expertise as well. But it was a process that got largely developed by people like Jerry and Terry working with those vendors initially. I just helped refine that process.

ZIERLER: How much did your day-to-day change once Keck II was operational?

WIZINOWICH: That's a long time ago. [laugh]

ZIERLER: [laugh] Did you feel like it was twice as much work? Was it twice as much science?

WIZINOWICH: Our staff increased as well. Certainly, it would be twice as much science because we were using both telescopes at that point, once Keck II was commissioned for science as well. Science productivity would've certainly doubled at that time, and new instruments coming along as well. Again, the power of the system is nothing without the science instruments on that back end, so it's that combination.

ZIERLER: Did the science objectives change? Did they simply double? Was it basically the same but more of it from Keck I?

WIZINOWICH: The science objectives have been driven by the community. People put in their proposals to time allocation committees, which are their peers, and they judge which science is most worthy. Then a nice feature of Keck is you've got your time, but if you decided something else was more worthy by the time you got to that science night, you can do something different. But then you have to be careful that that was definitely worth it for your next proposal. [laugh] I think the science objectives evolve. Now, the instrument objectives may evolve based on what science is coming out and what new ideas are out there. The next instruments that are proposed, and those are proposed by the community, will be influenced by what's cutting-edge in terms of science, and what PIs at Caltech or UC really want to build.

ZIERLER: Peter, when in the narrative to both Keck I and Keck II, when did they feel complete, and now it's really about doing the science, or is it always about adding and improving instrumentation, hardware, software? Is there ever a feeling of stasis with the telescopes?

WIZINOWICH: Never. [laugh] We're always trying to do the next big thing or the next better thing. I think I mentioned earlier, each year, we have at least 30 projects that we're trying to do. Some of that may be upgrades because we've got old telescopes now. They've been around for a while, and so we have to upgrade things, and we're trying to move to modes like unattended nighttime operations, which some other observatories like CFH and Gemini have already done, where we have no one at the summit. We observe just remotely from Waimea. We're commissioning new science instruments, new AO capabilities, improving our active control system or improving our safety sometimes. We had a safety hazard reduction project over the last few years to improve things that weren't as safe as we'd like. There's always trying to offer new capabilities to our science community, and keep the facility up to par.

ZIERLER: What about the role of competition? How closely are you following what's happening at other telescopes, and does it ever serve as motivation for when Keck needs to upgrade or change something?

WIZINOWICH: Yeah, and it works both ways, for sure. I was at this AO4ELT7 conference in France this summer, and Pierre Léna, who's sort of a father of adaptive optics and interferometry in France, who's in his mid-80s probably now, gave us a nice evening talk and talked about the history of adaptive optics mostly in Europe. It was a little Eurocentric. But in answer to somebody's question—which was because for a while, they'd put AO and interferometry to rest, and they were just worried about the VLT, just building the telescopes themselves. Then somebody in the audience asked the question, "What brought adaptive optics back?" He said, "Peter" [laugh]—

ZIERLER: [laugh]

WIZINOWICH: —because of the success of adaptive optics at Keck, the Europeans didn't want to be left behind, so they got that program back in gear, and the same thing for us. We're looking at what they're doing. The European Extremely Large Telescope drives TMT and GMT, and vice versa. Of course, we're at risk in the US now [laugh] of losing the historic leadership position. But we collaborate a lot. The adaptive optics community is not a huge one, and I've had active collaborations with folks in Europe or Australia or other places over time. We just had the person that leads the AO group in Florence, Italy, spend a few weeks with us here. We collaborate with a group in Marseille. In fact, I did a sabbatical of a few months there. ESO, we had a collaboration with ESO to come up with a better laser. We'd had two generations of laser: first, the dye laser from Livermore, then a solid state laser from Lockheed Martin, Coherent Technologies, both of which required huge hands-on efforts. Both Europe and us wanted a better laser, a commercial laser product. We collaborated, Norbert Hubin and myself, to put out a competition to vendors. We got five bids and then we selected two of those that were funded to go to PDR. From that, we supported the development of the TOPTICA laser, which we finally down-selected to, and now that's the standard. We have three physically at Keck. Gemini, Subaru, even the Air Force [laugh], and the VLT all have TOPTICA lasers. It's those kinds of collaborations we need to do because there's limited dollars in astronomy, and collaboration really helps.

ZIERLER: Peter, I wonder if you can explain, how do you quantify? The Europeans didn't want to get left behind because they saw all the success with AO at Keck. How do you quantify that success? Exactly what is Keck achieving? What is making AO make that possible that the Europeans are taking notice of? How do you package that to understand it?

WIZINOWICH: The bottom line is the science. If people are doing great science, people want more of that. It's the science. I think that tells me we're successful, going back to the Decadal, the fact that each time adaptive optics becomes more important. Something that was not that thought about when the Kecks were first called upon, or first being designed, now is an important part of our science strategic plan, which is driven by the science community. Why is there so much adaptive optics? Because most of the things are either adaptive optics or AO instruments, and it's because the community must be happy with it. That tells me it's the science that's the bottom line.

ZIERLER: Peter, you mentioned the Decadal process. When a new Decadal report comes out, how central is that for setting the overall strategic direction for you, for Keck generally? What does that look like?

WIZINOWICH: Because the Decadal was late this decade, we'd already started our own strategic planning. It turns out what we planned was very similar to the Decadal plan, but the value of the Decadal is it will drive funding. Seeing AO in the visible or high-contrast adaptive optics for exoplanets, or precursor kinds of high-contrast things on the ground for Habitable Worlds Observatory, those are all quotes [laugh] we can use in proposals, frankly. We can be part of that road map to achieving these longer-term visions of the US community. We've often quoted in our proposals that we're in alignment because we were trying to achieve the same things. But it allows us to have a route to funding things. Now, that may be more cynical [laugh] than you want, but we're actually after the same science goals. Our community wants to achieve those science goals in the Decadal, and we have stepping stones along the way using the world's biggest telescope, still, the Kecks to achieve those.

ZIERLER: Peter, ahead of you being named Chief of Technical Development in 2017, as optical system manager in that role for so long, what were some of your increasing areas of responsibility that may not be reflected with the lack of a title change after all those years?

WIZINOWICH: I'm not sure what the title change really meant [laugh], other than more responsibility.

ZIERLER: Oh, so that's really it? You were doing basically the same thing when you went from—

WIZINOWICH: I think I was largely doing the same things but just recognizing that, because people started being called chief of whatever, we started having those roles at the observatory.

ZIERLER: Is that simply a function of there's more people for you to manage as Keck got bigger?

WIZINOWICH: I don't know that it's more people; just a sort of a recognition of the role perhaps. My responsibilities have largely been telescope optics, interferometer, adaptive optics, more responsibility for annual planning for projects, so more projects. I was trying to take advantage of what we learned in terms of project management for things like AO and the interferometer, which were big projects, migrating that to other projects in the observatory, bringing more systems engineering into the observatory, because for our AO projects, or interferometry, we certainly start with requirements, science requirements, and then flow those down to technical requirements. A lot of times, we didn't do that for projects at the observatory, so following that flow through from science to here's what we need to do.

ZIERLER: If you're willing to name names, who have been some of your favorite astronomers who have come to Keck? Who's great to work with?

WIZINOWICH: Actually, we're really blessed with overall a great community, and the fact that they also recognize our role in that. They're not just, "Oh, you people do this, and we'll take the glory." There's more attention on the astronomy. Andrea Ghez, of course, has been very inclusive. There's a great group at UCLA, in addition to Andrea, Mark Morris, Eric Becklin; in the instrument side, James Larkin and Mike Fitzgerald. At Caltech, it's been people like Mike Brown was helpful for a phase of our adaptive optics in terms of leading our working group. Dimitri Mawet now is really a driver for high-contrast work. Shri Kulkarni was a driver and also [laugh] sometimes questioned whether we were doing too much of that. Richard Ellis before him, I thought, was very supportive of adaptive optics and the science. Before him Wal Sargent was a real treat as well, that era of gentleman astronomers, I think, Wal was one of those. Then we've also had good collaborations with people at Santa Cruz more recently. I've mentioned Phil and Becky, and Claire Max and Don Gavel in the past. The other part I've really enjoyed is that I've gotten to see people that are grad students and now are senior people. For example, Jessica Lu was a grad student with Andrea's group, and now she's our project scientist for our KAPA project. Shelley Wright, who was at UCLA as well, helped us with an early test camera for our Keck AO system, so we had a way to score performance, because the science instruments were late, and so we wanted to have some camera to commission with. She's now a professor at UC San Diego, leading the efforts for both a new instrument for Keck, Liger, and also for the TMT. I've really enjoyed—and there's a lot of young people in these groups that have gone on to other things. A lot of them actually in AO got educated through the Center for Adaptive Optics, which was centered at Santa Cruz.

ZIERLER: You mentioned Andrea being really inclusive. Is that to say that when she won the Nobel Prize, took care to make sure that everybody at Keck was part of celebrations? Was it was recognized as well?

WIZINOWICH: Yeah, she came out here. She did invite me to the Nobel Prize ceremony, but I'd already accepted this NSF review, so I couldn't actually make it. She took me once to another prize, the Crafoord Prize in Sweden, so she does that—I mean, me as being a representative of all the other people that have worked on it, of course. I do need to make that point that we've had a lot of great people at Keck over the years that have really made very strong contributions, and that continues today. I'm just the person that leads this, but so many talented people have contributed to the effort.

ZIERLER: Peter, when Jerry Nelson passed away, was that sudden? Did that shake Keck when he died it?

WIZINOWICH: First of all, when he had a stroke, it certainly shook us. Then of course when he passed away, it shook us. He'd already started fading from the scene at some level right after his first stroke. He was still coming into work, and things like that, but it shook. Terry Mast for me as well, that was a big loss. Those two together, I thought, were a powerful duo. They brainstormed well together, and Terry would go off and do the detailed analysis, and they'd brainstorm again. Jerry was also able to collaborate with a lot of good people, and unfortunately a number of those people have passed over the years, people that were instrumental to the observatory.

ZIERLER: What do you see as their legacy in emphasizing how Terry and Jerry worked together?

WIZINOWICH: Clearly, the Keck telescopes and the fact that segmented technologies, segmented mirror technology is used in JWST. I remember a JWST group coming out here, and I spent several days with them, sharing what we learned about our segments, and we did some experiments on the Kecks for JWST. Clearly, the TMT and the ELT are following in that heritage. Those are all part of that heritage of what they started.

ZIERLER: Peter, you mentioned there's always room to improve. There's always new instruments. At some point, do the telescopes just become full? Do you have to take out instruments in order to put in new instruments? How does that work?

WIZINOWICH: That's one we struggle with, because the load keeps getting bigger, both physically. The telescopes are a lot heavier than once were. But also the decommissioning, and we have decommissioned a couple of the very early instruments because they just didn't function all that well or weren't scientifically driven anymore. But something like the near-infrared camera, which was the first camera on Keck I, that took a force of will [laugh] to decommission because there were still people that wanted to keep it. We have to struggle with the same thing to make space for the next ones. Unfortunately, I mean, not unfortunately, it's great that the instruments still have a capability and some power to them, but we have to make space for the next generation of instruments.

ZIERLER: Moving the conversation closer to the present, when COVID hit, what had to stop at Keck, what could be continued remotely, and when did it feel like operations were finally getting back to normal for you?

WIZINOWICH: The first thing I would comment on COVID is how well I think the observatory handled that. I'm giving the credit mostly to the director, Hilton Lewis, here. But we all quickly responded, got people home. We shut down not for that long a period before we got a pajama mode working [laugh], so that, people didn't have to be physically here in Hawaii or physically at the Caltech observing room or places like that, but a mode where they could observe from home. We got a day crew back on the mountain. I don't remember the timescales for any of this, but I'm always appreciative of how the observatory responds to something like COVID or, previous to that, an earthquake, things like that, and we get back on air, so we're still mission driven, and also taking care of people at the same time. It wasn't that much harder for me to work from home [laugh], frankly, because I often do. I'm working on a computer a lot, and that was true of a lot of our staff. It was harder, of course, on the people that physically have to touch things. But I thought we did reasonably well. We did have a bit of a great resignation, like a lot of places, for some of the people that I think may have reflected more during that time. But we're back to full staff now, and we're continuing to do great science, we believe, with the observatory.

ZIERLER: Well, Peter, now that we've worked right up to the present, for the last part of our talk, I want to ask a few retrospective questions, and then we'll end looking to the future. A question about computational power. You're of a generation where you came of age when, you mentioned, you were working with punch cards, to what computers are capable of doing today. As a hardware expert, what have computers made possible? What's better, what's more efficient as a result of computational power now?

WIZINOWICH: First of all, the fact that Keck could be built as an Azimuth, Elevation telescope with an active control system, the fact that computers had gotten to the point where that could happen was critical. A lot of it's still electronics and things like that. Something like we have these node boxes, relatively large boxes under each, on the sub-cell of the telescope, to control the segments. Now you can control these things with a little board a few inches [laugh] size of thing. Oral histories don't do well with finger motions, do they?

ZIERLER: [laugh]

WIZINOWICH: But today we've had three generations of real-time controllers for our AO system. The first generation was very much a working on the edge kind of system that would quickly fall apart if you made any modifications to it in terms of the software, to a second generation which was much more robust. In our current system, we're using GPUs, and also FPGAs for part of it, and the technology is just so much easier to program that we're able to have a much more flexible real-time controller that we can build upon. I really want a system where grad students or postdocs could try out algorithms, and then we can make them more robust in terms of timing and things like that. But you're now at the point where a lot of this stuff can happen much more robustly, and that's not just in terms of compute power but also in terms of languages. We did a lot of stuff with IDL, in terms of our top-level structure. Now everybody can program in Python, and so replacing old aging systems with thousands of lines of operation software is much easier to do and much more software-engineered. Python code makes life easier. As you pointed out earlier, things like machine learning are now—whereas back in 1990 or '89, when we were doing neural networks at Steward Observatory, what was it? Occam was the programming language on transputers, so it was really cutting-edge there. Now that's easy to do with processing power.

ZIERLER: Peter, the road not traveled, you not going down the faculty academic route, have you had a chance to fill the gap of mentorship or teaching at all in your career?

WIZINOWICH: Yeah, like I mentioned, exposure to graduate students, for one thing, because they'll come out and visit, and we try to give them, more recently, opportunities to work on systems. Postdocs, we've had in AO 10 or 12 postdocs that have worked with us, and that's been a real pleasure. They bring energy. [laugh] They need to accomplish something during their postdoc years, and they bring talent, and they've gone on. That's been nice to see them go on to other opportunities. David Le Mignant, who was one of the key people when we were commissioning the laser guide star facility, ended up becoming the technical director in Marseille at their Laboratoire d'astrophysique de Marseille. Antonin Bouchez became the AO lead at GMT. . It's nice to see them having success—and some have ended up staying at Keck for quite a while too.

ZIERLER: Peter, do you have a favorite instrument of all the instruments on the telescopes? Is that too difficult to answer, like a favorite kid?

WIZINOWICH: It has to be an AO instrument, first of all. [laugh]


WIZINOWICH: NIRC2 has done a lot of powerful science. This is another Keith Matthews-Tom Soifer thing. It's just been a robust, solid instrument built at Caltech that is—wow, when was it delivered? Probably 2003. It was delivered after first light or first science of the AO system, so it must have been like 2003. It's worked reliably ever since. But I also like the integral field spectrograph, OSIRIS. I don't want to have too many favorites. That's on the Keck I AO system. NIRSPEC has been nice to put behind the AO system as well, and now the Keck Planet Imager and Characterizer is also on Keck II. We'll have new ones. We've got HISPEC being built at Caltech, and SCALES being built at Santa Cruz, and Liger at San Diego, that will come to Keck behind the AO systems. I got to mention them all. [laugh]

ZIERLER: There you go. [laugh] Peter, of all of the scientific discovery that Keck has made possible, what are you most personally proud of in terms of what AO has made possible?

WIZINOWICH: I think I probably already touched on the ones that are my favorites: the Galactic Center because it's just this wonderful science laboratory. It's not just the supermassive black hole but lots of others—there's young stars there, the paradox of youth, and things that we don't have good physics models for or are developing for, and measuring general relativity at the Galactic Center, things like that. To me, the idea that ninety-five percent of our universe is other than baryonic matter, that's pretty interesting. The fact that we can actually make measurements with adaptive optics to understand or at least characterize dark matter and dark energy, to me, is pretty exciting. The exoplanet work, of course, we could be detecting atmospheres, and we are measuring atmospheres on exoplanets. That's pretty cool. Looking forward to maybe measuring Earth-like planets in my lifetime, even if I'm not at Keck but hopefully in my lifetime, that's pretty exciting. Learning more about our solar system as well, volcanoes on Io, or geysers on Europa, and things like that, those are all things done with the help of adaptive optics, and powerful instruments behind adaptive optics, and a powerful telescope out front too. [laugh] What other favorites? I guess it's also a host of astronomers that come through and use these systems, like Mike Liu at University of Hawaii, who does all these T Dwarf and brown dwarf kinds of measurements, working down to protoplanets. A lot of enjoyable people come with the science. All the people I mentioned were enjoyable. [laugh]

ZIERLER: Peter, I wonder if you can comment or reflect on the two-way street of technological advances for both land-based and space-based astronomy. When is land-based astronomy informing what happens in space, and when is it the other way around?

WIZINOWICH: They're great collaboration, first of all. If you look at something like the Hubble Deep Field, where do you get the redshifts? Got a lot of them at Keck. The fact that something like Hubble can take that beautiful deep field image, and we follow up, so there's been a real win-win here where science advances by the use of both Hubble and ground based telescopes. The same thing is starting to happen with JWST, so you can carry out a certain class of observations with a larger telescope on the ground that you don't want to spend the time with or you don't have the resolution for in space, but together they make the science more powerful. The science side is one. On the technical side, I think what was learned on the Keck telescope certainly informed what happened with JWST, the technology that was chosen, and how it was phased, and things like that. One of the early people working on our adaptive optic system was Scott Acton, who moved to Ball, and led the wavefront control aspect for JWST, so using stuff he partially learned at Keck. It's also people going onto these other projects. We are working with a group at Goddard led by Eliad Peretz and John Mather on a project called ORCAS for ORbital Configurable Artificial Star, with the idea that you could put an artificial star in an eccentric orbit, going out to something like 200,000 kilometers, that can act as a true artificial star. Whereas when we project a laser up to 90 kilometers, that's only 90 kilometers, and actually it's not sampling the cylinder of light. The starlight's coming through. It's sampling in a cone.

But if you have a source on a satellite that far out, it's truly a point source, and so it's a great wavefront source, and it can be as bright as you want, zeroth magnitude or something like that. You can really get the best possible correction with your adaptive optics with a source like that. That sort of goes into this hybrid observatory concept where NASA and ground base could collaborate. John Mather has been advocating that for a while with things like star shades, for example. I see that as a potential combination of using the best of ground and using the best of—or maybe not the best of space but something in space to achieve that. Again, for Habitable Worlds Observatory or even the Roman Space Telescope before that, what you learn in terms of high-contrast science from adaptive optic systems on the ground informs the design of these space missions as well. It's a technology readiness level, if you like, both in terms of science and demonstrating the technology or the actual components that might be used in future for space.

ZIERLER: Peter, is there a Moore's law for adaptive optics? Is there some point in the future where the laws of physics will simply create a brick wall, and there's not going to be much more room for improvement?

WIZINOWICH: Yeah, that's another loss, by the way, Gordon Moore.


WIZINOWICH: He was a real friend of the observatory—


WIZINOWICH: —and recently passed away. He funded some instruments personally, and then of course the Moore Foundation's been quite generous to the observatory as well, and to the community. What a gentleman, just in terms of talking with him; just a normal guy [laugh], although you know he's not a normal guy. But, of course, Moore's law has gone on for quite a while, so where would I say—and we don't have the same timeframe as computer chips, unfortunately. Our projects take quite a bit longer. But where I'd like to go, and where we would end up getting blocked is by the Earth's atmosphere in terms of transmission. In my ideal scenario, we'd have adaptive optics working at the level that you'd think the 10-meter was in space. You can cover from where we are right now, working more on the infrared wavelengths, all the way to the ultraviolet. The problem as you go to shorter wavelengths is the wavelengths are shorter, so you've got to correct to a fraction of that wavelength. Going from 2 microns to 0.3 microns is a factor of 10 in how well you have to correct the wavefront, and it isn't just more actuators on your deformable mirror. You need more signal from your source above the atmosphere. You need higher bandwidth systems. But my dream is putting a 10-meter in space. [laugh]

ZIERLER: Finally, Peter, last question, looking to the future. If I heard correctly, at the beginning of our conversation, you're now interviewing for your successor.

WIZINOWICH: Yeah. It's not like I want to just retire, and hit the beach all the time, although we do have beautiful beaches here. It's that I want to position Keck well for the next decade or two and, at the same time, I want to do something a little different. I gave Keck a year and a half warning. [laugh] I don't want to be in a management position. I'm happy to help train my successor or help get them up to speed. I'm happy to support them after they take over, and so I wanted to have plenty of time to do that. My goal is to be in a position end of September next year where we've got a new person in this position. We've had a good overlap period where I've handed over relationships as well as the team and things, so really introduce them to the California community and other collaborators, and support them in achieving our strategic plan. I'm happy to play a technical role. I think it's time for a new leadership though.

ZIERLER: Is there an emeritus version at Keck? Can you hang around if you want? Is that something that you'd be interested in doing?

WIZINOWICH: I've never heard of an emeritus status at Keck, or nobody's taken that. Some people have stuck around half-time for a year or something, so I've offered to do that. But I'd be intrigued by that opportunity. I'd also be intrigued by spending some time at some of these other places. Rich and I've talked about spending some time at Caltech, for example, where you get to play with more of the technology, and it's exciting technology these days. Caltech has a great team working with Dimitri, including Nem Jovanovic. Those people are very talented, and there's a lot of groups like that that would be fun to spend some time with. Those are my personal fantasies, but my goal is really to leave Keck in a very good position for the next 20 years, so we achieve our Keck 2035 strategic plan.

ZIERLER: Finally, really last question now, in naming your successor, what will you be looking for? What are the most important things for your successor to be alive to in the future as technology continues to grow, as things become more complex?

WIZINOWICH: They need to have the technical management skills, at a minimum. I think we can provide project management. We've got good people here that can do the management. Again, I'm going to re-emphasize how many good people have been working on the systems over the years, and we wouldn't be here without all those good people, and that's a huge list of those people. Some of those people are still at the observatory. Jason Chin was key for the laser stuff. But I digress as I am wont to do. One of them is strong technical leadership. They need to be a technical leader in adaptive optics. Two is an ability to actually make it happen. One of the things I think I've done reasonably well is take something from the preconcept, working with the astronomers, saying, "What do we need? What are those requirements?" taking it from the concept, then a technical concept level, all the way through toit's doing science routinely. You want somebody that's not just interested in one phase of that but is interested in seeing it through to science, that science is the product. Part of that, unfortunately, has been a lot of proposal writing. [laugh] We've been very successful with the NSF, and we've thankfully had good support from foundations like Moore Foundation and Heising-Simons Foundation and, of course, Keck Foundation from day one. That's been very helpful. But they'll have to spend time making it happen, because I've learned over the years that waiting for somebody else to find the money [laugh] doesn't necessarily work. You've got to be out there making every aspect of it happening from the science, thinking about what you need to do next, all the way through funding it, to making it a science instrument.

ZIERLER: Peter, on that note, this has been a terrific conversation. I'm so glad we were able to do this. I want to thank you so much.

WIZINOWICH: I enjoyed it, David. It reminded me of a lot of things.