John Huchra

Lightman:

I wanted to start with asking you some questions about your childhood — how you got interested in science. Were you interested in science as a child?

Huchra:

At a real early age. I always had in my mind from the time I was getting involved in reading, which was very important, the idea that I wanted to be a scientist or a mathematician — a physicist or a mathematician. I think the thing that sparked my interest in cosmology was actually a series of books that I came across when I must have been about 10 or 12 years old — sixth grade. Books like George Gamow's One, Two, Three Infinity^[1] and Fred Hoyle.

Lightman:

Which one was that?

Huchra:

He had a book called… it wasn't The Frontier of Astronomy. There were two popular books on astronomy. ^[2]

Lightman:

Yes, I've read one of those books but I don't remember the title.

Huchra:

I can't remember the title. Then there was also The Birth and Death of the Sun. ^[3] I read those books when I was in sixth grade and I said, "Gee, this stuff is interesting. It's what I'm interested in doing." I grew up just outside of New York City, in an area of the world where it's not possible to see the sky at night except for those things that are flying at low levels. It wasn't a case of looking up that decided me.

Lightman:

It was reading those books?

Huchra:

It was reading those books… the general idea that it was an interesting thing to do.

Lightman:

That's interesting. Margaret Geller mentioned the same books by Gamow that had a big influence on her.

Huchra:

I have a feeling that there's a generation of young physicists, astronomers, and cosmologists who came across those books all about the same time. This was in the late 1950's; that's sort of when they were around. A lot of people saw them. They were very well written, compared to a lot of other things that were floating around at the time. There really wasn't that much in the popular science literature, unlike today where there's a vast mass…

Lightman:

Yes, books everywhere you go.

Huchra:

In those days it wasn't quite so bad or quite so good as the case may be. And they stood out. They were real markers.

Lightman:

Do you remember at this period of time when you were 10, 12, 14 years old when you were thinking about going into science — do you remember whether cosmology had any particular appeal above other sciences or were you just interested in all sciences?

Huchra:

Not particularly. I would say I got into the field in a manner which is maybe a little circuitous, maybe not all that compared to other people. But I was interested in doing science; as I said, pretty much physics and mathematics. That's what I settled on. There were a lot of possibilities I contemplated for a while when I started college… taking up nuclear engineering, that kind of thing. I went to M.I.T. I went when I was seventeen so it wasn't that many years after coming across those books, again mid-1960s, and I started out pretty much straight out in physics. I was trying to double major in physics and math, which would have been possible except for a small thing called the Vietnam War. It shut down classes for about a year, but that's Ok; I had a nice vacation: In physics, I was really interested in particle physics for the first two years I was there, in the basic idea of trying to understand grand unified field theories and the like, which were also just about coming to the fore at that time. There was a lot of renewed interest in theory. At the time, the experimental part of it was pretty much dead. That was the thing which finally decided me not to do particle physics. I ended up getting involved in laboratory research project when I was a junior at M.I.T. I looked around at a variety of different things. It was required that you do a lab project. I ended up in an X-ray astronomy lab, aligning detectors for rocket fights. That was sort of interesting, although at times a little dull. I had to make the choice then whether to get a math degree or physics degree. I decided to stick to physics because the last remaining course I needed to take in the math department was much too hard: One of those kinds of things. I ended up doing a senior thesis on stars and stellar [structure] — in theory, basically on stellar pulsations. ^[4]

Lightman:

Who did you work with?

Huchra:

Icko Iben, who is a very interesting character.

Lightman:

I want to take this up again, but let me first go back to the earlier years. There was some discussion of cosmology in Gamow's book, right?

Huchra:

Yes.

Lightman:

Do you remember having any ideas about cosmology or about the universe as a whole at that young age?

Huchra:

Not really. The one thing that I picked up reading the literature was that there was a bit of turmoil going on in the ideas of what the universe was about. I knew the words "steady state theory" when I was twelve years old, and I knew the words "big bang." It had even been coined by that time. I can't remember having… I don't remember having any profound thoughts at that time.

Lightman:

You don't remember having any preference for any particular cosmology?

Huchra:

No. Not at that age. In fact I still try not to.

Lightman:

Ok. I certainly want to get to that in a moment… So you don't remember thinking too much about cosmology other than just being aware of some of the ideas discussed.

Huchra:

That's right.

Lightman:

Let me go back to your college and your early professional career. Why did you decide, as a senior, to do your thesis in experimental physics rather than in theoretical.

Huchra:

I didn't. I did a thesis in theoretical physics.

Lightman:

Oh, it was in theoretical physics.

Huchra:

Yes. The stuff with Icko was theory. I didn't make the decision to become an experimentalist until after I had been at Caltech for a while. It's a different story. I should mention there's probably another point in my education at that time which had a fairly profound influence on me. I did take a course as a freshman at M.I.T., a seminar with Philip Morrison. I loved that course, it was really fun. I enjoyed it a lot. We played around with measuring distances inside the galaxy and stuff like that, talking about cosmology at that time. I can't remember, for the life of me, the contents of that course, but I remember liking the course, the fact that it was of interest to me. I remember a few of the things we did. I couldn't write down the syllabus, if that's what you're interested in. That I can't do.

Lightman:

So you went to Caltech.

Huchra:

The best way of describing it is that I wasn't sure what I wanted to do. I applied to graduate school and for some strange reason — I still don't know why, I can't remember why and I don't think I knew why then — I applied to graduate school in astronomy. At many places.

Lightman:

You don't remember why you [chose astronomy] after majoring in physics? Could it have been your senior thesis with Iben?

Huchra:

No. The applications to graduate school by definition all have to be sent in December.

Lightman:

Yes, I know.

Huchra:

It's long before you're really into doing your thesis. But I think I had become disillusioned with the idea of becoming a particle physicist, maybe because I didn't think I was smart enough to be a particle theorist and because the experimental end of the field was in pretty bad shape in 1969. But I think… again, I'm not exactly sure what the reasons were, but I think I decided I wanted to go in and do astronomy — not necessarily cosmology, but astronomy.

Lightman:

But you were already very interested as an amateur in astronomy, weren't you?

Huchra:

No. I told you I grew up in New York City. I never owned a telescope.

Lightman:

There's a fair amount of astronomy in Gamow's books, right?

Huchra:

That's right.

Lightman:

So you'd been exposed to it.

Huchra:

That's right. However, being exposed to it is not the same as building a telescope. They are very different.

Lightman:

So you didn't do any building of telescopes.

Huchra:

No. But while I was at M.I.T., I did make an effort to do things like go out to Wellesley to use the telescope out there. There was an astronomy course that I co-registered for. Unfortunately, I sat in only on the first two weeks’ worth of the lectures because I quickly realized that I knew more astronomy than the guy was going to teach in the course. I found that I wasn't too interested in the course itself.

Lightman:

How did you learn that astronomy?

Huchra:

A lot of it by reading popular books, or semi-popular books. A lot of it by getting involved in a couple of courses at M.I.T. that were — how shall I put it — a line course in astronomy. I took Icko's course. He taught a stellar astrophysics course which was interesting. I had thought of working in an electrical engineering radio astronomy lab. I actually took a radio astronomy course from Alan Barrett and Bernie Burke. And I took Irwin Shapiro's planetary astronomy course when I was a junior at M.I.T. Even though I didn't get very good grades in it; that also taught me a fair amount, just by virtue of having to do those courses. Those courses were much more advanced than the elementary astronomy course which I never took, if you know what I mean.

Lightman:

Yes.

Huchra:

You're forced to get the material to catch up or to know the material that's required as the basis for the course. When somebody started telling me what the distance from the earth to the sun is, that's a number I knew five years before. And I certainly had to know [it] for these other courses.

Lightman:

It sounds like you had a proclivity already for astronomy, because the normal physics major doesn't have to take any astronomy courses at all. You were much more interested in astronomy than the average physics major.

Huchra:

That's probably true. By my senior year I think that I was fairly certain that I was interested in astronomy. I don't know why. I still can't really remember why I picked it. It sounded like a good thing at the time. I also took a course with C.C. Lin. That too was a wonderful experience; it was in galactic structure. Again, I loved the course. I didn't like nuclear physics. But I loved galactic dynamics. I think that pretty much describes it.

Lightman:

So you went to Caltech then. What kind of courses did you take? You were in the astronomy department?

Huchra:

Yes. Yes.

Lightman:

How did you move in the direction of experiment rather than theory at Caltech?

Huchra:

Well, funny thing. First, I didn't think I was good enough compared to the other people in my class at Caltech to do a lot of things. I figured I was a dummy. It wasn't entirely true in terms of grades. I had the best grades of most of the people in my class, but somehow I never seemed to quite catch the right spark. But there were one or two people who sort of took an interest in me as a student. I worked for Guido Munch. By definition I had to, how would you put it… You go there on an NSF [National Science Foundation fellowship]? That's not enough, right. Two hundred dollars a month when you're paying $125 a month rent means that you've got to find a research assistantship if you intend to survive. The first way I started getting paid was doing plumbing for Guido Munch. We were building a pressure-scanned Fabry-Perot interferometer, something I knew nothing about, but what the hell. I've got to learn some time. And that was actually interesting. I learned a lot of things I didn't ever know and probably will never need again. The astronomy department at Caltech was not rife with theorists at that time. Most of the theorists, as you well know, were in the physics department there, although now there are a couple of theorists in the astronomy department itself. That wasn't the case in those days. Take a look at who was on the faculty. The people who you would most remember were in fact experimentalists. Just being in contact with those people as my teachers and the people I was running into in everyday life, and the fact that experimentation was actually something I had done before that — if you go back to junior year in the lab, working with the X-ray telescope. I don't know. I moved into being an experimentalist. The theorists always seemed off in ivory towers in the physics department, far away from where astronomy graduate students were. If I remember right, there were very Jew astronomy graduate students that ever went in the direction of doing a thesis with people in the physics department. There were some physicists who came over to work in astronomy. Paul Schechter is an example. John Kwan is an example; he did an astronomy thesis with people connected to the astronomy department. But in the entirety of the time I was at Caltech, I really only remember one student who went in the other direction. That was Charlie Alcock, and he didn't go all the way in that direction. He had half an advisor in the astronomy department and half an advisor in the physics department. The flow was usually one-sided and towards astronomy. My tendency was to stay in astronomy because I was shy and retiring. I didn't want to go too far outside the general vicinity.

Lightman:

I infer from what you're saying that you felt slightly intimidated by some of the physicists.

Huchra:

Yes, I think that's right. I was intimidated from the word go. I didn't understand how I had gotten into Caltech first of all; I mean I was Ok as an undergraduate in terms of my grades, but… The reputation for people getting into Caltech… they didn't take a lot of students even in the astronomy department, or especially in the astronomy department. A lot of the people I knew even at M.I.T. were applying in astronomy to places like Caltech. There's actually something that took place, a funny psychological thing. In the late 1960's, especially 1969 and 1970, those years, it was my impression, looking backwards now, that because of the Vietnam War and a few other things, many of the people who started out as physicists pure and simple, doing applied or whatever — particle, you name it — were swayed away from those fields, partly because of student politics. The Body Politic was very much anti-war. Getting involved in war or anything that might be construed as defense-related research was really anathema. I would say that out of my graduating class at M.I.T., of which there were about 80 physics majors, maybe half of them were applying to graduate school. Almost all who applied to graduate school did so in physics-related fields that weren't or that could not be construed as being related to the defense industry. Almost half of those people applied to astronomy or astrophysics. By definition, a lot of those people were better than me, so I was a little surprised at getting into Caltech. I think that the only thing I might have had going for me was that I started doing astronomy before they did. Maybe that helped, I don't know.

Lightman:

Do you remember when it was that you got interested in cosmology?

Huchra:

Interesting question. As I say, I was working for Guido; that was my [research assistantship]. As the normal course of events at Caltech, you have to find a research project to do, and I actually went up to Santa Barbara Street, which was then the headquarters of the Hale Observatories — now it's something else — and looked around up there to find somebody who might have something to work on. As I said, I thought I was sort of the low end of the scale of graduate students at Caltech. I was real shy. I felt that if I went uptown I'd have a better chance of finding a research project, There were a lot of people from [the Hale Observatory on Santa Barbara Street] who came down [to Caltech] and taught in the astronomy department. I ended up doing a research project with George Preston. My first year and a half's worth of time spent doing research was on observations of what are called Ap stars or "peculiar" A stars. ^[5] That was about as far away from cosmology as you can possibly imagine. Now, that was sort of interesting, but only sort of interesting. I wasn't really turned on. I had to hunt around for a thesis after doing that. I had taken a cosmology course at Caltech, actually two courses that were important. One was the extragalactic astronomy course, which was taught by three different people throughout the course of the year. Basically they were on the quarter system, so there were three terms.

Lightman:

Did Jim Gunn teach a section?

Huchra:

Jim Gunn taught a section.

Lightman:

Maarten Schmidt?

Huchra:

No, Wal Sargent and Leonard Searle. I decided that it would be interesting to try and do something with one of these guys. I ended up working for Sargent myself. Maybe Sargent took pity on me.

Lightman:

Did you start working on cosmology from the beginning?

Huchra:

Pretty much. I got a job — again, got to pay the rent. I got a job doing the Palomar supernova search. ^[6] That was an interesting thing to do. It did pay the rent, although it was a much harder not-useful-to-thesis job than anybody else in the department. It also made me the highest paid graduate student in the department. I started working with Wal and Leonard, who was a behind the scenes thesis advisor, on something they had started working on only a year or so before that. That was the topic of these little blue galaxies, extragalactic HII regions, and the question of finding more such galaxies, and starbursts and star formation in galaxies and the like. In a funny way… this is not "cosmology" as you'd call it, but it's definitely a related topic. Are galaxies still forming now and things like that? I must say it took me a long time to figure out exactly what it was I was trying to do. I started out doing a thesis with an idea, but the idea wasn't the idea of what the scientific problem was, but was rather the idea of how to approach an experimental problem. It was a different kind of thing. One thing that I did that I remember, that was very different from the normal course of events, is that after I finished my astronomy course, and while I was working on my thesis, I spent a lot of time taking other courses which had nothing to do with astronomy or cosmology. Actually they may have had a lot to do with astronomy and cosmology. I took a biochemistry course from Max Delbruck. That was also extremely interesting. Aside from taking physics from Feynman, which I didn't do, one does not often get to interact on a relatively high level with a Nobel Laureate, and that was good. He was very interesting. A physicist turned biologist. And I took some economics courses; that was sort of interesting. I was taking them because it turns out that there are interesting techniques in economics that can also be applied to stellar population synthesis, techniques which at that time no one in astronomy was dealing with, but which looked like they might be interesting… linear and quadratic programming techniques. Astronomy is one of those fields which sometimes pick up mathematical techniques ten years after they've been discovered by the statisticians or the economists or whatever.

Lightman:

It's the same thing for physics.

Huchra:

Yes, same thing for physics. And I saw an interesting chance to learn something about this technique. I took an economics course in that.

Lightman:

In your beginning scientific work as a graduate student, were you heading off in any particular direction in cosmology? The area that you're in now pays a lot of attention to individual galaxies. Can you trace that back to your work as a graduate student?

Huchra:

Not directly. Or I should say maybe indirectly. I was a dabbler. That's to say, I was trying to do an observational thesis, collect a body of data about a particular set of objects, to try to understand the properties of star formation in these objects, to try to see if the sample, which somebody else has selected, could be used to answer a problem. It actually took me a long time to realize what the "right" question was. Now I know that figuring out the right· question to ask is a very difficult problem. That may be the most important thing for a young scientist to try to realize. What questions should you ask? What questions can you answer? What questions do you have a hope of making any headway against? I didn't understand that quite at the time, but it came eventually. I did a lot of different things because I was trying to do this assemblage of data on this particular topic and because the weather was terrible. I had a great reputation. They used to say "What's the weather like at Mount Wilson?" and the answer was "Huchra's up there" in which case everybody would know that it was snowing. That didn't work too well. Because things were going very slowly in that department, I had time to do other things in astronomy, get involved in other projects. First of all, there was the supernova search. I was doing that as a job, but I got to learn a lot about the properties and the problems of finding supernovae and what that meant for stellar evolution and a variety of other things. By virtue of being at the telescope a lot, I had access, which is a very important thing. By virtue of being at the telescope a lot for that project, I discovered a comet. ^[7]

Lightman:

And you also probably got to learn your way around telescopes really well.

Huchra:

I eventually became the master of the 18-inch [telescope] and more or less in charge of some of the instruments on the 60-inch at Palomar, which is also a good thing… a lot of hands-on experience. That's something that's very bad today. It's hard to get students hands-on experience with equipment.

Lightman:

Things are so automated now.

Huchra:

Well, it's so automated, and the national observatories and even the bigger places around here really have rules against your touching things. In some ways that's a real bad thing for the field.

Lightman:

So you got a lot of early experience — a personal relationship with these instruments.

Huchra:

Right up front with the telescope. Exactly.

Lightman:

That's something I'd like to get back to in a little while, because I'm interested in whether your sense of cosmology is particularly immediate because of your personal [hands-on experience].

Huchra:

Well, as I was saying, I found a comet. Actually the first thing I did by virtue of doing photometry was to recover a lost asteroid. I didn't find any supernovae right away, but I found an asteroid which had been lost for 75 years. ^[8] Its name is Ganymede without an "e" on the end. It was interesting because it's a Mars-orbit crosser. In other words, it's an asteroid which has a small but still significant probability of someday smashing into the earth. Partly because I found this and partly because there was a fellow in the geology department who had this theory about cratering on the surface of the earth — namely Gene Shoemaker — a project developed which I really didn't have anything to do with starting, but I became the unofficial advisor for and eventually a consultant for. In the geology department, they do things like find and follow more asteroids. So for a year I actually had a part-time consulting job in the geology department to help those guys figure out how to find and to follow asteroids. So they're doing that.

Lightman:

That's dabbling, right.

Huchra:

There were a variety of other things that went on. I did some work^[9] on variability of Seyfert galaxies and looking at quasars. That's again a connection through the supernova search. You develop a fairly good understanding of what's going on with the photographic plates when you have to take 100 of them a night, and develop them and look at all the defects, by eye, bit by bit — that kind of painstaking effort is something which doesn't happen nowadays, but nonetheless is good for the soul and sometimes good for the mind.

Lightman:

Again, it's automated today.

Huchra:

That's right. That's right.

Lightman:

You took courses in cosmology as a graduate student even though you didn't immediately head off in the direction of cosmology.

Huchra:

We had to. The extra-galactic course is a required course which it isn't in this department [at Harvard].

Lightman:

Yes. In taking these courses in cosmology, in learning about various cosmological models — the open model the closed model and so forth — did you have any preference for a particular cosmological model?

Huchra:

By then I would say that the discussion, in courses, of cosmological models had really gotten to the point where there was only one primary model. Other models were mentioned in passing, but they were given fairly short shrift.

Lightman:

What was the primary model?

Huchra:

big bang.

Lightman:

Oh, yes. I was assuming that we were talking about the big bang, but I mean within the possibilities of the big bang.

Huchra:

Within the big bang. Well, in the elementary courses there wasn't any particular effort placed on describing [such details]. Remember, these courses were being taught by people who were primarily experimentalists, which is probably a good thing for me. The net result was that, aside from saying the "big bang" and the fact that it could be open or closed or intermediate, the people teaching the courses did not pick one or the other.

Lightman:

Were the open or closed or intermediate models, were they presented to you?

Huchra:

Made no difference to me.

Lightman:

They were presented enough to understand what they meant?

Huchra:

That's right. They were presented to me, but they didn't make any difference.

Lightman:

They didn't make any difference to you?

Huchra:

No.

Lightman:

You didn't have any preference?

Huchra:

No. No. No.

Lightman:

Do you remember visualizing the universe then or trying to visualize the big bang?

Huchra:

Yes, and I also remember failing, which is a toughie. I didn't get to the point where I could really think about the big bang in what you would call visualization or how things might go.

Lightman:

Did you try to?

Huchra:

For a couple years. Yes, I probably did. I can't remember exactly, by definition. But I don't really think I had a good visualization of it until I was well into doing my thesis. And even that was for reasons that didn't have directly to do with my thesis. Did I try to draw raisin cakes, things like that? No. No. I thought about balloons a lot. I did take a relativity course. I still remember Kip Thorne's spiders walking around on the surface of a balloon.

Lightman:

Did you think that was a good picture, or a good analogy?

Huchra:

Yes, I enjoyed it.

Lightman:

Did you use that in thinking about…

Huchra:

I used that in thinking about things, that's right. In fact, I would say that if I had any proclivity at all towards one thing or another, it was probably towards the closed model simply because the balloon was easier to think about.

Lightman:

Easier to visualize?

Huchra:

That's right.

Lightman:

So it was in Kip Thorne's course that you first confronted that metaphor?

Huchra:

I think that's right. That's really where I began to think about that.

Lightman:

You liked it?

Huchra:

Yes. I saw that, oh, in the latter half of my second year or maybe it was the first half of my third year as a graduate student.

Lightman:

I wonder whether we were in the same class.

Huchra:

I think I was a year behind you. Maybe we were; I don't remember.

Lightman:

You entered in 1970?

Huchra:

1970.

Lightman:

That's when I entered, and I took the relativity course in my first or second year.

Huchra:

I took it second year. I remember doing the final exam in the library at Palomar. I was observing on the 20-inch when it was snowing… and Allan Sandage walking in while I was taking the final exam, looking at what I was doing and saying, "Oops, better leave you alone," and walking back out; (laughter) curious kind of thing. There was one other thing while I was a student that didn't… one other series of things that didn't take place during the actual course-taking-part of being a graduate student. You probably remember the theoretical seminars? Right?

Lightman:

Oh yes.

Huchra:

I may have been scared of them in part, but I also found those tremendously useful. I learned a lot of things. I had access to a lot. I got access to a lot of things I wouldn't have thought about thinking about had I been every bit doing a thesis.

Lightman:

I remember the journal clubs.

Huchra:

The journal clubs were also good.

Lightman:

I thought those were interesting.

Huchra:

I think the theoretical seminars were really more interesting, because there you had a chance to interact with people. You were really forced to do the readings, to try to understand before you got there. So you didn't go in cold. It was a bad idea to go in cold, especially if your name got pulled out of the hat. I don't know how many series you went to, but in the course of about three years of these things, one every other term; we went through magneto-hydrodynamics, supernova models, cosmological models, and quasars. Those are the ones I remember, but that might have been all I [could take]. Those are all topics which are of great interest in cosmology, as part of cosmology theories. Astrophysical theory at that time, aside from that branch of theory that was specifically associated with compact objects, really was pushing towards cosmology, cosmological implications. There was a lot of that, partly because the seminar leaders were Sargent, Gunn, and [Peter] Goldreich. Sargent and Gunn, of course, were cosmologists. So I think that also helped inform me.

Lightman:

Do you remember any major questions in cosmology that they were particularly concerned with?

Huchra:

No, not particularly. I can remember what work it was they were doing at the time. I don't have a feeling… To some extent both Jim and Wal are real generalists, and to some extent that's sort of what I am. Although Wal is more an observer-generalist and Jim is a little bit of both. I ended up being somewhat like that. I do a lot of different things, as you saw. Today, actually I should say "yesterday," I was working on globular clusters. They happen to be extragalactic globular clusters, namely, those things around other galaxies, but nonetheless, globular clusters. They also happen to be tied to cosmology, because one of the questions in cosmology is how do galaxies form? And a great thought — as you well know — is that you might be able to use globular clusters systems as tracers of the formation of the halo of a galaxy. Anyway…

Lightman:

After your thesis at Caltech, were you then pretty sure that you wanted to continue working in cosmology?

Huchra:

After my thesis at Caltech, the best words I can use to describe my state was "scared shitless," because I didn't know if I could cut it, if I could think of new projects to work on, if I could come up with ideas that were doable and saleable. I had begun to get the idea that there are things you can do and there are things you can't do and there are things that are more interesting than others. I don't think it was really set in my mind that I would be able to do things. I applied for jobs. It's an interesting story. The first time I applied while I was a graduate student, I got a job in Australia, and I was all set to turn in my thesis and trundle on down to Mount Stromlo. This was in 1975. And I get this telegram from the director of the observatory down there, Olin Eggen at the time, saying "Don't come. The parliament has just had a vote of no confidence and the existing administrative government, the prime minister and the like, all federal jobs, all government-supported jobs and Stromlo is a government supported observatory — all government-supported jobs are frozen and, if you're not already here, we cannot pay you when you come." That was in 1975. By definition I didn't go. I had to find some excuse for not turning in my thesis, which was actually easy. Wal, fortunately, didn't know how far I'd actually come in writing it up so I just ate it back up and stayed on as a graduate student for another nine months, or whatever it was, until I could apply for jobs again in the next cycle. In some ways that was also very good for me, because it gave me a nine month period of time where I had my thesis in the can, like a film maker. I could sit down and actually polish it up and think a little bit more about the problems that I had been working on. I picked up some really nice insights in that year, which I wouldn't have had had I not had the time to think about it. I had also time to do a little dabbling in other fields that I'd been interested in. I wrote a couple of other papers, on things that had nothing to do with my thesis. Some had to do with cosmology, but some had to do with active galactic nuclei and the like that I had a chance to work on. I think life would have been different if I had gone to Australia. I had actually started working on a few things when I left Caltech. We had — we, the global we, there was a collaboration that was started by [Trinh] Thuan, who was a post doc at the time, and Jill Knapp and Wal Sargent and Thuan, who had come from Princeton and who had been basically learning at the feet of people like [Jerry] Ostriker and [Jim] Peebles and company, had come up with the idea that it wouldn't be a dumb thing to start trying to measure redshifts for a large sample of galaxies. Ed Turner had been there [at Caltech] as a graduate student along with me, and J. Richard Gott had come through as a postdoc from Princeton for a couple of years. Turner and Gott had written a series of papers^[10] on field galaxies and galaxy groups and all this kind of stuff based on a catalogue of galaxies, based on the Zwicky catalogue, but just on magnitudes and [two-dimensional] positions, with no information on velocities [which give distances to the galaxies]. So we decided — I think the motivator was really Thuan — decided that it wouldn't be a dumb thing to go out and measure the velocities. By that time I was known as someone who could reasonably get data, and I spent a lot of time at telescopes.

Lightman:

This was around 1975?

Huchra:

This was 1975. I spent a lot of time around telescopes. I was one of the masters, the remaining master at the 60-inch spectrograph at that time.

Lightman:

And there weren't new masters because things were starting to get automated?

Huchra:

That's right. Things were starting to change. The changes came about a few years later. Anyway, we started up this project. Wal and Jill were going to go to Arecibo and Greenbank to do 21-centimeter (radio wavelength) observations of spirals. Thuan and I were going to do — which meant me mostly — were going to go off and do the optical observations to get velocities for the elliptical galaxies in the sample. We got some [telescope] time at Palomar to start it up. There were [also] a bunch of proposals that had been accepted at Kitt Peak. Since this was a reasonably good proposal and could be done on a little telescope — that's the other part of the game — it got time. So even before I left Caltech, there was a project in the works that I hadn't really started, but nonetheless I…

Lightman:

A project measuring redshifts?

Huchra:

A project measuring redshifts. That's right. In fact, for the CFA [Center for Astrophysics] redshift survey, the first three or four hundred redshifts that ended up in [it] were measured as a part of that original program, at Greenbank and at Kitt Peak. Actually there may be even more than that, maybe more like 500 because I know I ended up getting about 350 galaxy spectra at Kitt Peak. I did all of the observing, which was both a bad habit and a good thing.

Lightman:

Do you think that when you measured the redshift of the galaxy yourself and you were actually sitting at the telescope — opposed to the way some people do this today — do you get any feeling for the galaxy and what the galaxy means that you don't think you would have if you were just looking at data that someone else had collected?

Huchra:

Yes. This is the question that we were edging towards before. I have a long and somewhat simple answer to that. I've actually spent a little time looking back over why I think sometimes the way I think about things. What I've come to realize is that I have a world view. Everybody has a world view. I have one, and my world view about astronomy is one that has developed by virtue of looking at things. It's a visual world view, or however you want to put it. Looking at things like scanning photographic plates. Doing a supernova survey is looking at those plates. It taught me a lot — not a lot that I realized at the moment but a lot that I now know because I've looked at the plates and saw what they looked like. I know very well what a cluster of galaxies looks like. I can draw you shapes of anything you're interested in. I have almost a catalogue of NGC galaxies sitting in my head, which sometimes surprises people. You don't need to remember it, but nonetheless it's up there simply because I've looked at all of these things. I've now spent a lot of time doing spectroscopy of galaxies, and looking at galaxies. I think I've probably set aperture to [measured the spectra of] more galaxies than any other living human, maybe the sum total of all other living humans, although that's probably not right. It’s awful close. It's awful close. As part of this redshift survey, we now have spectra of 20,000 plus galaxies. In addition to that, you have to remember I've also been involved on a couple other big survey projects of galaxies.

Lightman:

Can you say what your world view is? Or is it just this big amorphous body of knowledge? Can you describe it a little bit?

Huchra:

Yes. Patience, I'll get to that. I've got this world view. As I've said, the world view comes from having looked at lots of different things. What I find that I do is whenever someone comes up with a new theory or a new idea or even a new interpretation of observations, or new observations, I have a tendency to match those results against my world view, the accumulated body of knowledge, and ask "Does it make sense? Does it fit?" So I will match ideas against my world view and see if they fit.

Lightman:

What are some elements of your world view?

Huchra:

Something that's come into my mind as very important is the general shape of galaxies and what the distribution of different types of galaxies looks like. There's a game that's played a lot these days in cosmology that's called the N-body game. The N-body models have gotten a hell of a lot better, but the original game was played with point galaxies, all of which had the same mass. And the universe isn't like that, right. So, at least while that was the case with the models, I could say "Yeah, these are real nice pretty pictures, but gee, you know that's not quite right." There are a lot of things that keep going on because of the range of properties of objects that you certainly won't be able to see in the models. So the body of knowledge consists of things like knowing the range of properties in galaxies and some idea of what objects look like, what clusters look like how galaxies are distributed in cosmology, having some idea of what the spectroscopic properties of galaxies and the range of those properties are. That has been a critical element in deciding whether some relatively recent work is right or not. Mind you, I have applied the world view on my own stuff as well. If I make an observation, by definition I want to file it in this world view. If it doesn't make sense compared to what else I know, that usually means I have to go back and re-observe it or make checks to see if it is indeed correct.

Lightman:

Does your world view include any global quantities of the universe — for example, whether it's open or closed, or whether it's homogeneous or inhomogeneous?

Huchra:

Well, my viewpoint on that has changed as a function of time — as a function of getting more data. When we didn't have redshifts of galaxies — based on just the early work in the catalogues [without redshift data] you take the data, you take the view of what you've got. You take the papers that you've read that have analyzed the data that exists. You can look at that and assemble your world view. I would say that if you ask me what I thought of, say, the distribution of galaxies in 1975, the answer would have been: Well, there are clusters and then surrounding the clusters are field galaxies; maybe 10-20% of all galaxies are in clusters and the rest are blaugh, all throughout the field, uniformly distributed. That was the prevalent world view at the time, and I hadn't spent a lot of time looking at it myself then.

Lightman:

Did you accept that world view based on what other people were saying –- for the lack of better data?

Huchra:

Yes, for the lack of better data.

Lightman:

You just accepted that.

Huchra:

Well, there are things you can accept, and there are things that you cannot accept. Then there are things that you must accept until you have more information one way or the other. That's sort of the way things go, at least in my end of the game. I have found — and this is not always easy to do. I have found that for my role in doing astronomy and doing cosmology that it is exceedingly important that I not get too married to any particular theory. I can be married to the data, but can't be married to the theory.

Lightman:

Why is that?

Huchra:

Because if I do, I almost always get something wrong sooner or later. It's just practical experience. If I'm too married to a theory, I get into trouble. I've done it once or twice and it's not been a real good thing.

Lightman:

Can you give an example?

Huchra:

A classic example is this question of whether or not there are field galaxies. There is a real controversy, right. I had thought that there most certainly were large numbers of field galaxies. When we actually did some analyses — Thuan and I and Margaret Geller and I^[11] of how galaxies are distributed as a function of density, over density, in space, there is no easily identifiable field. Most things tend to be associated — maybe not gravitationally bound, that's different, that's a special type of association — but "not uniformly distributed" is the magic word. And, yes, galaxies are not uniformly distributed. In 1975, I thought there were a lot of uniformly distributed galaxies. That's not the case. [Here's] a better example, maybe for me really the turning point in my idea of why I should keep an open mind. I came from Caltech. I did some work with a lot of people [at the Hale Observatory] on Santa Barbara Street. The party line was that the Hubble constant was 50, 55, whatever it was, even back in 1975, some low number. And, when I was a graduate student, again during the period of time that I had nine months to spend not doing anything in particular, Brent Tully came through, to give a talk on this thing called the Tully-Fisher relation. And Allan Sandage got up and he and Tully got into a great debate over whether this relation meant anything, because Tully was getting a number that was more like 80 for the Hubble constant, based on the Tully-Fisher relation results. And Sandage wanted 50, 55. They really went at it in the colloquium. Anyway, it was interesting. It piqued my interest, you might say. It was interesting to watch the political process that was taking place, although I wouldn't have called it a political process at the time. One of the things I did when I came here was to try to think of a way of testing the Tully-Fisher relation, to try to answer some of Sandage's complaints against Tully and Fisher. Mark Aaronson was here and we had been doing infrared photometry of galaxies at the time, since as an extension of my thesis I wanted to do infrared photometry of some of the starburst galaxies. But I also realized that if you could do photometry at two microns, you could get around one of the real big problems of the Tully-Fisher relationship, which is the internal reddening in edge-on galaxies. So I came up with the brilliant idea of correcting the optical colors of the edge-on galaxies by doing infrared photometry. Mark had the photometer. We tried to find a connection at Kitt Peak to allow us to get on the telescope to try this out, because we didn't have observing time for this project at the time. [We] talked to Jeremy Mould and Jeremy said, "You guys are stupid. Why bother to correct the optical data? Why not just do the infrared photometry for its own sake to try to do this project." And that's how the IRTF [Infrared Tully-Fisher] calibration^[12] was born. So we went to Kitt Peak — Mark and Jeremy and I went up to the 36-inch telescope. You can do cosmology on small telescopes. [We] played the game as straight as we could, measuring the magnitudes for these galaxies, and damn if when we were finished we didn't end up getting 70 for the answer. Not 50.

Lightman:

How did you feel when you came up with that result?

Huchra:

Scared. What did we do wrong? That's sort of the first thing. Because it went against my world view, which at that time had been based on convention.

Lightman:

Conventional wisdom.

Huchra:

Yes.

Lightman:

And also, it made the universe younger.

Huchra:

Yes, all of those things which are not particularly pleasant when you've got that world view.

Lightman:

So you were scared at first.

Huchra:

I was scared that we did something wrong. We checked it and checked it and checked it six ways from Sunday. It was one of those crazy things. We couldn't make the results go away. I had honestly thought that when we started to do the experiment, we were going to take old Tully and Fisher and show that their stuff was garbage and that the Hubble constant was 50. No, that's not what we found. As I said, we couldn't make the results go away. We set out after that to do other clusters at larger distances; same thing. We can't make the results go away. That was really the first time I realized that one had better not go into an experiment with really strongly preconceived ideas because if you do, you might miss something. We could have sat there re-doing the data until we got 50. And it would have been wrong. Fortunately, we didn't.

Lightman:

Let me ask you a little bit about the difference between theory and observation. Later on I want to go to a couple of specific questions from theory, and getting to there from here. You mentioned just now that you think it's a bad idea to get too married to theory, being an observer. Do you think that theory in cosmology or in astronomy has provided a useful structure for interpreting the data and extrapolating the data?

Huchra:

Oh, yes. People sometimes talk about the conflicts between theory and observation, and other people will say "huh?" will pooh-pooh that idea. But I think it's there and it's a very good thing. What I found is that a good theorist should let his mind roam free, but periodically check back to the data, particularly through a good observer, to make sure it hasn't roamed too free, OK. A good theorist must make theories that predict things that observers can check. A good observer usually… there's a serendipity factor involved in the game, but, by and large, a good observer is someone who is making observations to try to check theories, to decide between theories, to do something like that; an observer who just goes out and points a telescope at some random place on the sky because that might be interesting — that's not a real useful activity. That's like a theorist who decides that the real answer to the universe is that some aliens from planet Zork created it 16 billion years ago, or whatever. That's not a real useful theory, right? In fact that's called a religion as opposed to a theory. So they need to interact; they need to guide each other. Sometimes the theory paces the observations. That was certainly the case when we started doing the redshift survey stuff back in the mid-70s — the theory was way ahead. The theory of what there ought to be was way ahead of what the observations were. We had no data. Right now, temporarily, the situation is reversed. Right now we have more data than the theorists are happy trying to explain.

Lightman:

And the data you do have disagrees with the theories up to date.

Huchra:

That's right.

Lightman:

How do you feel about that?

Huchra:

Win a few, lose a few. Specific or general? In general I think it's Ok because theorists are generally not dumb people. They'll figure out a way of making it all work. In specific, right at this point of time — I'm worried that the theorists are wed to a model.

Lightman:

Which model?

Huchra:

Omega equals 1, closed universe, inflation. Or I should say flat-universe, inflation, because it's not closed, which people forget. If they remembered that, they might not like it so much…

Lightman:

Why do you think theorists are wed to that model?

Huchra:

Because every theorist I know makes 99% of his or her models based on that assumption.

Lightman:

What do you think about the inflationary universe model?

Huchra:

I don't know. I really don't know the answer to that. My impression is that [taking] the data as it exists at face value, and making no assumptions about the fact that the data doesn't tell us anything about the universe, then the inflationary model must be wrong. If you just straight look at the data on things like masses, mass density, which is a key parameter in this game, you do not get an omega equal to 1.

Lightman:

And you think that the theorists may be unduly wed to this model?

Huchra:

The people who have been making the N-body models are unduly wed to that model, let's put it that way. And those are the people, those are the theorists who I've had most direct contact with in recent history. That may be a mistake. I don't think there's been quite enough effort placed on looking at alternative models, although a few people now — [Jim] Peebles, a couple of other people — are beginning to really start thinking about open-baryonic or even open-cold dark matter universes.

Lightman:

Peebles certainly seriously considered open models before the inflationary universe model.

Huchra:

That's right. Well, he did, but… There was a period of time — between about 1975 and 1980, before the inflationary model was first announced. During that period of time, the school of theory of which Peebles and a variety of other people were leaders in pretty much saw a closed universe, you know, omega equals 1. And the reason is that they had to have galaxy formation occur.

Lightman:

You didn't need omega to be quite 1 for galaxy formation.

Huchra:

That's true, but you needed it to be a lot bigger than you found ordinarily just measuring the masses of systems of galaxies. There's a fundamental assumption that goes in here. It may not be inflation itself, with which I see a problem now, but this particular assumption. The assumption is that the universe started out homogeneous. I have a sneaking suspicion — based on the data we've been collecting recently, data on things like the galaxy cluster distribution and the very large scale galaxy distribution — that that assumption, namely homogeneity in the initial epoch, is one which is going to make all theories based on it wrong or not work, or not workable. It may well be that something that comes out of these observations is the idea that we have to start out with inhomogeneous universes. It's an idea that's actually very old, but which was discarded you know [Charles] Misner and the mix master universe.^[13] That stuff was all discarded in the early 1970's.

Lightman:

Yes, he wasn't able to make it work. Let me get back to Peebles, again, in the late 1970's. Do you remember when you first heard about the flatness problem, posed by Peebles and Dicke?

Huchra:

Probably in the cosmology course.

Lightman:

Which cosmology course?

Huchra:

The one at Caltech.

Lightman:

That would have been before the…

Huchra:

Which flatness problem do you mean?

Lightman:

The fact that it seems highly unlikely that omega could be so close to 1, because if you track backwards in time that means the universe [had to have its kinetic energy and its gravitational energy extraordinarily well balanced just after the birth of the universe].

Huchra:

That problem! Didn't once upon a time a man by the name of [Paul] Dirac have the same idea? Does that really trace back to Peebles and Dicke? I'm showing my ignorance. I don't know the answer to that.

Lightman:

Dirac had a large number hypothesis, which I don't think is quite the same as the [flatness problem]. People recognized that omega was approximately of order unity [close to one]. But I think that it was Peebles and Dicke, in the Einstein Centenary book,^[14] who first interpreted this in terms of how close omega would have to be to 1 when the universe was one second old and said that "It seems to us to be extremely unlikely."

Huchra:

Well, yes, I heard of that problem when I first heard of inflation.^[15] In fact, I would have attributed the argument to Guth, but you're probably right.

Lightman:

Guth used this as motivation. Do you remember how you reacted to it? Did you think it was a religious argument or a physics argument?

Huchra:

I thought it was a religious [argument]. I'm a card player, one of my vices. The probability of getting any particular bridge hand is damn small. But when you play, you get hands. So I've never been convinced by arguments that say, "Gee, here we are. The probability of [omega] being so close to 1 but yet not 1 is very small; therefore it must be 1;" that doesn't wash. The first thing that came to my mind when I heard the argument actually, I heard it from Guth — was, Ok there is a probability that all of the air molecules in the room are up in the corner, and that's pretty small too. But the probability that the air molecules are distributed in this room the way they are is also pretty small. Any individual realization of a universe or a physical system or whatever, if there are lots of possible states for that physical system, has a probability that's very small. So what else is new?

Lightman:

So this argument didn't sway you.

Huchra:

No. There are equivalent "religious" arguments on the other side. In balance, I disregard them both. To me, it wasn't a clean argument. The universe is what it is. Just because we can't think of a good way to form galaxies doesn't mean that galaxies shouldn't be there. In the course of developing a world view, in the course of looking at the universe, I've seen a lot of awfully improbable things. Some are terribly improbable, terribly, terribly improbable. As an example: a couple of years ago we found a gravitational lens in the redshift survey.^[16] It turned out that [there was] this quasar right smack — by right smack — I mean less than a few tenths of an arc second, in fact right now the measurements are off about a tenth of an arc second - behind the nucleus of a nearby bright galaxy. The probability of that happening, when you go out and calculate [it], it's getting to be on the order of the probability that omega [is close to one] — the ones that you're talking about, one part in 10¹⁵ or so. That's right up there, but there it is. It's there. Here's an example. We shouldn't have found one [a quasar right behind the nucleus of a galaxy], but we did.

Lightman:

You're saying that you've seen a lot of strange and improbable things?

Huchra:

Sometimes those strange and improbable things had nothing to do with astronomy, but they're nonetheless there. I put those [arguments about the improbability of the value of omega being close to one] in the category of what I call hand-waving arguments, or what would sometimes be called motherhood and apple pie statements. Statements that sounds nice because they have some element of reason behind them but which you cannot use as an argument either for or against anything in detail because they lack detail strength. Nowadays I react violently to that [statement].

Lightman:

Let me ask you this. You mentioned [that] as a result of your own observations you think the universe might be a lot more inhomogeneous than formerly believed, and the theorists might have to go back to the blackboard, drawing board, or whatever.

Huchra:

Whatever, computer, these days.

Lightman:

Do you have any personal view of cosmology? You were talking about a world view before, but from what you mentioned, the specifics dealt with particular features. Do you have any global world view that you might call personal?

Huchra:

That's a tough one. I would say that if I took a look at my world view right now, I would favor — but hope I'm not wedded to — a universe that's of order 13 billion years old: a universe where the Hubble constant is of order 70 or 80, even though the measurements that we've been making recently give a higher number. I would like to see the number come down. I don't know if it will, but it might. There are things that need to be done to fix it up, things that will happen when space telescope flies. I think there's a small but finite chance that we might have to reintroduce the cosmological constant, although right at the moment it's not required by the data. In other words, there is a difficulty, if you take things at face value, between the ages of the globular clusters and the [universe's] expansion age. That difficulty at the moment is still a one sigma difficulty [not statistically significant]. But if in fact the numbers stay the same and the errors get smaller, which is a possibility, and those ages do not overlap, then one is going to have to do something. The only way of solving that problem I know of right at the moment is by sticking back in the cosmological constant. Although, I'm sure there are others. It's my impression that the limits on fluctuations in the microwave background are getting down at the level of embarrassing for forming galaxies. It's not the kind of thing where you've lost your pants and have to go running into the men's room quite yet. But the belt is loose or the fly is open and there may be some problem. I don't know quite enough about the field to really say one way or the other. But that I see as a really big problem the formation of individual galaxies given the limits on the fluctuations. The large-scale structure business, the really large-scale structure business, is still very vague. In other words, the data is in really bad shape. Some data. It's got a lot of problems. I'm a data merchant, that's one of my stocks in trade, and there are things I trust. If you ask me the redshift of a galaxy and I've measured it, I will tell it to you with some degree of precision that's pretty good. I know that. If you ask me if the catalogue out of which we pick distant clusters of galaxies is any good, I will say, "Probably not." In fact, I can offer you some proof that it's terrible, but can't offer you a better catalogue yet. It's easy to make the negative statement, but improving the situation will take some time. So, in fact, one of the things we're working on now, Margaret and I and several other groups of people, is to make some improvement on these galaxy and cluster catalogues so we can make stronger statements in the large-scale structure business. That will take another five or ten years, but that's what we're up to. So the data that exists from not such good catalogues, which is to say, not such good basic data, indicates inhomogeneity on very large scales. We need to do it better. If we do it better, and the answer stays the same, you can guess what happens next. I think that we'll have really produced substantial modification in the current big bang or the current inflationary models or whatever anybody else has to [select] as best.

Lightman:

Let me ask you one last question. If you take a big step backwards and I ask you to leave your normal scientific caution aside for a little bit and just give me your intuitive, immediate response — this is going to be a bizarre question. If you could design the universe any way that you wanted to, how would you do it?

Huchra:

(laughs) Well, I'm an observer and not a theorist (laughter). So I can design the universe any way I want to. Could I design it so that I could go off and be a novelist instead of an astronomer? If I were to come up with a design like that…

Lightman:

Yes, you could make that part of your design.

Huchra:

The universe would be exceedingly simple, with galaxies that were all the same shape, size, mass, luminosity. It would consist of only baryons that emit light — these dark things are bloody hard to detect, a real pain in the tootsies; you got to find some way of learning about them. It would be a steady state universe, I think, because that's the easiest one. It's a little weird, but nonetheless… that is to say, nothing dramatically… Gravity would be a very weak force, or there would be something to offset it. It's not the easiest theoretically, but it's the easiest to visualize. No change. I'd be a very lazy universe maker. Possibly the first thing I'd do is make a universe that contained lots of planets with lots of life forms. That would make it more interesting for purposes that have nothing to do with astronomy. Also, get rid of the speed of light limit. Yes, I think I would certainly do that. I'm not sure what I'd do with the human race. That's a different story; that's a detail of the cosmological model. Right now I'd design it with a ski chalet in New Hampshire.

Lightman:

I get the idea.

Huchra:

I don't want to be a universe designer unless I can put it in a science fiction book.