Oral History Transcript — Dr. Sandra M. Faber
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Interview with Dr. Sandra M. Faber
Sandra Faber; July 31, 2002
ABSTRACT: Biographical oral history with Sandra M. Faber. Topics discussed include childhood and education; family background. Classes at Swarthmore and Harvard. Extensive discussion about Faber's scientific research including her work on large scale structure of the universe and cold dark matter. Reaction to work of colleagues. Discussion about astronomy and religion. Large telescopes and current plans for bigger instruments. Changes during course of career.
McCray:Sandra Faber interview, July 31st, 2002, Santa Cruz, California, tape 1. Okay, why don't we sort of do like a good psychotherapist and start with your childhood?
McCray:Let's talk a little bit about your parents. Just give me some sense of what your childhood was like, where you were born and what their backgrounds were.
Faber:My picture of my childhood is boring and uninteresting. A child of the suburbs, 1950 postwar years, American optimism, shiny new cars. My father had a technical background though. He had a degree in civil engineering from MIT, but he was born in 1901. He lost his job in the Depression as an engineer.
McCray:What kind of engineer is he?
Faber:He was a civil engineer, and his specialty was hydraulics. And while he was working as an engineer he designed water gates and various hydraulic installations and oversaw the construction of dams, notably a dam in Georgia.
McCray:Okay. Did he travel around a lot doing this?
Faber:He did. Yes, right. And then he married, and soon after he married he lost his job in the Depression because nobody was building anything. Another thing he worked on was high-tension towers. So he was fortunate in getting a job with the Liberty Mutual Insurance Company, and for the rest of his life he was an insurance executive.
Faber:Their home office is in Boston, Massachusetts, and that's where he was living at the time. That's where I was born. But he wound up working for them in many different cities Kansas City, Minneapolis, Cleveland, Pittsburgh. They moved him around. I would characterize him as moderately successful. He never he topped out at an assistant vice president level which I can see with the maturity and wisdom of greater years meant that it was kind of a soft landing without bringing him back to the major hierarchy of the company in Boston. So he ended his career in Pittsburgh, which is where I went to high school.
McCray:Where did you go to high school?
Faber:Mt. Lebanon High School.
Faber:My mother had no formal education that is to say beyond high school but it's clear that she was part of that generation of women who would have done awfully well and probably felt thwarted and frustrated throughout her life at being basically a housewife and staying home.
McCray:How did you recognize that?
Faber:Well, in two ways. First, she was the valedictorian of her class at Brookline High School [Brookline, MA], which was one of these huge urban high schools, and she was editor of her school paper, so she was clearly somebody who today would be snarfed off and given a college scholarship. And in fact she was. She was offered a full scholarship to go to Smith College, which was a real plum in those days. We're talking 1918, thereabouts. And she refused to go, which I think says a lot about her. She said to me and to the family, she liked to say that she didn't go because her mother at the time was diagnosed with a heart condition and she my mother wanted to stay close to home and look after her. Well, as I say, the year was around 1917 or '18. My grandmother lived until 1952, so there is clearly more going on there, and I don't know exactly the circumstances, but I can tell you that in later years my mother was a very conflicted person I think now from the vantage point of maturity as I say, I think she suffered from severe depression and maybe even manic depression. I would prefer to have this omitted, if that is OK.
Faber:So she was a very difficult person to live with. However, she was very encouraging of me. I was an only child. That's a key thing I think in my development. And mother, especially when I was younger and she was more well, really focused on me, took me to the library. She was well read on a number of topics and I would eat lunch and ask her questions and she would just discourse on all manner of things. So she was a wonderful resource. In later years she became an alcoholic and she drifted downwards. And she ended her life in a very sad way. And people in the family did not have a fond memory of her at her death. I prefer to try to remember her as the mother she was to me when I was a much younger child. So she created a lot of trouble, and in my adolescent years I just really wanted to get away. But now, as I say as an older person I have a lot more sympathy and I'm sorry I couldn't have done more for her. I really didn't appreciate her problem.
McCray:Where you grew up in Pittsburgh, did you have an extended family?
Faber:No. That was another characteristic you see. First of all the family is overall small. My dad and I share the same personality. We are kind of buoyant. I would characterize us as optimistic American westerners. My dad was born on the frontier in 1901 in a little town called Clarkston, Washington, which is on the Snake River across the river from Lewiston, Idaho. His father graduated from the University of Pennsylvania as a civil engineer, and he and my grandmother moved out there in the 1890s. My grandfather designed and oversaw the construction of the first bridge across the Snake River, which was a railroad bridge. And then after that they settled there and he was a mining engineer, he did irrigation systems. He collapsed and died when my dad was thirteen. My dad had one brother only, and then the story of that family thereafter is a well-educated family headed by a woman schoolteacher, my grandmother, who was trying to make a living. So they were quite poor though genteel you might say. On the other side, my mother likewise had one sibling. So altogether I had one uncle on one side and one aunt on another side. Shortening things somewhat, I had two cousins on one side whom I never saw because they lived out in the state of Washington, and this one cousin who lives in Boston, which is where I was born. She is still living in the same house where I was as a little kid. And that's my family.
Faber:Very small. And no brothers and sisters myself. Yeah, so my feeling I think your question was triggered by my mother having difficulties. Did we have much of an extended family in Pittsburgh to provide a support?
Faber:We were a very isolated little threesome, and it made relationships really difficult. I think nobody in that family including myself, because I was just a teenager had much insight into the dynamics of personal relationships. And also it was a time when to say that somebody was mentally ill was a stigma. My mother would never have admitted that.
So I was lonely as a kid, and my loneliness was exacerbated a little bit of this comes through in the Alan Dressler book it was exacerbated by the fact that in a classroom of thirty kids you are not going to find in a typical suburban neighborhood, this was Cleveland you are not going to find a kid like me. So I really had nobody to talk to. There was nobody who was interested in math and science, there was nobody who was very intellectual.
Faber:And I always got better grades than anybody else, and people cordially disliked me for that. And I cordially disliked them because they were not interesting to me. I just didn't fit in. I was a weird fish out of water. So things have steadily improved for me in that regard.
Faber:I then went to this very excellent high school, Mt. Lebanon, where it was one of the two great high schools in Pittsburgh, the other being Taylor-Alderdice, and we were friendly rivals. And there I met a lot more people who were college-oriented and who came from college- educated families. And then finally I went to Swarthmore, and that's where I really came into my own.
McCray:Tell me a bit more about being a teenager. And I guess two of the things I am interested in are I mean you grew up, I can't remember when you were born. What year was that?
McCray:So you were thirteen when Sputnik was launched, and you also grew up against the background of the omnipresent Cold War.
McCray:And I'm curious how either of those two events impacted you.
Faber:Interesting question. I can remember feeling at the end of the fifties that nuclear war was inevitable. But curiously and this I think says something about the kind of person I am that didn't seem to matter that much. You might have thought that, if I really believed that, I sort of would have given up and gone and lived on a desert island or something like that, but I could somehow carry along this idea of impending doom but great optimism for my own life in parallel.
McCray:Sort of the omega woman concept, "I'll be the last person left on Earth"?
Faber:It wasn't even that concrete. I don't know. Maybe I paid lip service to this concept of inevitable war. But you're right, I mean that was hovering around. There's just no question.
McCray:Do you remember Sputnik?
Faber:I do. Yeah. I should say that what I was trying to do in giving you a picture of my family was that my family roots are very far from where I am now.
So I had no vision. I didn't know that people could make money being a college professor and doing research. People could see that I was interested in science and so they gave me books. I read at a fairly young age all those books by James Jeans, which were popular astronomy books of the twenties. I read a book by Fred Hoyle that had a big effect on me in high school. Maybe we should come back to that later. I knew about Albert Einstein, but the picture I got was that this was a pantheon of superheros who were a world apart, and they would discover these pearls of wisdom which would drip down to the common folks, of whom I saw myself as one, in popular books and so on received wisdom. I had no concept about the mechanism of science how science worked, how you could be a scientist, how the structure of science is all set up really to help ordinary people do great things. And that's kind of my view actually of myself as a scientist.
So I didn't know where I was going, and on top of that I had no role models as women. And this was a big uncertainty to me. I really didn't know how I was going to solve that problem. My usual way of dealing problems like that is just to push them off into the future and not think about them, and I think that's what I was doing. So the positive thing that was leading me along was the educational system, which I feel has been very good to me. Especially as soon as I got into Mt. Lebanon there were advanced placement courses there that were, I can see in retrospect, extremely well taught. There were teachers who took a great interest in me. I won awards in high school, I was valedictorian in my class, and it was easy for me to get into college. My dad wanted to send me to the University of Pennsylvania because he was very pocketbook-oriented. Having gone through the Depression and suffered as a kid, he never got over the fact that you always save money and spend less.
Faber:So my parents actually, although they loved me, they never spent much money on me. They didn't send me to lessons or summer schools or things like that. Anyway, he was going to save money by sending me to the state school. And besides, his father went there, and if it was good enough for dad it was good enough for his daughter.
McCray:Penn or Penn State?
Faber:Penn State. Did I say University of Pennsylvania?
Faber:I meant the Pennsylvania State University. That's right. And that's where my grandfather went. A high school guidance counselor, to whom I owe a lot, took him aside and said, "Mr. Moore, your daughter really should go to a better place." And she's the one who suggested Swarthmore. My parents were opposed because it had very left-leaning tendencies and my dad was a rabidly conservative person.
McCray:Tell me a bit more about that. I mean that sort of ties back into the earlier question of growing up and against the backdrop of the Cold War.
Faber:Yeah. Politics was always very evident in our house. I don't think my mother cared. What I remember are parties. My parents were pretty social, especially before my mom really went downhill, and we would have parties in which the people who came were good family friends and they were a lot of them military people a Major General, other people who had a military background. My father glommed onto these. I haven't told you a big facet of his life. He, the day after Pearl Harbor, went down and signed up and went from a Captain in the Reserves to a Colonel which probably, as he died, he thought was the most remarkable thing about his life. He helped to lead an antiaircraft battalion, and for the first years of the war taught people how to shoot in the United States at various camps. My mother followed him around. It was hard for her. And then finally he got shipped out and he saw action in the last big action of the war, which was Okinawa. And I was actually born while he was away. I was thirteen months old before he even saw me. And his return to civilian life was quite traumatic for him. It's clear that he never found anything else in his life that was nearly as exciting or fulfilling in a kind of perverse way; it was also horrible for him, and he spoke about the horrors of war and how shocking it was.
McCray:He would talk about that?
Faber:He would talk a little bit about it. But at the same time I think he was incredibly energized and felt that he was living to the max during those years in a way that he never did before or since.
Faber:How did we get onto this subject?
Faber:Politics. Okay. So our family's social gatherings often had men with similar backgrounds, and they would sit around and they would hash over their war stories. The women were in the living room talking about feminine things. I was in the kitchen listening to the men talk about military things. I always from day one have found men much more interesting than women, and this is still true. So I really loved these stories. And as part of the war talk and the military talk there was a lot of talk about the communist threat. And my parents didn't approve of McCarthy as a person, but they thought that there was a problem that he was trying to address even if he didn't address it properly. The main thing that my father loathed was liberal government and big government, and he hated Franklin Roosevelt. He regarded him as brilliant but totally manipulative, pandering to the worst instincts of the American people. My father as a westerner wanted to stand on his own two feet and thought that everybody else should too, and that involved in his way of thinking a minimum of taxes and a minimum of government services coming back.
Faber:And he would talk vehemently about this. You couldn't talk to him logically about it. He more or less the minute the subject came up he got onto a pedestal and held forth.
McCray:Okay. I'm gathering he voted for Eisenhower.
Faber:Totally [laughs]. Right. Eisenhower was a hero because he was a great general, right? But even people like Nixon, my father thought that Nixon was too liberal.
McCray:Okay. As a teenager what were your interests [laughs]?
Faber:Studying. I have really never been very interested in hobbies. I have always found the academic work that I am doing, whether it was studying in high school, learning in college or now doing research, which I'm currently doing, that's what I love best. So I did do other things, but I didn't really take that much pleasure in them. What I liked was learning math and learning science and doing homework. Sounds perverse, but that's the case. I was in the debate club. I did a little bit in dramatics. But you can't look at that high school record and say, "Wow, this is a person with a broad range of talents." I wasn't and you still can't look at my life and see that.
McCray:Okay. Science fiction. Did you read it?
Faber:Yes, I read science fiction. Loved it.
McCray:Particular authors that you liked?
Faber:Well, I haven't read it for years, so it's hard for me to remember authors like Andre Norton.
Faber:Mm-hm [affirmative]. Certainly Ray Bradbury. All the great people. Isaac Asimov.
McCray:Okay. Well you mentioned a bit about how you ended up at Swarthmore. Why physics? Although I guess given somewhat of what you said [inaudible phrase].
Faber:Okay. This is interesting. So you had to write essays to get into college, and this was no exception although I think then they gave you less space than they do today. Nevertheless it was daunting. And the Swarthmore application I don't remember anything about the other applications, but the Swarthmore application said, "What use do you think you will make of a Swarthmore education?" That's one of the first times anybody had really put the question to me, "What are you going to do with the rest of your life?"
So that was a challenge. And by then I could see that I had some talent in science and math, so I thought although I didn't have this marriage-career thing mapped out in any way, yet, in my mind, nevertheless I allowed myself to entertain the thought that maybe I would be professional scientist in writing this answer. And I said that I was really interested in the nature of the universe but I wasn't sure how you should study this. Should you study that by studying the universe at large, like cataloging the objects that were in it and looking at the properties of those objects and trying to deduce how they came to be, or was it really equivalent and maybe in a sense more fundamental to look at the microscopic processes in the universe, which after all must be the basic causes that generated the properties of all these macroscopic objects? I think this was a good thought for somebody who was in high school.
Faber:So, I went on in my little essay to say that if the macroscopic approach was the better approach then I might want to become an astronomer. If the microscopic approach was the better approach then maybe I wanted to become a chemist. Ah, now see this reveals the limits of my training as of that stage. What I really wanted to say was particle physics. I didn't know that particle physics existed. Right? But I was on the right track.
McCray:Biology wasn't something ?
Faber:Biology was never there for me. Well, even today I find first of all, biology, I didn't know probably about DNA. I mean we're talking 1962. I'm sure it had been discovered, but nobody was telling me about it, and so biology seemed to me to be just catalogs of things. Words that had been generated to describe something or other and then you learned the definition of the word.
McCray:Genus and species.
Faber:That kind of thing. It was too taxonomic. Too descriptive. And even today, even though many more principles are known, to me the only guiding principle in biology that makes any sense to me is one gigantic set of chemical reactions.
McCray:Okay. All right.
Faber:In later life, I'm much more interested in medicine, because at that stage of my life I was really rejecting people since I was a social outcast. Now I am much more interested in medicine, because I'm much more interested now in studying systems of thought, but as they relate to the mechanisms of human beings as well. So not only do we build big telescopes, but what are people thinking as they try to build those telescopes? Here is science, an enterprise. What are the human values and human strategies that people use to pursue it? So now I am much more interested in medicine because the people problems, the human problems posed that you have to solve to be a good doctor, are very apparent to me in a way that never would have been apparent back then. My daughter went to medical school, the younger one, and is now an intern, so I'm finding it absolutely fascinating to talk with her and learn about these human problems that she faces which are extremely severe and very interesting. But anyway, no, I'm not interested in biology.
McCray:Okay. So you chose physics because it offered a way to get to either one of those very big or very small?
Faber:No. No. So I got to Swarthmore, and since I was fixed on these two poles, astronomy and chemistry one of the reasons I decided to go to Swarthmore was that it had a little observatory, a 24" refractor run by Peter Van de Kamp. And the research program there was an astrometry program. They took pictures of stars and they measured the motion of the foreground star in relation to the background star. And the goal was, you know, if you saw a star going along and there was a planet near it maybe it would have a wobble. They were trying to find these wobbles. I remember vividly visiting the campus and being escorted by the campus guide into the observatory and seeing this 24" refractor. I had never seen a big telescope before. And I felt a real thrill. I loved the bigness of it. It wasn't that big really, right?
Faber:But I was immediately attracted by the machinery.
McCray:And big, of course, is a relative term if it's the only one you've seen.
Faber:It was big to me. Yeah. So, I liked Swarthmore because it gave me an astronomy avenue. Then I began to take chemistry classes to pursue my other pole, and I hated them. Because the whole idea was wrong. You know again, it was too much cookbook of atoms and so on. It was too much like cooking, standing at the bench and measuring out these things and adding. Uck!
Faber:And I began to sense also as I studied chemistry that it was not fundamental enough. Chemistry to me is an applied science. It's the applied science of quantum mechanics. I have always been interested in fundamental concepts. So I abandoned chemistry and I went to physics because Swarthmore required that if I wanted to be an astronomer and minor in astronomy I had to major in physics. And that's how I found physics. And I have liked physics. I have great respect for physics, and I wish I were a better physicist although I have always scored very well on all of my physics exams. And I think my teachers at Swarthmore thought I was a really great physicist. But somehow there is something in me that's missing to be a really great physicist. I think it's that I don't have enough math.
Now, in the meantime, the Swarthmore program was very classically oriented. And again, it kept me away from the particle physics concepts which I really needed. In other bigger programs that were closer to the center of the physics universe in those years, which were '62 to '66, great things were being discovered you know, the eight-fold way, the glimmerings of unified forces and so on. Had I been at a place like Harvard maybe this would have rubbed off on me and maybe I could have gone in that direction. A part of me feels cheated, because I never really learned the important physics that I need to know in order to understand these fundamental concepts. One of my goals, before I retire when I'm still associated with the university community here, is to sit in on some basic physics courses. I'm getting ahead of the story, but the astronomy department at Harvard, which is where I went for graduate school, discouraged you from going down and taking physics courses. They should have been telling all the astronomy grads, "Go down there. Learn about this stuff. It's new and exciting."
McCray:Why did they do that?
Faber:Yeah. And because, again, nobody had any notion that these fundamental particle physics concepts were ever going to play a role in cosmology. That had not emerged yet. So the physics that they thought was going on there (in Harvard astronomy) was the structure of atoms, fluid dynamics, you know, kind of semi-classical physics, and they thought that they could teach all that just as well with an astronomy flavor in the observatory.
McCray:Okay. So what types of physics courses did you take then as an undergraduate?
Faber:As an undergraduate I took everything. Now Swarthmore was a kind of place that there was a program and the faculty was small. They taught the program, you took it. I don't think there was a single physics elective. It was just a set series of courses and you took them. I really liked that. Given the fact that the facility were very classically oriented in teaching classical physics, they made excellent choices. And so I should digress for a moment and say that a feature of the Swarthmore educational program at that time was the seminar system, which had been introduced in the twenties by a famous Swarthmore president called Frank Adelot. And the seminar program, if you elected to do it for your last two years junior and senior if you decided to do a seminar, honors major in physics, then what you did was you took eight seminars altogether in your last two years. You took two in the fall, two in the spring; two in the fall, two in the spring. Four of those seminars were in your major, in physics. So what were my seminars? They were E&M, atomic and molecular, statistical physics, quantum mechanics. I actually did take an elective. I took a fifth one, which was mathematical methods of physics.
McCray:Did you get to use the 24" refractor when you were there?
Faber:I went to work for the observatory and I got paid, so I made my pocket money by doing observations.
McCray:Astrometric type stuff?
Faber:They had a research program. You were a cog in the wheel. It's not like our students here, who think up something, go use the 40" and do new research. It wasn't like that.
McCray:One thing that I'll probably keep returning to, I might as well start now, is how did you learn to use the telescope?
Faber:Oh. I got instructed. They had three or four regular observers who worked for the observatory and they used the telescope every clear night. So I quickly learned that ethic: when it's clear you observe. And they would schedule people for half-nights.
I was typically working like five nights a month probably, and I got paid by the plate per quality of the plate. If it was well guided, I got paid a dollar; if it was fair I got paid fifty cents; and if it was only poor I got paid a quarter.
McCray:How long would it take to make a plate?
Faber:Well, that depended. You would start the night with a bunch of handwritten penciled cards which Peter Van de Kamp had put together with the name of the star, its coordinates, and a drawing of the star field and instructions as to the exposure time. So there was a great temptation to take stars that required short exposures. But if you kept doing that he'd get on your case. Right?
Faber:So you had to put in a few long exposures. But a long exposure would be 30 minutes; a short exposure would be 5.
McCray:Okay. So you could earn up to as much as $12 an hour or as little as $2 an hour if you were making great plates.
Faber:That's right. Yeah. In a year I would make a few hundred dollars which was a lot of money for me then.
McCray:How was your life? Socially? I mean you described before going away for undergraduate school as somewhat isolated and antisocial I guess.
McCray:Did that change at all?
Faber:Totally. Overnight. Yeah. I just cannot describe the feeling I felt that first week at freshman orientation at Swarthmore when there were fun, interesting people to talk to who were all slightly weird. You know, they weren't beautiful like the popular people in high school. They looked like normal people, and they were fun and interesting to talk to. I just felt suddenly as though I had found my milieu.
Faber:And so I never thought of myself after that time as being a misfit. And I became much more charitable in my judgments of fellow people. You know, I was much more likely to like somebody because I felt comfortable in that social setting, whereas I had been burned a lot of times previously and so I was kind of negative about meeting new people. That all changed.
McCray:All right. Okay. You graduated in '66 and went to Harvard. Why Harvard?
McCray:Okay. I'm assuming you don't mean the romance of Harvard.
Faber:No. No, Harvard to me was a sacrifice, because again I was doing very well, got great recommendations, won a National Science Foundation and Woodrow Wilson Fellowships, both, so I had a resume that looked really strong and was accepted at all the places I applied. The place I really wanted to go was Caltech, because that was the Mecca of the world for an observationally oriented astronomer. And by this time I had been bitten by the bug of large telescopes, so I wanted glass. But in the meantime I had met my future husband, Andy, at Swarthmore. They call Swarthmore the Quaker matchbox.
McCray:Matchbox? Okay. I get it.
Faber:It's a pun.
McCray:Okay. I was thinking of something else. Okay. He was a physicist?
Faber:He was. Yeah, he was a year behind me, and we had been going out for two years. Well, at the time I had to apply for schools it was not two years. It was less than that. And you know, you can remember how awkward relationships are. I mean we really liked each other, but we had certainly not gotten to the point of discussing whether or not we had a future.
Faber:So when I applied, I applied to nearby places and faraway places. One nearby place was Princeton. They didn't let me complete my application. They sent back a letter saying, "We don't normally accept women into the graduate program, and if there is a reason however that you think that our program is particularly well-suited to your academic needs, explain this and perhaps we'll send you" perhaps "we'll send you an application." I really couldn't answer that letter, because to be honest it would have said, "Maybe my future husband is 100 miles away."
McCray:Probably not the best response to give to that.
Faber:So I threw that letter in the wastebasket and didn't apply. So the next closest place that had a reputation was Harvard. So when finally all the acceptances came in and I had to decide, I decided to abandon Caltech and choose Harvard. But I didn't do that by agreeing with my husband or my boyfriend at the time. I just made the decision and announced it to him that this was what I was going to do. And I think he was very pleased that that's what I did, but there was no negotiation at that point.
McCray:Did he have plans to stay in the eastern region?
Faber:No. He didn't know what he was going to do. A year later he applied to places, and it was logical that he would go to Harvard. During that year we had agreed to get married, and we did get married in June of 1967. So he went to Harvard for a year in applied physics, got a master's degree, and then the Vietnam War was looming. So he had previous connections in underwater acoustics with the Naval Research Lab. He knew people there and he got a job in a group that studied the propagation of acoustical waves in shallow water. And he stayed with them until he was twenty-six, at which point it was safe to leave, and in the meantime he had decided not to be a physicist. Partly avoidance of me, partly that but as he says now, "I decided I'd never win a Nobel Prize." This was stupid, because he got something close to 800 on his physics achievement score. By the standards of people who are actually physicists, he was enormously talented and abandoned the field just because he thought somehow he wasn't going to live up to his own standards for excellence.
McCray:Was his family background and upbringing similar to yours?
Faber:No, no. They were a Jewish family from the New York area. Immigrants from Russia and Poland. And my family was from England and Scotland, Christian background. Finding his family has been the best thing that ever happened to me next to finding him.
McCray:Okay. A big family?
Faber:Big family, wonderful parents, welcoming, who welcomed me. Andy had two older brothers and sisters each, one of whom had also married a Christian. So they had already gone through that and proved themselves to be welcoming and accepting of anybody. My family was moderately non-welcoming towards Andy because he was Jewish.
McCray:Yeah, I was wondering how that worked.
Faber:Yeah. I'll come back to that in a minute. All the intellectual stimulation which I had been missing in my family as a kid. It was like going to Swarthmore. In fact, Andy's brother and sister and their two spouses went to Swarthmore, Andy and I went to Swarthmore. All six of those kids went to Swarthmore and two more grandchildren went to Swarthmore.
McCray:The Quaker matchbox?
Faber:So just a word or two on my family's attitude towards Jewish people. Very suspicious. I remember a remark my father He was very upset. He thought that I was closing off all kinds of social avenues by marrying a Jew. And he said, "What country club are you going to belong to?"
McCray:Sure. Which wasn't an uncommon attitude at the time.
Faber:Yeah. Well, I think actually a lot of it is the east coast versus the west coast. My daughters went back to school, one at Princeton and one at Wesleyan, and they noticed that your group affiliation was more important. Out here in California it doesn't matter at all. So we're lucky in that way. If we lived on the east coast it might be more of a problem.
McCray:Okay. Did you like Harvard? How did you find the environment?
Faber:I didn't like it.
McCray:Too stuffy? Too what?
Faber:Well, the teaching was lousy, almost uniformly lousy without exception. I didn't know how good I'd had it at Swarthmore with teachers who really they weren't always fascinating lecturers, but they were prepared, they gave you notes, they gave you problems that you had to work. Another feature of the Swarthmore physics system was labs. Labs, each one of these seminars once a week you met in seminar for about four hours and then the rest of the time was yours. You had an assignment for the next week. It was easy to fall behind if you weren't disciplined. Then another day you spent in a lab which got started at 8:00 a.m. and sometimes went until midnight. And they had carefully and finely tuned these labs over the years in the sense that there was just enough to be done in one day. So you didn't come in and find all the equipment hooked up. You had to go into the stockroom and find the equipment and hook it up, you had to turn on the oscilloscope, you know, you had to do the wiring in some cases, then you would do the experiment, then you did the analysis and you wrote it up in your lab book. Nobody else I've ever met, unless they've gone to the Swarthmore program, has had laboratory training like that. It was superb. Another feature of the seminar program by the way I'll just mention is that you didn't have any exams for two years. And then at the end of your two years as you were graduating, you took a battery of eight 3-hour written examinations in each of your seminars plus a half-hour oral exam. This was the rite of passage of all rites of passage. Having gone through that, one could never fear anything again qualifying exams, whatever.
Faber:And the examiners were not Swarthmore professors. They were Nobel Laureates from Princeton and people who were brought in year after year who shot their best at you. It was terrifying to stand up in front of the room in front of John Hopfield and try to answer questions on solid-state physics. I think we all remember lapses in those exams that just horrify us. So Harvard was just not like this at all. I don't even think the science that was being done there at that time was very interesting. It certainly was not interesting to me.
McCray:You were there in '66.
Faber:I got there in '66.
McCray:So Leo Goldberg would have been the chair and director also of the Harvard College Observatory.
McCray:He started in '66. Donald Menzel was there before.
Faber:Leo was a nice man. And I remember him as the most dedicated teacher. He actually tried. Students would complain that he was insufferably boring. He taught using overheads, which were sort of unfamiliar at that time.
McCray:Sort of the equivalent of Power Point today.
Faber:Yeah. He'd give you the overheads and then he'd run through them but it was very dry. But at least I thought he was trying and you had the overheads afterwards.
Faber:The real fact of the Howard program was total lack of feedback in the sense that nobody gave any problems because they didn't want to be bothered grading them. So they would give lectures in a haphazard way, they would assign readings, the textbooks were poor partly because astronomy textbooks just were poor at that time and, I don't know, I just didn't feel very engaged. Now on top of that nobody, as I say, was doing work that I cared about. I was already gravitating to galaxies. That's another feature of my interest. I have said before that I tend to be interested in fundamental concepts. Well, part of that is that I'm not interested in filling in the details much.
Faber:Right? So stars would not interest me. We knew how stars shine, shone. Yeah. Obviously there still were many questions about them back in 1967.
McCray:But the basics were there.
Faber:The basics were there. So it was time to think about something else. Galaxies. Nobody had any glimmer whatsoever of where a galaxy came from.
McCray:And this didn't fit within the Harvard research program?
Faber:No. There was no class on galaxies. There was a class on Galactic structure (our Milky Way). I forget who taught that. Which I took. But you know, nobody could even enunciate an idea relevant to the origin of galaxies. At least nobody was doing it on the Harvard faculty. And so the course structure there was useful as background, but it didn't launch you at all into a research program. Do you mind talking about my thesis? Is that okay?
McCray:No, that's fine.
Faber:Well, I should say that one thing happened, and that was Andy had to go take the job at NRL down in Washington, and I early on decided that I was not going to live apart from my husband probably because we were poor and couldn't afford travel money.
McCray:Did you have children at this point?
Faber:No. That was another very deliberate decision that we made no children in graduate school. No distractions. So no kids. So fortunately I had finished my two years of courses. It was time to think about a thesis, but I had to move to Washington and make a new scientific life for myself knowing practically nobody there. I did wangle my way to get an office for a while at NRL, but that was not satisfactory to me. They had an astronomy program, but it was mostly high-energy physics. Again, nobody was doing galaxies. I had worked a previous summer for Kent Ford and Vera Rubin at DTM
McCray:So you knew them prior to coming to
Faber:I knew them. I didn't go there immediately, because they were on the other side of town and Washington traffic is unbelievable.
Faber:Hasn't changed. No. This was a miscalculation on my part. They called me up one day and said, "Would you come over here?" And the reason for that was that they were under attack by some kind of new legislation in Congress that was attacking financially so-called "grandfather trusts". People were abusing the grandfather trust to avoid paying taxes. Now Carnegie was a very legitimate nonprofit.
Faber:But a way to evade this attack was to say that you had students. So overnight Carnegie wanted to become an educational institution. To be such, they needed students. So they said, "Come, be a student here and we will say that we have a little catalog which offers thesis advice for extra-galactic research." Meanwhile you might say, what was my connection to Harvard? Harvard was very kind to me, and so was my advisor up there, John Danziger, who was really a stellar astronomer, but as I say there was nobody doing galaxies. He was doing his best to advise me.
McCray:Stellar in terms of what he was studying.
Faber:Yeah. That's right. So they let me go on something called traveling guidance, which meant that I had to go back once every six months and report to my advisor. But aside from that I was on my own. This in retrospect was very good. It made me independent at a very early age. So I effectively became a postdoc, and not even a supervised postdoc an independent postdoc halfway through my graduate studies.
McCray:How had you met Ford and Rubin before that?
Faber:All right. Back to Swarthmore, one of the nice things about the Swarthmore Astronomy Department was that they valued colloquia. They gave them on the campus, and they ferried you around to neighboring astronomy departments where there were other colloquia. And I met Kent Ford at a colloquium he gave the University of Delaware. And he came up to talk so this would have been my senior year, sometime during my senior year, and he came up to talk about this new device that he was making called the geez, what is it? It's an image tube. It was more than that. Image intensifier? "Carnegie Image Tube" I guess is the way that people ultimately referred to it. He had a grant from the National Science Foundation to put together these image intensifier systems, and then he'd ship them off to various observatories to be used. They could be attached to spectrographs. Shall I say a few words about it, or is it obvious?
McCray:Yeah, it's okay. We can skip that. I'm curious so you met Ford through this colloquium.
Faber:I did. But again, this sort of says a little bit about me. I was deeply impressed because he was arguing it wasn't quite true, but he was making the case that you could jack up the quantum efficiency of a photographic plate which was about 1 percent to the quantum efficiency of a photocathode, which is more like 20 percent. Right?
Faber:That's the first time I ever heard a concept like that.
McCray:Okay. Stuff like that wasn't taught at Harvard.
Faber:Well, I wasn't at Harvard yet. I was at Swarthmore where they were taking these plates with a refractor that was built in 1910 and it was anti-technology.
McCray:Okay. I understand.
Faber:So as I say, I have this latent technical streak. I have never really much worked in the lab or built things or tinkered, but I have a huge respect for technology and interest in technology, and this keeps coming out in my career at later stages. So I was very interested in this project, and I don't know if it was at the colloquium or later I learned where he was working. I asked if I could have a summer job. And that's how that connection was made. So the summer following my senior year before I went to Harvard I worked at the Department of Terrestrial Magnetism with Kent Ford and Vera Rubin, equally, with the two of them. I spent half time in the lab helping Kent put image-tube systems together, where I don't really think I was that useful. And the other half in the research realm helping Vera do a scientific project.
McCray:How did that relationship go?
Faber:Great. Vera's wonderful. We became instantly excellent friends. She deeply impressed me. She's the first woman astronomer I had met who was actually doing research.
McCray:Would she take you observing at all?
Faber:Kent took me observing. He took me I don't know what it was actually I think we tried to make it work. He had a newfangled scheme for a flexure compensated image tube, and he was collaborating with Bill Baum at Lowell Observatory. And so he and I went out there and I met Bill Baum, who later came into my life because he was a member of the Widefield Camera Team at Lowell, which is a very funky little place. I had great fun. It was a wonderful summer.
McCray:Again, coming back to the question I keep asking throughout, what was observing like at this point for you, having gone from the 24" to then working now with some more cutting edge electrical instrumentation?
Faber:Well, I really barely remember this little bit of observing during that summer.
Faber:So if I'm really going to answer that question, it would have to be the next real observing I did.
Faber:Okay? Which was a master's degree project with John Danziger that brought me to Kitt Peak for the first time, where I did photoelectric photometry on a 16" telescope.
McCray:16" [unintelligible word] the really
Faber:It's one of those Boller and Chivins 16" telescopes. This was my first exposure to a modern observatory.
McCray:Okay. Had you been out west before, to Arizona?
Faber:My father took myself and my maternal cousin on a six-week tour of the west. This was after I graduated from high school. A wonderful trip, but had nothing to do with astronomy.
Faber:I had not been to observatories. I really didn't know what they looked like except in picture books.
McCray:Yeah. I'm trying to think. So this would have been '67 when you were out there.
Faber:Or eight ['68], something like that.
McCray:So they were building the 4-meter then, but it wasn't
Faber:That's right. They were building it.
McCray:The biggest they had at the time I guess was the 84".
Faber:The 84", that's right, and my advisor This was a project on stellar rotation, which was a good project actually. He took spectra with the 84" coudé‚ from which I measured the rotation velocity of the stars. And while he was observing on the coudé‚ I was on the 16" doing Stromgren photometry to get the characteristics of the stars. So that led to a master's degree.
McCray:Okay. Your CV mentions that you were injured there on one of the observing ones.
Faber:That was later when I did my thesis.
McCray:Okay. We can come to that later. Okay. So coming back to when you were living in Washington, you were commuting then back and forth between I'm guessing you were living probably closer to where NRL was located and then
McCray:Okay. And then commuting. DTM was out where?
Faber:Rock Creek Park.
Faber:DTM is a great place. Are you familiar with it?
McCray:I haven't been there. I've just been to the main building.
Faber:Since you're a historian of astronomy, you ought to go out there and talk to the people there. You must have interviewed Vera.
McCray:I haven't, but she has been interviewed exhaustively by others. Did you ever go up to the Naval Observatory and spend any time there?
Faber:Yes. Yeah, in fact I did, and in fact I even went there more often while I was a Swarthmore student. As I said, there was this tradition of taking kids the group to local colloquia. And on several occasions we made the trip all the way from Philadelphia down to Washington because there were important colloquia. Remember this was an astrometry-oriented department. The nearest neighboring sister department was USNO.
McCray:Would they take you to Allegheny Observatory also?
Faber:No, we never went there. No. But one of our graduates, Bob Harrington, was now on the staff of USNO, and what's-his-name. It will come to me. The director. Kaj Strand.
McCray:Yeah. We can fill that in.
Faber:He was good friends with Van de Kamp.
McCray:Okay. While you were a graduate student there was the moon landing. Did that have any impact on you?
Faber:I remember it very, very vividly. Now let's see, that was '69, July '69. Andy was I don't remember the circumstances exactly. He was in New York and I was driving from Washington to New York to be with him and his family, and the Eagle landed when I was on the New Jersey Turnpike. And of course everybody is listening on the radio, we're all glued to the radio. I remember when it was successful, everybody honked their horns and flashed their headlights. It was quite a moment. And then that night at Andy's family's apartment we all watched the televised stepping down onto the moon. Oh, it was fabulous.
McCray:Okay. I imagine also to an astronomer that must have had some certain special import to it as well.
Faber:Yes, it did, but you know I know people who were even more deeply touched than myself. Tod Lauer, for example, one of my students, is an incredible Apollo buff and has an extension collection of videotapes, Apollo literature, I mean he's got a real hobby following this and he knows every detail of every flight.
Faber:He's an example of somebody who went ten times farther than me.
McCray:Okay. I guess I'd like to talk a little bit about well, first of all, did you do a lot of observing at Kitt Peak?
Faber:Yes. I'd say altogether I did.
McCray:Okay. How did the process work? How would you get time?
Faber:Interesting you ask this. Good questions. Well, first of all I had a big problem. I was interested in galaxies. When I went to Washington, for a while I didn't have any facilities to do research there and I just sat in the library at NRL. They had a pretty good astronomy collection. For six months I did nothing except sit in the library and read. I think I read virtually every important paper that was ever published about galaxies. I cannot get my students to do this today. That was an incredible foundation, because I just knew everything that had ever been done. And I absorbed all this before I developed a thesis. The main challenge of my thesis was how to do observations on objects that were quite faint with a telescope that was small. Because realistically I could not expect to get 84" time. Harvard had a 60" telescope in Massachusetts, but forget that, it didn't work. Bad site. So it was the National Observatory for me or nothing. So after the 84" comes the 36". How is a person going to do forefront research on galaxies with a 36" telescope? And you didn't have the capable spectroscopic detectors that you have today. Kitt Peak had one of these systems built by Kent Ford, but it was on the 84". So the only option on the 36" was to do photometry. I had already done photometry, so that seemed good. But there was a lot of UVB photometry on galaxies by that point. De Vaucouleurs was churning it out at a great rate. The obvious next step was to adopt a set of filters that were narrower that would give you somewhat more spectral resolution and insight into the spectra but at the same time were wide enough that you could get enough light. So I put together a ten-color system which was a hybrid of two other systems. One of them had been developed by Sidney van den Bergh. And another system had been developed by a student named Wood, but he didn't go on in astronomy. Anyway, these little filters there were ten of them altogether covered what were known to be big absorption features in the spectra of early type galaxies.
Faber:Early type galaxies such as ellipticals. These are the objects that are red and consist of old stars as opposed to a spiral which would be still making stars and be quite blue. So my advisor bought for me a set of these interference filters. Pretty expensive. And I took them out and installed them on the 36" telescope and used them to observe thirty-three galaxies for my thesis.
McCray:How did you select them?
Faber:Okay, so coming back to the problem of getting time, that was a miserable story.
Faber:I think it was the one time when my advisor failed me. He really should have said, "This proposal, which asks for way too many nights of telescope time will never get accepted. You've got to pare it down. It's just not realistic." So I wound up putting in a proposal which in some ways is typical of all the work that I do. Can I digress a moment?
Faber:I think there are two ways of formulating observing proposals. And there is an analogy in going to the supermarket, which since I'm a lady and do a lot of cooking I like to be indulged to share.
Faber:One way of going to the supermarket is to read a cookbook. Guests are coming for dinner. You decide what you are going to serve, you read the recipes. You buy half a teaspoon of sugar, you buy a small bottle of vinegar, etc., etc., okay?
McCray:Everything you need to make specific things.
Faber:And nothing else. Right? And you come home and you do exactly what you said you were going to do. You had a vision and you execute it.
McCray:That's my way of cooking.
Faber:Okay. That's not my way of cooking. And it's not my way of doing research.
Okay. So the second way, which is my way, is the unfocused but flexible way. To make that work you have to have either some experience or some intuition that certain ingredients are powerful. And you don't necessarily know exactly how they're going to be powerful when you get them, but you just sense that you are going to get something good. Right? It's hard to write exciting observing proposals in this vein, and I think my proposal as a student to Kitt Peak suffered from being too big and simultaneously too unfocused.
McCray:Did it sound like a fishing trip?
Faber:It sounded like a fishing trip. Now I tried to make it more focused by saying that I was going to observe binary galaxies and I was going to look to see if there were correlations between the pairs. This was a fishing expedition in a sense because there was no reason to expect that there would be such a correlation and what would that be.
So basically what I was doing was I had the good sense to get galaxies over a wide range of luminosity. That was a little subtext that I knew about but nobody else knew about. I was just going I was sampling the spectra very carefully in a way that had not been done before to look at the individual absorption features in a bunch of old-star populations. Pretty unfocussed. So anyway, Kitt Peak was appalled. The referees came back and said, "This is impossible, she can't do this much photometry, she can't get this many nights, it's not well focused. No."
Faber:Art Hoag was kind to me though. And they didn't want to just say no, because you know they were sympathetic to the poor student. He said, "Apply again with a more focused and trimmed down proposal."
McCray:He was the director at that time of the, I guess they call it the Stellar Division.
Faber:I think so. That's right. In any case, he was the guy who had life and death over me. Very nice man, sweet man. So, I got time the second time around, but it was grudging. And I went there knowing that the whole system there thought there weren't enough photons and that I couldn't possibly do as many galaxies a night as I said I was going to do.
Faber:So I was under, I felt under a cloud, under a great deal of pressure. So what happened? Well, the second night I fell off the telescope and got a concussion and earned myself the back trouble that I've had for the rest of my life.
McCray:Did they treat it there? The concussion?
Faber:Well, I went down and went to a clinic, but you know basically that was a day later. There wasn't very much to be done. The bad thing was that I wasn't getting the counts. And you know, I got out my calculations, I did all my calculations again thirty times, and I always came to the same conclusion that I should be getting ten times more counts than I was getting. And there was another little suggestion. It was a good thing I had had previous photometric experience. The counts were not really quite as stable as they should have been. On a good night they should not vary from time to time by more than 1 percent.
McCray:What would cause them to vary? Cloud cover?
Faber:Cloud cover. Yeah, but if there are no clouds the other major factor will be just scintillation. Due to the twinkling you get more or less light through the aperture, right? My counts were wandering by 4 percent on nights where other observers said it was perfectly clear.
Faber:I went down to Art Hoag, who was on the mountain, and I said, "I don't understand it. Something's wrong." And his first words were, "Well, we told you you wouldn't get the counts." I said, "No, it's something else here, because I don't think the tube is stable." He said, "Well, I don't have any more S-20 tubes." The S-20 is the number to refer to the brand of photocathode, the wavelength sensitivity pattern. "I've given them all out. I don't have anymore of those. But I do have an S-1." An S-1 had more red sensitivity but overall one-tenth, roughly, the sensitivity of the S-20. And I said, "I'll take it, just to see what's going on." I got the same number of counts with the S-1 that I had been getting with the previous S-20! I reported that. He took the S-20 down to the lab in Tucson, they checked it out, and it turned out that one of the internal electrodes was missing there's a chain of amplifier stages. You know, one electron becomes ten becomes a hundred, etc.
Faber:Okay. One of those was disconnected. And that's why it performed at only one-tenth the level it was supposed to perform at. It didn't have enough oomph to get through the gating threshold. So, that first run I didn't learn this until later. That first run was a disaster, health-wise and every other way. Came back without any data. I didn't have that many more runs, I think maybe two more after that. But things after that improved enormously and it began to go well. The net result was Oh. In addition I also took a lot of calibrating data on stars in the 16". I actually had many more nights I think I had twenty-nine nights of 16" time and about ten or twelve nights of 36" time altogether.
McCray:Spaced out over periods of time?
Faber:Yeah, it was about a year and a half probably. Yeah. So the next result is, it's one of my best papers, my thesis papers. I discovered a trend which is still unexplained, to be fair. I mean even thirty years later. The trend was that the brighter galaxies had stronger metallic absorption lines. So that features due to a CN molecule, a magnesium atom, a sodium atom, all of these features were stronger and the overall continuum was redder in the galaxies that were most luminous. You could make a plot of line strength versus brightness and get a correlation. This was new.
Faber:So, as I wrote up in the main paper describing the results, there were two hypotheses. One was that the bigger galaxies were more metal-rich and had You understand the term metals?
Faber:Okay. The other was that they were older. And I said, "I really can't decide, but I think for various reasons it's metals," but I didn't make a really strong statement about this. I just recognized the fact that there was a question. We still don't know.
Faber:And this has spawned a fairly large industry, which I've continued to pursue with much higher resolution spectra here from Lick and Keck and lots of students have been involved in this. It has led to people wanting to make exquisitely accurate model spectra of stellar populations of various compositions and ages, and I think it's turning out now that probably both effects age and metallicity are at work. Added to this this is how I'm now still pursuing this question you could see that if you thought that a local elliptical galaxy was really young or had young stars in it, then you would be tempted to look back a little bit in time to see even if it existed at all at that time.
Faber:If your model says this stellar population is 4 billion years old, we can now look back to 10 billion years old. You shouldn't even see galaxies like that. You should see ellipticals coming into being, right? It looks as though that's not the explanation. What seems to be the explanation is that ellipticals originated very early but have a continuing dribble of star formation over billions of years. This flies in the face of all the established wisdom about ellipticals as of a decade ago.
McCray:How does that compare with how the evolution is in a spiral galaxy?
Faber:Well, spirals have continuing trail of star formation. It's just in the ellipticals it's much reduced, so that the population can look overall quite old. But you put in this little frosting of recently formed stars and you can jack down the apparent mean age to really being quite young. So this has raised a major question of how these early type galaxies, these ellipticals, form stars over time, and we still don't know the answer. But now our group here at Santa Cruz is using the Keck telescope to look back in time, and we are trying to compile statistics on the ages of stellar populations, their metal line strengths, the numbers of galaxies, the brightnesses as a function of time. And all of this seems to be now pointing to the fact that ellipticals are a lot more active over many billions of years than people had thought.
McCray:Okay. At the time that you finished your dissertation 1970?
McCray:Okay. At the time that you finished, did you see yourself primarily as an observational astronomer?
Faber:Yes. By that time squarely. Yeah.
McCray:I understand how you ended up falling into that camp, but did you ever consider it would be nice to be a theoretician or "I wish I were an instrument builder"?
Faber:You know, you couldn't be a theoretician and study galaxies, because there was no theory. Literally.
Faber:There was no foundation. I never read one paper in graduate school that theorized about how galaxies formed. It was a complete blank. So if you wanted to study galaxies you had no choice but to go out and observe them.
McCray:To study them first.
Faber:Yeah. And it was truly amazing, the number of basic parameters that weren't known. That was really for me the great terra incognita.
McCray:I'm also trying to get a sense and this is a fishing expedition of my own, this question, but how did your research program fit in with the overall research at Kitt Peak? Because I understand they were my understanding is that when Goldberg arrived at least that he tried to shift things away to more extragalactic studies.
Faber:Yeah. This is true, but I'm not sure that I really have much perspective on this. What I remember is that yes, people were doing extragalactic things, but the famous person was Roger Lynds. He was using one of these Kent Ford image intensifiers, but he was studying AGNs. AGNS and quasars were the thing.
McCray:Yeah, I mean they had just been discovered and I guess that became the hot thing.
Faber:They were the hot topic. And people like myself on galaxies were few and far between.
McCray:Did you ever consider going in the quasars field?
Faber:No. Because quasars aren't fundamental. Quasars are frosting [laughs].
McCray:Okay. All right.
Faber:You are getting a sense that my standards for what is really important are either crazy or extremely high, one or the other.
McCray:I can imagine talking to other people who would say the quasars are you know, that's what you have to study.
Faber:Well of course now in later years I've really gotten into black holes, but that only came later. Yeah.
McCray:Were there any other people I mean you mentioned John Danziger, your advisor, and then Kent Ford and Vera Rubin and then Was there anybody else at this time who was either particularly instrumental or particularly difficult in the ?
Faber:No. Fortunately, nobody was ever difficult. Yeah. I never had obstacles like that.
Faber:No, I wouldn't say so. DTM was a very warm and comforting kind of place. Lots of people to talk to, although aside from Vera really, Kent didn't know that much astronomy aside from Vera, nobody she was very interested in galaxies by the way. She was the first person I met. You want to hear a funny story about dark matter?
Faber:Okay. I might have written about it before. I'm not sure. Vera was good friends with Mort Roberts who then I believe was the director of NRAO in Charlottesville, not too far from Washington. He was a radio astronomer. He studied 21-centimeter, but also very interested in galaxies. He studied gas and galaxies. One day when I was at DTM it would probably have been roughly '71 he called up Vera and he said, "I have some very strange observations about M31 and I'd like to come up and discuss them with you." So he showed up, and there was a little sort of conference room in the library in the basement of DTM, and being a very small and intimate group I mean there were probably four astronomers there plus Mort obviously I was going to drop everything and sit with this group and listen. So Mort laid out we got a picture out. A Hubble Atlas existed. He got out the picture of M31. We looked at it. And he placed on this picture where his 21-centimeter pointings had been made. These would have been made with maybe the 140' in Greenbank? I'm not quite sure what telescope he had been using. There were spot pointing all along the major axis. And his point was that he had detected gas at all these points and he could measure its rotation velocity.
Faber:Now I think he could only go in one direction, because the other direction you get into the Galactic plane and you get messed up by local hydrogen. Now the motions of the inner part of M31 were known, and in fact I think Vera was already working on or had published her famous work on the rotation of M31 based on H-II regions. I'm not quite sure if it had appeared in print yet, but at any rate, a lot of the motions of the inner part were known from her work. And that's why he wanted to talk to her. And then you add on the gas in the outer part. So he had a plot. And maybe in fact he went to the blackboard and took some data of hers and put on his points. His outer points had the same rotation velocity as her inner points.
McCray:Okay. But they were outer?
Faber:Much, much further out. They were way far out, so you looked in an optical image, the galaxy appeared to end, and here his points are out here when there was gas but no stars. Vera's jaw dropped, I remember, and I'm thinking to myself, "What's the big deal?" He said, "Don't you understand? The galaxy has ended, but the velocities are flat." This was the first time I ever heard of a flat rotation curve. And he said, "What is the mass out there? What is the matter? We can't see it. There's got to be matter there, but it's invisible." It was the first enunciation of dark matter. Now my reaction to this as a student was extremely blasé. I understood the argument, but in the course of finding binary pairs for my own thesis work, I had gone through by hand, I had combed the entire De Vaucouleurs Reference Catalog which was not in any electronic form, so I did this by hand, looking for pairs, and I looked for things that were close by, I looked for things that were isolated and not parts of bigger clusters, and then I looked at the radial velocities to see if they were associated, and I had already noticed that, in my sample of galaxies, there were many objects that were nominally pairs but with velocity differences that were much bigger than you could plausibly account for.
Faber:And people had already wondered about the motions of galaxies and clusters. There was a famous Santa Barbara conference in 1961. I think it was in which people were wondering about missing mass. That was what they called it back then. So I was very blas‚ about strange velocity data, because I didn't believe the velocities. I sort of carried around the notion that the velocities were somehow bogus.
Faber:And so I didn't believe his velocities either. Or at any rate I said, "There's nothing new in this. It's all part of the same problem. Velocity has never made sense."
McCray:Okay. I have a question that is related to this. Various people I have spoken with have either given a lot of the credit to Vera Rubin for discovering dark matter.
McCray:And other people have credited Ostriker and I guess the paper with Peebles and Yahil.
McCray:What's your perspective on this?
Faber:Neither. I wrote a review in 1979 with Jay Gallagher entitled "Masses and Mass-to- Light Ratios of Galaxies." And actually a lot of people credit that review with kind of nailing the subject. Right?
Faber:I thought that the key There were two key things that really nailed it. One thing was rotation curves of galaxies, but it wasn't Vera's. It was Albert Bosma's.
McCray:How do you spell that?
Faber:And we actually put Bosma's rotation curves in our review.
McCray:That's not a name that you read in popular accounts.
Faber:No. Because he's European, so the Americans don't think about it. But he was very much in my mind, because he carried on in the tradition of Mort Roberts. It's much better to study dark matter around galaxies using 21-centimeter than it is optical rotation curves. Because the optical rotation curves are generated from the H-II regions, which come from the star-forming regions. The whole point of Mort's presentation to us that day was that the galaxy ended, i.e., the optical image ended, and you could go way beyond it using gas.
Faber:Right? So to go farther out and to show that the phenomenon was still very strong much farther out was to me a much more convincing demonstration. And I would say, with the benefit of hindsight now, you can look at Vera's rotation curves and say, "Oh yes. We can see very clearly a signature of dark matter in these curves." But if you had been a skeptical person and there actually were skeptical people. What's his name, the guy who's now in Australia? He [Agris Kalnajs] was a very good friend of mine from Harvard. He was a Harvard student, a theoretician. He gave a talk at Grenoble in 1979 debunking Vera's results, showing that for 90 percent of those rotation curves within the uncertainty of mass-to-light ratios of stars and so on, you could fit all the data except maybe one point at the end of each rotation curve using a constant mass-to-light ratio, no dark matter.
Faber:Right? So I would say at the time people were not overwhelmed by Vera's results. Somehow I think that over time, they have taken on a mythic force.
McCray:That's why I'm asking, because again, you have newspaper accounts and popular accounts, and yet there's a standard narrative that is told and I think the narrative probably is more interesting, or more complicated than you typically get.
Faber:Right. Okay. So for Jay and me when we were writing our review, Bosma was really important, and then the other piece of evidence was evidence that had been around since 1931, Fritz Zwicky, the motions of galaxies and clusters of galaxies. So that for us kind of nailed it on two size scales. Now, what about Ostriker and Peebles? I give a lot of credit to them for It's interesting. They weren't new either.
Faber:The key diagram in that paper was by the way, there were two Ostriker and Peebles papers. Shall we just recapitulate what they are?
McCray:Sure. I guess I'm thinking of the '74 one?
Faber:Well, they're both right around the same time.
McCray:Yeah, then we better. Okay.
Faber:Okay? The first one was an observational paper, and I think that's the one by Ostriker, Peebles and Yahil. That has a diagram in it that shows that the mass discrepancy gets worse as the scale over which you measure it increases.
Faber:I was annoyed by that paper when it came out, because the very same diagram had been published by this astronomer back in the 1950's at Wesleyan University who actually studied galaxies back then.
McCray:Who was this?
Faber:You can see I'm incipient Alzheimer's. I really notice this about myself. I can't remember anything. Thornton Page.
McCray:We'll fill that in.
Faber:Right. So he was a senior guy, and he published a very nice paper pointing out the fact of the discrepancy. He had a diagram almost identical to theirs. So, people were making a lot of noise about this paper and the diagram by Ostriker, Peebles and Yahil), and I said, "Well this isn't fair. Somebody's already done this." And I'm not even sure that they referenced him. Now, as you read through their paper, it's not new, it's not new, it's not new. There is the diagram. It's not new, not new, not new. Finally, in the very last section, there is the real contribution, and that is the physical model. And the words "dark halo" are used for the first time. That I think is what the important thing about that paper is. It gave people a mental image.
Faber:Before it was just discrepant plots and a bunch of numbers that didn't agree.
McCray:But now there is this image that you can
Faber:The conceptual peg that you could hang all kinds of models on. So I think it was a very important paper, although there were these annoying tendencies to reproduce what other people had done without proper attribution. And this dark halo business is almost in passing. It really doesn't seem to be the force of the paper. The second paper by them I think is Ostriker and Peebles or Peebles and Ostriker by themselves. It was a purely theoretical paper, and it was the one in which they showed that if you tried to make a rotating disc all by itself that it was unstable. And so that the discs of spiral galaxies, if they existed in isolation with no dark matter, would quickly break up, develop bar instabilities and become elliptical galaxies. Right? That was likewise an extremely seminal, influential paper, because it was kind of a kick in the butt to all the people who were then doing N-body models. This had been noticed by previous people, but you know Ostriker and Peebles, they have a knack for making the point and getting people's attention. This problem had been noticed before. I think it had been chalked up to technical difficulties in the n-body models. They did a lot of experiments which seemed to suggest that no, it was fundamental, and the solution was to have dark matter which was not flat and rotating but round, creating a stable potential for the disc.
Faber:Another thing that Ostriker did at that time was go around the country buttonholing observers like me and asking them whether there was any low-intensity halo light around disk galaxies. People went out and tried to observe it, failed, and this showed that dark matter was dark. He really generated interest, one on one, which is another reason he deserves credit. I think it was a dynamite combination of papers. And of course all the N-body experts neither Peebles nor Ostriker were experts, but the N-body experts tried to take lots of potshots at that second paper for years, but in fact the answer is at least roughly correct.
McCray:Okay. Let's take a break for a second. [recorder turned off, then back on...] But before doing that, why don't we just also sort of move you from the East Coast out to here. So how did you end up out at UC-Santa Cruz?
Faber:Okay. Well that you know, I think this is true in [unintelligible phrase] but I can look back and see many lucky accidents. The first lucky accident scientifically for me was meeting Kent Ford, which led me down the DTM route, meeting Vera. The next lucky accident was meeting Bob Kraft at an Ohio State University conference on stellar rotation. Recall that this master's work that I did was on rotating stars with John Danziger. And John, who was always a very generous person really, you know, he had many wonderful qualities as an advisor. I felt he was very good to me. He sent me to this conference, and that's where I met Bob. I think you would have to talk to Bob. I have never actually asked him point blank
McCray:Yeah. I will tomorrow when I talk to him.
Faber:Okay. But I think that that meeting might have played a strong role in my ultimately getting hired here. Yeah. Probably played a role in at least getting invited out to interview.
Faber:Right. So, I think all of these interviews are traumatic. Andy came out with me on this one. He by this time had decided to be an attorney, got an 800 on the law boards, could go anywhere. There weren't that many law-astronomy combinations. We applied to all four, and the only astronomy job offer I got at one of these four was Lick Observatory. I have no idea what would have happened to me if I hadn't gotten this offer here, because none of my other options were nearly as good as this one. So it was a very near miss.
McCray:What were some of the other ones?
Faber:Caltech didn't want me at all. I didn't get a Gibbs Fellowship at Yale. Harvard didn't want me. There was a very low-level job to put together a little observatory at MIT which they were going to use for teaching purposes, and they wanted me for that job, but that was not very good. Berkeley didn't have any openings, so it was Lick. There weren't that many jobs. And I wasn't very competitive, because my thesis was the kind of a thesis which I try to discourage students from having today. You work and work and work and work you know, 85,000 computer cards, punch cards, finally you make the plot which you have been struggling for two and a half years to make I mean, talk about heart in the throat kind of thing. Finally this is what these data look like. So at the job interviewing time a year in advance, I had no results. Thank heaven I had done this little master's thesis, because that's what I was giving my job talks on. And I came out here and I gave a colloquium on stellar rotation at Lick Observatory. But, you know, people would ask me about my thesis work. I didn't know from nothing. I just had been grinding through it, I had no insight, no cute stories except that I had fallen off a telescope. Nobody wanted to hear that.
McCray:Yeah. Not a good story to tell.
Faber:Not a good story. [laughs]
McCray:Just curious. I mean this relates tangentially, but you mention in your CV that one of the things you liked about being at Santa Cruz was that you didn't encounter any discrimination. And I don't want to go down this path too far right now, but I just
Faber:There's nothing much to say.
McCray:Was that unusual do you think, what you didn't experience?
Faber:I think it was somewhat unusual. I had seen evidence of some discrimination before. First of all Princeton, which didn't send me the application. Then there was, a little bit later I went observing with my advisor John Danziger helping him out with some of his work, and he observed at Mt. Wilson, and on the same trip Caltech. So at Mt. Wilson they had no room for me and I had to sleep on the groundskeeper's cottage sofa. And I think they allowed me into the dining room to eat meals, but I definitely felt as though I wasn't welcome there. At Caltech it was better, but in a kind of curious way. Margaret Burbidge had been refused time on the 200". Vera was refused observing time at that time. And that was unpardonable, because it was the same institution. She worked for Carnegie Institution of Washington. You know, she still bears scars from this. It's just incredible.
McCray:Yeah. Rightly so.
Faber:So I'm allowed to come because I'm only an assistant. I'm not getting time in my own name. But they've had like two women ever stay at the monastery. Monastery.
Faber:And the way they dealt with that, they tried to be very nice. There's an upstairs floor. I walked in, there's this red velvet cord across the bottom of the stairs with a sign there. It says, "Female upstairs." And I later found out that that was me. They made a big to-do because the bathrooms were shared. Right?
McCray:I remember talking to Virginia Trimble and I think she described a similar arrangement, you know being somewhat like a zoo animal.
Faber:They were trying to be so nice and give us privacy and everything, but in fact of course the result was the opposite.
McCray:Let's talk about your early experiences at Lick.
Faber:Well, for my thesis I had done this ten-color photometry of galaxies. But I had never seen an actual galaxy spectrum because I had had no device with which to take a spectrum. One of the things that was wonderfully attractive about Lick was the image dissector scanner, which was a really path-breaking instrument built by Joe Wampler and Lloyd Robinson. And I think that's another reason why they hired me, because again it's my technology streak. When I came out here to interview and learned about this instrument, I was wildly excited. And I was just enthusiastic and probably they said, "Wow," you know, "If we hire this staff person she'll use it." So I immediately wanted to see in detail what these spectra really look like. You know, here I had had these bands that were 100 angstroms wide. What were the features inside them? So I immediately started to take spectra of my own thirty-three galaxies plus others of so-called old stellar populations, these early type ellipticals and S0s. And another thing that Lick had done that was path-breaking, not only had they built this instrument whose data came out over a signal cable so you didn't have to stand there. You didn't have to put a plate in, you didn't have to look through the spectrograph. They had also put a TV camera at the focus so you didn't have to look through the telescope! They had made a virtue out of necessity. The 120" was built economically with no Cassegrain focus and no way to get at it. So when they put an instrument there, they had to make it so that you didn't stand there, so they built a little data readout room where you could see the TV camera picture and you could see your spectrum displayed as it came in and so on. It was the first system of its kind. And the rest of the world I think looked on in envy. It was five years before any other observatory did anything like this.
McCray:How did that experience, working that way, compare with what you were used to?
Faber:Oh! It was a luxury. First of all you didn't fall off the telescope. And you know a lot of nights at Kitt Peak were cold, so I had been accustomed to observing sometimes as long as 13 hours and you know at 10 degrees, wearing big, bulky down parkas and all of that sort of stuff. Sitting down for 15 minutes to have a little bite to eat in the middle of the night but otherwise working like crazy. Wow, this was such a relief. You could sit at a computer terminal, and that was a totally different world. Warm, and you didn't have to look through this crazy little eyepiece to see that little faint, fuzzy galaxy you know.
McCray:Keep it centered on the slit to take data?
Faber:Yeah. I immediately lost all my observing skills. I took my newborn daughter, who was six weeks old, observing with me.
McCray:Which you couldn't do if you were up in the prime-focus cage or something like that.
McCray:Okay. Other people listening to this later on might not understand. Could you just give a brief description of what the image dissector scanner was.
Faber:How did it work? Okay. It was like the image intensifier tube, except so that there was a photocathode and there were three stages of amplification. In the image intensifier you slapped a photographic plate on the back of that and so that you could take, using photography, the spectrum of something now that looked bright. Okay? But with the image intensifier scanner instead of the photographic plate you had another photomultiplier which had deflection coils that scanned the beam across an aperture at the back of the instrument. So again you were making another photoelectric image, but the image was being scanned up and down and back and forth over this little hole. Okay? So, and then, finally there was something that actually counted photons. So the whole trick was you had many stages of amplification. The phosphors have a time decay. So I don't know, maybe something like 10 milliseconds? In 10 milliseconds you could scan the whole image. And you made the whole thing bright enough that from every little pixel you got at least one photon. Okay? So you use the latency effect of the amplification process to allow you to scan. If there was no latency you would only be seeing one spot at a time and you wouldn't have won any multiplexing. But because the image stayed there for some period time you could scan it all before effectively a new image came in. They started scanning in one dimension only, along the spectrum. This was the first panoramic detector that anybody ever made, and it was nice and linear because it was a photoelectric process. Not like photographic plates.
McCray:What did the final output look like?
Faber:It looked like a series of counts in wavelength bins. It looked like numbers versus wavelength.
McCray:Okay. So you could then take that as a make like a histogram or something.
Faber:And then you could plot that and make a spectrum. You know, you plotted it. You made a spectrum. Okay?
McCray:Okay. All right. And the resolution was particularly good?
Faber:It wasn't very good, no. Each bin was 1.25 angstroms. There were about two thousand bins. And however, as part of the amplification process, the spots got blurry. So one photon actually could be detected with a full width half maximum of around 10 angstroms. So the effective resolution was a lot lower.
Faber:It's interesting you make that point, because we're on the subject of the Faber-Jackson relation. What I noticed as I was taking the data was that some of the spectra were a lot smoother than others.
Faber:It looked as though they had been convolved with some kind of broadening function. So you could look at a star and the spectral lines were very sharp and narrow and going up and down a lot. And then you looked at a galaxy, especially a big galaxy, and it was much smoother. It was as though somebody had take a Gaussian smoothing function and taken the stellar spectrum and convolved it and blurred out. Now this had already been done. The first measurements of so-called velocity dispersions in galaxies, there were about three papers on this subject. There were not many. But, it was known that stars were moving in galaxies at a few hundred kilometers a second and the effect is that for any spectrum some of the stars come towards you so they are shifted to the blue; others will be going away from you, shifted to the red. The net result would be to take a sharp stellar spectrum or a composite spectrum of billions of stars but still sharp, and broaden it by the velocity distribution function of the stars.
Faber:So I could see this coming out in the data, and I got diverted since this seemed new and interesting.
McCray:The smoothness of it.
Faber:The smoothness. And the variable smoothness from object to object. So I decided to put on hold my investigation of the absorption line strengths, which was where my thesis had been going, and instead take a diversion and study this broadening effect. Because I realized in so doing I would be measuring the velocity dispersions in the galaxies. I also could see that the broadening was bad enough that if I really wanted accurate measurements of the absorption line strengths I was going to have to have some measure of the broadening first, because I was going to have to take stellar spectra, which were sharp, broaden them by that amount and get a broadening correction. Okay? So the rest is history really.
McCray:But before doing that, was this I mean shifting this from where your dissertation research was headed to this, was that something you were nervous about doing?
Faber:Not at all. No. No. Why would I be nervous about that?
McCray:Tenure, promotion, new area of research.
Faber:I was a lot more worried by the fact that I wasn't publishing any papers because I had a young child, and thank God I went into a faculty position. I just don't know how people are doing it with postdocs now, because to move on to the next postdoc If you look at my early publication records and my thesis papers, I don't think I published anything for three years. The first paper the next one was this Faber-Jackson paper, which was a good paper, fortunately. So I was very lucky in getting a permanent faculty job. I was like the last person in the United States to get one. It was normal, but then it suddenly became totally abnormal. And I was right there on that transition.
McCray:So good timing.
Faber:Very good timing.
McCray:Yeah. How did the collaboration with Jackson come about?
Faber:He was just a student in the department. Yeah. And I would say, you know being frank, he didn't have that much input into the method of the paper. What was new about the paper was that it was an attempt to use Fourier transforms to measure a velocity broadening.
McCray:What's important about that?
Faber:It was a new mathematical technique. I had used a new a sort of an unfamiliar mathematical technique called principal components to study absorption line data among these galaxies in my thesis. I fancied myself as somebody who was up-to-date on forefront statistical techniques and could employ them. I've gotten a lot worse at that as the years have gone by. But back then I was attracted by any new and novel analysis method.
McCray:How was the data collected for this work?
Faber:It was collected at Lick Observatory on the 120" telescope.
McCray:Okay. Coming again back to the question following through, what was that telescope like to use and how did you learn to use it?
Faber:Well, by this time I was pretty experienced as an observer. I had observed at Swarthmore, and I had these two projects at Kitt Peak. Observing at Lick was a lot easier than Kitt Peak because, for example, you didn't have to stand at the telescope and the art of using the eyepiece, guiding and so on, was ever so much easier. I just didn't really much have to work at it. I'm not sure that you needed anybody to teach you, except you know the first afternoon somebody said, "Here's the computer. This is how you use the computer." I actually wrote a program in very low level machine language in order to analyze my spectra. It was quite primitive. You couldn't even use an advanced language like FORTRAN. The language was a line-by-line compiler which was very, very low level and tedious and hard to debug. So, it was kind of being more in tune with the guts of the machine if you will, but I wouldn't call it hard.
McCray:What did you like about observing?
Faber:Oh, I love observing. Observing is addictive. Yeah. The image dissector scanner especially was very nice because you could see the data as they built up. Not like a CCD detector of today in which you expose and then you read out and only then can you look at it. But you could see it. You could see it coming and you could stop when you were satisfied. It was wonderful. And we got a lot of our results, especially Alan Dressler and I later, when we did a radial velocity program. We could measure the radio velocities right on the little cathode ray screen. We'd see the spectral shift and say, "Wow! That one's in the cluster, that one's not in the cluster." So there was a lot of immediate reward. I like being alone with the telescope at night. It's almost a mystical experience. You sort of feel special. Everybody else is sleeping, you're awake, you're communing with the universe and these peons, these pedestrians are
Faber:Are sleeping. [laughs] Right. I like the thought that this is a wonderful thing about observing the universe is so full of so many different objects. In my case it has been true. I am looking at things that nobody has ever looked at before. I like that feeling. I am the first person in the history of the human race to make this observation small as it might be, just one more spectrum. Nevertheless, nobody has ever done that before. I like the thought of somebody looking back. Who am I really looking at when I look at this galaxy? So these thoughts run through my mind, but basically it's very satisfying. It's also to do it well demands total concentration, so there is also the kind of climbing a mountain peak aspect to it. You forget the rest of the world, because you have to. You have to be completely focused. I like the thought of being super efficient. I sort of look down my nose at observers who come ill-prepared and who waste telescope time. At Lick at that time there was very much an Avis versus Hertz mentality. Hertz was Caltech. Avis was Lick, "We try harder." We were outperforming them with a smaller telescope in a worse site because we had a super coudé‚ with great throughput, and we had the image dissector scanner, which just couldn't be matched.
McCray:Can you say more about that inter-observatory rivalry? I find that really interesting.
Faber:Well, in my case I think I came along as part of a young generation. I think in the older generation there might have been a little bit more animosity, but I certainly never felt any personal animosity towards Caltech. I was just jealous as hell of them, because of their access to resources.
And my jealousy continues today. This business of the Avis and Hertz, even though we're sharing the same telescope (i.e., Keck), is still very much present. We look at them as being kind of spoiled children. An individual faculty down there could have twenty nights of Keck time. Staggering. And it's true they do great things with it, but do they do great things in the proportion to their opportunity? That's not so clear. And again, we on the UC side are really focused on getting efficiency out of the Keck Observatory. And we feel that that urge for efficiency isn't shared. Why do they care? They have more photons than they can use. If they lose nights, if they don't guide perfectly, if they don't set up in two minutes instead of five. Maybe it doesn't matter to them. We're hungry.
McCray:This is getting away from where I was thinking of going, but this is really interesting so I'd sort of like to follow it. What does it take to be an efficient observer?
Faber:Planning. You must arrive with all the materials and all the numbers that you need. It would be very helpful if you had walked mentally through a script of the entire evening or observing run. This usually consists of afternoon calibrations and then twilight calibrations, evening observations and more twilight calibrations. So you had better have thought through exactly what you're going to look at, what the pointings are, what the exposure times are, what the position angle is, all of these parameters that you need for every observation. You should either have written them down or know them so well that you don't need to write them down. So I would say that's the first and foremost thing. Then attention to all the details as the data are coming in, because things go wrong. So you can cheerfully if you're not paying attention, you can pile up reams of data that you will throw in the wastebasket. So you have to be extremely attentive. And this is probably the most wearing part of it, because you have to worry about it. Now at Keck I find that the Keck observing experience is not really so much to my liking. I like observing on a smaller scale where fewer people are involved, the instrument and the program are a little simpler, and things work more reliably so that there are fewer surprises during the night. I think I really was at my best observing at Lick.
McCray:So this is a function of the size of the instrument?
Faber:And the complexity of the instrument. And for example, just to give you a feeling for this this is something that just happened at Keck focusing the telescope is important. The telescope should be in focus at all times. Elementary, right? At Lick, to focus the telescope there's a TV camera with a very quick latency period. Go to a bright star, press a button, it runs the secondary, the image gets fat; press another button, the image comes down and then you go through focus. You do this a few times. In 20 seconds you can see nicely where the minimum is. You're done. Right? It's such a painless procedure that you can do it every hour if you want. Just zip away to a bright star. Sometimes you can even do it with a star that's visible in the TV field of view. Right? At Keck, focusing is an enormous production. The TV cameras are not quick and nimble. They have many other strengths we have gone to a different kind of TV camera but it's more complicated and it doesn't have this particular facility. So there ensues at least a 10- minute-long period in which a pre-canned script runs the telescope through focus and plots a focus curve and finally tells you where to focus. So what happened on our last night was that it died partway through this because there was a segmentation fault in the computer.
Faber:That's just a fancy way of saying that the computer got confused and it couldn't continue. So, we lost almost 10 minutes and we had to start over again. The computer system at Keck is very shaky. Many computers are hooked together. There is the computer for the guider, there is the computer that you are using usually two to control the instrument, to control the data; and then there's a computer that runs the primary mirror. And then finally, ah, there is the computer that runs the drive and control system. And these computers are always having problems.
McCray:And they all have to talk to each other.
Faber:They all have to talk to one another. You can be going along and suddenly pow, your exposure is ended, and sometimes you don't know why or you can't continue, can't guide, something awful happens. So there's the constant interruption of momentum that I find very annoying. It's very hard to get into a rhythm much harder than it was with the simpler system.
McCray:How about the numbers of people that are involved, comparing it like say using the 120" versus Keck?
Faber:To observe with the 120" was a two-person job: there was the telescope operator and me. And sometimes there was a student, but usually the student wasn't doing anything.
McCray:Mm-hm [affirmative]. So you have a person driving the telescope and then the person reading
Faber:Taking the data. That's right. At Keck you again have the person driving the telescope, but you really need at least two people on the instrument side and I think probably three is better. So it's not ten people, but it's more.
McCray:What are the well, I'll save that question.
Faber:Okay. Save that thought.
McCray:I have a whole block of questions actually about that. Actually I want to just pause for a second. [Recorder turned off, then back on...] Okay, so we were talking about how you collected the data for the Faber-Jackson relation, which is how we got off on this. How was it received by the community?
Faber:I don't think people thought it was that important. I was a little disappointed. But see, this is typical of my science. Right? It seems that the Faber-Jackson relation to me was like buying the bag of sugar at the supermarket. It seemed clearly important to me, but I couldn't tell you what it meant. It didn't lead immediately to anything. But my instinct was that it was important, because it was the first firm scaling law for elliptical galaxies.
McCray:Now why are scaling laws important?
Faber:Yes. Why are they? [laughs] That's why I wanted to come back to this subject. Right? For me scaling laws are the essence of doing astronomy. Now I recognize that there are many ways of doing astronomy, but in my way of thinking about the universe, I was very influenced as a student by the HR diagram. So, just to recapitulate, the HR diagram plots luminosity versus surface temperature for stars, and there's a relation there called the main sequence. So when you're confronted, when I'm confronted, with a diagram in which X correlates with Y, that stimulates a lot of thinking for me. I actually don't do much thinking in a vacuum. If I am not looking at new data I'm not thinking. This is a defect.
Faber:Yeah. It's kind of curious. Show me new data, wow, the juices start to flow you know, because any new trend cries out for explanation. This was no different back in the beginning of the century when people saw the HR diagram. It stimulated a lot of speculation about stars. It wasn't explained for twenty years, until people understood that there was nuclear burning and that this was a mass sequence. A lot of people thought it was an aging sequence. Stars start out bright and hot, cool and get dim and red. Right? It seems so natural, but that is of course not how it was at all. Nevertheless, you just look at that diagram. With the mindset of an astronomer you know that this is the secret of stars; if I can understand this diagram, I am going to understand stars. That's how I felt when I saw the Faber-Jackson image. I said, "This is a diagram for elliptical galaxies. If I can understand this diagram I am going to understand how these galaxies formed." Okay? I'm not sure that the paper says that. I haven't read this paper since I published it. I don't remember what the conclusion said. Certainly there was no theory in it. There was no attempt to explain what was going on and, as I gave my talks, I think people were much more interested in my measuring technique "Ooo, wow, she can measure velocity dispersions" than they were really in the result. I remember giving a colloquium at Minnesota where Ed Ney was located, very nice man, infrared astronomer and very smart. He said, "You gave a nice talk, but it didn't mean much to me," which was kind of a nice, frank thing to say actually. Right? And I had to admit at the time, "I don't know where this is going. I don't know where it's leading." So either you intuited that there was something there and got excited or you didn't, and if you didn't there was no way to be persuaded. It was an aesthetic judgment. Yeah.
McCray:Say more about that aesthetic judgment.
Faber:I don't know if I have anything more to say. Okay? Good question, but I can't rise to the challenge. Okay. Now, what I think really made my paper stand out is that soon afterwards the Tully-Fisher relation was discovered. Now the Tully-Fisher relation is tighter than the Faber- Jackson relation. You remember they are both basically the same thing: one is for ellipticals, one is for spirals. And both plot the brightness of a galaxy versus the speed of motion of the stars inside. The Tully-Fisher relation over the years has had much wider application to all manner of galaxy research because it's tight.
McCray:What do you mean by tight?
Faber:Meaning the scatter is low. Okay? From day one, the scatter in the Faber-Jackson relation was non-negligible. It's not a perfect relation. It has scatter. Tully-Fisher relation has zero scatter pretty much. It's almost at the level of measuring errors. So not only is that more impressive, it's much more like a main sequence instead of a fuzzy main sequence. Okay? But it's very practical, because now you can use it as a distance measuring technique. The Faber-Jackson relation has so much scatter in it that if you do know the velocity dispersion of a galaxy you still don't know its luminosity that accurately.
McCray:To measure the distance.
Faber:To measure the distance. Right. But people over the years have tried to refine more and more the distance measuring technique of the Tully-Fisher relation, and so there have been maps mapping streaming motions, locations of galaxies in space, and so on. So practically speaking, the Tully-Fisher relation has been a lot more important.
Faber:Now, what we now know though, if I can jump ahead a little bit, is that they're really the same thing. That we should think more globally and more generally. We should think of a three-dimensional space like the HR diagram but that only has two dimensions, add a third, and imaging plotting galaxies in this three-dimensional space. I'll tell you what the axes are in a minute. But for the moment, there is this curved manifold which is all connected, but it's not a plane. It has some curvature to it. If you make one projection of the past inhabited by spirals, you see this manifold exactly edge on. That's the Tully-Fisher relationship. If you try to do the same thing with the elliptical part you're onto the tilted part, and so therefore you get a correlation but it's fuzzy because you're not seeing the elliptical plane exactly edge on. Right? But there is another projection using a different combination of axes that shows the elliptical plane edge on. That's called the Fundamental Plane. And we did discover that later, but the right way to think about the Faber-Jackson relation is that it's an important projection of the Fundamental Plane, and the Fundamental Plane for ellipticals is just as narrow as the Tully-Fisher relation is for spirals.
McCray:Okay. If you look at the Tully-Fisher relation along this fundamental plane, is it fuzzy?
Faber:If you use the fundamental plane projection for ellipticals to project the spirals?
Faber:I've never done that, but I think the answer is yes it would be, because it would be the wrong angle for the spirals.
Faber:This took over ten years to figure out though. Yeah.
McCray:What are the axes?
Faber:The axes that I prefer are (1) velocity dispersion or rotation velocity. (2) Radius.
McCray:Of the galaxy?
Faber:Of the galaxy, and (3), surface brightness. So to make the fundamental to make the Faber-Jackson and Tully-Fisher projections, you take surface brightness and radius and you combine them in a way to get the total luminosity of the galaxy. [drawing a plot]
McCray:Take one over the other or ?
Faber:You take the radius squared, .this is the area, and the surface brightness is the brightness per unit area. So radius squared times surface brightness is the total luminosity.
McCray:And then you plot that versus the velocity that's emerging?
Faber:These are all by the way logs, and that's what makes it all work. Astronomy is basically logarithmic, and when you take logs, then to take this thing squared times that, that's two log that plus that, which is a linear combination. And so I think we sort of finished this topic.
McCray:Yeah. Okay. Let's stop for now then.
McCray:Let's talk some more about your research. Why don't we start with the Blumenthal et al. paper?
Faber:Blumenthal et al. Okay. So what was Blumenthal et al? I think it was the first complete coherent view of galaxy formation, although many of the ideas had certainly been put forward before. Even though I said, when I was a graduate student, there was no glimmer at all of how galaxies formed, I think that's not quite true. People like George Field had been writing papers about gravitational instability, and by gravitational instability what I mean there is the notion that an expanding universe is inherently an unstable system. You could make it uniform in the beginning, but unless it's absolutely, absolutely perfectly uniform, then the peaks, density peaks, will pull matter in around them as the universe expands. And conversely the valleys will lose their matter as it falls onto the peaks. And so universes, like pencils on their points want to fall over, expanding universes want to become lumpy. And I don't even know who figured this out. I mean it's really the fundamental thing. It probably goes back to the forties or fifties. But when I was a grad student, nobody told me that.
Faber:So in the sixties some papers began to appear. George Field wrote a discussion of galaxy formation at some point based on this I would say in the early sixties, and I can't even tell you where that paper is now. It's never referred to. It's interesting. It's sort of gotten lost.
Faber:The first real big paper that made a big splash about this is the paper by Press and Schecter, and I'm not sure of the date. I think it was around 1968 or maybe early seventies. I remember reading it just after I got out of grad school. I couldn't understand it although I could get the point, but I couldn't follow all the mathematics of it. It had a good introduction. The introduction was very helpful to me, and then I got lost somewhere later. I understood when I read this paper in the early seventies that it was an important paper and later, with the help of other people helping me to understand things, I came to understand the paper quite thoroughly, and it's referred to constantly. It's one of the most quoted papers in modern astronomy. So what that paper did was kind of neat. It put forward the mathematics of structure formation. And so it said that if we imagine the early universe has a spectrum of density fluctuations and it used the notion of a power spectrum or Fourier transform of the density fluctuations. It said, "Let's imagine that that's built in at the outset. We will now tell you with our little formulas how lumpy the universe is on various size scales as a function of time." And any reasonable density fluctuation spectrum is such that on small scales you have big lumps, but then when you average over larger and larger regions it gets smoother and smoother and smoother. It's just, you know, statistical beating down of the noise. And so they made the point that clustering structure formation would become hierarchical.
Faber:Here is a little lump with a certain percentage fluctuation difference from the mean. Here is another one with a fluctuation difference that is smaller. Confusing and not helpful. The universe expands. The first one will collapse first, and then the second. The first one essentially has a head start because it's already a bigger perturbation. It's lumpier. So since small scales are lumpier, as universes expand the natural idea is that little bodies of matter will fall first. And then they will fall together to make bigger objects, and then those bigger objects will fall together to make yet bigger objects. This is what people call hierarchical clustering.
McCray:Okay, so it's sort of like crystallization.
Faber:Is it? I wouldn't have thought so. That's interesting that you use that analogy. Is that how crystallization works?
McCray:Somewhat. Yeah, where you have a nucleus and then that nucleus grows.
Faber:Okay. It's kind of interesting that you have objects which for a while have separate identities, but then they fall together and lose their identities in making another object. So, this is the whole notion of galaxy and structure formation and I'm quite sure that it's correct because it's now predicting many, many things that have actually been seen.
I feel that understanding this process is one of the most deeply intellectually fulfilling things that a scientist could possibly ever achieve. I played a small role in this, a very small role. I mean most of the activity came from other people. But just to have been part of this process of unraveling all of this has been great for me. Why? Because the key to the whole thing is where the density fluctuations come from. And what we now suspect very strongly you undoubtedly heard this is that the density fluctuations were generated during inflation. And so it's almost a religious joy in thinking that we look at these macroscopic objects, these huge galaxies today, beautiful things, hundreds of thousands of light years across. Every one of them had a genesis in a quantum fluctuation at 10–35 seconds or so. I think that's just one of the greatest intellectual leaps that has ever been achieved by human scientists. And it's just really been thrilling to have been a part of this wonderful intellectual odyssey.
Faber:So I started out as an observer, and not trusting myself very much to put forward any explanations for things. My job was to measure data and let other people figure them out. My first departure from this was writing the review paper on masses of galaxies with Jay Gallagher, in which we went a little bit farther than just measuring numbers. We critically looked at other people's numbers. We tried to figure out what was important, what wasn't, and the end of that paper has a little section called Coda, which was kind of uncharacteristic for me at that time. It said, "Where are we now? What does this all mean?" And it's a statement now about the importance of dark matter, what we guessed the importance of dark matter would be, for the future study of cosmology in galaxies. I haven't read it for a long time. I don't even remember in detail what it says, but it did point out that the gravity of dark matter dominated the gravity of the universe and therefore that unraveling the physics of dark matter would be the key of understanding galaxy formation. This of course proved to be true.
Now, soon after that I was invited to go to a Vatican Conference in 1981. And I don't remember what I was asked to speak on. What I did speak on was galaxy formation. There was another very influential paper in this period, 1978, by White and Rees.
Faber:Yes. And it was very much in the spirit of the Press and Schecter idea except it built in the notion that by now people were really beginning to believe in dark matter. And people could very early see that dark matter would fulfill its needed roles only if it was non-interacting.
Faber:I.e., if it acted under gravity like a bunch of point-mass particles that didn't collide with one another, didn't radiate, didn't lose heat by radiating photons. Okay? It had to be inert except for gravity. And so they realized that early on a simple model would say that the dark matter and the baryons were well mixed. But they said supposing the lumps consist of dark matter and baryons uniformly mixed in universal proportions. This is the so-called adiabatic model. So if you have lump if the universe in general is 10 percent baryons and 90 percent dark matter, then in this lump that's the same ratio.
Faber:A simple model. Then they said, "Okay, what will happen as the universe begins to cluster? What will the dark matter do vis-à-vis the baryons?" And they realized that in the initial phases of a lump collapse, the two fluids would collapse together but the baryons since there is always substructure here there would be clouds of baryons and they would run into one another. They would get hot, and this would cause the baryons to shrink and fall. Whereas the dark matter has no way of losing its energy and would stay in a more diffuse cloud looking probably like a star cluster. So it was becoming clear that this was the dark halo of Peebles and Ostriker. And within that, we have a much smaller baryonic galaxy developing. So a question was, what's the fraction of baryons to total matter, and when we look at a galaxy, how big is the dark halo relative to the visible galaxy, both in mass and also in linear extent. And a burning question: Why do we get different kinds of galaxies in the middles of these halos if the process is basically always the same?
McCray:Different kinds meaning ?
Faber:Spirals and ellipticals. Okay, and then there was another interesting paper right along in here, and it was by Fall and Efstathiou.
Faber:There had been lurking in the background work by Peebles which had shown that if you had lumps collapsing in a hierarchical universe they wouldn't each collapse purely radially. Rather lumps would typically be irregularly shaped not spherical and therefore they would have some quadropole moment. And the tidal field created by neighboring mass would set the lump spinning and vice versa. So there would be ever so slight tendencies to rotate among these various incipiently forming lumps. So Fall and Efstathiou took that idea and there was even a number floating around for how much rotation there would be on average. They took this idea and they said, "What will happen if the baryons are shrinking within the holes?" They got some angular momentum when the whole lump was still well mixed. But then the baryons shrink and like a skater they spin up. So they said that the rotation of spiral galaxies, which seem to be very strongly rotating, was just sort of an amplified rotation from a collapse from a much bigger but slowly rotating halo. This solved a longstanding problem, because Peebles had already noted that if he just took his original halos with slight rotation made of pure baryons you can do the arithmetic, it's actually a back-of-the-envelope calculation and say that's all the rotation you have, you have a big problem. Let's let the baryons collapse and let's let them collapse as far as they can until everything is in circular motion so angular momentum is conserved, now we're just much smaller. Ask how big is the collapse factor? It turns out to be huge. You would have to consider that every galaxy originated from something that was fifty times bigger. There is not enough room in the universe to fit all the galaxies in.
McCray:So you can't fit the universe in the universe.
Faber:Exactly. That's right. So this was a conundrum. It was nice to know that you got some angular momentum from this hierarchical clustering process, but also it didn't seem to be enough. Magically, if you say that the baryons collapse within a structure which stays the same namely the dark halo or rigid dark halo now you need a collapse factor that's only a factor of ten. It seems a little bizarre. It's kind of like one of these rabbits out of the hat kind of things. Yeah. Again, you can see it on the back of an envelope but understanding intuitively why that should be true is not obvious at all. But now suddenly the protogalaxies could be much smaller and there was to fit them into the universe. . So that was a very, very promising way of going forward. Those were the items that existed for me when I had to talk about galaxy formation at this Vatican Conference. What I was interested in was the relationship between the original density fluctuation spectrum and the sizes of galaxies that we can see today. I put forward a toy model which wasn't very different from the Fall and Efstathiou model and I said, "Here is a halo. It's rotating a little bit. Let's imagine that baryons collapse in it. Now I am going to make a plot." I think I was the first person to do this, and the plot I chose to make was the density-inside a galaxy versus its internal velocity. So it was a density internal motion plot. And I put galaxies on it and I put clusters of galaxies. And then I had some rules for this collapse and I said, "Okay. If a galaxy is here in this plot, this is where the halo was that it came from." I generated the properties of dark halos and the visible properties of galaxies.
McCray:Properties being their location in space and how far out they extend?
Faber:Their densities. I wanted to put the dark halos in the plot. Their densities and their internal velocities. Okay? I said nothing about their distribution in space. That came later. And so I came to an interesting conclusion. I said that what everybody was saying about the density fluctuation spectrum was incorrect. People had been assuming that it was white noise. Okay? Meaning that the fluctuation amplitude declined as one over the square root of the mass. Basically it's a property of Poisson statistics. If you put more points in something then you are averaging over N points instead of fewer, then the amount of noise that you get or the size of the fluctuation should decline as one over the square root of N. So N, the analog of N here is the mass of the object. So this fluctuation spectrum had been in everybody's papers, and I said, "That can't be right. The fluctuation spectrum has to have more power on large scales." Because looking at the properties of galaxies and inferring the properties of halos I could just tell that that was true. So I went beyond that and I said I thought that the properties of visible galaxies were intimately connected with their dark halos. And therefore we had a new way of studying the distribution of dark matter in the universe by charting the visible properties of galaxies. Then I also wrote a separate paper on the structure of elliptical galaxies. Now this plot of density versus velocity you will recognize. That's another scaling law plot. Right? So this was the first paper which said that there is a relationship between the scaling laws of visible galaxies and the scaling laws of the dark halos which gave birth to them, and furthermore those scaling laws all come from the initial density fluctuation spectrum of galaxies.
McCray:Okay. So this is beginning to link these different things together.
Faber:That's right, that's right. Now about the same time the particle physicists were really getting going, and one of the exciting things about this Vatican Conference was that there were people there who knew a lot about the particle physics end of it. Steven Weinberg gave a talk which was largely incomprehensible to me. It was one of the first meetings in which astronomers and physicists came together and tried to share ideas.
McCray:How did that interaction work?
Faber:I don't really have a very clear memory of it. As I say, I felt way in over my head. I had had some really good thoughts at this meeting, original ones about galaxy formation. But I didn't know from nothing about the particle physics. Now floating around in all of this was the notion that maybe the dark matter was composed of one or more elementary particles. A very hot theory at that time was that the dark matter was made of neutrinos, massive neutrinos. Putting this very briefly other people could talk for years about the subject if dark matter was comprised of neutrinos then the hierarchical clustering picture wasn't correct. A universe full of neutrinos doesn't make little structures which then coagulate to bigger structures. It starts with pretty big structures and then by pretty big I mean like a huge cluster of galaxies, say 1015 solar masses. Then to get galaxies, you had to appeal to some sort of internal instability inside the big cloud. While the big structure is collapsing, you had to appeal to some entirely separate set of fragmentation physics to make the smaller structures within it.
McCray:Is one more intuitive than the other?
Faber:Well to me the hierarchical picture was completely intuitive but this was ridiculous. Right?
McCray:Okay. That's what it sounds.
Faber:It had famous names behind it though, notably Zel'dovich, who was a force to be reckoned with.
McCray:Was he at the conference also?
Faber:No. I think they invited him but he couldn't come out (of the Soviet Union). So that was my first foray really into thinking about galaxy formation.
McCray:When was this conference by the way?
Faber:I came back here and I forgot what I was doing at that point, but it turned out that on campus (at UCSC) two people were thinking about this. One of them was Joel Primack and the other who was thinking about this was George Blumenthal.
McCray:Now are these all astronomers or ?
Faber:Primack is a physicist and Blumenthal is in my department. He's an astronomer. So Primack has all the advantages. He really has the education I wish I had. You know, he grew up in physics and understands group theory and all the kinds of things that you need to understand particle physics. He has been a wonderful stimulus and a huge person who has played a big role in my education. He's been very, very helpful to me. So, separately they were considering the very point that I just made, namely if the dark matter consists of different kinds of elementary particles, how would this affect the density fluctuation spectrum? And I've just said that if it's neutrinos you don't get these small fluctuations; you get only big ones. Well, they or somebody else right around in then coined the theory "cold dark matter", "warm dark matter" and "hot dark matter". And those are bad names. What they really mean is massive dark matter, intermediate mass dark matter and light dark matter. And basically if your dark matter particles are heavy, then they slow down early in the history of the universe.
McCray:And become cooler.
Faber:Yeah. That's right. It's just that at a given temperature if you've got a more massive particle it's moving more slowly.
Faber:Right. So the critical thing is when do the particles start moving slowly relative to the speed of light. And a really heavy particle becomes non-relativistic much earlier in the history of the universe. But a massive neutrino, which is light, stays relativistic until quite late times, like 100 seconds or something like that. No, this is much longer. Needs checking. More like 107 years?
McCray:So it should be hotter.
Faber:Yeah. That's right. Well, it isn't really hotter in the sense that it that's why the names are so bad. They all have the same temperature; it's a question of how fast they are moving.
McCray:So they have different energies.
Faber:No, they have the same energy. mv2 is the same. If m is big then v is small.
Faber:Okay? Yeah. The jargon is horrible.
McCray:Okay. So but there is an inverse relationship.
Faber:Exactly. That's right. So, because the neutrinos are very light, they rush around at the speed of light until quite late, and it turns out that you can't make a clump out of something that's going at the speed of light. And so their clustering is delayed. And all the early lumps that would want to collapse early, they just get wiped out and suppressed and only later then the universe is very smooth on these small scales only later when the fluctuation spectrum says, "Ah. It's time for a 1015 solar mass guy to collapse" does a neutrino lump collapse. Whereas if there's cold dark matter in the universe you can you become non-relativistic very early, and effectively you can make things of all masses, starting from a million solar masses on up.
Faber:Okay. So Primack and Blumenthal were systematizing this. At the point we got together it would have been 1983 or 4, something like that, and it was one of the most intellectually satisfying periods of my life. We had intensive meetings. I was having horrible back trouble. I suffer from back trouble. And I was in one of my sessions where I was at home. For practically six months I didn't come to work. People came to see me. I lived on the hill at the bottom of campus, and I'd have a parade of visitors every day while lying on the sofa. And George and Joel would come by and we'd have these wonderful discussions. Basically what we did was we sketched out what the spectrum of density fluctuations would look like if the dark matter was comprised of cold dark matter. We realized that it would make small things all way up to big things. And then we figured out what the resultant galaxies would actually look like. And that's what this paper is about.
McCray:How did Martin Rees then get brought into the club originally?
Faber:Joel went off and talked to him in some sort of summer school. I was never part of that.
McCray:Okay. I'm curious. How did you fit in with primarily an observational background into this collaboration?
Faber:Into this collaboration. Well, the thing that was really good about this paper were the figures. There were two figures, and they made the point that by assuming a cold dark matter spectrum they predicted two scaling laws. One of them was effectively the Tully-Fischer relation and/or the Faber-Jackson relation. That's one of our pictures. I was the one who did the figures. So it was my job, they gave me a density fluctuation spectrum with a certain amplitude and I went away and I figured out what all the galaxies would look like, and then I said, "Okay, these are the predictive galaxy lines. Let me get some real galaxies and I'll put them in the figure, too." So I plotted densities of galaxies and galaxy clusters and their radii and all that sort of stuff. They would not have felt comfortable dealing with real data. I was kind of the glue.
McCray:It sounds as if you were providing the empirical data to go along with the ideas that you all had come up with.
Faber:That's exactly what I was doing. I had some independent theoretical ideas because I had done this separate paper for the Vatican Conference, but those two guys, they were the one who knew all about the cold dark matter spectrum and why it behaved the way it did. They explained to me what I just explained to you about the masses of the particles and the hot, cold and warm and all of that sort of stuff. The great thing for me was that cold dark matter provided just the slope of density ???????? spectrum that I had said was needed at the Vatican Conference.
McCray:How was the paper received when it was published?
Faber:I think it was very well received.
McCray:Okay. There wasn't hue and cry that this ?
Faber:No, no. I think people really liked it. Yeah. Peebles had written a previous paper about cold dark matter, and I can't even remember what that says, but ours was the first paper that said, "It's cold dark matter." Period. And Peebles went off later and wrote a bunch of papers about baryonic dark matter which never went anywhere. One of his rare forays into crazy ideas, because he's basically fantastic. So I consider that my best paper.
McCray:Okay. What effect did it have on your career?
Faber:Oh, I don't know. I couldn't tell you that there was any immediate effect. I mean it had more of an effect on me, in the sense that I felt, "Wow. We've really figured something out. And it might not be right in detail, but the ideas in this paper are going to survive." And they have. That's true. It's the standard paradigm.
Faber:Now this paper said a little bit about large-scale structure, but it was really focused on galaxies. There were some clusters properties that were plotted there.
McCray:Now the paper came out in '84. Had you begun to work on the large-scale structure problems as well?
Faber:Yes. Right. Independently, but I blundered into that, and I didn't really realize I was doing the same thing. Go back a second. I said that the Faber-Jackson relation was fuzzy. So we didn't realize that there was this plane and it was fuzzy because we weren't viewing the plane this way but that way. I had a bunch of friends David Burstein, Alan Dressler, Roger Davies and Roberto Terlevich. We were all interested in elliptical galaxies. We thought, from a small sample, that we understood the origin of this fuzziness. We thought that little galaxies were down here in the relation sorry, flattened ellipticals, highly ellipsoidal ellipticals, were down here, and round ones were up here. So we showed on the basis of a small preliminary sample that we could tighten the relationship a lot if we took flattening into account. And then we went from there to saying that we had a distance indicator.
McCray:A distance indicator.
Faber:That's right. And so our plan was to see whether or not in fact this tightening actually worked. I'm getting ahead of the story. Forget what I just said about the distance indicator.
Faber:We had thirty galaxies. We said, "If we had three hundred then we could really test this." So that's how the Seven Samurai project got going.
McCray:Is that how you like to refer to it, do you prefer the Great Attractor? Do you have a preference?
Faber:No, I don't. Okay. So I really totally mis -spoke. There was no thought of any distance indicator. We were studying the galaxies and we wanted to know if our notion of tightening the relationship would work. So we got three hundred galaxies in those days to observe. We needed both photometry and spectroscopy to do the velocity dispersions. It was a giant project for that time.
McCray:In terms of getting the telescope time to do all that?
Faber:That's right. So we enlisted that's how we got Alan Dressler. He was actually not quite in at the beginning. We asked him to come in because he had access to southern hemisphere telescopes. We thought it would be a good idea to have a survey that went clear around the sky. And Donald Lynden-Bell got invited in because he was a friend of Roger Davies.
McCray:And Roger at this time was at Kitt Peak, right?
Faber:He was in Cambridge. No, maybe he was at Kitt Peak. Yeah, I think you're right. So anyway, we mapped out this big observing campaign, big for the day, and it pretty quickly became clear that our original idea was incorrect. But then I'm trying to remember how this happened. Donald Lynden-Bell came along with an idea for a way of defining a new diameter. Donald's diameter was defined such that within it the galaxies had a certain surface brightness. It's wonderful to have a theorist in a group like this. His motivation was nothing physical whatsoever. He was just after a number that you could get accurately, a size that you could get out of bad data and still have it be pretty accurate. So he was thinking kind of like a statistician and no thought whatsoever to the structure of the galaxies. So we used to call this the "Donald diameter". And soon when we had a bunch of data, we plotted the velocity dispersions versus the luminosities, i.e. the Faber-Jackson relation. It looked awful. We tried to tune it up by looking at the flatness of the galaxies, the elongation. Didn't work. Then we said, "Well, let's plot the velocity dispositions versus the Donald diameter." [claps hands] Amazing. Things just got incredibly narrow. And then the whole thrust of our project we had been feeling a little blue because our original idea of elongation hadn't worked. Then suddenly the whole thrust of our project changed. We realized we had a distance indicator as good as the Tully-Fischer relation and we giving credit to Dave Burstein he was keeping big data catalogs for us. He had noticed that there was an area of the southern sky where all the galaxies seemed to have the wrong velocity. If we predicted their distances based on the Donald relation, their velocities were all too big or too small.
McCray:Do you expect the velocity distribution to be homogenous across the sky?
Faber:Yeah. That's what we thought. You could read papers at that time, especially Alan Sandage. People were claiming that the noise in the Hubble flow was 60 km/sec.
McCray:Is that a lot or a little?
Faber:60 km/sec? That's very small. Okay? Andromeda is falling towards us with that velocity. So now there were skeptics. Vera Rubin was one. Because Vera thought that the universe was quite lumpy. A whole separate subject would be the Rubin-Ford effect. But maybe we won't go there because there might not be time, but you know, sometime in the future.
McCray:We can always come back to it.
Faber:Okay. She had done a study with Kent Ford which had shown that there were huge holes in the universe. Voids what we would now call voids.
McCray:Okay. I'm going to pause for a second.
Faber:I would say that I already knew that the universe was very lumpy extremely lumpy. The Kirshner [research] work did not come as any surprise to me at all. Why? Going back to my thesis, I had combed through the De Vaucouleurs catalog looking for galaxies to observe. I got my time in the spring at Kitt Peak, I found galaxies, no problem. It was time for a fall run, I went to the catalog to look for galaxies to observe. I was in a desperate situation. There were no galaxies to observe. It was almost embarrassing, in the fall. Finally I did find some, but I could just see that using redshift as a measure of distance, looking out into the fall sky there were huge, empty regions with nothing at all.
McCray:Okay. The voids.
Faber:Thousands of kilometers across. Yeah. So I already knew about voids. I didn't think of publicizing that in any way. I think De Vaucouleurs knew it fairly well also.
McCray:Was this something that observational astronomers just knew intuitively?
Faber:Yeah, I think so, because you go through the data catalogs, especially in those days when there was no way to go through them except read them, you quickly got in touch. Quicker than theoreticians would.
McCray:So you'd have a sense over the course of the seasons what the sky looked like?
Faber:Yeah, exactly. Right. In-depth as well as on the sky.
McCray:So this discovery of voids then really was something then that people knew?
Faber:Some people knew it, yeah, but some people definitely didn't. And you know there is nothing truer than "a picture is worth a thousand words." I never made a picture. Yeah. So, people who got these catalogs and made the first computer-generated pictures, they were very powerful. Where was I?
McCray:The Rubin-Ford effect.
Faber:Right. Okay. So then a point that Vera had made with the Rubin-Ford effect, she was always very powerfully motivated by another measurement which I think came from 1968. That was the absolute motion of the Milky Way. She would say and they did say in their paper, the Rubin-Ford paper how is it that the Hubble flow can have a noise of only 60 km a second and yet our Galaxy is moving with respect to the microwave background with a velocity of 600? And in their paper, they basically had a shell of material around us at a distance of a few thousand kilometers a second, which they found was populated very inhomogeneously from one side to another. They said, "Let's imagine that the motion of the Milky Way was generated purely by this shell of matter. Let's figure out what the direction and velocity of the Milky Way would be." And they got something that was sort of vaguely right. I mean it didn't point in quite the right spot it was kind of like that, you know.
McCray:Slightly different direction?
Faber:Slightly different direction, but it was plausible. It was a good point to make. I think actually, although Vera's gotten maybe a little too much credit for her rotation work, she's not gotten enough credit for the Rubin-Ford paper. It was very controversial and people just trashed it I think pretty much unfairly.
McCray:What was their primary objection to it?
Faber:The primary objection was a critique that was written by Mike Fall. And he said the following. He said, "Yes, let's imagine that the universe is very lumpy." They (Rubin and Ford) wanted to believe that their galaxies were in a shell. To get the shell, they used a distance indicator based on the luminosity. It wasn't perfect. Mike said, "Look. Supposing there is a big lump of galaxies right beyond your shell. Some of them will be scattered into the shell just by errors. And likewise if there's a lump on the fore side, on the near side, galaxies could be apparently scattered into the shell. Basically they were making the point that you couldn't believe that the objects studied were really in this shell they might have scattered there from either the foreground or the background by errors. Vera is not a strong statistician, and she really hadn't thought deeply about this effect and how it might affect her analysis. But nevertheless, Rubin and Ford were essentially right. The basic notion that they found that the universe was very lumpy is true, and particles of it are moving at hip speed, pulled by the clumps.
Faber:Anyway, so we were very attracted by Dave's pointing out in our data set that one whole side of the sky was going at the wrong velocity. This was of course the Great Attractor. And about the same time we generated this really nice distance indicator out of the Donald parameter, and so kind of overnight our whole thrust changed from studying galaxies to studying motions, because we could compare the observed velocity with the estimated distance and that gave a peculiar motion.
McCray:Peculiar motion defined as?
Faber:A peculiar motion meaning a motion of that galaxy with respect to the microwave background. So this was people had tried a little bit of this before. There had been some work by Paul Schecter and Marc Aaronson trying to measure the peculiar motions of galaxies as they fell into the Virgo cluster, which was considered to be the largest big inhomogeneity in the nearby universe. But their sample was small, much smaller in space. Ours went probably three times farther in all directions. And we ran into this perturbation over there in the southern hemisphere, and suddenly people realized there was a supercluster over there that made Virgo look like podunk.
McCray:Was it a gradual realization that there was this point that all these galaxies were streaming toward? I mean, I'm trying to get a sense of the time frame or the time scale at which this realization came to everybody.
Faber:Well, it's interesting. We knew that that region of there were a couple of points here. We knew that region was peculiar because Dave kept saying, "I see peculiar motions of a thousand kilometers a second over there," so we knew there was something going on there. But we were a very methodical group. I wasn't thinking about what anything meant, because I was still in the process of getting the radius for galaxy A and the velocity dispersion for galaxy B. You know, I just wanted to get the data table done. So Dave's point was always in the back of my mind, but I wasn't ready to think about it yet. Then another point occurred when all of this seems elementary now somebody said, "What frame of reference are we going to work in?" We had always thought, well, we shouldn't work in the frame of reference of the earth, because we know the earth is moving around the sun; shouldn't work in the frame of reference of the sun, it's moving around the Galaxy; we know the Galaxy is moving relative to the Local Group. So the standard frame of reference was the center of mass at the Local Group, and that's the frame we had been plotting all of our data in from months and months and months. But then somebody said, "Well, that's not very fundamental. We know that the Local Group is moving at several hundred kilometers a second, 600, with respect to the microwave background. Shouldn't we be thinking about the microwave background?" Everybody said, "Yeah, okay, that's good. That sounds fundamental."
On a street corner in Hanover, New Hampshire, Donald Lynden-Bell and David Burnstein and I were crossing at the light. We were standing there waiting for the light to turn green, and suddenly we looked at one another and said, "My God! That means that everything is going to move at 600 km a second with this change of perspective." It's funny how these little things suddenly hit you. And so we could see that velocities which had been looking small were going to suddenly become gigantic by the standards of the day.
McCray:Okay. Because they're all going to be speeded up by the same amount.
Faber:That's right. Some of them would get small on one side of the sky, but others are going to have 600 km a second added to that. Wow. At that point, we could see we were really onto noise in the Hubble flow, and that's where our focus was after that. Now, at this point the story bifurcates, and this is the story that Alan tells in his book. Alan was impatient with our group. He always wants to get things done rapidly. He's very focused. He's the kind of guy who goes to the grocery store and buys exactly what he needs for his project. Our project had been lagging, partly because I was sick. I had horrible back trouble, and I would do nothing for months and then manage to be with the group. Over the summer we'd get something done, but Alan was very impatient felt he had put a lot of work into it and nothing was coming out. But nevertheless things were proceeding. We finally got our data and the people who figured out how to analyze it were Donald Lynden-Bell and me. And, as part of our contribution to this project, we thought about how to analyze data that had errors. It was the exact same thing that Rubin and Ford didn't really do very well in their paper.
Faber:And there had been floating around the concept in astronomy called "Malmquist bias". Malmquist was an astronomer from the twenties. We all learn about Malmquist in graduate school in one way: If you make a magnitude-limited catalog, say you take all the stars in a catalog brighter than tenth magnitude, those stars will be brighter than average. Because the ones that are intrinsically slightly brighter can be seen to larger distances, and there will be a larger volume of them. So there is this constant tendency in magnitude-limited samples to be sampling objects that are a little bit brighter than the mean of a typical object. Okay?
What we developed in the mathematics of this paper was a parallel notion which is now also called Malmquist bias and that is that if you measure the distances to a catalog of objects, typically you are underestimating the distance to a typical object unless you measure with perfect accuracy. The typical object is a little bit farther away than you thought it was. And it's the same kind of volume effect. So Donald and I puzzled over that and we developed the mathematics of how to measure our sample and take that into account. And we were writing a paper. Donald also did even more. He wrote a computer program that could take all the data points and fit to a simple model, a model that had some bulk motion and some streaming along different directions and some well- defined attractor points in it this Great Attractor over there and the Virgo cluster. So it was a pretty complicated model with about a dozen parameters altogether. And Dave's peculiar region was really showing up so strongly as a point at which galaxies were falling towards. And it was. I was visiting Donald, it was January, we were working over there in England where the weather was very bad, but we were extremely excited: no matter what we could do, all our fits had this gigantic in-fall to this place over here at the edge of the survey. Meanwhile Alan, in disgust, had decided to go observing. He never told us about it. He went to Chile and he just decided that he would measure I'm not exactly sure what his measurements were, but he was making measurements of galaxies in this key direction. And he sent us an email or a letter that said, "I found something really important in this direction." And he might have even sent us a draft manuscript to Nature in which he wanted to publish his new results. We were furious.
Faber:Well, because he's a member of the team, he's upstaging us, right?
McCray:So you're furious.
Faber:Yeah. This was the worst scientific dispute I've ever had. Yeah. Especially with somebody who was so close to me. And there was probably right on both sides. Ultimately there was a gigantic apology, but some feelings were permanently wounded. Anyway, Alan decided he wouldn't publish his paper because Donald and I were saying the same thing in what was going to be the culminating paper of the collaboration, and it was said more thoroughly and more carefully in our paper. So anyway, that's the end of that story. That's where we published our final results and claimed that there was a very large supercluster over there that was perturbing the local Hubble flow.
McCray:Do you feel that his book is a pretty accurate telling of how it all happened?
Faber:I think so, yes, I think so. It's a very fair telling. Yeah.
McCray:Okay. Is there anything that's not in there that should be?
Faber:Not that I can think of at the moment. I haven't read it for a long time, but I liked reading it. I thought it was very fair.
McCray:It's well written.
Faber:Yeah, he is a really terrific writer.
McCray:I guess one of the things I find interesting is at the same time as your group is doing this work, the CFA redshift survey is going on and the results by and large came out roughly at about the same time. I think they go through release '86, '87, '88, in that time period.
Faber:Yeah. I remember that very distinctly because I had to give a talk at was it the Houston AAS or maybe the Austin AAS? There was a AAS meeting in Texas that I went to, and I gave a talk because, I think, it was the talk where I got the Heinemann Prize. Anyway, I gave a major talk there about our work, and that happened to be the same conference in which Margaret Geller showed the "stick man" figure. And I was miffed, because first of all, as I've said, I already knew about these voids for a long time, right? Second because measuring redshifts is about 1 percent as hard as measuring distances to galaxies. And our project had fewer galaxies but was infinitely more painstaking and difficult and more work. And I thought, "Yeah, it's easy enough to say where the galaxies are, but to measure how they're moving is another thing." Yeah, so frankly I felt upstaged by that.
McCray:Okay. Have you interacted at all with ? I mean I guess I realize the CFA Redshift Survey was the product of several people but Huchra and Geller are the two names that are associated with it the most.
McCray:Especially in its later formulation when Marc Davis had moved on.
McCray:But have you interacted with them as a group at all?
McCray:Any particular reason why, given that both projects to someone in my position seem to involve roughly the same thing?
Faber:They do look rather the same.
McCray:Not the same thing, but they both are addressing the same issue, the large-scale structure.
Faber:Yeah. Well, I wasn't interested just in maps of galaxies. I really cared about how things were moving. So their data set didn't have much to tell me about that. They were also notoriously stingy with their data. They didn't release catalogs. I think it was damaging to them. People didn't like it.
Faber:Well, because you shouldn't sit on unique data sets for too long. People get mad at you. And my experience in astronomy has always been the more you give away the more you get back. And that's not how they ever treated their data.
McCray:Is this a personality-driven phenomena, or is this more of an institutional you know, are astronomers at CFA notorious for sitting on their data for example?
Faber:I wouldn't say that astronomers at CFA are notorious, but speaking completely frankly, people have deep difficulties with Margaret, and she has had many kinds of disputes and disagreements with a variety of people. John is not known for this at all. So people have told me that sitting on the data and keeping it close was really something that Margaret wanted to do more than he. Beyond that I can't say. I don't have any more insight.
McCray:You mentioned that the 1984 paper, you felt it was your best, that Blumenthal et al. was the best paper.
McCray:But I'm curious also, the work on the Great Attractor. What effects did that have on your career?
Faber:That had I think a more positive effect. I think at the time that work was really That's an interesting case. I think most people when they write great papers, more often than not they are not recognized at the time but history sees in hindsight that this was really a terrific paper. And I think actually the Great Attractor paper was a paper which made more of a mark at the time than it has in light of subsequent history. It was very good psychologically. I missed a key meeting. This was Dave Burstein's greatest moment. As we were getting our results, there was a conference in Hawaii run by Brent Tully, and Dave stood up and gave his talk and it was the best moment of Dave's life. I mean, he tells this story with relish, because people just could not believe it. So it's hard to remember, it's hard to put yourself back into the frame of reference of people of that time how deeply ingrained the notion of the smooth Hubble flow was and now groups of people coming along and saying in places that perturbations are a thousand kilometers a second, that was very powerful stuff. Now that that notion has all sunk it, what else is really lasting about our paper? Not much. And the reason is that it's proven to be very, very difficult to measure these distances with sufficient accuracy. As you look back at our paper, they were good enough to say that the Hubble flow was very irregular. But we tried to do a lot more than that. We tried to actually deduce what the spectrum of fluctuations was. Avishai Dekel spent a lot of time trying to make maps out of this and subsequent velocity flow studies, and I think that the gist of all of that is that all of the data are completely consistent with the current model, but they're not good enough to add anything extra to the current model. Other ways have emerged of measuring cosmological parameters even better.
McCray:Was there any strongly positive or negative reaction from the science community to your work that you recall, to the Great Attractor paper?
Faber:Well, I think personally Well, first of all I got many invitations to speak. I probably gave more colloquia revolving around that work than anything else I've ever done. I might have given thirty colloquia altogether in the years 1986 to 1990. It was a very hot subject. And then, indirectly of course, people like Dave would tell me these wonderful stories about meetings that I unfortunately wasn't at. But I felt as though that work was really at the forefront at the time.
McCray:Since you mention about giving colloquia, I just want to jump ahead to another later question, and that's along the ideas of the astronomer as a public intellectual figure. And I noticed in looking over your CV that you have given a lot of talks to a really wide variety of groups everything from it's been a while since I noticed it, but it looked like you had high school groups, civic organizations, the whole panoply of organizations. And this is interesting I think because not many scientists, especially astronomers, are recognized by the public. And I find this odd because there appears to be a great public interest in astronomy, so why aren't more astronomers visible to the point of being household names? And your CV indicates that you have made an attempt to reach a pretty broad audience, and I'm just curious about your thoughts on this experience.
Faber:Okay. Can you focus the question a bit?
McCray:Have you chosen the groups that you speak to? Are you typically invited to give a talk at a high school?
Faber:How do people come to me? Yeah. Well, first of all, going back to my early times, it took me a while to figure out that I was a good public speaker. Didn't know that. But I gave a few talks on I'd have to look back through my CV for inspiration. I just felt at the time they were very successful. But especially those lower-level organizations and groups, you notice they are local. So they are calling in all the time to the Observatory and Department, this or that group wants a speaker. So I certainly didn't accept every invitation, but I have an ethic to speak to the public. The reason is simple: astronomy doesn't produce anything much that's tangible the way other sciences do I mean drugs or chemicals or industry or And yet at the same time on a per scientist basis it's one of the most expensive sciences. I mean, the Keck Telescope is a dollar a second to run. So, not only do I feel I'm very well paid, but I also feel that my work is very expensive and therefore is in some sense precious. And I feel a great duty to the taxpayers of the State of California. What are they going to get back? Do I sit here expecting to get a completely free ride? How can I give back? I have to give back. So the only thing that astronomers really have to give back is knowledge, and people thirst for this. Not everybody. I'd say about half the people. It's kind of like an interesting religion. Some people could care less, and I meet them on airplanes, and you know they are very skeptical about the worth of everything that we do, and even if I try to engage them in conversation they are still skeptical. It's like saying, "I don't like blue. No matter how you talk to me about the beauties of blue, I still don't like it," you know.
McCray:What are they skeptical about?
Faber:They don't see how it's at all helpful. It's not relevant. At least, not to their own lives.
McCray:Okay. Well, that actually leads really well to the follow-up question which was, what could astronomers do to make it appear more relevant or make people see some value in this?
Faber:I have been working on that, and in my recent talks I'm exploring a theme that actually, of all sciences, astronomy is the most relevant and the most important. And that's developed I'm trying to develop the notion every time I give a talk I go a little bit farther that there's some basic background knowledge that's important to being a citizen of Earth. And you really can't be a responsible citizen and you can't think about the future of the human race unless this basic background knowledge is at your disposal. And of all the sciences, astronomy provides that knowledge more than any other. So, examples we're small, we're fragile and we're far from any help.
Faber:Okay? People should know that. The Apollo pictures, which you see all over the place, you know it's almost that these messages are subliminal. You kind of absorb them almost in a subconscious way, but once they're inside you they inform all the rest of your thinking. This message is obviously at the heart of the environmental movement. To understand the scale of human activity relative to the scale of the planet; to understand that we're safe here and only 10 miles up it's the vacuum of outer space. This incredibly thin layer. What a better picture than a picture from a NASA orbiting spacecraft showing that the atmosphere is this tiny, thin layer and you know that's all that protects you from death.
Faber:So those are some of the thoughts. Then another thought is the fact that the Sun has another 4 billion years to go. That's an incredible gift. Part of the story is the notion that we got here as fast as we possibly can. It took us 14 billion years, right? But you go, you walk through all the steps. Galaxies formed as fast as they could, we built up metals in the Milky Way. You don't make intelligent life without carbon and stuff like that, so you had to have nucleosynthesis.
That went on, and then bingo the Sun if you think about it, it's one of the first stars around here to form with as high a metallicity as it has. It actually was a pioneer. Only now, 5 billion years later, is the average interstellar metallicity coming up to the level of the Sun. The Sun must have formed in a little pocket that wasn't well mixed where previous supernovae had gone off. And actually there is some evidence for that in meteorite metallicity abundances. Amount of aluminum 27 I think or something. Anyway, so we were a forerunner and we got a head start. That's interesting, because maybe there's nobody else around yet. Maybe there are a whole bunch of intelligent civilizations at the center of the Galaxy, where the metallicity went up much more rapidly in the beginning and you could have a lot of planets, but maybe around here in our part of the Galaxy there's nobody else around. People are interested in these concepts. I don't know what we're going to do with that one yet, but I'm also on the board of directors of SETI, looking for intelligent life. Maybe this is a hopeless prospect because there is actually nobody else around here... yet.
McCray:A lot of what you're describing just now lies at the intersection of cosmology as a science, religion, theology, philosophy.
McCray:Right there, I mean what you just were talking about, the center of the Venn diagram of all these different things.
McCray:Are you comfortable with all of that? I mean if you talk to people for example like you said on an airplane and you mention work about cosmology and the conversation veers to theology and religion, what's your take on all of that?
Faber:I'm totally comfortable with it. I'm an atheist. I don't have any although I think that people who believe in God can get a lot of reason to do so from modern cosmology. There is the well-known fact that the universe seems to fit together beautifully like a precision clockwork you know, so one very rational solution to that is that God created the universe and it could be made in only one way and that's why it is that way. These all fit together beautifully, precisely because that's how you make a universe. So people who look at the wonder of creation and how beautifully everything fits together and conclude that God must exist, I think it's a perfectly rational conclusion.
McCray:But not one that you share.
Faber:It's not the one I share. I don't know if you want to hear about my theory.
Faber:Okay. The other alternative which is equally rational is that there are a semi-infinite number of ways of making universes and some of them will probably fail and can't exist at all in any form. Others will exist but they won't give rise to the kinds of beings that we are or even our periodic table of the elements. If you don't want to talk about intelligent life, just talk about the atoms in the universe. And so there is a window of opportunity for people like us, and we're in our universe has the properties that it has basically because we live in it. This is the anthropic principle. But I think the anthropic principle is eminently simple and not nearly as complicated as other people have made it out to be. What is the thrust of it? Really, the interesting conclusion if you like this way of thinking is that you must believe in the actual existence of the other universes. So you conclude and in what sense do you really conclude? What kind of logic is this? Sitting here on Earth just looking at our universe, going through this thought process you conclude that there must be other universes. How could you even do that? But there is a perfect analogy which we know from history would be absolutely correct. Let's put ourselves in the shoes of a Greek astronomer thinking of trying to understand the properties of the earth. Now in the Aristotelian model of the universe the earth was a very, very special object. It was the center. And let's pick a property the radius of the Earth. Supposing you were thinking in that way and you tried to figure out why the Earth has the radius it does. What else could you do but fall back on some kind of God that made it that way? There was no other reason for it to be that way, right? However, if you had been a very free-thinking Greek astronomer of that time you might have thought that there were other Earths and planets out there. You might have thought about what their properties would be like the strength of gravity, whether they could retain an atmosphere, et cetera, et cetera, and you would have concluded that the radius of the Earth was roughly as it is simply because you couldn't live on any other kind of planet. But you would also at the same time conclude that there were other planets.
McCray:Okay. So if I lived on a different planet it would have a different radius and I would be different?
Faber:And you would be different. That's right. You might not be able to think.
McCray:So it's a question of why do my pants fit me. Because they're my pants.
Faber:Yes. That's right. But what's really interesting is the notion though if you really believe this, you've got to believe in the other guys the ones that you can't see. The pants that belong to other people.
McCray:I've been to The Gap, so I know there must be other pants. [laughs]
Faber:That's right. So I believe in many universes.
McCray:Okay. I don't want to go too far down this path, but just one last question. When you explain this idea again, I'm thinking of the mythical person sitting next to you in an airplane what's the reaction that you ?
Faber:Again it's as though people's minds are in two categories. The one person will think, "Wow, this is really interesting. The work you do is the most interesting thing I could possibly imagine," and will get into a discussion with you about this and probably want to tell you what they think. Versus other people who are completely incurious and think it's irrelevant and speculation about things that cannot be seen and touched is not interesting to them.
McCray:Hmm. A lot of your work deals with correlations. Do you see any correlation between this one property that you just identified, interest or lack thereof, with other properties?
Faber:Well, I never get to know these people well enough to know what other properties they might have.
McCray:Yeah. And I would imagine the people that you do know
Faber:Are all like me. [laughs] Right.
McCray:Okay. All right, fair enough. I'm going to pause here for a second. Okay, we're back on. I thought before we talked about telescopes I kind of wanted to come back to something else which is sort of related I guess. At various points you have been critical of the national observatory system, and I was curious what is the root of the criticism?
Faber:They don't lead. And I've been critical of the optical system. I haven't been critical of the radio system.
McCray:Yeah, I should have clarified that. That's what I meant.
Faber:They don't lead and they're expensive, and the combination is deadly.
McCray:Okay. When did you begin to notice that problems were developing in this system, since you had been involved with them from an early point in your career?
Faber:Well, I don't really I can't think back to when I noticed problems. This is interesting. Good question you are asking me, and I can't tell you the history of my thought process. I can tell you that I wrote a memo which brought the house down. And that would have been probably around 1993 or '94. There was a committee called the Committee on Astronomy and Astrophysics, and it was set up as a follow-on to the Bahcall Report.
McCray:Okay. Was this the one that Dick Mc Cray chaired?
Faber:Yes. Well, no, no. I don't think he was chair of this committee. This committee produced his committee, and he went off to review the state of NOAO. Why did it produce his committee, it was because of my memo, which I'm happy to share with you if you want. It's one of those little pieces of paper that I won't throw away. It's in the computer.
McCray:Good. Keep it. What was the thrust of it?
Faber:The thrust of it was that the optical astronomy observatory ought to model itself better on the radio astronomy observatory. And it should team, partner, much more closely with the universities. The universities were viewing it as a soaker-up of funds and a competitor rather than a facilitator and a helper. And I think the gist of it was that the optical observatory ought to act much more as a flow-through mechanism for money to go to the university community rather than spending money on telescopes that were sort of also also-rans to service people in small departments who were not at the forefront of research anyway. It was brutal. And it got loose in NOAO by accident.
McCray:You didn't intend that to happen?
Faber:I didn't intend it to happen. I sent it to Tod Lauer who is a staff member there and I said, you know, "I'd like your reactions to this." We were talking about several subjects and emails crossed and he sent me an email and I thought he was talking about this other subject and I said, "Sure, fine." What he meant was, "Is it okay if I share this with my colleagues?" And that was the last thing I wanted to have happen. And so it got loose in NOAO even before my committee (CAA) even had a chance to see it. It created a firestorm. Oh, I was cordially hated there for many, many years. Yeah. People took it very negatively. They took it as though I wanted to get rid of them. How could I want to get rid of the National Observatory? I did my thesis there. I think it's very important to have a national observatory. But I only wanted to make them more beloved. They took it in a very, very unfriendly way, so matters were difficult for some time. And my reaction to this was I thought that my thoughts were so negatively perceived that I should get out of the action. So I stood back for many years and I didn't express a single opinion on this subject. And the McCray committee went off and it did its thing. The people at NOAO widely viewed that as a sort of a hatchet job that they had me to thank for. So this whole thing has had to kind of die down in the interim. Meanwhile, they have hired Steve Strom and the new director, Jeremy Mould, and I think both of those people see a need for change. So NOAO is going to change. I don't know how it's going to change, but it will.
McCray:One of the things that I think is really remarkable is in the last ten years well, twenty years ago people were making plans to build 8 to 10 meter class telescopes. But I think what became remarkable was the number that ended up being built. I mean, well over a dozen, which I think if you had gone back to the 1970s and you said, "Okay, imagine yourself now thirty years in the future. There will be close to fifteen 8 to 10 meter telescopes," I don't think people would have believed that.
Faber:You're so right.
McCray:But what I'm finding curious now, is now people are starting to talk about the next generation of large telescopes. And I guess the sense I get is that it's hard to imagine a dozen 30- meter telescopes existing. At some point it seems that there is a drop-off in the number that the environment can support.
McCray:But I'm curious. I mean with plans for the California 30-meter telescope going forward, what would be the effects on the community if that's the only one that's built?
Faber:I think it would be disastrous. Yeah. Well, I think it would be disastrous if it stayed purely in private hands, i.e., California hands. I'm extremely worried about this motion to large telescopes. And I'm not part of the movement.
Faber:First of all, I feel there has been a certain rhythm to telescope construction in the past and I think there's a logic to it. I think it takes a good twenty-five, thirty, maybe forty years to milk a new telescope. Technology has to catch up. Paradoxically, it's easier to build the telescope than it is to build the instruments that go on it. And also, shaking down an observatory takes quite a while. I feel that within our organization now, the California community, Keck is getting woefully short-changed because people are thinking way too much about this next generation of telescopes when they should be thinking about perfecting Keck. This is kind of my personal style though. I really like to tie off jobs. I have a long attention span. I don't get bored quickly with what I started, and I started Keck. Well, not just me obviously, but you know what I mean.
McCray:You helped write the scientific case for it.
Faber:That's right, but for years I also served on the Science Steering Committee, and now I've spent ten years building an instrument for it. So I feel as though I'm heavily invested in Keck, and it just galls me to go there and see it not working perfectly and know that it could be working better and more efficiently. It could be singing if it just had a little bit more money. It's being operated on a total shoestring. It's way underfunded by about a factor of two. So all my impetus, which comes from wanting to do a job really well and finish a job that you start, is to put my efforts into Keck and make it better. And I think I view the bigger telescopes as a distraction. You asked me why I don't like them, so that's reason one.
Faber:Reason number two is that I think they're too expensive, and I think it's kind of like the efforts to build the Superconducting Supercollider, which ultimately collapsed under its own weight. I don't really see the resources anywhere in astronomy to fund an undertaking of this magnitude ($0.5-1.0 billion). I don't really see it. My advice to my colleagues is if you're going to build this telescope you better procure all the funding up front the funding not only to build it, but the funding to operate it for a very long period of time, the funding to build all the instruments, and, if you don't involve the national community, you better have the funding to do all the research because you are not going to get any research money out of the National Science Foundation. For two reasons. First, people are going to hate you; and second, what you do is just going to be way too expensive. The National Science Foundation's funding for astronomy is pathetic, and its budget to cope with big projects is just absolutely pathetic.
McCray:I don't know if you get the FYI notices that come out from the American Institute of Physics, but
Faber:Yeah. I read them regularly.
McCray:The one that just came out yesterday was that the
Faber:Fifteen percent increase.
McCray:But the facilities budget was cut by 47 percent.
Faber:Oh really? This I didn't see.
McCray:Yeah. Anyway, that's neither here nor there I guess.
Faber:It's absolutely tragic.
Faber:Yeah. So, meanwhile of course astronomy has been a focal point of competition in other countries. Japan and Europe are eating our lunch.
McCray:Okay, I'll have a question about that, but I have one other thing related to what you have said. Why are astronomers now at this point in time barely finishing one observatory before they're already scrambling to get the next one off the ground?
Faber:Oh, I think Jerry Nelson is the reason.
Faber:Yeah, I think Jerry I'm speaking really frankly now. We better put this deep in the archives here.
I think Jerry had a wonderful time and did a fabulous job building the Keck telescope, but I think he was a little lost after that. He didn't immediately find another project that he wanted to become involved in. And I think this building of the new telescope is a way of you know, that's how he wants to promote and further his scientific career.
Faber:But you know the world was not talking about 8 to 10 meter telescopes until we talked about Keck. And as you say, the idea caught fire. The world was not talking about 30 to 100 meter telescopes until Jerry started talking about them. And now that idea has caught fire, too.
McCray:Hmm. Interesting. Since you became an astronomer, how has using a telescope changed? And I guess I'm sort of the banal, "Well, it was more computers," etc., involved. I'm trying to get sort of a broader picture of what does it mean to be an astronomer as the telescopes have become more complex.
Faber:Well, you're certainly more a part of a team. I was trying to express that fact earlier in talking about what it's like. I think I feel less communion with the universe. When I sat there at Swarthmore and listened to the crickets chirping at 3:00 a.m. as I took my pictures and I could look up and see the stars through the slit, you know, that's sort of the quintessential observing experience. When you are surrounded by computers you are kind of insulated from reality. Well, it's another form of reality I guess. I'm sounding old-fashioned. On the other hand, I wouldn't trade it for anything. I mean, you have such power at your fingertips that when I looked through the telescope at Swarthmore and I saw a star that was 30 light years away and now I can get an image with the Keck that looks back 10 billion years in time. If that's the way you have to do it, that's the way I'll do it.
McCray:Okay. Is going to the telescope as important as it once was?
Faber:No. No. I don't think so. I think people are trying to avoid it at Keck, because it's 14,000 feet. People don't like to go there.
McCray:Okay. I should have clarified that. I guess I'm still I'm thinking more in terms of whether it's in a control room at sea level versus the telescope up here, but I'm thinking about, you know, the current trend towards virtual observing, data mining, archives, all of those sorts of issues. You know, if one reads about National Virtual Observatory, you hear statements like, "Oh, well it will make the observatory obsolete because you can just sit at your computer terminal."
Faber:Yes. There is always going to be that. I think that's going to be a growing trend. I don't think we're near the point though where we have observed the universe in sufficient detail that there's no more to be observed. We're way far from that. And given the continuing advance of instrumentation I think we are very far from that. On the other hand we are archiving much better than we did before. This is my other complaint about NOAO. In my opinion the way they could serve their public best is to put money into archiving and to insist in this new partnership with university-run observatories, that observatories run archives and make their data public. It's been a scandal, the tradition in optical astronomy that the observer who takes the data owns the data forever. Not when we have massive facilities in which so many people have worked and cooperated. I should be making my data public. The trouble is, it's expensive. But if somebody like the National Observatory came along and said, "We'd like to start a Keck archive. Will you put your data in it?" of course I would.
McCray:Institutionally, how do you think that would work in terms of trying to set up a system where all the public data and then the Magellan, LBT, you know, could that be arranged in the current climate of astronomy, or is that ?
Faber:I think if there's a quid pro quo it's becoming more and more possible. Because observatories like Keck that are expensive to run are more and more willing to give something back in order to have their operations furthered. So if the NSF came to Keck and said, "We'll give you $5 million a year, but you have to give us all your data," I think that would provoke a real discussion. How come nobody has done that? Lack of imagination. That's how I diagnose it. Now, in the Keck community, the UC observers are much more open to this. The Caltech people, again, are much more steeped in the tradition of "it's our telescope and our data." And again they have so much less incentive to try to improve the situation because they are already very well off.
McCray:Is that due to the historical momentum of Caltech having access to the 200"?
Faber:I believe so. I believe so. Here's an interesting thing. You say it's hard to imagine that fifteen years later there would be all these big telescopes. This reminds me of the situation in the Field report. The Field report was two reports back, and that was the 1980 committee. So it began deliberations in 1979. This was right when the Keck, which was then called the TMT for the Ten Meter Telescope, was taking some shape. The people, the optical astronomers on that committee that I remember were Joe Wampler, Margaret Burbidge and myself.
Faber:And Jim Gunn and Maarten Schmidt from Caltech. Now there may have been optical astronomers from other observatories but those are the people I remember. The radio community had just built the VLA.
Faber:It was obviously optical astronomy's turn.
Faber:If the optical astronomers could have gotten together and said, "We know how to build 10 meter telescopes, let's have one," we could have had that could have been the premiere ground-based project.
Faber:We couldn't get together. Gunn and Schmidt thought it was a silly idea.
Faber:Because I mean you can look at you can try to diagnose them subconsciously or you can take their words at face value. Their words at face value said that money would be much better spent building bigger instruments and better detectors for the telescopes that we now have. We don't know how to instrument these new big telescopes, they said, and specifically they were thinking about CCDs, which at that time were tiny postage stamps.
McCray:Yeah. Which was an area Gunn was involved with himself.
Faber:Very much. And he is an authority. He's very influential. So the UC astronomers did not convince them. The optical people did not speak with one voice, and as a result another radio project came in. It's the VLBA. This is what this was a real injury we can now see in hindsight to NOAO.
Faber:Because it essentially delayed their participation by another ten years, and they became followers.
McCray:Yeah. That period of time is really interesting, because in the seventies they were the ones leading with, you know, they had plans for a 25 meter telescope that got scaled back to 15 eventually, but they entered the 1980s it seems at if not the forefront very close to it, but they finished the decade behind.
Faber:Yeah, and Geoff Burbidge was very forward-looking. He hosted a conference which produced a two-volume set, and actually my paper in there is one of my things I am more proud of.
McCray:Yeah. I have read it. I enjoyed it.
Faber:Have you? Right. It was a cry for big telescopes. So he wanted to lead there, but he didn't get any support from this particular astronomy report. It was very, very sad. So I've sort of forgotten what the main thrust was here.
McCray:So have I, but that's okay.
Faber:That's okay. All right.
McCray:It's all right to have that happen. I wanted to ask about, in terms of doing astronomy, what has the effect of the Hubble Telescope been? And I guess I'm speaking only about optical infrared because you know if you were in X-ray I guess you've only had space observatories, but for the optical community.
Faber:Well, it's become so important that it's hard to imagine living without it.
Faber:It's become indispensable. I think it's going to be very hard we're going to be in the position of the X-ray observers of a few decades ago who lost a telescope for ten years. It's terrible. Well, I don't know. Hubble is just a fantastic success. For my own work, it's opened up many things. I'm now interested in distant galaxies. And Hubble and Keck worked together just like this, hand-in-glove. You can't have one without the other. So it's a perfect example of space- ground synergy.
Faber:And I'm utterly dependent on Hubble. And deeply disappointed that I wasn't able to participate in the first Treasury round.
McCray:The Treasury round?
Faber:These Treasury proposals which Hubble advertised a year ago. It was a call for a proposal to put in larger than normal proposals. The idea is, we're now looking to the time when Hubble is going to go away, let's start salting away large data sets instead of trying to you know piecemeal it here or there. You know, let's get large, coherent data sets that address major problems.
Faber:So, I was part of a team that put together a proposal to observe deep, take deep pictures of the universe for the purposes of studying distant large-scale structure and distant galaxies. Looking back typically to about a redshift of one or beyond. And we didn't win. Another group of people won. So now my primary political occupation at the present time is how I can get access to these pictures, because from my point of view just taking spectra with DEIMOS is only part of the story. I've got to have the Hubble pictures to show me what I'm looking at.
McCray:If you don't mind my asking, why do you think the proposal wasn't funded?
Faber:I think it was a bad proposal, for a couple of reasons. We misread the political winds. We figured there were two teams. We knew about them. We tried to join forces, they disliked some of the people on our team. They didn't want to join.
McCray:Who is "they"?
Faber:They are the GOODS team, G-O-O-D-S.
McCray:I'm guessing that's not the name of somebody, that's an acronym?
Faber:Yes, it's an acronym. Right. And the two leaders are two scientists at Space Telescope: Mark Dickinson and Mauro Giavalisco. There had been a workshop to plan an extragalactic Treasury proposal, and that workshop, I have a talk there. I thought that there was a lot of support for a really big proposal. Got too influenced by my own words. We wrote a really big proposal. It encompassed their proposal plus another wider but shallower field. Two different approaches, but very expensive eight or nine hundred orbits of Space Telescope time.
McCray:What would that translate into in dollars? Or days I guess, although I'm not really sure.
Faber:Well, take the number of orbits and divide by sixteen to get days. We could do the arithmetic. I forget
McCray:Yeah. A long time?
Faber:Yeah. They had a more focused proposal. They did two small areas deeper and their total time was about half ours. The TAC just liked these better. They thought it was they couldn't see the worth of our extra-huge numbers of orbits, and I think there was merit in that. So anyway, we didn't get the time. Hopefully we'll put in a much smaller proposal for a smaller, more focused ones, later.
Faber:So at the moment I'm feeling a little desperate at having invested ten years of my life building DEIMOS, starting a spectroscopic survey, taking pictures so that you know, to do these multi-object spectrograph surveys you have to have three [correct word?] photograph
Faber:So at the present time I'm sort of in the position of having made a large investment in certain regions of the sky and not having any prospect at the moment of getting Space Telescope pictures for the galaxies, which would really be sort of a tragic outcome.
McCray:Okay. For your students, thinking of the ones that you have now or maybe you've had in the past five years or so, what do you see that is different in them in terms of how they view doing astronomy?
Faber:Yeah. I think astronomers have always had sort of the same outlook. Astronomers are cheerful by and large as a group. I think they feel that they love their subject very much. There is a lot less cynicism. There is a lot more sense of personal fulfillment. Of course there are exceptions.
Faber:But I meet business people, my husband is an attorney, and the level of cheer in astronomy is much higher. And this has not changed. The students are the same. There was a lull there where the students were really worried about not getting jobs. But now we're all dying the older folks [laughs] and so this big bubble of people who were hired after Sputnik are coming to the end of their career and a lot of opportunities are opening up. So I think I don't notice much difference.
McCray:How about in terms of the nuts and bolts of doing astronomy? Whether it's research problems that they are interested in, how they approach doing the research, do you see any differences from what you experienced?
Faber:Well, I think that there has been some change and some not change. The basic rhythm of having an idea now speaking as an observer having an idea, developing it, writing a proposal, going observing, analyzing the data, that is still there. What has really changed though is that you better graduate from graduate school with some special weapon in your toolkit. And I think this says that people are more specialized than they used to be. And collaborations are formed not so much on the basis of intellectual contributions, but more on what you can contribute skill-wise "Oh, we need an N-body modeler," "Oh, we need somebody who can observe," "Oh, we need somebody who can do image analysis." It's that kind of thing. And so if you don't have one of those sought-after skills, I think life is hard for you.
Whereas when I graduated I could barely do anything. You know, I could program in FORTRAN and I knew how to observe in sort of an old-fashioned way, but I didn't build stellar atmosphere models, I didn't build N-body models. Nobody did any image analysis because there weren't any images worth analyzing. And that I was very injured by my back trouble which occurred in mid- career and prevented me from sitting at a computer for about ten years. I could sit there for short periods of time, but as a result I never developed really firm computer skills or image analysis skills. So I'm noticing this now. I mean I almost can do nothing by myself. I really have to collaborate with people who know how to do these things. So I become the strategizer, the people manager, the paper writer, the editor, the interface to the outside world. Much more typical I think of people running chemistry labs in which the PI gets the money and sort of sets the scene but all the work is done by more junior people. That mode of working hasn't yet so permeated astronomy in general, but it reflects my style because of this critical dropout that occurred at a critical time.
McCray:I can recall a similar, in one of the bio sketches that you sent to me, that you referred to particle accelerators and telescopes as cousins. And I wanted to come back to that because I wanted to get your sense of how astronomy and particle physics compare and contrast.
Faber:Well, there are similarities. It's just that particle physics is more so. You know, we're not to the point where we have 400 authors on a paper, but
McCray:Will it happen?
Faber:No, I don't think so, because telescopes differ substantially from accelerators, as I understand it, because of the flexibility of the number of scientific projects that you can build with them. So in physics here is an accelerator. Now they do put lots of different kinds of experiments, detectors, you know, the business end, but each one of those is very carefully crafted to do a particular kind of experiment. It can't do other experiments. It has a lifetime. It's a very big deal, 400 people work on it to do this one thing, which sometimes takes years, and then that thing goes away to be replaced by something else. A telescope also collects flux, photon flux, and there are a small number of things that can fit on the back end. And making those things often involves a lot of work, but less work than particle experiments.
What's really different though is that each one of those instruments can do a thousand things instead of one thing. And so the field of a thousand astronomers doesn't have to be fixated on this one problem. It can break up into groups of six and have, you know, a hundred different problems. And I don't see that changing in the near future. I do think that the analysis skills are getting so specialized though that you don't do much with one person but with a half a dozen people you can do wonderful things. But we're not up to the point of 400 people.
McCray:Okay. Pause for a second. So the final question I have for today would be, as you look back over the course of your career, what do you see as the single biggest change? And feel free to answer that whether it's research, instruments, sociology, whatever.
Faber:A factor of a million.
McCray:Okay. All right.
Faber:I calculated the data rate in my thesis relative to the present data rate. It's a million. So, for me personally, that's been the biggest change, the ability to address problems that are infinitely more difficult, and in particular, most recently, the look back effect with the big telescopes looking back in time, exploring a completely different dimension the time evolution of objects. That's the biggest difference for me.
Faber:Well, you know, now that I have to think about it, I have to say one other thing.
Faber:Okay? I have repeatedly said that when I was in grad school there was no theory. So obviously the other big change is that there is now a very well developed theory, and a picture which we are continuing to test but more and more seems to be falling into place. I actually find that I am a little uncomfortable with this, because as I noted before, I tend to lose interest when things get too clear. And I feel to a degree that my chosen subject, galaxy evolution, is getting a little too clear in that most of the great discoveries are behind us and we are in the mopping up mode. So this is a good time for me to be looking towards the end of my career. I don't think I'm going to be one of these astronomers who hangs on you know into my seventies and even eighties the way many of them do.
McCray:What would you do?
Faber:I really we touched earlier on the social obligations of astronomers. So I have been trying to do a little bit, but to get where I have gotten has required really a sort of a ruthless degree of focusing on just doing research. And I have foregone a lot of contributions to the community that I felt that I wanted to make in other ways. So I'm a good spokesman for science. Is there a role for me as a science advisor to public television or public radio? Something like that. Should I try my hand at influencing science education in elementary schools or high schools? Should I simply become a friend to the teachers at the local high school some of whom are very good, and go down and just help the students, bring projects, get them excited, bring a few of them up here? My ideas are ill-formed, but you see what I'm saying.
Faber:I could very easily foresee at the age of sixty-five dropping my research and moving on into a completely different venue which probably would use the scientific skills that I have and the communication skills but would be much more public spirited and outreach-oriented than I have been so far.
McCray:Do you see physics and astronomy which have been fairly autonomous fields do you see them beginning to interact much more closely on a professional basis in terms of meetings and things like that? I'm thinking of this because you had talked about an interest in the very small and the very large, and also mentioning at this Vatican conference that you went to how there were some particle physicists there. Do you see more of that happening?
Faber:Oh, it's been a continuing theme ever since 1980 or so. And this whole statement that I made a moment ago that now we have a theory, I don't think astronomers could have ever produced that on their own. It really was a product of the marriage of the two fields, which now we call it cosmology, and it's neither physics nor astronomy, it's a completely new fight.
McCray:So I guess one thing I think that people will be interested in, phrased crudely, is when did cosmology become a science? How would you see that?
Faber:I would say it was the discovery of the microwave background in 1964.
McCray:Okay. Everything prior to that being speculation?
Faber:Pretty much. Yeah.
Okay. Well I think that's a good place to pause for now. I'm going to turn this off.