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Oral History Transcript — Dr. Jesse Greenstein
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Jesse Greenstein; July 21, 1977
ABSTRACT: Childhood in New York City; studying astronomy and literature at Harvard (1925-1929, M.A. 1930); work during the Depression in real estate and at Columbia; graduate-education in the new astrophysics at Harvard (1934-1937), contacts with H. Shapley, C. Payne, H.N. Russell; work at Yerkes from 1937: nebula spectroscopy, stellar composition, stellar atmospheres; contacts with 0. Struve, S. Chandrasekhar, B. Stromgren; optical design work during World War II. Move to Cal Tech, 1947, contacts with W. Baade, I. Bowen, F. Zwicky, N. Schmidt, L. Dubridge, etc.; organization, administration, research conditions, and allocation of observing time at Mt. Wilson and Palomar Observatories; work in building up astronomy department at Cal Tech, character of staff relations, and fund-raising. Postwar work oil, abundances of elements, white dwarf stars, high-dispersion spectroscopy, radio astronomy, and quasars; ideas about cosmology and other topics. Involvement with military advising at Cal Tech from 1950, satellite reconnaissance, and industrial advising; early work on rocket astronomy and as senior adviser to NASA (ca. 1957-1977). Editor of Stellar Atmospheres series; work with National Academy of Sciences and author of its 1972 astronomy survey; efforts to popularize astronomy. Ideas about large space -- and ground-based telescopes. Particular attention is given to the organizational strengths and weaknesses of important astronomy organizations.
Session I | Session II | Session III | Session IV
Weart:Jesse, I have a few things I noticed going through the last session, a couple of small questions I always ask. First, since you have read it now, is there anything you noticed that we missed, that we ought to catch up, about the whole period up through the end of the war?
Greenstein:Possibly just what the rest of the Yerkes group did during the war. And what happened immediately after in the organization.
Weart:Well get to what happened after.
Greenstein:OK, all right.
Weart:What about what the rest of the Yerkes group did during the war? That would be interesting.
Greenstein:With a few exceptions the staff in fact left, and went into various major projects. Gerard Kuiper went into the radar countermeasures work being done at Harvard, and in the process learned something about radio astronomy that would be useful in judging radio astronomy later. He also learned about infrared instrumental developments for the first time. That was particularly important, because his observations after the war, at McDonald Observatory, using Cashmans lead sulfide photo-conducting cells, were as far as I know, the first important planetary observations in the infrared. Essentially, that was a gain, perhaps one of the first examples of the incread technological trend in astronomy that began right after the war.
Weart:Did he learn it because of military use in infrared?
Greenstein:Yes. But then it was primitive. There were very few heat-seeking missiles. There were very few guided missiles for practical use. But there had been a support for infrared detectors, I think it was at the University of Illinois or Northwestern, or both. Cashman was usually credited with developing practical leadsulfide cells. Gerard Kuiper more or less commandeered some of these as soon as it was possible. He brought back an near-infrared German intensifier. Another group went into anti-submarine warfare countermeasures. This included degaussing ships to protect against magnetic mines and countermeasures for other types. I would guess that a good number of the staff, both old and young, postwar, returning from these enterprises, had learned something new in the way of technology. Chandrasekhar had stayed pretty much aloof, except for the encounters that I have mentioned already with Enrico Fermi. But out of those years came a strong interest — and Fermi also developed a strong interest — in magnetic fields in space, the acceleration of cosmic rays. So it almost meant that he switched from radiative transfer to the beginning of plasma physics.
Weart:That was not related to the war work?
Greenstein:No, but I think essentially from the growth of magnetohydrodynamics and contacts with Fermi, in particular. There was a symposium at which both Chandrasekhar and Fermi spoke; the first observations of interstellar polarization were described, and attempts to interpret them made, right after the war. I feel that there was not direct causation, but a kind of feedback, a switch of interests toward the higherenergy physics side of astrophysics. It was clear [thats] what people did very soon. The nucleus of observers stayed — I even went to McDonald Observatory during the war, and immediately afterwards.
Weart:You went to McDonald to observe?
Greenstein:Yes. I didnt have much time to do anything with it, but I did.
Weart:You had lots of time on the telescopes —
Greenstein:Yes. Thats right. Struve stayed there a good deal. Some of the younger staff, by the way, went into operations research, and never left that area.
Weart:Is that so? They stayed with the military?
Greenstein:Stayed with the military. I dont remember specific names, but Thornton Page, I believe, became president of the Operations Research Society. I think interest in that also existed in the antisubmarine warfare groups. So, there was a very strong seductive effect of new fields. The major technological improvement, certainly, was in photoelectric amplifiers and near infrared work, which moved quickly.
Weart:Did your own war work have anything to do with what you subsequently did, aside from the all-sky camera?
Greenstein:Oh, a little bit, yes. The first outside activity I took on was to build a nearultraviolet spectrograph, which was launched in a V-2 in 1947. There I worked with Johns Hopkins, it was called the Applied Physics Lab. They gave me a small grant; I designed and built a two quartz prism UV spectrograph, which was launched and which failed to operate in flight. It would have been the highest resolution solar ultraviolet spectrum at that time. The same group at Johns Hopkins did get the first UV solar spectra, showing, for example, the magnesium II emission, equivalent to the H and K line.
Weart:Was this an outgrowth of your war work?
Greenstein:Well, because of my interest in optics, and design of gadgets. Henyey and I designed a new multicamera grating spectrograph for McDonald. You know, learning how to design lenses and mirrors — Most astronomical applications are relatively simple compared to, say, a complex zoom lens on a miniature camera. That was about half built. We designed a new image slicer and things like that, most of which didnt get built. But I think that the eventual 82-inch McDonald Observatory spectrograph was essentially on outgrowth of the war.
Weart:I see. What about organizationally? Did you or other people come back with a different feeling about how astronomy should be organized, or research should be organized?
Greenstein:At Yerkes, I would think not. Our major interest, I would say, was in seeing that we werent technologically lagging. The people at Wisconsin, only 60 miles away, had adopted new amplifiers. I designed the circuit for a new amplifier for the microphotometer, which made it essentially a densitometer rather than a linear device. There was a sort of a feeling that photoelectric astronomy was in, and Yerkes was not up at the forefront there. Certainly the forefront was at Madison, with Joel Stebbins and, in particular, Albert Whitford. And they were just so near that you couldnt help but notice that we were not doing that kind of thing, and they were doing it very well.
Weart:Did you get together with them?
Greenstein:Oh yes, we had very excellent relations.
Weart:You would go there, and —
Greenstein:Yes. The Midwest Astronomy Society that I mentioned earlier was one of the devices used. From an organizational point of view, almost every observatory became less insular. People had been elsewhere, knew that there were things being done elsewhere. Whitford, who was a good personal friend, had real impact on astronomical electronics. I believe its correct that he was the first person to have the idea of using an amplifier after a photo-cell. Photomultipliers were just coming in, and that was a natural thing for a physicist to do. So we had to modernize. The other part of the interest was Kuipers, trigged by Grote Rebers radio astronomy activities, just 50 miles away in Wheaton, Illinois. Reber had been working in some company, that built radar, I guess, and he liberated what may have been at that time still classified highfrequency lighthouse amplifying tubes. I saw those, right after his first papers began coming in to the ASTROPHYSICAL JOURNAL. And that certainly aroused our interest in radioastronomy, or re-aroused mine, and —
Weart:Did you used to see Reber?
Greenstein:Oh yes. We were pretty good friends. You may know the ridiculous story, that people thought he was a fake. When the ASTROPHYSICAL JOURNAL editor got this paper about detecting the Milky Way at 160 and 480 megacycles[1], from an unknown who never got a BS, he actually sent Kuiper, who had the radar experience, to see if Reber was turning a dial behind the panel to make the signals. I met Reber about that time, perhaps even before Kuipers visit, and I used to visit him often. He certainly did stimulate the paper by myself, Louis Henyey and PG. Keenan about the free free emission from interstellar gas[2]. Because he first suggested that the radio continuum was free-free emission of a hot gas. Although not in any way a trained theoretician, he had excellent physical intuition; He hadnt worked it out right, but it suggested to us both the possible existence of very high quantum number radio-frequency hydrogen transitions, and the continuum as possibly free-free. That didnt work because the signals were too strong; the optically thin gas just couldnt emit that much.
Weart:And he used to come up to Yerkes often?
Greenstein:He used to visit Yerkes, but we used to visit Wheaton, and I met him at Chicago, often. He, of course, was very much of a lone wolf. He had no collaborators and no financial support. Perhaps my first and last organizational effort at Yerkes — was to help Reber, by trying to help him get support, either from the Carnegie Institution, Department of Terrestrial Magnetism, or, later, after Id left Yerkes from the new National Radio Observatory. (Which eventually got his antenna, its up there as a showpiece.) So I must say that I would put the impact of the war, and people working elsewhere, as mainly an opening up of horizons. Kuiper switched from being interested in stellar astronomy to purely planetary astronomy, which hed always been interested in but hadnt worked on so much till postwar. There were books about the upper atmosphere, an early conference on the upper atmosphere studied by rockets, which he edited. There are two editions of that. And my interest in the V-2 program -
Weart:— yes, I wanted to ask you a bit about that. Its going a little ahead, but since its come up — it was about 1947, you said. How did that come about, that you got involved in rocket shots?
Greenstein:I had, of course, been doing high dispersion stellar spectroscopy. The sun was the brightest object. The V-2s were essentially not guidable, leaving the sun as the only target. I dont remember how, but I had known one of the leaders of the Johns Hopkins group, thats Jim van Allen, before or during the war. And since the V-2s were there to be used for scientific experiments, it seemed an ideal thing to try. My first inclination was to get the highest dispersion practical in a spectrograph that it could carry. It would have, been roughly a thousand angstroms coverage. It was a prism spectrograph and not competitive with modern instruments, but given the way V-2 experiments had to be done, it was about as big as you could build.
Weart:And this was funded by Hopkins?
Greenstein:Yeah. I think by a subcontract from their military funding.
Weart:I take it you sort of went to them, to ask them?
Greenstein:I asked them. They had a thing called Project Bumblebee, which involved telemetering information from the rockets. It was a really pioneering thing, because after all, thats how we now communicate with spacecraft. In that general area they were doing cosmic ray experiments, where you didnt have to recover anything, but were willing to try a spectroscopic experiment. I believe Hopfield, and Clearman had already obtained a fairly good solar spectrum beyond the ozone limit, and identified many of the lines. The younger fellow, I think his name was Clearman, came and spent some time at Yerkes with me, because I was interested in high-resolution spectroscopy; they were physicists that didnt know anything about spectra, but theyd gotten the solar spectrum. I think one of the first papers published about the solar ultraviolet is by them[3].
Weart:Ill look it up. After this one rocket effort, did you —?
Greenstein:— I gave up. It was a little traumatic. It was a very individual effort. We had to build the instrument and the control mechanism. I carried the spectrograph, which was about a meter long, in a wooden box by train to White Sands; saw it mounted; worked with the Germans, who didnt know how the V2 behaved at high altitude, actually; met [Werner] von Braun, with whom I kept up a kind of contact over many years. It was an adventure. But it was a failure. And it was a failure because, I say, of early lack of sophistication on just what an experiment in see does to an instrument. It was not the takeoff acceleration but it was the fact that a rocket in free flight has completely different structural stresses than it does lying on its side on the ground. And as elementary a thing as putting the spectrograph in when the rocket was horizontal, under gravity — and so the V2 bent between its supports — and using it in a zero gravity flight environment, bound up the spectrography drive. So it tried to turn on, and tried to turn off, but it never could move. I think it must have stripped gears. It was really pathetic. But you know, it would have been fun had it worked. Van Allens work was in cosmic rays, and several interesting papers about with Howard Tatel about cosmic rays essentially above the atmosphere, instead of at balloon altitudes, come out of it. They were doing good scientific work already in space.
Weart:OK. There are many things about your scientific work I want to ask you, but I particularly want to ask you about one of the things you did. You went back to Upsilon Sagitarrii with Paul Merrill[4], and also Walter S. Adams[5], identifying a thousand lines and so forth. What I first want to ask is how that came about that you were collaborating with them, and what were the various roles of these people in your collaboration?
Well — perhaps the story of Mt. Wilson, as it was right after the war, fits better elsewhere. Let me just say that they had, without doubt, the best spectrographic equipment ever built till then. Most of the ideas came from Dunham, who loved to design better and better optical equipment. He was head of one section of optical research during the war, and had a good deal of his own money, family money. And so the Mt. Wilson Coude spectrograph, with which the first really good stellar spectra at high resolution obtained by Adams and Merrill, was designed and built by Dunham. It was a major problem apparently, to prevent him tearing it apart and building a better one. It was the first spectrograph with gratings and a variety of longfocus cameras, the shortfocus ones being Schmidt cameras. And that came out of the Mt. Wilson war program, in a certain sense, also — (not the ruling of gratings, which was an old program) — the optics, because Mt. Wilson had been in optics as well as proximity fuse research during the war. They built lots of aerial cameras and shutters.
Bowen had designed cameras with short exposure shutters to photograph rockets in flight on a test range. The were very good at such equipment, and well before the war and right after they were preeminent. The McDonald spectrograph had been a 1 1/2 prism Littrow, equivalent to three prisms, but it had no ultraviolet transmission at all and variable dispersion, with one camera lens. The one that Henyey and I designed was modeled after the Mt. Wilson Coude. So these highdispersion spectra existed. I had visited Pasadena for a month or two, I forget how long, in I think 47, (perhaps wrong by a year). The characters of Merrill and Adams, as spectroscopists and as gentlemen and as observers, were quite unparalleled. They were different from the Yerkes group. Their life was rather leisurely; they had the best equipment in the world; they were non-theorists — and they were superb observers. Some of the most beautiful plates of multiple interstellar lines were taken by Adams, who didnt care whether he took a six-hour exposure or a three-night exposure. The spectrograph was very stable. All he wanted were the best, widest, most noise-free spectrum possible. And Merrill was very much like that.
Weart:In what way was this different from the Yerkes group?
Greenstein:Well, Yerkes had tended to be more competitive, to start more from the physics, and try quickly to answer questions — get enough data to answer the questions. The Mt. Wilson attitude was that it was the best place in the world, and nobody would ever be a real rival, so lets do a good job. But unfortunately, they tended not to interpret material. This provided an ideal opportunity for a young, aggressive person like me, visiting, to see and use these storehouses of plates.
Weart:I see. The plates were already there.
Greenstein:They were there. Adams had been following Upsilon Sagitarrii for many years, after it had been recognized as an interesting object. And Merrill worked on all kinds of peculiar stars. I forget exactly when he found Technetium, but it wasnt all that different in time. They tended not to worry too much about the implications of results) feeling that superb instrumentation and good data would provide the answers that counted. In a certain sense, its a real stylistic difference.
Weart:You havent distinguished between Merrill and Adams. Were there differences between the two of them? In their scientific style or personalities?
Oh, they were quite different as people, but they were both extraordinarily fine, generous people, with very much the same attitude toward how science should be done. Merrill was more of a spectroscopist, knew more about atomic and molecular Spectra. He did try and interpret what he found. Adams was a data gatherer, measurer, but had been, after all, one of the inventors of the luminosity-classification technique on low dispersion spectra which had led to some 4000 spectral types and luminosities in the Mt. Wilson catalog of such things.
Bill Morgan, who was a really superb classifier, by far the best at Yerkes, had enormously refined what Adams had done, but never had gone into this kind of massive direct observing of thousands of stars. Morgan was a little more physically oriented. While there was a good deal of physics going on at the early Mt. Wilson, — it had been founded because of the discoveries in atomic spectra, really. It had contributed greatly in the interpretation of laboratory spectra — but the application to stars was usually non-mathematical. Let me put in that way. Even in my first papers on stellar spectroscopy, I was trying to get a number, some answer on composition, temperatures. But it was a style which complemented the Yerkes style. Certainly when I first visited here, it made me feel, you know — not compunctions about what I had been doing, but a realization that there were many gateways to heaven. It was not enough being a young, short-problem, bright guy, but I had to take large programs as a more serious side.
Weart:Was it that they simply had more money and better instruments?
Greenstein:They certainly had better instruments. They probably had more money. They had a smaller variety of interests, if you wish. The staff at Santa Barbara St., under Carnegie, say, just pre-war or just postwar, was larger then now. Even adding Palomar and Las Companas.
Weart:By staff, youre referring to the scientific people?
Greenstein:Yes, scientific people.
Weart:I did have here, to ask you some questions about the difference between Mt. Wilson and Yerkes, but lets finish about Upsilon Sagitarii. One of the questions I want to ask you is why you did this particular problem?
Greenstein:I think we covered it very briefly. It was soon clear that it was the first object of enormously different composition from a helium star from normal stars that had been studied; it was bright enough to be studied in great detail. What little we knew then about nuclear reactions suggested that we were seeing effects of nuclear reactions. The same question was in my mind, though answered in a different way, about the so-called metallic line stars which I started about the same time at McDonald. Upsilon Sagitarii is a very complex system. Its gotten more complex with time. Its a very strong infrared source, which we didnt know then. Its got a big dust cloud about it. Weve not yet seen the hydrogen-rich companion, although its a binary. We would now say, there was mass exchange, and that its a system embedded in its own dust, highly evolved massive stars. So its interesting now, but then it stood out, because of its composition. In some of the first work on nuclear synthesis it was an archetype of what was different.
Weart:I see. So it was not interesting just because it was a peculiar object in itself.
Greenstein:No, I always have had some vague hope that something in astronomy would have something to do with something else. Peculiar stars are not fascinating for their illnesses, but for what they signify.
Weart:Just as in physiology, you can learn most by studying somebodys whos sick.
Greenstein:Thats right — if he survives long enough.
Weart:Well, that leads, I guess, into the your 48 paper on spectrophotometry of the F stars, Tau Ursae Majoris[6]. You wrote that you were concerned with possible variations of abundances in the elements from star to star. You did really a lot of curve-of-growth work, theory, the physical and mathematical thing you mentioned. You concluded that there were some exceptions, but mostly stellar and solar abundances were not that different: Im quoting, For the first time, we may with some confidence say that the spectrum of a star can be predicted in some detail from that of the sun. I guess Im interested not only why you chose this kind of problem, but why perhaps this was possible at this time, why this could happen at that point.
Greenstein:Oddly enough on September 5, 1947, the NEW YORK TIMES carried an article on this topic.
Weart:In the scrapbook that you have here.
Yes. The first big meeting of the American Astronomical Society after the war was at Northwestern, and there I reported on the abundances of elements in Tau Ursae Majoris as compared to other stars. The quantitative studies showed details of the abundances of the metals, and especially the heavier elements, in the so-called metallic line stars. They showed that it wasnt just an overall enhancement of metals but certain peculiar elements stood out more than others, and other were rather strangely deficient, like the common element calcium. In fact, the metallic-line stars had been recognized as being calcium-deficient, first, it was supposed even that two stars were involved, one having heavy elements and rare earths and the other a hot star. I disproved that, from the equality of velocities from all different lines.
But in the process I found that the so-called differential curve-of-growth method, which, while I didnt invent I did popularize, was a good quantitative way. Using what was then known of the opacity of the stellar atmospheres, given the temperature and the surface gravity you could, as mentioned, predict from the solar spectrum what a star maybe three or four thousand degrees hotter would look like, and in quite successful detail. This worked for the body of stars (I think in that study I had four or five other stars). It did not work for the metallic-line stars, which had over-abundance of the heavy elements. We had no nuclear synthesis theory for the heavy elements, and we couldnt understand why the calcium wasnt there. It did bring up, at least in principle, some serious questions that arose again when I came here. These things expanded greatly. The other thing it did bring up were questions of what is now called non-local-thermodynamic-equilibrium. Could this be a result of a strange atmospheric structure? This was gone into, in a superficial way; I invented a process of non-local-thermodynamic-equilibrium ionization, which would differ from one element to another. That process, I fear, doesnt work. But for the first time ever things like crosssections for ionization and recombination of metals were needed. I had to guess them. It was about the most primitive struggle one could have, since we knew so little, with the question of peculiar structures versus peculiar composition. Thats a question which in many ways still exists.
Weart:But this was because for the first time you sort of knew what the normal structure should look like?
Greenstein:You knew that youre successful with ordinary stars.
Weart:This is particularly interesting, that this happens with you in 1948, rather than with somebody else at an earlier or a later point.
Greenstein:Well, the normal stars had been done in a rough way, in a semi-quantitative way, by Cecilia Payne in 1930 or whenever, STELLAR ATMOSPHERES. And not since. And the high dispersion spectroscopy, at Mt. Wilson, had never been applied quantitatively to composition. Dunham had observed an F supergiant, Gamma Cygni, and published a paper on it. But its a non-quantitative thing. Had Henry Norris Russell turned his mind to it, he would have said that although Gamma Cygni, which is a supergiant and hotter than the sun, looks very different, its got solar composition. Im sure that Henry would have done that. It was just about the right time, given data you could get, from the fact that were now doing quantitative rather than qualitative descriptive work, to do it for the stars. I didnt invent it. Unsold maybe didnt invent it either. But hes very important in it. And —
Weart:— was it valuable that you had a better idea about the sources of opacity?
Greenstein:Oh, the opacity was one very important thing. Unsolds stellar atmospheres book is completely wrong on the hydrogen-to-metal abundance, because he didnt have the right opacity source. Ten years later, we did. And Chandra was working on the theoretical crosssections for the negative hydrogen ion, and published paper after paper, improving it, essential features for the success of stellar atmospheres theory.
Weart:You mention in your paper some theoretical discussions with Chandrasekhar and Stromgren.
Greenstein:Yes. I should have mentioned Stromgren. Stromgren was, I think, one of the great additions to Yerkes. He was at the height of his career in stellar interior theory, and he had invented — knowing opacity sources — a sort of interpolation formulae for the strength of lines as a function of temperature and pressure and hydrogen-to-metal abundance, in a small Copenhagen publication. This was a sort of basic theoretical advance. In fact, you didnt have to do all the numerical work, in a certain sense; if you believed his results, you could say lines would strengthen as the square root of the metalhydrogen ratio, and as the one-fourth power of the surface gravity, and things like that. Stellar turbulence also entered, which was not in his theory, and which was very much in the observations. The observations, beginning with Struve and Elvey, ten years earlier, had showed that stars had intrinsic small-scale turbulence, microturbulence.
Weart:The picture I get of this is of a whole lot of different elements that were sort of lying around for this very complex picture, curve-of-growth and opacities and so forth, and then you had always had an interest in this kind of problem, and through discussions with other people, you began to pull it together — would that be a fair description?
Greenstein:Yes. No one person really creates a field. It has to be ripe. The techniques existed. The theory of stellar atmospheres — Chandrasekhar had radiative transfer theory completely in hand. Atomic theory was beginning to grow. In fact, you often find in my and other papers pleas for more transition probabilities, more ionization cross-sections, for the heavier elements. Hydrogen, ionized helium, neutral helium and H-minus were all that we knew, quantitatively. And even hot helium one didnt know in much detail. The physics had stopped dead just when astrophysics needed it. Atomic physics died, sort of. The stimulus of atomic physics on spectroscopic understanding of the stars got it started, but then physicists dropped the stimulus. And so we were on our own. In Upsilon Sagitarii I put in the transition probabilities guessed them, and said, The abundance is so and so, subject to their being a large transition probability or something. It was pathetic. And its not awfully much better [now]. We were proselytizing physicists, I remember, to do applied quantum mechanics.
Weart:In the fifties.
Weart:Is this the movement where the Joint Institute for Laboratory Astrophysics and so forth, came out —
Greenstein:Sort of, yes. Quite right. There, and the sun. That impetus may have come out more from the sun, because there you knew so much more, and you had the non-equilibrium —
Weart:You could really see where the gaps in your knowledge were.
Greenstein:Yes. You had the corona, you had the chromosphere you had temperature inversions established; you could not use equilibrium theory, and you needed cross-sections. It was a good vision, by the way, on the part of the Bureau of Standards, to take that on seriously. I served on an advisory committee for NBS and for JILA.
Weart:Now, weve been talking about this quantum mechanics aspect of it. What about the nuclear synthesis aspect? You were interested in this — was there anybody around Yerkes or Chicago that you could have discussed this with?
Greenstein:Well — a little bit. Again, I think I found an extraordinary clipping, which I dont remember. Ill see if I can find it. [leafing through scrapbook] I gave a lecture on nuclear energy.
Weart:You ought to Xerox that book —
Greenstein:I ought to get it in order first. Its a mess.
Weart:These newspaper things really deteriorate with time.
Greenstein:Yeah, thats a good idea. I gave a lecture on nuclear physics, and pointed out that the energy sources for the earth were incredible, that we would be living on nuclear power, and that one of the problems would be control, because of explosive potentials for the nuclear sources we then knew. I think that was in 47. At the moment I cant lay my hands on it. It was rather interesting to see that, although I didnt know any nuclear physics at the time, I must say, the problems were already obvious. They were in my mind when I came to Caltech. Well come to that.
Weart:Do you mean the social problems or the scientific problems?
Greenstein:Scientific and social.
Weart:There was quite a pack of nuclear physicists at Chicago.
Greenstein:Yes, that was it. Harrison Brown, who did the composition of meteorites, and Hans Suess, working with Urey also, did the first physical discussion of meteoritic abundances. Whether they were like the sun or not was an early question. And Harrison, a nuclear-chemist, helped found the Federation of American Scientists[7], together with whats his name, the Hungarian who did — Leo Szilard. I was a good friend of Harrisons. By the way, Harrison is leaving to head a foundation.
Weart:Did you get down much to Chicago? Did the Yerkes people in general?
Greenstein:After the war, yes. Before the war we were isolated. During the war of course we were very isolated. I got down to Chicago on mundane things like getting alcohol for our optical lab. I drove several hundred gallons of alcohol up in my car. It was a priority item, and I could only get it from Chicago. But after the war I got in much better contact with the nuclear physicists. I was interested in the bomb physics of it, and the impact of the bomb on the future. And in the process I learned some nuclear physics at Chicago.
Weart:Were you involved in some of these discussions in the early —
Greenstein:Let me say it clearly; I was not involved in it, because I was opposed to it. Of course, Id never been in the Manhattan District, the Metallurgical Lab[8]. Id never had a Q clearance, and so I couldnt talk to them during it and afterwards only about what had been declassified in the Smyth Report. It was clear the problems were getting very close to astronomy. But I was not an enthusiast, as some people were, about a unilateral sharing of the secrets of the bomb with the whole world. Id been scared by the Germans too much to believe in international good will. So the very strong move to have complete civilian control of atomic energy, and make it open perhaps even put it into industrial applications quickly — I was more or less opposed to. I heard much of the discussion, because I had good personal contacts with the people like James Frank, some with Urey who had themselves been involved with the bomb and knew what it meant; I didnt. I still was politically opposed to the FAS and what it wanted.
Weart:Did you have any conversations over lunch, that sort of thing?
Greenstein:Well, yes, rather serious conversations, because some of the bomb builders in Chicago, you know, had gotten together on this appeal not to use the bomb on Japan. I was not involved with that, On the other hand, Id known James Frank very well, and admired him enormously, and he was terribly involved with the Civilian Control struggle. So that was at a specific place, many evenings at his or another persons house. I admit Frank had every reason more than I, to worry about the Germans, having been a target, and he had been involved with the bomb. They were on one side. I found myself on another. I find myself, thinking back, to have been pretty conservative, politically, in international affairs — possibly because of World War II, Id been a liberal before. I guess Im becoming a reactionary in retrospect. Not really, but more so than I should be.
Weart:Were other astronomers involved in any of these discussions? Were these things discussed at Yerkes, anything like that?
Greenstein:Well, after the war we had lots of interchange with, I guess youd now call them particle physicists, but they were cosmic-ray physicist. Rossi, for one, was a frequent visitor. Fermi, very frequent.
Weart:He would come up?
Greenstein:Oh yes. Fermi was a frequent visitor, and in all things, maybe an ideal man, Id just sit on the floor and listen to Fermi talk about science, about magnetic fields in space, acceleration of cosmic rays, and about politics. And about the bomb, a bit. I was on the fringe, just too young, but certainly as a group, most of the Chicago physicists were very much for the FAS and what it stood for, and for civilian control.
Weart:What about the Yerkes astronomers? Did they have any interest in these things?
Greenstein:I guess the younger ones did. I dont remember whether Chandra did. Im trying to think whether Kuiper did. Struve did not, to my knowledge, have much, Kuiper — no, I would think not, actually. I forget details about the younger people; Im sure the younger people were dreadfully interested. After all, we had students, you know, who had been two or three years in the project, whod been trapped in the middle of their PhD and disappeared somewhere into New Mexico.
Weart:Its the physicists you think of in connection with this.
Greenstein:Its the physicists, yes. Not astronomers — I cannot think, that an astronomer was a leader in the FAS foundation.
Weart:OK, let me press on, then, and ask you about some of the things that happened at Yerkes up to the point when you left and after that. I know that in July 1947, there was a big shift: Kuiper became director of the observatory, Morgan became managing editor of the ASTROPHYSICAL JOURNAL. Chandra was supposed to lead a sort of section on theoretical astrophysics, Struve stayed head of the department. The year after that, you left. The year after that there were more changes, Kuiper asked not to be reappointed as director and so forth. Did you have much connection with the various things that were going on there?
Greenstein:Yes, Unfortunately. I was unhappy, and I was not alone. Henyey was unhappy. Though we had the deepest possible affection for Struve, and admiration for him, and respect — in my mind hes still the ideal director, theres not been another one in astronomy — I think several of us felt that his decision was a dreadful mistake. He had been doing administration a long time, but of course he had also done science at all times. He worked harder, did more science than anybody else. And he naturally wanted to be relieved. But he had a defect, he did not understand human beings terribly well. He admired — and I did admire throughout — Kuiper as a scientist. But as a human being, he was dreadful, yet Struve did not take that into account. (This better be in a five-year holdback, or death holdback — hes dead.)
Weart:You can take any section of it and hold it back.
Greenstein:I shouldnt have made that remark. He was a -
Weart:Dont forget that after were through with this, you get the transcript back, and you can do with it as you please — but please tell me all about it.
Greenstein:He was very selfcentered. And his first remark to me, when he decided to accept the directorship, was that it would be wonderful; think how much research he can now have done in the areas he liked. That was a characteristic remark. Not, what can I do to help Yerkes-McDonald or all astronomy; but that if I got a position of power, I will have more done in fields I view as important. Kuiper was rather insensitive to other people, not dreadfully interested in other peoples work, and he had a consuming ambition to understand the origin of the solar system. Which is a praiseworthy thing, but it may not happen in anybodys lifetime. Certainly it didnt happen in his. And he worked on it all the time from then on. He was an outstanding scientist, but he was not, even in potential, the kind of person to lead a cooperative venture with a lot of good scientists. Had it been a European setup where theres a professor and ten stooges, he would have been quite justified in saying, Well, one man has worked such and such an area, now that I am head, the whole group will work in a new area. But unfortunately, Yerkes had some very good individualists, scientists, and the younger ones were mobile. He was a threat, to, I would call it, the freedom to choose areas one thought important. I felt it as a personal threat immediately.
Weart:Did he specifically tell you, or was it just a general feeling?
Greenstein:No, a general fear. He didnt have time. Henyey left the next year. I left in two years, and I could have left earlier also. Youre interested in sociological history of institutions — well, even though I had never run anything large at that time, I could see no real future. Not for myself in that sense because I had a job and tenure, but I just didnt see where we would be going, that way. Stromgren, who was the other potential leader, and later became director is unfortunately not a good administrator. And so the whole leadership aspect, the getting instruments built, fair allocations of observing time and other support, the very limited funds — this before government support was common — left us no doubt from then on. I think that history unfortunately showed that my intuition was correct. So, while it [the reorganization] sounded great, it was a disaster. Yet all institutions have natural life cycles - who knows what would have happened, anyway?
Weart:Was this the general feeling among the younger people?
Greenstein:I think the younger people felt that way, and the people who came afterwards felt that way. There was much difficulty. I guess theres a cultural difference with a European background. The strength of Yerkes had been the fact that Struve had invented the device of importing brilliant theorists and observers from whatever country — which was not done at Mt. Wilson, which was insular, xenophobic almost, and its much more true, even of Lick which sort of just wouldnt have a foreigner on the mountain. Struve had this international sense of whats good in astronomy, and that was something which I felt was about to be lost. The trouble was, though, that we had this extremely good staff of very brilliant individual people, who did not work particularly together. I got things from other people by osmosis —
Weart:There wasnt a disciplined team.
Greenstein:There was no team. Lots of bright people, which is perhaps a good thing, and a very morally permissive leadership. It was going to change. And it did change.
Weart:Were there any incidents? Was it the kind of thing where, as soon as you heard there was going to be this change, you felt, Oh my God? Or was it the kind of thing that came up through various incidents?
Greenstein:None affecting me. Struve told me first personally about the reorganization. And I think that day, I decided I was going to leave. I had such affection, and such pride, if you wish, in the whole group to leave me afraid of being in on the downfall. I was just saying, being near such great men — and they really were great men, they were pioneers in so many fields of astronomy, even Kuiper was such a person — was a real pleasure. And the place, though it might have internal tensions which I didnt know about, was a wonderful place to work. There were bright people next door. It just seemed to me it was a hopeless time ahead.
Weart:So how did you start looking for a job? Was the Cal Tech job the only one that came along, or were there various jobs?
Greenstein:Oh, I never looked for a job. By then I think I was moderately well known. I had not run anything, but people thought our social life, as well as scientific activities gave me a wide knowledge of other places of me as a potential runner of things. I dont know why. I was offered the directorship of an institution, (Id rather leave the name out), which needed a complete buildup of staff — which would have been, I think, also rewarding. I somehow didnt like. Perhaps I was a little frightened of responsibility. Perhaps I didnt like the idea that thered be nobody there, essentially, in the way of a scientist. The first interesting suggestion was that I come to the Lick Observatory, which I had great regard for, and which was a very exciting possibility. I would have been just a staff member, but it was a good group then, as it had stayed good.
Weart:You had been out there before? You had seen them?
Greenstein:Id visited Lick. At that time, Lick astronomers lived on the mountain. And that was essentially the major drawback, a purely personal one. I was a little more interested in sophisticated and cultured areas of life than one could be, living on an isolated mountaintop. I knew California as some kind of primitive area where the Indians lived. Scientifically it would have been OK; it would, by the way, have involved quite a change of interest, because they didnt have a big telescope then, in our present sense of big. The next thing was that I heard I was being considered at Caltech just about the time I had to make up my mind about Lick, I guess somebody leaked the fact that I was being considered for Cal Tech. The background may have been, (I think its probably generally known) that they had wanted Martin Schwarzschild to come from Princeton to start a department here. He had been so deeply involved with Lyman Spitzer, beginning the fusion plasma project, that he didnt do it. I think there was even a chance that they would both have come, which would have absolutely marvelous for astronomy, and which remained my dream for about ten years. I kept asking one, then the other, and then finally both.
Weart:They both went to Princeton.
Greenstein:Thats right. They were at Princeton. It was such an obvious thing. They were the two best, and are still in many ways the two best astronomers, in my opinion. It was the right thing to do. But at the same time, it was rather a difficult thing to swing. And somebody sort of told me that I was in the line for Cal Tech and Palomar. I never asked for it. I would say I was flattered at being in that line. And the Lick living circumstances just didnt seem one that went with our personal lifestyle. I decided not to go to Lick. I visited here that same year, for one of these collaborations with Adams or Merrill, I forget which, and essentially found the old Carnegie Mt. Wilson staff congenial. Completely different from Yerkes, There was at Cal Tech essentially only one scientist, Fritz Zwicky, active in astronomy. I waited. I think I told Lick I probably wouldnt come. And that was about it.
Weart:And then they did make you the offer.
Weart:Who was it, by the way, who picked you? Who is they?
Greenstein:I would rather not know. No, I really dont know.
Weart:It wasnt that kind of situation?
Greenstein:No, I think the Mount Wilson staff knew me a little, at least some of the staff. They viewed me as some kind of wild-haired radical theorist, which is funny. In their view, that was what I was, and therefore a little bit dangerous. Id probably ruin the place. Yet I was a reasonably good candidate, and I even feel that Martin Schwarzschild and Lyman Spitzer may have had some things to do with my being considered since they wouldnt come themselves. I dont know. There is some history available in the Caltech archives, but Ive tended to let it be a mystery — and a happy one.
Weart:Im interested in what you say about their worries about you. Did this have anything to do with the fact that you came from Harvard? Was there any effect, when you came here, of the antagonism between Mt. Wilson and Harvard and Shapley? Or any effect on you?
Greenstein:It could have been an appreciable component. And Yerkes wasnt that popular. There is, really, a very odd thing, which persisted for many years after I was here, that a man who had used the Crossley 36-inch reflector at Lick was viewed as experienced with large telescopes — while a person who used the McDonald 82-inch was called an inexperienced observer.
Weart:Did the Yerkes people sense this?
Greenstein:Well, I didnt know it at the time. But I gathered later from Struve, who may also have had something to do with my being asked to come here, that he felt it. He felt essentially that there was hesitancy both in recognition of theory in particular, and of the work done at McDonald. But it wasnt serious. One thing one can say about the older Mt. Wilson tradition, based on the strength of their observational equipment and the amount of time they had, the lack of competition, is that they were selfassured. They didnt worry, you know, as to who was Number One. They knew they were. And this meant that they could — they probably just completely disregarded the rest of the world. I mentioned my experiences with Hubble, as my only cosmological work till then. But in general, in spectroscopy, there was the same attitude. Merrill, for example, was one of the editors of the ASTROPHYSICAL JOURNAL (by law almost, or by tradition there was always a Mt. Wilson man). Mt. Wilson papers werent referred, till much later. Merrill said that as the JOURNAL grew, and the APJ SUPPLEMENT was invented, that all long data lists and all theoretical papers should be in the SUPPLEMENT. Its a rather funny combination — lists of wavelengths and Chandrasekhars theory. Merrill had little or no interest in the theoretical interpretation.
Weart:Merrill actually tried to do this.
Greenstein:Yes, But he was only one editor and it didnt work. But Mt. Wilson is very powerful. It invented large telescope astronomy. And I dont think they were all that sensitive to what others were doing. They really just didnt care. Its a typical establishment attitude. The converse of it is that because of this non-competitive tradition, they were the most generous and gentlemanly people on sharing information, One just couldnt imagine it in this present competitive world. But what, say, Merrill had spent 20 or 30 nights at the telescope, acquiring, he would give to some person if he thought him competent and if he was interested in it. Just, Heres a drawer full of plates.
Weart:Which other observatories at the time would not have done?
Greenstein:Well, they couldnt. We all had too little. The same was true of Joy. Id gotten interested in T Tauri stars, new stars formed in dust. And on one visit here, he gave me literally hundreds of plates. And a little office and a magnifying glass and pencil and paper and a measuring machine, to do with them what I wanted. They were much better than the plates I had got at McDonald, mainly because hed been doing it for so long. Hed gotten the stars at interesting times. Hed been the first to discover stars being born in dust clouds. I must say, the whole Mt. Wilson group was like that. Later when I did some work on the spectrum of the sun for the Carbon 12/ Carbon 13 ratio, and the lithium, the solar observers just went and got me plates. I never used to solar tower. Anything I wanted. It was a sharing kind of non-competitive world. It was a very interesting difference.
Weart:These are your initial impressions, of the contrast, when you came?
Greenstein:Well, it was a feeling I already had before. I think I visited here twice, once for a couple of months and once for one month. I just felt that it was different. I felt, of course, a certain loss in not being able to talk about what I viewed as hot subjects, like nuclear power, magnetic fields, radio astronomy. That Pasadena is a world gone forever, Im afraid. You have to appreciate that it had some impact. To sit in an office on Santa Barbara St., hear the Pasadena mourning dove, the pigeons cooing, no wind, no storms, every day quiet, and just have all this wonderful data it made a very powerful emotional impression. It certainly also made the place seem appealing to me.
Weart:Their facilities probably seemed a good deal better than at Yerkes.
Greenstein:Well, they were much better than Yerkes, and better than McDonald. All the facilities.
Weart:Did you sense any contrast in the level of research done, the amount of effort that was put in, the working hours, that kind of environment?
Greenstein:Well, it was different, yes. First, and still now, there was the devotion to very long-term important programs. You could commit yourself, because you had 30 or 40 nights at a big telescope coming to you, that year, to solve a problem, and it didnt matter if you published a paper or not. Nobody was going to scoop you. It wasnt a matter of publish or perish. It was that nobody was going to do better. This was very important in the cosmological problem, or course — the accumulation of red shifts and brightnesses of galaxies must just go on. You continued to work on it over many years. Other people would work with you. Hubble had many people who worked for him, especially since, late in life, his health was bad. You just lived in this world of less interpretation, very little theory, largely description at a high level.
Weart:What about the social environment, the way people interacted, contrasting that with Yerkes, including your initial impressions?
Greenstein:Well, I would say the Mt. Wilson group tended to be older, and somewhat more formal. In the Yerkes group there were more young people around, and there was a lot more social interchange. I wasnt lonely when I arrived here, but in fact, over the long pull, as Ive lived here, a smaller fraction of my personal friends are astronomers, a fraction almost approaching epsilon. Its not that we have any antagonism, its just that there is a bigger world around.
Weart:Well, this is sort of about your initial impressions, I wonder if you could tell me how things have changed over the last 30 years? I know thats a very big question, and well be getting back to specifics, but in general what do you think have been the main constants and the main changes, in the whole astronomical community here in Pasadena?
Greenstein:Within limits, the majority of the staff is still devoted to major programs with large telescopes, with the best possible equipment. Thats the style. Its a position which has been based on some leadership in telescope square inches — number of telescopes times area; in having, in certain fields, been able to keep up leadership or equality with anybody in the auxiliary instruments; and based also on the idea that a permanent staff member is likely to stay in more or less the same field, and become the expert on it.
Weart:They sort of expect it.
Its expected, and it has happened. Though there came a rift in that lute, as older Carnegie staff retired. New staff has built up, down at Cal Tech. There were my choice at first and many of our students got on the Carnegie staff. And the new man grew up with a different added tradition. One was, physical interpretation is terribly important. The other was a strong competitive element. The world changed. The characters in the play changed. Instead of the gentlemen, we have the ideal brilliant, aggressive young genius interested in everything, careless of whose feet he steps on, and very anxious to make the discovery of the week or the year or whatever. Its a loss, and of course, its a gain. Its my fault, because thats how I am, a little bit, and many of these people are my children, in a way. But its also a reaction to the outside world.
The pace of astronomy changed. The competition because powerful. Insularity had to vanish that part is gone forever. Cant help it. But there has been a kind of an extra aggressiveness, added to having the big guns. Its a loss, I guess. On the other had, I wouldnt hire a Merrill, a great describer and discoverer, any more. It would be impossible. I couldnt get it past the Cal Tech professors who vote on tenure. The other thing thats very different, something which the whole department here grew up on, was the idea that astronomy was a branch of physics; that not only the education but the work was going to be highly correlated with people in other buildings, with other titles — professor of physics, professor of theoretical physics, professor of space physics — even with other bosses, it happens, although thats not an important issue. And the observatory has expanded and accepted these other groups and people, put them on the staff, infrared astronomers are, most of them, physicists, are members of the staff of the Hale Observatories, on the Owens Valley Radio Observatory.
When Bowen was appointed director, following Adams, he had been a professor of physics at Cal Tech, a cosmic ray physicist interested in optics, a good teacher. He resigned his professorship at Cal Tech and became director, was paid by the Carnegie Institution, and lost his Cal Tech identity. He also lost his contact and interest in the physics going on. Thats not a good thing. The real truth is that every major advance in physics, I would say, including solid state, has had an impact on astronomy done here. Radio astronomy was another breaking point in style and tradition. We got into high energy electrons. I knew what the cyclotron frequency was but I didnt know what synchrotrons did. In fact, I went and saw synchrotron light and tried to get its spectrum, here. We had a synchrotron. Thats become the style.
Weart:Its such a big question. I have a lot of individual questions, but in each of these, we have to think of covering the whole period, starting with what the initial situation may have been, and then maybe some of the changes. Lets start with Mt. Wilson-Palomar Observatories, then after that well get to the Cal Tech side, and then maybe we can talk about the relations. One of the first things that interested me about the situation when you came here, 48 lets say, is, I noticed there was a research division that had several categories: a physics division, a stellar spectroscopy and motion division, a nubular photography, photometry and spectroscopy division (Hubbles division) — Babcocks division, Paul Merrills division and Hubbles division. I wondered, this sort of breakdown you see in the Annual Report, to what extent did that involve real distinctions? Did people in the different categories have different approaches? Did they work in different parts of the building?
Greenstein:I dont know about different parts of the building, but they surely did have different approaches. They had very little contact. And thats something that weve broken down. I think, evolution toward people talking to each other is an absolute necessity. It wasnt Cal Tech versus Carnegie, it was just that the world changed. I mean, when youre looking at galaxies that had a spectrum like a K giant, that was one thing, but the minute you went into more details on emission line galaxies, radio galaxies dominated by emission lines, Seyfert galaxies, you had to be in atomic physics, even though you were in the socalled nebular division. The divisions barely exist. What was the solar physics division is now Bob Howard. In a certain sense he is isolated. Building a magnetograph meant that he had to have Mr. Horace Babcock behind it, and that a commitment must persist to solar research and as &n observatory goal.
Weart:I noticed in the reports, that they stopped listing them under separate divisions in about 1954, I think.
Weart:What was it like back in the forties and fifties? Did the different groups have different approaches, different ways of doing things?
In the spectroscopic division, Ive mentioned some of the leaders — but omitted some names like A.S. King and Sanford — those people were the older generation. They did know atomic and molecular physics. They were getting on in years; many of them lived many years after retirement and continued to work. But they were close to each other and isolated from the others, They were not interested in radically new instrumental developments, for example; and this beautiful Mt. Wilson Coude spectrograph lead to the Palomar Coude, more or less the same, designed by Dunham, Bowen, Merrill. It was just an extension, it could go fainter. The cosmological nebular division really was originally centered on Rubble, who had good contacts with theorists at Caltech, notably Tolman and Robertson and Humason, who worked for Hubble, having little of his own scientific background but was a superb observer and terribly patient and competent. They were off by themselves pretty much. It was isolation, but I think they respected each other.
On the other hand, in the nebular division also were Baade and Minkowski, more physicists, forward-looking new men. Not all that young, but really forward-looking, fascinated by radio astronomy and peculiar galaxies; Baades new concept of populations had immediate impact also on spectroscopic work, you see. Baade and Minkowski were in the nebular division, but not of that older school. I quote a famous anecdote of Baades — Baade didnt really think much of the spectroscopists, he thought they were dull. Its not quite fair, but he was given to being amusing. He liked me and I loved him and we got along fine. Jesse, He said, those spectroscopists, they dont eat, they dont drink, they dont love. Only he used a different word. That was sort of true. They were old fashioned beyond their years. The solar group was shrinking from the beginning. Unfortunately, it didnt have any single very good man in it. After each one retired or left, they werent replaced. It was a good judgment. And until now, younger staff got things started again; it was the right thing to do. It was unfortunate. You see, with no theoretical tradition thats really it you cant do solar physics just by observing.
Theres just too much data. They produced the magnetic maps every day patiently; there was a routine observer for that. But on the other hand, we also had the horizontal Snow telescope, and with the lead sulfide cell whats his name, Bill Livingston, and somebody else, came from outside, used the high resolution snow spectrograph, made it into an infrared spectrometer, and made the first infrared atlases of the solar spectrum. By the way, the guest investigator policy really kept solar physics going. Because now you have really quite important work being done, including the earths own atmosphere, absorption lines of methane and ammonia being found, the CO2 in the earths atmosphere — all these things were going on with the support of the old solar physics group, but not by them. It didnt cost us, since we had three solar telescopes; so if somebody want to use one of them over many years for solar infra-red, great. And thats been a very positive contribution to solar physics.
Weart:To get back — Im particularly interested in the nebular group, because these people are not here to be interviewed, so Im interested in what you may have known about the interrelations within the nebular group. You talked to them, evidently.
Greenstein:Oh yes. Some were my best friends, Baade and Minkowski, From the Carnegie group.
Weart:You indicated that they had different feelings about things from Hubble and Humason.
Yeah. Both were physicists in background. Minkowski much more so, I would say, Minkowski was a well-trained physicist, period. Came on a postdoctoral fellowship of some kind and eventually stayed. Im not quite sure whether Baade came, went and returned[9]. But their style was a modern style. Baade was no great spectroscopist, but he had, gotten a lot out of the European tradition of stellar statistics concerning galactic structure, galactic kinematics specialized on correlating kinematical and physical properties of stars. He had an incredible encyclopedic knowledge of any fact relevant to the structure of our galaxy that was based on any property of a star. He didnt work on stars, but he noted, for example, this famous difference between long period variables with long and short periods — one group is very high velocity, the other not, being the old disc population. He knew all about R R Lyrae stars; he tried to get the distance to the galactic center from R R Lyraes. He knew about interstellar reddening.
He worked on our Galaxy because it was important for other galaxies which he was interested in. He was an unbelievably good observer. The legend, and its true, I think, was that because he was an enemy alien during World War II, he got all the good observing time on Mt. Wilson during the blackout, and thats when he resolved the older stellar population of the Andromeda Nebula into stars. He was almost the apotheosis of the tradition of superb equipment, lot of observing time, and the practice of sitting on it, until you get the best data. He analyzed his results slowly, looking forward to the next years observing to answer the questions. He unfortunately never reduced a large fraction of it. Its a tragedy. He left Pasadena instead of staying on the way other retired people stayed and worked, and he went back to Germany. It was a mistake but his wife wanted it. But he had also tended not to publish his discoveries. Many of his unparalleled discoveries are in the Directors Report[10], under the report of the nebular division. And thats too bad. But I understand him, because Im getting old, and I wont stop trying to make new discoveries. I feel, like him, impatient to be the first to see something new, hoping to figure it out later.
Weart:He didnt want to take the time to write up a publication and so forth?
Greenstein:No. He hated to write and loved to talk. Most of his importance was in verbal communication to everybody in the world. Everybody who came to the United States from Europe wanted to see Baade. They were not quite clear where Mt. Wilson was. It was 3000 miles from New York. But they came, and Baade shared. He was a terribly generous person in sharing information, and encouraging people to work. He did leave things unfinished, but what he did is just of the best quality. Minkowski, having been a physicist, was the kind of person who would be interested in a new discovery because it was a new branch of physics or something. He represents first modern approach to galaxies, in my opinion. But his papers speak for himself the observations of supernovae and the attempts at quantitative interpretation, studies in radio galaxies; when the radio telescopes came along he was interested in identification. I must say that he started what I would now all nowadays work, in the nebular division. Humason, you know the history of — an uneducated person, did very little interpretation, in fact an incredibly modest, reserved person, generous of his time and equipment, who did all the redshift observing in the later years of Hubbles life. So he and Baade and Minkowski used up all the dark time on the big telescopes and —
Weart:The spectroscopists didnt mind?
Greenstein:I minded, eventually, because I got into dark time work. It was Humason who showed me first (and stayed with me in the 200-inch prime focus) how to use the delicate nebular spectrograph after Id been using the Coude for years, but the nebular spectrograph instrument is one that only he and Minkowski had ever used. Baade, I dont think used it, Zwicky a little. But the ultimate spectra of the ordinary galaxies and the emission-line galaxies were taken with it, by Minkowski and Humason, Humason mostly for the redshift. And Zwicky, a little. Now, you have to put Zwicky in the nebular group, but he was such an individualist that there was nothing but lack of contact there.
Weart:Even with the other members of the nebular group.
Greenstein:Zwicky and Baade did not get along. Baade said at one time he was afraid that Zwicky would kill him. Zwicky had a terrible temper and called Baade a Nazi, publicly. And Zwicky was of course very jealous of Baades discoveries and of his large use of the 200-inch. Zwicky in a sense, was in the modern aspect of galaxies, especially peculiar galaxies, interacting galaxies, compact galaxies, things that have turned out to be Xray sources, strong radio galaxies. But he literally had nothing to do with the others. It was a real organizational problem to manage Zwicky, to give him some observing time, when most of the other felt it was pure waste. But this is a different chapter.
Weart:Tell me about Hubble. How did people consider Hubble? How did they regard him, the astronomers?
Greenstein:He was remote. Thats the only word I can say. He — by then, when I arrived, he was not well. When did he die, do you remember?
Weart:No, Im not sure. It wasnt too long after that[11].
Greenstein:I saw him hardly at all. He was clearly a great man. You asked about social contacts. Hubble had very early become a social lion in Los Angeles among wealthy people and intellectuals, and that was the world in which he in fact moved, socially, and his wife. On the other hand, it would be ungenerous to say that he didnt care about the astronomers. He certainly had close contacts with Humason, whose work he essentially directed. The first of the students here probably would have some direct impressions, notably Sandage. Sandage was the only person who became a frequent, welcome visitor to the Hubble house, especially to the widowed Mrs. Hubble. But the Hubbles were isolated. I was never in their house.
Weart:Did the astronomers have any strong feelings — hed been such a wellknown figure.
Greenstein:Yes, but by the time I arrived, no. The trouble was that he had a heart attack, and he was frail. He never used the 200inch. I think he stayed on the mountain a few times in the late stages of the [mirror] polishing up on the mountain, in a bedroom which has a hospital-type pushbutton switch to ring in the stewards quarters. It was one of the tragedies that the 200inch had been built in a sense because of him, because of his glamour and discoveries, and he couldnt use it. I wish I had known him better. I knew Tolman pretty well, who was the theoretical person in that partnership, in interpretation of the red shift, and I had just clear discussions with Tolman of the situation in cosmology. But not with Hubble.
Weart:Did the spectroscopists, or people not in the nebular division in general, show much interest in cosmology? What did they think about the nebular cosmological work?
Greenstein:Well, I think everybody viewed it as the central theme of the observatory. They didnt all view it equally with joy. There were plenty of stellar problems which required the telescope during the dark of the moon. There were plenty of interesting problems about galaxies which required spectroscopists. In the early days there was very little interchange, and the interchange was probably all through Minkowski, and a little later, with me and Minkowski. But cosmology was one of these remote and dreadfully important things. A central issue in the assignment of observing time for the big telescope in the dark of the moon has always been how much you concentrate on the cosmological question. Are there other, more important, things that are worthwhile rivals? Xray astronomy, interesting faint sources, supernovas are examples. Youve just got to recognize that there are a finite number of dark, good nights. The struggle for them now, with all our new equipment and more telescopes is still ferocious. In the dark of the moon, in the January to April period, the over-requesting for dark nights is still by a factor of three or four. It might have originally been ten. The increase in equipment, the fact that we can use some of the equipment in quarter-moon, even on very faint objects, because they subtract the sky, [background light] has ameliorated this a little. The dark run, by the way, instead of being 14 days, half a month, is now averaging 18 days. You see, theres less and less left. I get whats called grey time, because I do spectroscopy that can stand it, and do sky subtraction. I get more grey time than I do dark time, by far. Its been a deadly conflict, really, and theres no solution. Either the cosmological problem is the central one of astronomy, or isnt. And if its the central one, a big observatory, privately supported, which can redirect i1resources, should take responsibility to make straight forward attack on the cosmological problem. Its been a bitter pill for everybody else who was still doing [spectroscopy], and now for those interested in faint stars.
Weart:Has this changed at all, this general problem?
Greenstein:No, its just as bad. There are more people in it, thats all, and there are more gadgets. There are more people trying to work on the cosmological thing. It isnt any longer, say, Sandage and friends (replacing Hubble). Its Sandage and several rival groups. Gunn and Oke are trying to find faint clusters of galaxies and get larger red shifts. Kristian Christi, Westphal and Sandage are doing the same thing; they have slightly different technological gadgets. But its still a major program. Were trying to get cluster of galaxies which have red shifts, say, prospectively on the order of unity, 100 percent, which are not emission-line galaxies, not radio galaxies, not quasars, so that you know that youve got the stellar spectra, and that you can study the brightness-red shift relation without worrying about how much is synchrotron radiation from some explosion in the galaxy.
Weart:You know, that makes me think — this might be jumping ahead a little bit, but, has the growth of other large telescopes with cosmological programs, has this changed the way that observing time is given? Gee, we have to give these guys a problem because otherwise somebody else will beat them to it?
Greenstein:I doubt internal rearrangements are made for fear of external competition. But we do run scared, The rivals are clearly Lick, which with the 120-inch is one of the best observatories possible, unfortunately in a deteriorating location. It has consistently done wonderful auxiliary instrumentation development. They are right hot on our heels. And the whole University of California faculty is much bigger than Mt. Wilson-Palomar.
Weart:This has been the case even from the forties?
Greenstein:Right. One of Sandages first papers is a joint publication, I think its Humason, Mayall and Sandage, of — I dont know, a thousand red shifts, a major paper, the result of years of work[12]. We used to collaborate much more than one would Think. But were straight-out rivals for success. The Burbidges use the Lick telescope, and others like Spinrad are also looking for the biggest redshift quasars and galaxies.
Weart:Thats sort of always been the case.
Greenstein:Its always been. Nothing can change it. And if we put all our resources in the cosmological program wed maybe go twice as fast with respect to Lick. Were just neck and neck. Its a silly thing to view as a race. I mean, this subject has such enormous requirement of observing time and brains and gadgets that two, three places wont exhaust it. The Southern Hemisphere has to still be done. Kitt Peak is in the competition. But it doesnt change planning, or policy. We just shouldnt react that way. At least I cant.
Weart:Tell me, weve been talking about the allocation of resources, but Im also curious, in terms of the way the spectroscopists viewed cosmology, as to whether thered been any changes in the way they thought what they were doing might relate to cosmology.
Greenstein:Well, I think that the gap is infinitely narrower, if theres any. The point it that almost any emission-line galaxy raises a difficult spectroscopic theoretical problem. If all you want is the red shift, theres no problem. Even then, when the quasars were found, spectroscopies had to predict what lines were coming in from the ultraviolet, which they had never seen. But to make physical sense of these compact galaxies, you find that the cosmologists have become theoretical astrophysicists. What are you going to do with a galaxy where most of the lines are permitted iron II? — I just have one. Unfortunately, iron II has hundreds of lines, all blended here, so you have to synthesize. We are actually synthesizing, in a computer, the iron II blended spectra.
Weart:I never understood why iron lines turn up so often anyway.
Greenstein:OK. I have no theory. Some of them have forbidden iron, some have permitted iron, some have both. I have one object which has iron X and oxygen I in emission. What am I going to do with that?
Weart:I dont know.
Greenstein:Its the solar corona with condensations in it but its a galaxy. So, the current astronomer can no longer be that specialized. He cant be on the staff unless hes willing to be open-minded, so divisions have to disappear.
Weart:Can you think of any point is this a very recent development? Was this already beginning to happen in the late forties? Did it come in at some particular time?
Greenstein:It happened in the early fifties. Radio astronomy must have been the break point.
Weart:And yet what weve been talking about has nothing to do with radio astronomy per se.
Greenstein:Well, Seyfert galaxies were found before, but let me just say that when the radio objects were looked at, almost all were emission-line objects. And next, they were Seyfert galaxies, many of them. And later the X-ray objects became interesting galaxies. So youre really in the soup. You can no longer have a divided astronomy. We cant make an appointment of a superb cosmological observer if he doesnt know atomic physics, or at least if we do were making a mistake.
Weart:I see. Perhaps for some of these reasons, theres been a growth of teamwork around the observatories here?
Greenstein:Oh yes. There was always some teamwork. The old habit was, you know, the man who did most of the observing would publish it. Everybody would throw their plates in. That was one of these wonderful charming things about the past.
Weart:Is that so? One person would publish it under his name?
Greenstein:Oh, Merrill gave me just dozens and Adams gave me 40 or 50 plates of Upsilon Sagitarii, when I arrived. He just gave me, you know, a years observing results, even measurements.
Weart:Well, this is certainly what I would call teamwork.
Greenstein:Yes, but my name is on it, not his. Thats how it was done. I think it came from the feeling of being successful and the leader. You didnt have to worry.
Weart:Well, how do teams function differently now, other than who puts the names on it?
Greenstein:Now its gotten too complicated. Theres a gadget. The gadgeteer is not an engineer, hes a good astronomer. Jim Gunn and Bev Oke developed gadgets. I find something, or somebody else finds something, and now I need to observe it again, so I ask Bev, Are you going up? I see. Will you get me a spectrum? He does, he get interested. I go up, I get more. Pretty soon the two of us (its his gadget originally), share observations. Then the only question is, whose name is first? And that depends on who did the writing of the paper, usually. Ive been in teams of half a dozen. We have a visitor, Boksenberg, who brings the most superb high-resolution device for spectroscopy. Thats what this was done with [pointing to spectrum map]. He usually has a guy with him whos a programmer; during the night he has to sit there and rewrite programs as we see the data coming in. Both assistants have to be on the paper. This study of AM Herc has Boksenberg, Tod Boroson, (a former Cal Tech undergraduate now a graduate student at Arizona), Sargent, whose observing time it was, and myself, on it. Im writing the paper. I dont know what the name order will be; I think thats a rather typical team. Heres another example. Chip Arp comes in to my office. He observed a strange, he first thought, blue galaxy at the galactic pole, which had an emission-line spectrum at zero red shift. It turns out to be one of these cataclysmic variable, U Geminorum stars. His name will be on a new paper together with a young colleague, Shectman, who developed a new gadget.
Weart:The whole thing sounds more rapid and intense, than the sort of old lonely —
Greenstein:Its that. And the fact is, I guess, that we do feel the competition a little bit. [Pointing to materials on desk:] This paper on AM Herculis, if I dont get it out next week, its very likely it will be scooped, because enough people have seen these preliminary pictures that theyve gone and observed it too. Were not alone.
Weart:Im taking too much of your time —
Greenstein:Its a trivium. I mean, I dont care. I publish enough papers. But we do now have, I think, a little sense that youve got to keep pushing a little harder. And I find that a bit unfortunate, but its the way the world is. Very big programs, like discovery of faint clusters of galaxies and getting their red shifts, require two or three observers.
Weart:Why is that?
Greenstein:Just because they dont have enough time in a year, observing time.
Weart:I see, so they have to pool their observing time. In the old days, one person might have had that much observing time.
Greenstein:Thats right. Baade used to get about 45 nights on the 200-inch, in the dark run, and always at the center of the dark run, and the months he wanted. That had to end. And it did end. Sandage tends to get most of the desirable time. So does Gunn and so does Oke.
Weart:Nobody gets 40 nights.
Greenstein:Nobody gets 40 nights. My ration of dark time, since I also use a little light-grey time, is down to about 12 nights this last year, and at one time it had been about 25. The first year or two when I went into the dark sky stuff there was still enough time, Baade and Minkowski were gone, and I got a decent allocation. Ive been just squeezed into the moon, even though Im working on the faintest objects Ive ever worked on.
Weart:Yet you say that the staff in fact, Carnegie staff, is much smaller than it used to be?
Greenstein:Were terribly over-rushed.
Weart:Im still curious about this allocation of time. Is it because the Cal Tech people are so much more numerous?
Greenstein:Everything is more numerous. First of all, let me remind you, Cal Tech brought into the partnership the 200-inch telescope, and owns the 200-inch telescope. In principle it could have used it exclusively.
Greenstein:The situation is that the Mt. Wilson 100-inch has become less useful for dark time work, because of the city [lights]. That was already so before the war, and much more so now. The 200-inch is over-subscribed. But there are other pressures on all the telescopes than our staff. One, we have the guest program, which we take seriously as a public service, bringing in a lot of people we cant afford to hire. Thats taking, over all telescopes 20 percent of the time; of 200-inch dark time, more like 10 or 15 percent. But still, we do have visitors like Sidney van den Bergh and, when he was younger, Oort, who have major problems which were viewed as worthwhile, and theyre in direct competition. Next, the younger people, since life has changed — even post-docs get dark time on the 200-inch.
Weart:Why this change?
Greenstein:Well, call it democratization. Plus the fact that some of them are bright and have good ideas. We would probably not give dark time to a postdoc to do a stellar program. But if hes got some new idea on galaxies — one of the major problems recently that the graduate students and postdocs have been in has been the distribution of light in galaxies and trying to separate the different populations, especially in strange galaxies. This is a thing where observing time, usually electronic sensors, and a large amount of computer processing are involved, That means that most of the older staff are probably not able to do it — unless they have somebody to do their computer programming, (which they may have). Plus having them actually measure plates, the direct photographs, with intelligence, which means that you have to reprogram as you go — its a really interactive process, now, between the data and your computer. Younger people are really very good at it, and theres no way of saying, You cant have to 200, you have to work with the 100-inch or the 60-inch — (The graduate students work mostly with the 60inch).
Weart:Right. What about the outside people, though? You mentioned that youve always tried to keep this up. Has the outside use decreased with time?
Greenstein:The outside use overall is steady. The 48-inch is very popular — theres no other big Schmidt, and good programs get time on it. But really, weve had to swallow our pride in the guest investigator program, which has been the pride of the directors, and one of our few justifications for public support, if you wish. Weve had to really make sure that the 200-inch dark time is allocated to the best scientific programs, and unfortunately, the outside user who wants to observe quasar red shifts isnt going to get any time, because weve got good enough observers interested in the same problem. Outsiders had better go to Kitt Peak or Cerro Tololo. But we have done our best, and I think its an honest best, to maintain the program as an important one. If there were more applicants for use of the Coude, bright of the moon thing, we would be happier. But unfortunately spectroscopy is dying; very few people do high-dispersion spectroscopy. So we dont get enough applicants. And we do get too many in the dark run. For us, its been a matter of principle. It started when I arrived. There was a guest program. Every now and then, wed say, Well, we dont get any money from the government to hell with the guest program —. We cant do it, and we dont do it. Bob Bacher, who was division chairman most of the time when I was running this department, said that it would be impossible for Cal Tech to view the 200-inch as a privately-owned facility for our own use. He just felt that it would have such adverse consequences on the national support of Cal Tech as a whole, that we had to view it as a nationally available treasure in which we had a certain particular interest and right, but not exclusive.
Weart:Now, all this time youve been saying we, I have some idea who we is but Id be curious if youd just say, for example — has there ever been any kind of formal decision such as, now well start having a little more time or a little less time for outside observers? And who participates in this?
Greenstein:Well, the actual decisions, Im no longer involved in. I say we because I was involved for 25 years.
Weart:Thats what Im thinking about.
Greenstein:The process is, all formal decisions are made by the director of the two institutions — in my time, Adams (who was just retiring, Bowen and Babcock). But theyre made with the consent of the observatory committee, which consists of three representatives from Carnegie, three from Cal Tech, and the director. This is under a joint operating agreement which is quite formal and was rewritten once when I was in charge and once a little later. The observatory committee represents both institutions, and the time allocation committee represents both institutions.
Weart:A subcommittee?
Greenstein:Yes, advisory to the observatory committee. The observatory committee formalizes that and approves or disapproves. The director executes these orders or decides to slightly change them. The time allocation committee meets once a year. Proposals to it have to be in early. I think the decision is in November, and it goes for the next calendar year. Which is a rough way of working, because if you find something new you havent enough time. So you have a little teamwork forced on you, just by the fact that you cant plan ahead on discovery. There have been continuous discussions, mainly based on the chronic serious financial problems of the privately owned observatory, as to the guest investigator program, whether we can afford it. It actually costs us not only time, but just plain out-of-pocket money.
Weart:These things get discussed on the observatory committee essentially.
Weart:And the time committee meets for, what, a couple of days?
Greenstein:Yes. But its very conscious of the need. The general policy, I think, hasnt changed — though Im not on these committees now — that we have a public obligation. And that public obligation requires a certain minimal number of nights. Of course, if there are no good applicants, or if all the applicants want to do what staff is doing, youve got problems. After all, Kitt Peak has the legal obligation. But thereve been enough pressures on us that, — if you look at the annual report, where it lists the guest users you can get a better idea. Its been, I think, a real contribution. At one time, till a couple of years ago, we gave away more square inches of telescope time to visitors than the National Observatory.
Weart:Square inches times days or whatever?
Greenstein:Yes; its changed now with Cerro Tololo coming in. But weve got a new 100-inch, and I dont know what well do there. We dont have a big enough staff to man the Las Campanas 100-inch.
Weart:To use it, or to man it?
Greenstein:To run it, to operate daily, weve got just enough money, but we dont really have enough scientific staff for constructive oversubscription for it.
Weart:So youll go outside people?
Greenstein:Oh, we are in principle, anyway. That was how the money was given.
Weart:On this committee, did you ever feel that you were there representing the spectroscopic people? And that Sandage or whomever was representing the cosmological people?
Greenstein:Well, I would say that his voice would have been listened to more when it came to the fine points of exactly how many nights went to somebody in the cosmological problems, and mine, in the spectroscopic area. But there has been so much shuffling of people between the two groups. As I remember it, formally everybody votes on everything.
Weart:You mean the whole observatory committee?
Greenstein:No, the whole time allocation committee. Even if you dont really understand a proposal in some other field, youre required to vote on it, It may end up with a middle grade.
Weart:About how many members does this committee have?
Greenstein:Its usually been small. Just a couple from each institution, and the director.
Weart:Are these always members of the observatory committee?
Weart:They may be other people. I see. Has the composition changed very much?
Greenstein:Yes, its rotated. It used to be stationary. Again, democracy hit, and now theres rotation.
Weart:About when was that?
Greenstein:Oh, I dont know; rotation must have begun about 15 years ago. Before then, it could have been accused of being a closed corporation, where Baade gave himself all the nights. That wasnt true. He didnt care what the spectroscopists did, so I could have given myself all the nights. It didnt work out that way. Its been a remarkable exercise in, I call it, friendly cutthroating. You cant help cutting people. And yet, its been done with the best intentions.
Weart:Have there been — either on that committee or in general on the observatory committee Cal Tech Carnegie divisions?
Greenstein:Oh yes, enormous. Less on the observing time committee. Thats straightforward scientific. The overall management has two different philosophies, in the two institutions, and theres nothing but difference of opinion. On the other hand, weve managed to survive. The joint operating agreement is pretty clear. Were devoted to research, both institutions. Were both putting facilities into the pot. We support our own mountains; all financial support of any mountain comes from its owning institution. Caltech pays for Palomar auxiliary equipment. If Carnegie wants to build a new sensor to go on its 100-inch, it gets money internally or from the government, thats its worry. If we do, its our worry, for Palomar. However, the observatory committee has to agree that its a good thing to do, and that means that there is some sharing. Our structure is a little complicated, but lets start — Any proposal to the government has to be looked at by the Cal Tech business office, by the Cal Tech [physical sciences] division chairman, and by the administration from up to the president of Cal Tech. Any proposal from Carnegie has to be looked at by the director [of the observatories], who happens to be an employee of Carnegie at present, and by, I guess, the president of Carnegie [Institution] in Washington. The signatures on these proposal are always the director, the provost (or acting president now), the business officer of the relevant institution, and the principle investigator. People from both places see the proposals, in other words. And so you dont get two pieces of equipment being built which are needlessly different. Hal Zirins solar observatory he tries to run more or less autonomously, but the director has to sign off on it too, thought its a Cal Tech proposal. The structure is unworkable, but has worked.
Weart:What are these philosophical differences that you spoke of?
Greenstein:Well, one fundamental one goes back a long time; Carnegie didnt take money from the government until rather recently. I had to threaten to resign, I think in 1957, to get a big project on the composition of the stars and nuclear physics started. There has been since that always some minimal government support here. The radio observatory is an example. But we have several problems. We have different employers, therefore different salaries and benefits structure.
Weart:Oh, I didnt realize.
Greenstein:The Carnegie benefits are all paid by Carnegie. They have a medical plan and they have a retirement plan, its all their own money. Ours is through TIAA[13], where the Institute puts in money and the individual puts in money. So its hard to really make salaries equal, because then Carnegie people would get more. Carnegie always used to pay very low salaries. It had to grow into the modern world and pay comparable salaries. But this business about government money was serious. And next, the employment of people on a temporary basis that was another difficult thing. Carnegie was not used to people coming and going. At Carnegie, by the way, you got no tenure — you got a contract for one year, when you were employed, and then you got a letter every year, after it, about your new salary. But you never had tenure. It was a year-by-year appointment.
Weart:On the other hand, I dont recall anybody being let go.
Greenstein:Well, they pressured some people out. Some of them unfortunately, in the solar group, where they werent given a raise for ten years — and got the hint. Nobody was let go, thats right. Cal Tech, as an educational institution, is to students, graduate students, postdocs, assistant professors without tenure, associate professors without tenure. So the idea of turnover was a rather radical thing, when everybody on the Carnegie side was there forever. There were conservative versus liberal tones, styles of working, sensitivity to status. I think Cal Tech also, from the beginning, accepted as a goal the idea of large government support, even if they hadnt got a lot; and Carnegie wouldnt. And when I wanted to —
Weart:You mean, even from the late forties, Cal Tech was sort of sent on this.
Greenstein:Yes, when I came, in the physics labs. Cal Tech before had only one astronomer, Zwicky, had been a physicist, with tenure in astronomy. And a temporary person for the elementary teaching.
Weart:At any rate, you and the president and so forth, the division of physical sciences —
Greenstein:We began to live in the modern world. Ill discuss what happened when I came, how things changed. There was a real problem. I was at first pretty much alone, and the group grew up with younger people, and Carnegie had this marvelous, successful traditional approach. We were in different worlds. I became involved with outside activities. People got into radio astronomy and the space program early. On the other hand, there [at Carnegie] was a rather stable organization with a fine tradition. Our side was a growing organization with quite a different tradition. I dont know which is better, but they were different in philosophy. So we had all kinds of minor difficulties. As I said, the thing has worked from the 1948 agreement till now, and I think been successful in spite of other internal frictions which I wont discuss. Weve managed to produce a lot of science I think it shows you that a joint operation works with good will. It takes a positive contribution of good will; you have to want it to work. And I think its worked because people have had the big goals first, the big question: whats out there?
Weart:Aside from the Cal Tech Carnegie sort of differences of philosophy, on the observatory committee, have there been any persistent differences of philosophy along other lines?
Greenstein:Probably the most obvious one is: is cosmology so important that all available resources should be put on it?
Weart:Has this been proposed?
Greenstein:Its continuously there. You cant not propose it. I mean, until we become the third or fourth ranked observatory, cosmology, if its important as some believe it is, is going to be central. And it still is true that much of the observing time and much of the instrument development is centered on it.
Weart:Has the consensus on this changed over the last 30 years? Or is it just something that keeps coming up?
Greenstein:It keeps coming up. You see, what happened is that Rubble and Tolman thought that the cosmological question was either answered, or would be answered when the 200-inch had worked for three to five years. I think now the best people are severely divided. Sandage thinks that it is soluble within his lifetime. Thats a long time from when [Rubble thought] it was going to be solved, People who know about some of the questions about evolution of galaxies, agglomeration of galaxies and clusters, stellar evolution at long lookback times, are worried. And some people feel that its an insoluble question, although it may be central.
Weart:Insoluble in principle, or ?
Greenstein:In principle. That we will never know enough to look back.
Weart:This is a philosophical position.
Greenstein:Well, no, its a scientific position.
Weart:Which side do you fall on, by the way?
Greenstein:At the moment, I tend to be a little on the side of the negative. I dont think its going to be easy. I think there are severe scientific questions, too many bold assumptions. See, its all very well to say we can understand things to lookback times of the order of unity — lets call it very roughly, halfway. Beyond that, I think I have severe qualms: The quasars are the thing that damaged my faith, very severely.
Weart:Were going to get back to some of these things about the current situation; I do want to ask you some questions. But Im interested now in the evolution. Do you think this was a general thing, that the quasars had this kind of impact on people?
Greenstein:It was a destructive if exciting impact. At first, God, here we were with red shifts of 2, we were in business. But when every quasar turned out to have a different luminosity, and they turned out to be variable, and all the mysteries about them came up, it must suggest that things at long look-back time are going to be tough. And now a new question has arisen, from theoretical work at Princeton[14] — galaxies in clusters seem to be swallowing each other up.
Weart:Right, theyre eating each other up.
Greenstein:And that is a tough one. Because we see [nearby] clusters as they are now, not before they began swallowing each other, and maybe there wont be any very high luminosity galaxies in very large red shift clusters.
Weart:Uh huh, you wont have a largest cluster member.
Greenstein:Thats right. And that will hit Sandage very hard. However so far, to red shifts around 6/10, it looks all right.
Weart:Now, if I think back over what youve told me I get the impression that you might say that pre-quasars the feeling was, lets give a lot of telescope time to cosmology and well solve it. And post-quasars its, lets give a lot of telescope time to cosmology because the problems are so great?
Greenstein:Thats right. It made no difference. One way or another, you have to work on these faint, difficult objects. Theres no way out, and I dont know the solution, except another telescope in a better location with more electronic gadgets. All I need is 100 million dollars, and I can at least tell you that with it, we might have a chance to go back to galaxies with red shifts of 1.2.
Weart:Youve been describing the large space telescope, in a sense.
Greenstein:Yes. Thats why I backed the large space telescope.
Weart:OK. All of this is so interesting — but I have a couple of questions again about the organization, the observatory committee. How much has the observatory committee changed what the director wanted to do? Whats been the balance of power between the director and the committee? Maybe thats a question about individual directors, or is it more general?
Greenstein:Under Bowen, I would say, it had a great deal of influence, and I would guess that the observatory committee made the decisions. Babcock happens to be a somewhat stubborn person. He more or less decided things-sometimes policy, sometimes every detail, till perhaps a half a dozen years ago, at which time the staff and the observatory committee decided that things were not all that healthy, and theres been an enormous democratization. We had an experiment of whats called the staff council, in which important questions were discussed with everybody there, including the post-doctoral fellows. It meant around 25, 30 people, depending on who was away on the mountains, meeting monthly. Theres been a pretty strong difference of opinion between the director and the observatory committee, in recent years, where I think the observatory is taking very strong stands, with a strongly stubborn director, and this is a little difficult situation which will end in less than a year[15]. The new director will be employed by both institutions, and is a rational approachable human being.
Weart:Are these philosophical differences, or simply —?
Greenstein:Well, some of them go back to cosmology, some go back to prejudices inherited from the dead days of the Mt. Wilson isolation —
Weart:— taking care of things by yourself?
Greenstein:Yes. Life has changed too much. And the director lives too much on past glories while the young staff know that things have to be done differently. You may or may not know, I dropped out of administration in 1972, after just one year short of 25 years. I got off all committees at that time. So, I am isolated, but I know whats going on.
Weart:You got off because you saw what was coming?
Greenstein:No, no I got off because it was 24 — I wanted it to be 25 years of being at the center but I was going to Copenhagen, on leave.
Weart:Oh, I see.
Greenstein:And it turned out that Maarten Schmidt was willing to replace me, why not have him do it right away? And it was successful. Unfortunately they raised him even higher, and now theres a new head, Wal Sargent. The staff choice is one of the other fundamental, basic things. Each institution decides on who it wants but must consult the other. Appointment is joint.
Weart:Were at the end of this tape.
Greenstein:Cal Tech has opted largely for people with good theoretical background, interested in observational astronomy, and people who, at least in principle, are or were good theorists and who can teach. Not that teaching is a major load. We do only two-thirds of a course a year, on the average. Thats all the teaching. But we deal more with students, graduate students and postdocs, and that produces a different impression of whos good. And since our staff, in both places, is fairly small, there have been differences which are resolved in every case on who should be appointed next. When I started this group here I made those decisions, and then had to persuade the director. That was a much simpler world. Now, the guy or the girl has to be satisfactory, to both places.
Weart:Now this is sort of a question of the persons individual capabilities, but is there also a philosophical difference?
Greenstein:Not so much. Were a little more international at Cal Tech. Not that theres any prejudice at either place. Both places have tried to hire women, have quite honestly done their best. Its a difficult operation because, having a small staff and a large number of telescopes, every new staff member is terribly important. It isnt like a place with —
Weart:— not like a big astronomy department —
Greenstein:Its not Smithsonian-Harvard, its not Kitt Peak. Each person makes a difference. The ideal qualified person, at the moment, would be a woman who loves to design electronic equipment, is handy in the shop, a good theorist, and has marvelous encyclopedic knowledge of astronomy in all fields. Otherwise, its an easy job. You know, weve failed to make a new appointment at Cal Tech two years in a row. Weve failed to appoint, to authorized, advertised positions, anybody. Just couldnt find the right person. And thats hard. [Break for Lunch]
Weart:Im interested in the structure. Youve told me a lot about it. Im interested in the things which dont show up in the formal agreements, and so forth.
Greenstein:Well, any joint operation of two different groups has inevitable problems. One current change, which will take effect with the new director, proposed by the president of Cal Tech, was that in fact the new director be an employee of both institutions no matter the difference in regulations and benefits, etc., those could be worked out, but in principle he reported, not only by lip service but in fact, to both institutions. This will be adopted next July. The other kinds of things are curable. We were unfortunate in one area, which depended on money. We had a straightforward project to build two buildings on the Cal Tech campus for astronomy, one for Carnegie and one for Cal Tech.
Weart:What period was this?
Greenstein:Oh let me guess around 12 years ago. Funding for science was beginning to become a little tight. Private donors werent all that anxious. The idea was a good one. It was to build, essentially, structures with common laboratory facilities, which would be a saving. We badly need a new building. Were all over the campus. Carnegie is a little physically remote, people dont go up there and they dont come to lunch as often as they might. I used to go, a few days a week, and eat in a hamburger joint with the older people — but I dont any more.
Weart:Would you drive up there?
Greenstein:Yes, drive up there. Its not so far, its a few minutes. We do try to get together for Friday lunches, but then you have an enormous table of people, There isnt as much personal contact. There is one collaboration, again made a little more difficult just by physical separation. All the plate storage for the spectra is at Santa Barbara St., and all the 48-inch plates are here, and ultimately all the direct photographs will be here. Again, its a pointless division, and were duplicating facilities. Anyway, that went so far as several hundred thousand dollars spent on building plans by Edward Durrell Stone. These were beautiful buildings; I would have had the top office on a solar pyramid. In fact, they looked like these Mexican temples of the sun. But just about that time money became a little hard, and Carnegie decided to go for a Southern Hemisphere telescope. So the money for their building in part went for the Southern Hemisphere telescope. The Southern Hemisphere telescope is an example of a decision made almost unilaterally by Carnegie. Its going to put it in a financially difficult position for a long, long time. Had it been fully discussed, I think, with Cal Tech, probably we would have talked them out of it. Were not against it. Were certainly going to use it. Its part of the Hale Observatories now. But it seemed too late, too little — and we might have done other things. But thats gone. Its kind of difficult to have two organizations. Theres a little sensitivity and rivalry as to who gets mentioned in the Directors Report as the master stroke of the year in science.
Weart:People are quite aware whos Carnegie and whos Cal Tech?
Greenstein:Oh yes. Well, today Eric Persson was down with the infrared group at lunch, and hes a Cal Tech PhD up at Santa Barbara St., on the staff. The infra-red people see him, because he works a lot with Neugebauer etc. down here, but otherwise he doesnt meet our optical astronomers much. Its inevitable, but it has not led to bloody clashes. Theres no gung-ho attempt to push the other people into the soup. I think were all proud of each other, at least try to be, if weve done something good. If a guys in a different field what are you going to do, to work with him? You cant. But just to know that theyre very good, and successful, gives one a sort of group feeling. And how to encourage that, when youre divided physically, is the problem.
Weart:You feel youre a member of a particularly important group —
Greenstein:— Like the solar physics group here. They have their solar physics lunches. Ive seen people come and go, and Ive never met them. They stay a year or so. Sometimes I do; some of them are more vocal. But these are organizational questions to which theres no easy answer.
Weart:OK, let me just go back to some of the more specific questions. Back in the time — to go back now to the late forties or early fifties when there were separate research sections, a nebular section and spectroscopy and so forth there were people who were supposedly heads of the sections, Hubble and Merrill and so forth. Did these people in fact have any kind of administrative role?
Greenstein:The custom when I arrived was that the head of the section and it wasnt Hubble, it was then Baade, in fact would assign the nights for his section.
Weart:And the committee would sort of decide how many nights each section would get?
Greenstein:You decided that the dark run belonged to the nebular, the light to the spectroscopic. And youd have to break that usually at a little more than half the months for the dark run, and they would decide internally.
Weart:That would be decided by Baade or Merrill.
Weart:Did they serve any other role? Did they have any other role, for example, in deciding what type of research might be done, or encouraging it?
Greenstein:No, I think by then everybody was pretty much on their own. When I arrived the only people who took any strong interest in encouraging work in special areas, to be quite honest, was Baade and Minkowski. They were generalists, they were interested in everything, and would come down and talk to people here. Especially with radio astronomy and supernovae problems. They didnt have any power to tell anybody what to do, but of course their brains and their knowledge did have that effect. If anybody had any authority of power it would be Baade and Minkowski, and I cant separate them. Probably Baade. Except he hated all organizational or administrative things.
Weart:This was just a problem of his personality.
Greenstein:Yeah. There was no power. There really isnt any authority anywhere, that I can see, in this institution. Thank God.
Weart:Tell me, speaking about authority and so forth, how did Ira Bowen function as director of the observatories? What sort of administrator, director was he?
Greenstein:He was liked. He was devoted to instrumentation; his only major interest was instrumentation. He was good at answering questions about atomic spectra, and he was available. He was a very easy person to talk to, and he did almost all of the work on optical design of the auxiliaries himself.
Weart:So he spent a lot of his time, not as director but as designer?
Greenstein:We have had non-interfering scientific directors since — except for Hale, theyve all been interested in letting people do their own thing, as the current phraseology goes. Nobody was told anything to do. Bownes major problems, that I remember, were that he did not know many astronomers. He was a rather retiring individual, very Middle-western and non-pretentious, and he did not have any feeling as to outside for new appointments; that all came from the staff, through the observatory committee lets say from individuals who had somebody they wanted.
Weart:Then he went along with that.
Greenstein:He would go along. I was refused only once, in my 20-odd years, on an appointment. And that wasnt by Bowen but by Bacher, the division chairman. And I guess he was right. We would have gained notoriety, but not necessarily in science. I wanted Fred Hoyle.
Weart:I see.
Greenstein:I brought Hoyle here first in 1952, I think it was, and I thought he was just what we needed. That was the only time a suggestion from here on new staff was refused. To me, we havent spoken about the most interesting thing — and thats the staff, how do you get good staff? That is the creative part of it. Bowen, unfortunately, by personality and background, was a little remote from other astronomy. He was enormously self-effacing, he just was unselfish. He worked like anything on the optical and mechanical problems.
Weart:How did he function in terms of his relations outside the observatory — with the university, with Carnegie, with the public and others?
Greenstein:He was very quiet. They respected him at Carnegie headquarters. He had been a Cal Tech professor, and he was certainly respected for his scientific ability. I think that everybody liked him, is a fair statement. The cases which were difficult involved outright conflicts, where he could not, perhaps lacking information and background, do what he ought to have. We had a series of crises with Fritz Zwicky. Papers that were not publishable, that shouldnt be published.
Weart:That was back in the days when there was no refereeing?
Greenstein:No, even after that. That refereeing was internal. The papers still are submitted by one publications secretary at Santa Barbara St. The director is supposed to look at them, and there is a publications committee that looks at them from the point of view of public relations. Fritz would just write some intemperate paper attacking somebody. Bowen would have to squelch it, and he was just embarrassed and helpless doing that as could be. It wasnt his style; but he did act. And there were fights about observing time assignments. Thats another kind of crisis which Bowen couldnt cope with. He was fortunate in having a president of Carnegie, Caryl Haskins, who was himself, oddly enough, a shy and modest man — and the two to them could get along fine. Neither of them were pretentious, and I think Caryl was probably quite fond of Bowen, I think everybody was fond of him.
Weart:How would these conflicts be resolved?
Greenstein:I think with Zwicky, he just eventually got pushed by Zwicky so hard that he might let it go in, and the JOURNAL would turn it down, and then it would get published usually some place in Europe, I forget what its called, PHYSICAL A or one of those things.
Weart:But conflict over observing time or whatever was this finally decided by a formal vote on the observatory committee?
Greenstein:Yes. I would almost always, if I were there, say, Now, look, Fritz has had nine observing nights a year for the last five years, and while his work isnt terribly good, hes a senior staff member, and youve got to have academic freedom, I didnt vote that, my heart was not always in it. Eventually Zwicky was better treated. He had been badly treated on the idea that he was erratic and that much of his work went unpublished. But unfortunately — or fortunately for him but unfortunately for that point of view — as high-energy phenomenon in astronomy came in, it turned out that Zwicky had been righter than the conservatives. Therefore, toward the end, he had more time. He used the 48-inch a lot. Unlike anybody else, he had a lot of stooges. You see, you asked me about the nebular group — in a sense, Hubble had Humason to do his work. But Humason was no stooge, and next, Hubble was ill. During my period, it was Humasons work, though it was for Hubble. But Zwicky had incompetents who he would import. They did enormous amounts of the work, e.g. cataloging the galaxies. Meanwhile, Zwicky would be viciously attacking me or Alan Sandage or the Lick people. It was unpleasant, but it was bearable, because in fact, he is more respected by our younger staff now that when he was alive. If he were alive, Im not so sure hed be so popular. Wal Sargent has Zwickys picture up in his office, which I think is very nice.
Weart:I understand. OK, well, how about now talking about the Cal Tech side of it, and building up the department here? You were brought in — it was specifically to do what. What did they tell you?
Greenstein:It was in connection with the opening of a graduate school in astronomy. It opened with only six specially selected students, and three or four courses. And it was eventually to provide a research staff for Cal Techs side of the Mt. WilsonPalomar operation.
Weart:Because of the 200-inch?
Greenstein:Yes, because the 200-inch was formally dedicated in 1948, which was when I came. Though it didnt really work for two or three years, in full I used it first in 1952. But the idea was that we would eventually build up a research and teaching staff, I was led to believe, of the order of 15 or 20.
Weart:15 or 20 faculty?
Greenstein:Faculty. The staffing with post-docs was not yet an academic pattern, there were too few. There were no department heads, because of the Caltech divisional structure, but I think my letter of appointment from the dean, said that if there ever were departments, I would be the department head.
Weart:Thats a nice way of putting it.
Greenstein:And that my responsibilities were to bring together a teaching and research staff of the highest caliber, to use the big telescopes.
Weart:And Cal Tech promised the money for this development?
Greenstein:Yes. The other thing I was promised was that those of the younger members of the Carnegie staff who wanted to, and could, would do some of the graduate-teaching. And for some years I had, say, two or three terms or courses taught by Baade, for example, or Minkowski, Nicholson, Wilson or Bowen, or even the photographer.
Weart:Paid for by Carnegie?
Greenstein:Yes. They were chipping in, after all, We were paying the operating costs on one mountain, then on another. We had the teaching responsibility. They were sharing in this joint operation.
Weart:Did the Carnegie people see the teaching thing as being an important thing? In the 1948 agreement, it was agreed specifically that there would be a graduate astronomy department.
Greenstein:Yes, but unfortunately, the younger people who would have had such views found it hard. Many had never taught, literally. Maybe Olin Wilson, I think, had taught at Berkeley for a year. It was hard, and the courses were not well organized, and changed all the time. But many that were given were quite inspirational, to put it mildly. Alan Sandage, who was one of our first graduate students, had the experience of being taught how to use the big telescope by Walter Baade. He sat night after night on Mount Wilson when Baade was observing, listening to Baade talk. As far as deep instruction goes, thats a little bit better than a one year course on math physics.
Weart:Did the observatory committee have anything to do with you, did they advise?
Greenstein:I was automatically on the observatory committee.
Weart:Did the observatory committee discuss the educational program?
Greenstein:No. They were to advise the Observatory and pretty much out of the Department. I was responsible, and I had decided how to go. Which was that astronomy was physics. So from the beginning I didnt want many astronomical courses. I wanted more people, but I did want the astronomy graduate students to follow the physics curriculum, and they did. For many years they studied almost all of the first two years of graduate physics.
Weart:Why was this?
Greenstein:One, because I thought thats where the action was. Well, I knew its where the action was. Next, not everybody was going to be an astronomer because he so declared himself. And next, many people who came to graduate school, or were coming to graduate school, had no astronomy. Physicists gradually learned astronomical techniques — like Gerry Neugebauer, 15 years ago a particle physicist. So I started right at the beginning with physics as the center.
Weart:Did you discuss this with anybody?
Greenstein:Well, I told Ike Bowen, and he agreed. I mean, there was no doubt about that. Also, by the way, the Cal Tech tradition is, no matter what you did in physics you all took the same courses as an endurance test, including some despicably dull, like electricity and magnetism.
Weart:This fitted into their educational tradition.
Greenstein:It went in well. And I worked very closely with the physicists from the very beginning. After all, I was here alone. I taught a one-year course on stellar interiors and a one-year course on stellar atmospheres. Thats enough astrophysics.
Weart:That covers it.
Greenstein:Well, no, there were other things. Nicholson, gave a course on solar physics, one term. And interstellar matter, and molecular spectra by Merrill. It was hard on them, though. Every year when it was time to write the catalog I would call Ike and say, Can you get me somebody next year? And hed say, Well, Ill try. Usually hed get me one, sometimes two, and they were fine. That part of the agreement was never fully lived up to. Caltech had to do it ourselves, and given the age of the Carnegie staff, it was about right. Looking back, I didnt show an enormous amount of imagination in the people I brought in. I brought in all the characters I knew from Yerkes, that I could. In fact, I think the first three appointees were Yerkes PhDs: Code, Osterbrock, Munch (Munch was first). Theyre good people, extremely good, and that was a good nucleus for a long time.
Weart:Did you model the educational program on anything particular, on Yerkes or anything else?
Greenstein:Well, no. Here, it was more intense. Yerkes had a relaxed teaching business; there were only, I think, two or three courses a year given. And Chandra taught; he would change the subject with his research. Ours were a little more rigorously mathematical. I must say, I now read my notes on interiors and atmospheres without understanding them. They were pretty advanced. But since the students were fairly good mathematically, it was OK.
Weart:Did you have a feeling you were doing a new thing, by introducing more —?
Greenstein:Yes. My ambition was to make this the best physical astronomy department possible. And I didnt think it was all that novel. It seemed to me the only thing I could do, especially at Cal Tech. I had all these marvelous physicists around, and they were interested. So that, plus the fact that the students had once the 200-inch came into work, pretty much unrestricted access to the 100-inch. The student theses at the telescope were 100-inch theses. And thats a good telescope for a student. So there were some pretty good results. Sandage and Arp got on the Carnegie staff right away. Sandage went away for six months to Princeton, learned age-dating of stars and clusters. Arp was some kind of post-doc at Carnegie and then got a job, so they soon had some younger people. I also had some influence on the people who were appointed at Carnegie, through the observatory committee, and the fact that Bowen did not know too many astronomers. So I think the direction of staffing in both places was pretty much what I would still call the modern way — you know, good physicists interested in astronomy.
Weart:Oh, you looked for a physicist first?
Greenstein:Well, he may have had a degree in astronomy. Theres no harm in that. It was sort of continuing the Yerkes tradition of interpretation. Osterbrock was extremely bright. Code was bright and somewhat active in those days; they were both real assets. Code knew a lot of technology; Osterbrock was more theoretical.
Weart:Did you try to make a balance between theorists and —
Greenstein:No, we had so much imbalance to rectify, I wanted theorists. And they all were. In fact, it was a joke — it was no joke, Im sorry — I got a letter from Chandra criticizing me for turning Guido Munch, his best student, into an observing astronomer.
Weart:Because he had started as a theorist.
Greenstein:Yes. He was a very good theorist, very bright mathematician. He wrote quite a few purely theoretical papers when he was here, things like, obviously, the above equation reduces to the so and so lemmar, which Id never heard of, in hydrodynamics. He got interested in turbulence and shocks very early. So did Osterbrock.
Weart:Do you think they were converted just by being here?
Greenstein:Yes, Guido, in answering — but he never wrote it to Chandra — he said [in Munchs accent:] Well, you know, do a lot of work in theory and its no use; you make one observation, you may be lucky. Hes German Spanish English. He was a real asset, and he introduced planetary science, too, into respectable astronomy here. So I started with all theorists, as far as I can remember the list.
Weart:Did you try for any kind of balance or emphasis in terms of the type of problems they were working on? Spectroscopic or extragalactic or whatever?
Greenstein:Well, let me see. One example, I would have liked, but actually failed, to make an appointment in general relativity, which was dormant subject in those years.
Weart:You were interested in that then?
Greenstein:Yes. I was a good friend of H.P. Robertson; in fact he proved one of my best friends, perhaps instrumental in bringing me here. But when I arrived he was in general relativity. He worked with Hubble, redoing the mean density of the universe and the qo after Tolman died, and making novel, interesting suggestions on tests of general relativity. I wanted somebody more in astronomy, and so relativity was a luxury that we didnt absolutely have to have, with Robertson here. Unfortunately he died young. I would say that anybody successful who was going to do observations of galaxies would have automatically work with the Santa Barbara St. staff. I think we sort of could equally divide, as we could expand, make new appointments, between convertible theorists, who would become observers, and people who were dominantly observers, who could go to Santa Barbara St.
Weart:Theyd go and be hired there?
Greenstein:Yes. And if there was a very bright student and it was a question of where — there could have been a difference of opinion for example, I did want to have either Sandage or Arp down here. One time Arp got a little unhappy and wanted to come here, proposed it. With Zwicky in extragalactic work, [it would be] really not very useful for the students —
Weart:— it was a question of what you needed for the teaching.
Greenstein:That was one aspect. We needed some for the teaching. And next for what I thought, led many people agreeing with me, was the future trend of astronomy. I had the backing of the physics group here from the beginning. As I said, Roberts may have been instrumental in pushing me for the job; wed known each other a long time. And Fowler, whom I made friends with very quickly. Then, oddly enough, electricity, and magnetism and electrical engineering, because of radio astronomy, were places where we could send students for courses, and in addition where I got support within the division, from the physicists, for new appointments.
Weart:So you would suggest people for them to appoint and they would suggest people for you to appoint?
Greenstein:Yes. Right. It was a good happy establishment, when and we were growing rather rapidly. I think there were six appointees in the first nine years, which, had it kept up, would have really gotten somewhere. Then we slowed down and went the younger, temporary, post-doc route. That was very much strengthened by the radio astronomy group, where there wasnt a single person in radioastronomy you could appoint a professor at Cal Tech, literally.
Weart:There wasnt anyone?
Greenstein:Not in the country. When I wanted — with all this fuss about radio galaxies, identification, Baade and Minkowski yelling and screaming how great it was (and it was) — you couldnt find an academic person in that subject. They were electrical engineers originally, or amateurs like Reber, or Europeans, mostly English. We were a very cosmopolitan department. I think at one time Code and Osterbrock left at the same time, to set up a big department at Wisconsin and of what was left, I was the only American citizen, except the secretaries, in the group. John Bolton, head of radio astronomy, was English, and so forth and so on; Zwicky was Swiss, guess I was a bit copying Struve, in looking around the world, in these early years. And I had good backing from the physicists. We had very good undergraduate physicists, a luxury which few astronomers can really enjoy.
Weart:Did they make some difference?
Greenstein:Oh yes. Kip Thorne, for example, was an undergraduate at Cal Tech, worked one summer for me and wrote an ASTROPHYSICAL JOURNAL SUPPLEMENT article as a result, as a senior.
Weart:I see. They were pretty high caliber.
Greenstein:You know, the good ones are what you fight for. I must say, I had a very easy time at the beginning, though it was lonely. It was stimulating, and produced what you might call instant creativity. That is, you could do things and get a difference. One person made a difference.
Weart:As the group grew larger, this must have changed.
Greenstein:It saturated unfortunately. We didnt need the people for teaching. I mean, no matter how many students we had, we had too many faculty. I think at the highest, we had three graduate students per faculty member. We had 10 or 11 professors and 30-odd students. Weve cut the student population and the faculty is just a little bit larger, though its now in danger of rapid shrinking, losses, since. Everybody is the head of something, now. I was very fortunate in having sympathetic people to report to. And of course the president of Cal Tech, Lee Dubridge, who came just a little before I did, six months before, was superb. He was interested in astronomy and was a very good listener and a very good money raiser.
Weart:I was going to ask about that, did Dubridge play much of a role?
Greenstein:Oh yes. I was so lucky — its an experience which is not going to be repeated. I came in with the 200-inch as my lever, with a very intelligent physicist as my boss, (Bob Bacher) and a very intelligent physicist as president. Lee Dubridge had a flare for quickly recognizing something interesting and communicable, and selling it. I never, as I said, was turned down. The first time was four years afterwards, on getting Hoyle as a professor, but that was on principle; he thought he was unsound —
Weart:Unsound scientifically?
Greenstein:Unsound scientifically. And the observatory —
Weart:Dubridge made that kind of decision?
Greenstein:No, Bacher made that decision. He wouldnt recommend it to Dubridge. He said, You want to go talk to Lee? And I said, Well, if youre not going to back me, I dont want to get turned down the first time, you know, publicly. Well put it off. And now I think he was right. I dont regret it greatly.
Weart:You mentioned that Hoyle had nonscientific notoriety.
Greenstein:Yes. It would have also a negative effect on the older Carnegie people. It would certainly have upset Bowen. He was really unhappy — said he would do it if I thought it was a good idea —
Weart:Im not sure what you mean, were you thinking about things like his steady-state theory, or writing science fiction?
Greenstein:Science fiction. Talking, the newspapers, too many popular talks about subjects he didnt understand. He made himself oddly unpopular by giving a talk on Shakespeares motivations. It turned out he believed that Shakespeare wrote his plays to make money, and thats why he had that wonderful language. Its a secret which other writers would love to know, not for the money, but to be able to be Shakespeare. No, Fred was a brilliant and marvelous person, as a visitor, and always has been, still is. He sold himself to some of the physicists, specifically to Fowler, less so to the others. Feynman always thought he was a chairman, you know, that kind of thing. Well, Feynmans standards are better than I need for astronomy. But I would have had trouble with Feynman and Bacher — it was a rough one, and I didnt win.
Weart:I see, and the physicists had some divisions —
Greenstein:Well, it was more than that. I depended on them. You see, we had an electron synchrotron, so we had a pretty good high-energy physics group. They were interested in plasma physics, and that was coming into astronomy. We had an outstanding low-energy physics group, and although Willy [Fowler] was in favor of Hoyle, most particle physicists felt he was a little superficial and a little showy. Cal Tech is, I guess, conservative. Most good places are. And it certainly would have upset Santa Barbara St. For one thing, the steady-state versus the expanding universe, that would have been — but thats a straight scientific issue. At the time at least, you know, there was no answer. Is there any evidence for the Big Bang, really? That really is only the microwave — I mean, without the microwave background, I dont know that Id believe the Big Bang.
Weart:Nevertheless, even before the microwave background, people at Santa Barbara St. were pretty much committed to it?
Greenstein:They were committed to the Big Bang, period. No doubt about that. Sandage, might have tolerated it. Humason wouldnt have cared. I think Baade — or anyway, Minkowski — had hesitations. They found Hoyle very fascinating to talk to, but didnt believe what he said. It was one of these fine points of judgment, where you never know whether youre right or wrong. To the outside world, he was obviously, except for Carl Sagan, the greatest astronomer in the world. But I dont agree with either of those names as being in there for science.
Weart:Im glad weve talked about Hoyle because I think its on these difficult decisions where you really begin to see all the different forces, all the different inputs... Could you tell me a little more about Dubridge, you say he raised funds?
Greenstein:I guess I have to remind you, or maybe I didnt tell you, that Palomar still lives on Institute funds, and we do not have an endowment specifically for it. We have and endowment which is about a third of what it should be —
Weart:I didnt know there was any endowment at all.
Greenstein:Well, there really isnt one so-named. Its a very odd history. When the Rockefeller [Foundation] board gave the 200-inch to Cal Tech, the then chairman of the Cal Tech board of trustees, a man named Robinson (after whom this building was named) promised to give the endowment to operate Palomar. Rockefeller would provide only capital costs, he would provide the rest. Because of the Depression, he could not live up to that commitment. Oddly enough, his widow died wealthy. But in her will she gave the money to biology, because he (or he) had died of, I think, cancer, and she was sure that basic biology was the thing to support. But Caltech did get from his estate a good share of an oil pumping beach, which was for some years valued at — and these are old dollars — I think something like three to five million dollars. It was producing at 10 percent, so astronomy had more money than we could spend. I think the wells are closed, but there was still quite a credit on the Institute books, in the vague shape of an endowment. Ive raised a little bit extra miscellaneous maybe less than a million. Were looking for ten million now, actively.
Weart:Maybe I should ask you now about your fund raising. I dont know how far back this goes, whether it goes back to the fifties and so on?
Greenstein:Well, lets stay with Lee. Lee Dubridge is an example. He loved astronomy. He got very excited, and because of his knowledge of radar, he was fascinated by radio astronomy. So when it came to getting it started, he had no compunction about committing Institute capital funds, for a while, to get it going. His main concern was whether it was a good subject.
Greenstein:Scientifically. Whether it would last more than a few years. That was an interesting question then. Having a growing institution, relatively well off financially, and private, things were disposable. If I needed two new professorships, and there were two good men, I probably could have gotten them, in a year. We cant get a new professor in less than six years, I think, is the time schedule now. If he needed more money, say to guarantee it for a few years, hed ask a trustee. And the relation between Dubridge and the trustees and funding was just one of these things which will never happen again. Whatever he wanted to do, within reason, he could do. If it was good, and he was excited — and he could be easily excited, he was enthusiastic about astronomy and radio astronomy. There was no endowment, no budget. We would just crawl upward. I think the average growth rate, for some years, in budget, was something like 10 or 11 percent. And that was before government funding; Im not talking about government, but about our in-house money.
Weart:Did he find astronomy useful as a selling point in his fund-raising?
Greenstein:Oh yes. Obviously. Palomar was still in everybodys mind. It had been dedicated, they had a postage stamp about it. Everybody knew it, the Giant Eye. It was easy to talk about, and I did an enormous amount of popular lecturing, soon after I got here, and he did.
Weart:You did this on your own initiative, or did he ask you to?
Greenstein:Somebody might say that they would like somebody to talk to such and such a club in Los Angeles. In fact — well, its now public — I talked twice at the California Club, which would they not admit a Jew through the doors, if they knew about it. I got along with the Establishment.
Weart:I see.
Greenstein:But, Im asked to talk at Bohemian Grove, or other prestige event in California — and twice at the California Club. Id sit next to multimillionaires, or Im invited to every trustees meeting. Down in the desert, usually, they have an annual meeting where they invited faculty. At almost every one, I gave a talk, till 1972. Astronomy is a saleable product, and Dubridge was a salesman it helped all Caltech. But in addition he was the warmest-hearted, intelligent scientist Ive ever met. Hes just enthusiastic for science. Incidentally, thought hes 76 or 77 now, if you see him — he gave a commencement speech in 1977 — hes younger than I am, in spirit. Hes just an amazing man. You know, you dont study the sociology of institutions as based on individuals. But I couldnt have had a better bunch of individuals.
Weart:A couple of things we missed. You were saying, he wasnt sure how long it would last.
Greenstein:Oh. Well. Let me get my little oddities. [Looking in scrapbook] One of the problems with the early days in radio astronomy was the extremely low resolution of the radio telescopes.
Weart:Right. You could barely tell whether it was coming from the galaxy or not.
Greenstein:Thats right. The Australians built the first interferometers, and they improved positions enough so that the first radio galaxies were discovered. The relations between them, the British and the Australians, were very good. The positions were improving, so optical objects were found, and the very hot universe was discovered as soon as objects like that were identified. The origin of the radiation from high-energy electrons wasnt clear, by the way, at that time. It was suggested by Shklovskii — it seemed a little bit speculative, but anyway, it was true. But even then, with low-ish resolution, and only a continuum, how long would it take to map the whole sky, if you build the biggest possible radio telescope? Id say it was the discovery of lines, first the hydrogen and then OH, and then the improvements from interferometry, that made the subject. As a result, the question arose whether it was a subject that would be in for a long time if we were supposed to go into radio astronomy, Dubridge was enthusiastic, Baade and Minkowski ditto but how much would you want to invest in it? So Dubridge suggested, and I was chairman of the committee, that organized a conference funded by the NSF. The results were published in 54, about, what was possible in radioastronomy; what was its future? That had two results. One was the founding One was the founding of the National Radio Observatory.
Weart:Yes, I wanted to ask about that.
Greenstein:And the other was the decision to go ahead at Caltech. Here it is.
Weart:The announcement of the Radio Astronomy Conference, sponsored by NSF, Carnegie and Cal Tech. January 46, 1954, Right.
Greenstein:And all the characters who dominated radio astronomy and its organization were involved. Merle Tuve, Lloyd Berkner (I dont see his name), Taffy Bowen, Hanbury Brown (whom we tried to get), Reber, Van der Hulst, Charlie Townes, Jerry Weisner — and we had people from Bell Telephone, I notice, also, Pierce, and John Hagen, of U.S. Naval Research. Well, that conference grew out of a hesitation on Dubridges part to invest in radioastronomy.
Weart:I see.
Greenstein:And it convinced him; it convinced everybody. It convinced the NSF. We got money eventually from the Office of Naval Research to build our antennae. We hired John Bolton later tried to get Hanbury Brown. There were no Americans who could do it. They were non-academic people completely.
Weart:What was your involvement in this?
Greenstein:I did the pushing. Its clear that the best Mt. Wilson - Palomar people wanted radio astronomy nearby. There was some conflict, since it would divert energies at Cal Tech, by appointments of professors lets say, and by loss of interest in optical astronomy. That had to be resolved. Bowen was not delighted, but he didnt object. Thats really a fair statement. But the forward looking younger people wanted it. And then it was a question of building it up. So we tried to make academic appointments, and couldnt. Literally, there was not one good professorial level radio astronomer in the United States.
Weart:Was there a reason that it was done entirely at Cal Tech rather than under the observatories? Was it ever proposed that it be done through the observatories?
Greenstein:That was suggested, that it be amalgamated. But it seemed that the mission of the observatories was optical astronomy, and they could be parallel developments. Incidentally, the electronic technology at the optical observatory was then either a single photo-electric cell, or photographic plates; radio astronomy was all electronics. If we started now, it wouldnt be strange you see. Were all in electronics.
Weart:I see, in those days it was very different.
Greenstein:And we are way behind radio astronomy in our electronics. What we develop as an abstruse system, theyve been doing since [they were] children. I think I started propagandizing for it the year after I came, in 49, after the discovery of magnetic fields in space from interstellar polarization (where I worked with another physicist, by the way, Leverett Davis.)[16] I was convinced that cosmic rays were guided by magnetic fields, that high-energy electrons might be present, that the collisions in galaxies might produce high-energy electrons. Now we dont believe there are collisions, but there were then thought to be. Thats what Baade and Minkowski said. I had my old interests, so I pushed hard for it, as a new venture. Radio astronomy, by the way, stayed in the department and division, and still is in the division, rather than in this peculiar optical joint operation. But we couldnt appoint a professor. That was really too bad. We lived off a lot of visitors.
Weart:I dont quite understand. You had John Bolton.
Greenstein:He wasnt a professor. And the year we made him a full professor, he resigned and went back to Australia. I dont know if it was cause or effect.
Weart:— why couldnt Bolton have been made a professor?
Greenstein:He could have been, on his talent, but he wouldnt profess. He wouldnt teach.
Weart:Oh, he didnt want to teach.
Greenstein:He wouldnt.
Weart:I see.
Greenstein:He probably couldnt, to be exact. Incidentally, he never got a Masters degree. He only had a Bachelors, not that that matters. Hoyle has a Masters, I think, but not a doctorate —
Weart:That wouldnt have necessarily prevented it.
Greenstein:No. But it was just that they were the non-teaching type. They came from radar, from active military field operations, and they were dead set on building up instrumental excellence and new kinds of antennae; they were awfully remote from the academic or even the interpreters side.
Weart:OK. Now, you started pushing in 1949. Why did it take till 1955?
Greenstein:One, I had to get enough other people around. Theres no doubt that the optical identifications, 50, 51 or thereabouts, had considerable weight. Then there was the question, literally, of who? They had to be non-academic appointments. Next, was it a good subject? — which we cleared up, although I think it was pretty clear by the time the conference got organized that it was going to come out well.
Weart:But you say, except possibly for Baade and Minkowski, many of these people didnt feel that it was necessarily going to be an important subject?
Greenstein:I dont remember who. I think Zwicky, sort of grunted and thought it was a good thing, because high-energy physics would be involved. Robertson was dead, unfortunately, by the time the real push came, in 51 roughly. But I must say, though I dont have the papers any more, that I probably started sending memos about possible appointments as early as 49 and certainly by 50. We had another distraction Ill tell you about, at Cal Tech, that really may have been the other delay. Cal Tech got involved in a thing called Project Vista, one of those supersecret military studies of the time, which eventually contributed to J. Robert Oppenheimers troubles. It was a study of tactical versus strategic nuclear weapons. Dubridge was head of it, Fowler was the operating head, and I became head of part of it. For about a year and a half, the senior faculty here was pretty much out off business.
Weart:You mean you were all working on this?
Greenstein:The senior faculty was pretty involved. It was a very important project, that has never been declassified. It was so highly classified, that even in the military you couldnt see it.
Weart:I want to get back to talking about that, but maybe we should come back to that later and go on with the radio astronomy business, I was going to ask you about that. Or do you want to go on and talk about that now?
Greenstein:No, I was just saying, because you asked me why the delay. It was in large part that. You may remember the Korean War.
Weart:Oh yes.
Greenstein:And the implication was, in the early 1950s that the Russians would have strategic bombing of the United States by 1954, that was the target date. We were not in a completely healthy state, in those years.
Weart:Getting back to radio astronomy, I noticed in 1954 you were a member of the National Science Foundation advisory panel for radio astronomy, this is about the same time, Tuves committee. Was this connected with the other business?
Greenstein:Yes, I was the chairman of the NSF Astronomy Advisory Committee, in any case, from 52 to 55, 56.
Weart:Thats the panel for astronomy. Well talk about that too. Im just wondering about the radio astronomy.
Greenstein:The radio astronomy thing came out of how to implement the results of this NSF sponsored 1954 meeting of the leading radio astronomers of the world. It was a very good meeting. Charlie Townes by the way, invented sort of on his feet, the molecular lines and their likely strengths and abundances right there. Because OH had just been found. It was an amazing time, you know very rapid progress.
Weart:What about the development of NRAO? What part did you play in that?
Greenstein:Well, that came out, you see. This is such a long story.
Weart:We cant cover everything.
Greenstein:No. After the conference, there was just a little meeting of leaders, and at that point Lloyd Berkner —
Weart:— after the conference?
Greenstein:The last day. The last day, we sat around (asking) what to do next. It was proposed that there by a very large radio facility in the United States, sponsored by the federal government; and that various universities go ahead and expand or build radio astronomy facilities. The only question was, how would the large facility be operated? Could it be at a university, say, actively in the subject? There were quite a few then — Cornell, Ohio State, Michigan, Cal Tech was interested with some money committed. Or should it be by a consortium of universities? Lloyd Berkner, I believe, at that time was president of the Associated Universities[17]. I think he was president; If not, he was certainly the brains. He was also a big shot in Washington. Hed always been an advisor to the military, and he knew the military were interested in radio astronomy. It was still soon after the war, and it was therefore a natural thing for him to take a leadership position. Tuve, who was at the Carnegie Institution of Washington (Department of Terrestrial Magnetism) was interested and eventually within a year or so, built a 21centimeter radio telescope out in the country near Washington. Tuve and Berkner couldnt agree on the time of day. They had worked together for too long. Together, you know, they really invented radar; they detected things with laboratory apparatus. They invented the proximity fuse, although somebody else has the patent. And the fact that Berkner thought that AUI[18] couldnt be the operating consortium for a radio observatory got Tuve very upset. Unfortunately, he carried with him Baade and Minkowski. They both wanted a big radio telescope in the country. But they got into a dreadful fight, with Tuve lost, and I lost, because I had to be on their side, though I didnt really agree with them. They invented at the last minute, a seven-university consortium that would operate the national facility for the National Science Foundation. (The Science Foundation hadnt committed anything but was interested). I thought it was a rather unfortunate jurisdictional squabble, and I was perfectly happy if Cal Tech could build a modest but not a national facility. This thing went on for quite a while afterwards, because NRAO got started, without us. Now we were outsiders, enemies almost. Struve, you know, went to be director; a man named Dick Emberson was operating the future NRAO from the Empire State Building in New York for AUI, from AUI headquarters. He knew nothing about radio astronomy, but he did a good job. There was a conflict between big shots, like the people whod identified the radio galaxies with Cal Tech carried along — and the national facilities concept. I was in it, but our side lost, and Im not sure it was bad that it lost.
Weart:At the time you were sort of willing to see a national facility?
Weart:— their idea was that you should —?
Greenstein:We didnt have any — well, we had one man chosen. Bolton was going to build a 30-foot antenna; in fact, the 30-foot antenna was on Palomar, just to have a place in the country, with logistics and some support. You know, organizational things — when you begin to think of using a national facility — we had no idea of what was involved yet, but that it would be big. Like an accelerator. In those days, accelerators were universityoperated, but were nationally available. For many years after that our group — doing its own radio astronomy, practically inventing and re-inventing various interferometers, doing good work with it — was also dreaming of a very large array, which was the rival to the VLA, called the OVA (Owens Valley Array). Again, it was doomed to fail.
Weart:We might get back to that one when we get up to the sixties.
Greenstein:It was a complex world, and I guess there was a bit of snobbery. We were very bright. Bok had started radio astronomy at Harvard, but we felt we were going to do better, and I think we did.
Weart:Well, let me get back a little bit to the department here. The thing Im curious about, during that period when you were not the chairman of the department, but would have been had there been one — how did you divide up your time? How much of your time was spent on research, how much on teaching, how much administration? What sort of schedule did you keep?
Greenstein:I certainly did less research than I did at Yerkes. And many times I felt that I had lost out. I took on completely new research interests. Administration, given the fact that there were few students and few faculty and no government money, was not all that hard. Again, the smallness of Cal Tech made everything easy. I never worried about signing papers. I think I got an administrative aide only about 62, 63, 64. I did everything myself with a secretary. I was very fortunate in having Bruce Rule, who had been the chief engineer for Palomar. He was in the building, operated the accounts the money and did the employee supervision for Palomar. You see, the director [of the Hale Observatories] is scientific chief, but we operate Palomar from this building. We pay the bills, hire the people, pay salaries, get in money from the government its all done here. But for my first ten or fifteen years Rule, who had finished building the telescope and who was responsible for the electrical control system himself, did all the dirty work at Palomar. Although I should have, I didnt have to.
Weart:Tell me, you were head of the department (sort of) in 1948, but from 1964 to 72, your title was executive officer for astronomy in the division.
Greenstein:They changed it.
Weart:Was that a significant change?
Greenstein:No. They instituted — since there were no departments, there were what were called options. There was a planetary science option, an astronomy option —
Weart:But in terms of your daily life —
Greenstein:No, it made no difference. It was just an honorific title. I think what happened is that they had one for astronomy, one for physics and one for mathematics. Since there really were differences between mathematics and astronomy, there were different people, but there was no substantial change. The idea was to recognize that somebody was doing it. It was originally an indefinite appointment; now, its a five year term appointment.
Weart:I see. Now, some questions about the general atmosphere in the department, not now, but lets say in the 1950s, and also changes. Where did the staff get together to exchange ideas?
Greenstein:The most important feature of life at Cal Tech, different from life at Santa Barbara St., was talk. The talk was usually at lunch. Our lunches were, in my opinion, the best thing that ever happened for us. The food at the Athenaeum[19] isnt great, but we could stand it, and people would talk of what they had done or what they had found.
Weart:Every day?
Greenstein:Every day. Weve lost that. People tend not to; weve gotten a little more divided.
Weart:People get together by groups now?
Greenstein:Yes. The infra-red has a sack lunch. The solar people always meet together. The senior members of the department, and some of the good graduate students, used to sit around a table, swap astronomical yarns. This was most exciting during the pre-discovery of the quasars.
Weart:That period?
Greenstein:Yes, but it went on all the time. And only, Id say, in the last eight or ten years has it slowed down. Were down to Friday lunch, which is no good.
Weart:When did the Friday lunch start?
Greenstein:Somewhere in that, a long time ago. There, we made a point, and Santa Barbara St. people made a point, of coming down every Friday. Now, almost nobody does. The total group, including postdocs, radio astronomy and infra-red and X-ray, is enormous. You couldnt get them together. Ive tried several times, and I think Wal Sargent eventually will do it, to use the Princeton system where you reserve a dining room. There Spitzer or Schwarzschild or Ostriker, terribly bright vocal people, run a discussion over lunch. Ask completely idle questions, How would we ever find uranium in space? Its a stimulus, and people come up with ideas. I was at Princeton, at the Institute, and went to these lunches when pulsars were first being worked on scientifically. You just practically wrote a scientific paper, even a theoretical paper with equations, at lunch, in that atmosphere. That is a togetherness thing. Now we tend to talk, even when were together, about some problem with one of the pieces of equipment. Its gotten a little off what the scientific results are.
Weart:Originally, I suppose, it would have been you and Guido Munch and Osterbrock or whatever, sitting around a table -
Greenstein:Yes, and as I said, we tended to include the better students from the beginning. Also the radio astronomers.
Weart:Would people from Santa Barbara St. drop in occasionally at lunch?
Greenstein:Oh yes. You see —
Weart:— not on Friday but just any old time -
Greenstein:— During the radio astronomy formative days when Baade was around, and even later when only Minkowski was left and was in not such good health, he would be down at least once or twice a week to hear the latest. And that is a very important thing, in mutual stimulation. With physicists, for example, when I had the so-called abundance project for ten years, we almost always had Fowler or Hoyle or an experimentalist there, and some passing theorist, and some observer whod found something anomalous in stellar composition.
Weart:Theyd come in and theyd sit at your table.
Greenstein:Well, wed work it up — say, Weve got something, we want to talk to you. Wed have lunches about topics. And how we can get back to that, I just dont know.
Weart:Would you or some other astronomer go sit where the physicists were sitting?
Greenstein:Id do that too. The physicists oddly enough, for many years, maybe because theyre dirty from working at equipment, tend to eat at the Greasy Spoon[20] and talk science. But the Athenaeum has been a marvelous center for astronomical conversation.
Weart:What about chemists? Any relationship with the chemists?
Greenstein:Less so. The only relation would have been in the interstellar molecules. On two occasions, weve tried to make joint appointments with chemists, in — what would you call it? — formation of unstable radicals. Theyre interested in that too. In fact, one of the chemists works in it, with very rapid chemical reactions. Its just that joint appointments have not ever succeeded. We tried to get a rather senior person from Harvard to come as a joint professor of chemistry and astrophysics. It didnt work. Our relations have been excellent in the other areas.
Weart:How did the seminars get started up? Have they been important in getting together with people from Santa Barbara St. and so on?
Greenstein:I think there have always been seminars. They used to be in these groups; these various groups that you mentioned, that have withered away, used to have regular days when they met and they would chew the fat about recent work. When I came of course we alternated, in fact had them at both buildings. They got rather big.
Weart:Every week?
Greenstein:Yes. Every other week. Actually, there were more seminars of the public kind in the first ten years than there are now, when we dont even have one every week. Weve gone over to the specialist group approach more, which is not altogether a good thing. Bringing people together is a thankless job, if they dont want to be brought together. If they do want to talk, they can talk. Its a small town, its a small campus. But it is unfortunate that even within. Cal Tech, weve got people who are members of the Hale Observatory staff in I think six different buildings — weve got them in two different geology buildings, this building, West Bridge, the Annex (so called), infra-red and X-ray — Im sorry, theyre in eight different buildings.
Weart:Not to mention whoever is on whichever mountain.
Greenstein:Right. Its a much bigger than it was. You see, when I say the growth was rapid at the beginning and slowed down, if you add the fact that we have seduced into astronomy the whole infra-red group and Leighton; we have a cosmic ray group thats doing space experiments; an X-ray astronomy group; we have radio astronomy; we have planetary sciences. The actual collaboration with Kellogg [Hall], with nuclear physics, is way down from what it used to be —
Weart:But at one time, it was —
Greenstein:At one time it was very strong. The divisional structure, as an idea, is a good one there. Weve even got the best of all worlds, in that the planetary sciences division pays Peter Goldreichs salary, although he does really astrophysics. I must say that a small institution is easier to get this kind of thing going.
Weart:Youre able to expand your group by propagandizing, so to speak.
Greenstein:Yes. You asked me what I spent my time on — I didnt have a hell of a lot of administration. I did have a good deal of time at first doing almost all the teaching. The other administrative, planning things, you know, they take longer to talk about than to do. So the rest is propaganda.
Weart:Did you spend much time on fund raising?
Greenstein:Not time. I spent a lot of energy. And I did some, yes.
Weart:What kind of energy? Its very important, the whole question of how astronomy interfaces with the public.
Greenstein:[Looking through papers:] I was looking at this material to see where I stood on biography. Its terrible. Lectures. In 1966: American Association of School Administrators; Boeing Scientific Research Laboratories; Blaisdell Foundation; Naval Ordnance Test Station; Air Force Office of Aerospace Research, Albuquerque; Anniversary Symposium, Cal Tech, 67.; Texas Symposium of Relativistic Astrophysics. 68; Pasteur Lectures, Georgetown; Science and the Destruction of Values, Cal Tech YMCA; NASA Lecturer, John Hopkins. 69 — Ill skip — Dedication of Physical Science Building, Southern Illinois University; dedication of Astronomy Building, Michigan State University -
Weart:Why did you go to all these places? Its not necessarily —
Greenstein:No, theyre not fund-raising. Its popularization of astronomy as a subject, I would say. Some of them are honorific — R.M. Petrie Memorial Lecture; Two Universes, Hot and Cole, URSI: TV film, Birth and Death of a Star, Montgomery Lecturer, University of Nebraska — Another one, California Club; alumni...
Weart:Did you do that sort of thing from the beginning, after you came here?
Greenstein:I got into it very quickly. I have no records, because mine at home are only recent. The committees I got onto were internal, community, national, I got invited because. It just — I think, being here. Its really not me. Its the Big Eye that I represent.
Weart:Its the 200-inch.
Greenstein:Its a symbol.
Weart:Tell me, what is it that sells astronomy?
Greenstein:Well, I hate to tell you that I think its almost all wasted.
Weart:You mean, that these things dont do much?
Greenstein:Dont do much good. Ive found from bitter experience that newspaper publicity is worthless. Not one person has walked in and said, I read something about astronomy in the paper, and it said you said so and so, and Id like to know more about astronomy and how I can help. Every dime — I shouldnt say that, everything which I have at the moment in a separate account, I where it came from, a gift — has come from meeting people socially. If you ask me what is the emotional strain attached, even the financial strain, its been a dreadful thing for my wife. We have gone to the damnedest places with rich bitches (sorry). I am the executor of the estate of a very wealthy woman. She plays it so close to her chest, I have no idea if theres a dime in it for Cal Tech. I was to be recipient of a large extra annual gift to the department from a wealthy woman who did die, and who unfortunately changed her interests at the end. But I will go to any prominent persons house, in the hope that somewhere there will be some crazy person who cares for astronomy.
Weart:How do you get invited?
Greenstein:Im not like Hubble, Im no social lion, but Im moderately well known. I know very strange people in Hollywood and Beverly Hills and Bel Air. I had a very good prospect who didnt pan out, but may yet, an American importer of Japanese electronic products — computers, you know, radios, TV, everything. Ive stayed in the house of, a man whose company was taken over by Robert Vesco.
Weart:Oh yes.
Greenstein:I dont know where Ive been. I dont like to go into this —
Weart:OK, but do tell me — what is it that sells these people on astronomy?
Greenstein:Glamour and beauty, poetry, romance. The most non-intellectual aspects of astronomy. And the enormous vision. A lot of my talks, where I have them, are about that — about why it is, in fact, that people support astronomy. I claim that in a way its a substitute for the religious impulse. Its a willingness to support something that has a grand, enormous vision. Not just that the 200-inch is the biggest, or that the numbers are big. Somebody says, Oh, the universe is so big. Dont you feel lost in it? And you say, No. Youre looking at the universe. Its you who are understanding it. This satisfies peoples needs for finding their place in nature. I hate to repeat the hypocritical — but theyre not really hypocritical — things you say. You say, Wouldnt it be nice if your family foundation could be involved in this wonderful adventure, of searching out where man has never been, where his eye has never reached? Theyre rich, intelligent. But most people Ive gotten money from are rich; some of them well-educated; most have no technical knowledge of science, and dont want it. They want the feeling, the beauty. And a lot of them say that astronomy is the poetry of nowadays. People with Andy Warhol paintings on the wall say, You know, really, its more beautiful, this picture of the North American Nebula - I pass out pictures of the North American Nebula, Youd in? it? think it would be passe, buy we just fixed up a 16 X 20 inch picture for General Motors Corporate Headquarters. They wanted one. General Motors gives $150,000 a year for Institute purposes. I raise a lot of money for the Institute, not for my department. Some of it ends in our own pocket. When I was going well, I used to raise, Id say, about two to four hundred thousand a year.
Weart:Just for astronomy?
Greenstein:No, for the whole thing. The last few years, its more like $100,000.
Weart:Is this because of a change in the times?
Greenstein:Yes, change of the time. And actually, its other peoples jobs now. It was a lot more individual before we had a big development office and things like that. I do happen to believe in the private enterprise support of astronomy, and Ive been supported in my scientific career at private institutions — I went to a private school; then Harvard; Chicago, Rockefeller; I was an NRC fellow, Rockefeller; Im here, Rockefeller — Im a Rockefeller stooge, if you wish, but thats where the science comes from. And Carnegie, you know — that intelligent individual Andrew Carnegie. He came up to Mount Wilson, he liked it, he liked the people, he liked Hale, and he began giving money.
Weart:Did this also play a role in your fund-raising? Do you emphasize to people the value of private support?
Greenstein:Absolutely. How can I tell them that radio astronomy costs a million and something a year and its all from the federal government, except for two half-salaries? You cant get a dime for radio astronomy. I got $100,000 for Bob Leighton for his millimeter wave setup, from a regular donor whos given me $900,000 in several different gifts, but I could only get $100,000 for radio astronomy. The donor was very disappointed, because it was just a little bit into a million-dollar-a-year pocket. And these are wealthy people, very wealthy people. Theyre willing to see their money matched. Or if you tell them, Ill get a million from the government if youll give me $100,000. Theyll do it. But not when they are just going to put in a 10 percent increment.
Weart:But in terms of raising money for optical astronomy, you emphasize the importance of continuing this private support?
Greenstein:Absolutely. I hate to tell you, because it sounds most reactionary — that my pitch would be ruined by the tax law (reform?) changes liberals want. But if the liberals get it, it will be the end of high-quality education. If we kill private donations, were going to end up like the New York State University system. Im not prejudiced. I really dont like the arrogance of the rich people. But they are nowhere near as unpleasant or arrogant to deal with as an assistant deputy administrator in an agency. As you well know. Or an NSF —
Weart:Im laughing because I dont know rich people that well, but I certainly know the deputy administrators.
Greenstein:Look, when I went on the Harvard Board of Overseers the wealthy people there, like David Rockefeller who was chairman for three years, and before him that very charming guy (Ill think of his name in a minute, Douglas Dillon) — I was Jesse right away. They wanted to know about my family. Here I am, a nouveau-middle class Jew, appearing on the ancient and reverend board founded in 1639, and it is accepted that were all gentlemen and friends together. What do you think is important? What can we do for each other? Its just such a strange world — it comes from being powerful and rich enough so you dont worry. Though Ive never gotten any money from Rockefeller, if I were urged here, if they thought it was a reasonable thing, I wouldnt be embarrassed to write him and say Id like to see him about an important fund-raising idea. You have to tell them in advance you want money. Lee Dubridge was so honest with these people. He communicated this romance about all kinds of subjects — biology, astronomy, geology. In chemistry, for example, where Ive never done anything, theyre successful because they deal with big corporations that use the product, i.e., knowledge and students. And the amount of money that flows in from corporate gifts is very large.
Weart:Astronomy is very different. Theres nothing that theyre buying, nothing that will profit them economically.
Greenstein:I dont know how Hale did it. Its not written down. And I never knew him. But it must have been, one, his personality, the fact that he was rich himself I think helped; and next, that he had this enthusiasm, and he could communicate it. Dubridge had it. By the way, among the last monies I raised was part of my own professorship, which is little over a million dollars. I didnt raise it all. When I went to somebody - an alumnus, or whatever, an Associate, they asked me to talk to a few people — and said, Were setting a thing up to honor Dubridge — their faces lit up. You know, they wanted to give money. This is sort of a funny world.
Weart:Jesse, tell me, do you find theres a difference between people who will give money for astronomy and other people? Can you tell, when youre approaching somebody, do you begin to get a feeling whether hes this kind of person or not? Some characteristic?
Greenstein:Well, take a big failure, where I thought I had support — a self-made man, interested in science, quite competent, has his own computer company — I had him up at Palomar and I showed him things. And I think what I sensed in him was: well, it was a nice gadget, but he was impatient, because he didnt see the universe expanding. It may have been a failure of emphasis on my part. It may be that eventually well get back together. Very rich people are cold, at first. They have to be, because so many people want things. So you dont get put off by [their] being cool. I think it depends on how long theyll pay attention to you. Youre having dinner and have had three drinks and are on the second bottle of wine, and they say, Now, tell me more about it, and I say, NO, were boring the people enough. This happened. They say, No, listen, theyre talking nonsense shut up, shut up! Jesse is going to tell us more about black holes. Nobody there knows anything. Nobody knows what potential energy or kinetic energy is, but theyve all heard about black holes, I sit there and hold forth, half an hour maybe, and they listen. And this guy who said, Shut up, has given $50,000 to the alumni fund. We lost a major donor to Carnegie recently, where Bev Oke was sure wed get at least $100,000 a year.
Weart:Is there some kind of personality that finds astronomy better to give money to than something else?
Greenstein:Romantic, honest people who are not cynics. I would not say that I could succeed with a cynical New Yorker. But the more straightforward kinds, Mid-westerners, personalities open to poetry and romance and familyoriented.
Weart:You mentioned that theres a religious impulse are these people who feel religious impulses, or something is lacking somehow?
Greenstein:Well, they must have had it. I think many of them still have it and are ashamed of it, and astronomy is a substitute for it; I mean in a way. And of course, a lot of people are interested in intelligence out in space. Again, its a search for significance in life. We dont have much to offer them, except vague philosophical platitudes. If theyre cynical, theyll turn them over and forget it, and if theyre romantic, it will stick in their minds.
Weart:In what way can astronomy substitute for religion?
Greenstein:Just the grandeur. The size, you know. And I think, oddly enough, the fact that you can feel part of the universe.
Weart:This is what you stress?
Greenstein:Yes. Well, in the good old nucleo-synthesis days, I used the analogy of the fact that in the hemoglobin in the blood, the iron, had to come from a so-called E-type, equilibrium, very high-temperature, rapid nuclear process, and the carbon had to be formed in a red giant at roughly 80 million, the iron at a couple of billion degrees, the neutron addition process in a red giant star. They were all made of different pieces of different stars. And that our evolution was guaranteed on Earth and billions of years, it was up to men to make the earth livable. Theyre all platitudes, but theyre true, and theyre true, and they happen to be rather fundamental, you know. The sun has to shine. I found that I like, for example, Midwesterners, though we havent got awfully much from them. Theyre naïve. Its a certain naivete and honesty. My major donor is a Midwesterner, and hes just so excited by these giant visions. I am still in need of ten million dollars.
Weart:I heard Willie Fowler use that same line, about atoms in out bodies having come from the stars.
Greenstein:I think that came from us jointly.
Weart:When you try to sell to a company, is it the same idea? Youre actually looking for some person in the company who has this feeling?
Greenstein:The company business is more, I think, my talking to make better public relations, where others, the development people, to follow it up.
Weart:And the company gets public relations benefits from the donation?
Greenstein:Yes. And Cal Techs image with the company is built up. Ive talked at Bell Telephone Labs several times, both to the administrators and the scientist engineers. Ive talked at several oil company labs. Its pretty remote, but on the other hand, theyre interested in the origin of chemical elements, in the sense that theyre interested in chemistry. And the only thing you can say there is, its good will, and they give Cal Tech money anyway, and someday when somebody says, Lets cut Cal Tech off, somebody will say, Hello, no, gee, that was interesting when so and so visited. [Looking at list of talks given:] Aerospace Corporation, the Edison Foundation, Science Youth Day — just random looks — Office of Ordnance Research — you know, you get into funny company. But astronomy is a saleable, beautiful product. I think this area is going on too long.
Weart:No, because this happens to be of great interest to me, for my own research in 20th century astronomy. How have your colleagues reacted to all your popularization work, writing and lecturing and so forth? Do they sympathize?
Greenstein:Theyre grateful for the money. Theyre not happy when I cant bring any in. I need some right now, I need 50 K -
Weart:I mean about you popularizing or writing popular articles.
Greenstein:Oh, I dont do so much of that. Im not Hoyle, Im not Sagan. I wrote one or two. I wrote something for the SATURDAY EVENING POST[21]. Writing a popularizing article for a science magazine or for SCIENTIFIC AMERICAN or our ALUMNI [magazine] ENGINEERING AND SCIENCE is a duty, its not —
Weart:Your colleagues would do it also.
Greenstein:Yes, they all do it. I think the unpleasant problems arise when you someone goes off on the lecture circuit for his own benefit. That is bad, and here, people who write books are not highly viewed.
Weart:Popular books.
Greenstein:Popular books. We havent got a one.
Weart:Thats right, I cant think of any.
Greenstein:While George Abell must have sold hundreds of thousands[22].
Greenstein:Even textbooks. We dont have a textbooks out of this place.
Weart:Thats right, it never occurred to me —
Greenstein:Monographs, a few. Its a delicate thing. And of course, you have to isolate this social whirl because if you bring an ordinary square astronomer into it it turns the astronomer off terribly. They really find it upsetting. A few times when Ive had some glamour pusses over and had some scientists, they really rub each other badly. Rich people, arrogant rich people are hard to take until you learn how to do it. I must warn you of that. You may not like them.
Weart:You serve as a buffer, so to speak.
Greenstein:I did. I have to drop out soon, and I am.
Weart:Are there other astronomers who have been doing this, around Caltech or around Pasadena?
Greenstein:Not yet. The most likely is Maarten Schmidt. He has a wonderful public personality. He may do very well.
Weart:Is this the sort of thing that you expect that there should be somebody around who does this? Would you say that your colleagues expects somebody to go out and raise money?
Greenstein:The colleague doesnt expect it. But if you dont do it and dont raise government money, youre going to have a hard time financially. The Administration sometimes expects and facilities it. I did it most when Dubridge was here, because there was a personal contact — somebody Dubridge had met; Id take them to Palomar, drive them up and down, show them the glories of the place, stay overnight sometimes, let them look at the television screen. That was often with people Id hardly know, and whom the Boss knew. Could we cut this a little? It may impress you, but its a sordid subject.
Weart:Thats all I had on that question. We were talking about socializing after hours among the astronomers here. Did astronomers talk about subjects outside technical astronomy — biology, politics, philosophy?
Greenstein:They actually have been a rather sociable group. Many of them are young; some of them have attractive wives; theres even been dancing; people like to eat and drink. I think its been on the friendly side. Do we have any interests outside of astronomy, to talk about? Yes. Certainly politics, world and local. Schools. Art. Very commonly music, certainly. Its a typical academic group, I dont think I notice anything different. I dont know anybody who plays cards.
Weart:Is there much discussion of the philosophical or religion or whatever implications of cosmology, astronomy? Has there been, over the last 30 years that youve been here?
Greenstein:Well, you sure can get one from Alan Sandage, yes. He views astronomy from a religious perspective. He will talk about it. Most of the others wont. Most of them, I think, would almost be embarrassed.
Weart:They might have the thought but not talk about it?
Greenstein:It takes a semi-popularizer like me, a self-confessed one, to talk about — it in public, even. And you can see than when somebody has to put something about it in a public talk, theyre embarrassed, Im not. I just think that its what people want to know about.
Weart:I have some questions about your scientific work. Backtracking, we left off the scientific work when you came here. Theres so much to talk about. Im curious for one thing about your search for helium-3 in the sun, your study of lithium, with Richardson, beryllium with Tandberg-Hanssen[23]. In one of the observatory [annual] reports it says this all began with the suggestion that P-P reactions might be important in the sun. I thought maybe there were other things that got you interested in this problem?
Greenstein:Well, I dont know. The orthodox history of nucleo-synthesis you know, and Burbidge, Burbidge, Fowler and Hoyle[24] gives a lot of it. Id say from the magnetic stars, their peculiar compositions — we always had left something over called the X-process, spallation possible, or surface nuclear reactions. The wave of opinion is up and down. There is one school that claims that its got to be high-energy particle reactions. You may remember I, with Fowler and Hoyle, tried to produce elements and isotopes in the presolar system material, and I notice that somebody recently wrote a new paper, I think Dave Schramm, in which he refers to that as a probably too early but noble attempt. I think the idea of high-energy particle reactions was with us, in addition to the orthodox thermonuclear ones, all the time.
Weart:By orthodox, you mean supernovae?
Greenstein:— supernovae. Now, the Little Bang supernovae, giant stars exploding because they cant make it to stability, mini-quasars, lets say, supermassive stars dropping into black holes -
Weart:You call all that orthodox?
Greenstein:I call that orthodox.
Weart:As opposed to things that sort of are happening just in space, around?
Greenstein:Yes, or on the surface of the sun. Now, clearly, from the debris of a solar flare you can see tritium and stuff like that. While it may be in toto neglible, or be only blown off, or (since the sun is probably convective) get diluted too much — I have not given up on its possible important effects. And I am unable really to be happy, though Im not working on it — with peculiar isotope abundances in the magnetic stars being caused by gravitational diffusion or differential radiation pressure in the complete absence of convection. I think thats almost too much. I dont know where that idea (highenergy reactions on stars) first came from. It must be quite old.
Weart:Where did it come from that you started looking for these things in the sun?
Greenstein:Oh, that came when I began to learn nuclear physics. I began to look for tests of it.
Weart:And how did you start learning this nuclear physics?
Greenstein:Oh, when I came here — remember, were talking about compositions, peculiar compositions — I wanted to blame them all on nuclear physics. I didnt take any courses, but began reading and talking, looking at reaction cross-sections. A whole list of exoergic reactions had already been developed by Hans Bethe, quite early. There were other obvious ones. Im not sure which came first, the discovery of a large amount of lithium in a T Tauri star by I think Kurt Hunger while visiting Lick, certainly if that was before my work that could have triggered it. But it happens that if you want to understand nuclear reactions, the light elements are the easiest. If you start with pure hydrogen you immediately come up against helium-3, helium-4. The helium-3 plus helium-3 thing, by the way, was an example of how astronomy and physics cooperated. I looked for the helium-3 and couldnt find it. Helium-3 was the major product of the P-P cycle, and if the sun is well mixed there should be surface helium-3. There is no helium-3. I gave a talk on this one evening at a Kellogg seminar. They used to have them Friday nights and then go and drink beer. Charlie Lauritsen, who founded the Kellogg Lab, a pioneer in low-energy nuclear reactions, got up to the blackboard and began trying different things. He invented helium-3 on helium-3, giving alpha plus two protons, estimated the cross-section, and said, Jesse, itll be less than l0-5. I said, OK, Charlie, I cant see it then. That was it. That was the kind of lively cooperation one could have. It was a pioneering subject. The C12/C13 was obvious from the carbon cycle. There had been measures of stars with abnormal C13. The beryllium was the next one. The deuterium I tried, but never published. I tried the chromosphere and I tried the Orion Nebula and planetary nebula, over-exposing the H-alpha line by thousands, getting only scattered light instead of the nearby deuterium-alpha. We had now better way of doing it. It can be done now interferometrically how. But I tried them all, one by one. Boron was hopeless. Not now; you could detect it from space. About boron, oddly enough, Henry Norris Russell had asked me, years ago, whether there was any way of finding boron in the sun.
Weart:Independently of the nucleo-synthesis ideas?
Greenstein:Just his curiosity, can it be done? I would think that the developments in nucleosynthesis, as far as I went into it, were fairly straightforward. I was devoted to it enough to get the abundance project rolling. I turned off completely, myself, some time in the middle of that, and have not tried to think of it since.
Weart:But the idea was to provide the data that people would need?
Greenstein:I would say, the ideal would have been to test every critical prediction of nucleo-synthesis, all possible environments. Also, Harrison Brown, Hans Suess and Urey had done the meteoritic abundances; how well did the meteoritic abundances match? I did a lot of the pioneering. But since I dropped out its sort of lost in the past, even as far as Im concerned. I invented one nuclear reaction, more or less by accident, in a lecture at UCLA, oddly enough, to engineers. I was talking about abundances, and I invented a neutron-producing reaction, carbon-13 and alpha. I didnt realize Id invented it. I said, What you do is, you just add up the masses, and see if it goes or doesnt go. I had an undergraduate class a few years ago, when the neutrino, problem was lively — everybody knew about it, including undergraduates. So I gave them an assignment (they did it by computer, naturally) of putting in every possible element and looking for every possible reaction even those with a negative Q, (taking temperatures less than 100 million degrees) up to l04/ [electron] volts. They just had to look up tables of all exact atomic weights, and add everything to everything. Nothing new came out of it, by the way, nothing interesting. I think all interesting reactions have been thought of.
Weart:It was along here, early fifties, that this idea really became very strong that you could just start in the beginning with only hydrogen, and build everything up from that. Do you have any recollections of any particular point did you notice this idea, that it hit you? Notice that it was being talked about?
Greenstein:I would say, as long as I remember the subject it was a puzzle. If you remember, Gamow in his popular books sort of skipped over the famous mass-5 and mass-8 holes where there arent any stable nuclei. It was a puzzle, and they tried different things. There was nothing you could do. Neutrons on alphas are no good to get mass-5. The decay is so fast that if you had that many neutrons, you wouldnt worry about 5, youd worry about stopping it at lead; it would go too fast. I think it was an intellectual game, in which you said, The universe started with hydrogen. The only person who really took it seriously was Fred Hoyle. That is his famous visit here in 52, I believe, when he proposed a reaction with negative Q — that is, the alpha-alpha-beryllium-8, which takes collisional energy equivalent to roughly 100 million degrees, l04 volts, negative. And you got a little beryllium-8 in equilibrium, you then formed carbon-l2 by adding another alpha, by a resonant reaction. He predicted in a lecture he gave here that since carbon existed and was abundant — there should be an energy level in the compound nucleus, beryllium-8 plus alpha, which is carbon-l2 but in an unstable state. If you had a stable energy level, to which the unstable nucleus could switch to get rid of some energy, and have a gamma-ray decay to carbon-l2, then by this sequence of three alphas colliding, youd have carbon, skipping the unstable mass 5 & 8 nuclei. He predicted the location of the excited C12 energy level and what its transition strength was, i.e. the probability of the gamma-ray emission of an excited C12. And the Kellogg people, Fowler and Lauritsen, did the experiment and found that carbon-l2 had an energy level at the right place. That was perhaps the greatest triumph of a straight intellectual approach to nucleo-synthesis.
Weart:You were aware of this all happening at the time?
Greenstein:I was there. The only trouble was, and its been the persistent trouble, that although the level exists, the reaction rate is very slow because the so-called gamma-gamma is too small. The C12 will come apart. You understand that beryllium-8 — which is too heavy to be stable, theres the two alphas — plus an alpha, weights much more than carbon-l2 in the ground state. Thered be an enormous energy excess. Normally, that just breaks the carbon-12 back into three alphas. It happened (I think Fred literally didnt know it) that Opik had computed the straight three-alpha particle reaction to make carbon-12. I didnt know it. But Id invited Fred for this set of lectures, and I was very excited, and everybody was very enthusiastic. Unfortunately, its almost certain thats not how carbon is made, because the yield is negligible. Its almost certainly more nearly a threealpha particle reaction than through the beryllium-8 intermediary. On the other hand, this is how science ought to be done. You predict that nature cant be the way it is unless something is true and something is true. It wasnt true enough. I must say that those were very exciting days, and I guess I regret having given it up. But I certainly did. [Looking at papers.] Lets see. Ive got a review on nuclear reactions affecting abundances of elements in 1953. I have a paper on the same subject in an IAU symposium in 52. I have a paper on it about 51, Technetium, 56. Not in the sun, thank God.
Weart:OK. Another thing you were doing, beginning in the early fifties, was a program to measure lines in F and G stars. Looking for differences in composition between high and low velocity stars. How did you get into this?
Greenstein:Well, its one of the major composition differences between stars. And if you wish to go historically, in the famous classification of 4000 stars by Adams and others on Mt. Wilson[25] they had some half-dozen stars which they called intermediate white dwarfs. These had sharp hydrogen lines, therefore were not white dwarfs, but nothing else that they could see, (in fact very weak lines). These stars turned out to be what we now call C sub-dwarfs, metal-poor stars. It was one of those that I first observed, and in a paper with Lawrence Aller we did the first composition analysis of a metal-poor star. I dont know when that was, in the midfifties somewhere[26]. Lawrence [Aller] I had known well before I came here; he was a very quantitative person, and we worked quite well together. [Looking for paper in bibliography.] In any case, it was one of the gross differences you would see by inspection. I think because of that, I just had to follow it up. And having a big telescope made it possible.
Weart:Were you interested in using it as a probe of the evolution of the chemical content of stars?
Greenstein:Yes. We also, by the way, already knew from the Baade population work that chemical composition differences existed. I notice that I had a paper in 51 called Abundances of Elements in a HighVelocity F Star[27]. There are no such things. In other words, that was almost certainly a C star with very weak metals. So this kind of thing was obvious, or at least obvious if you were going to work in the area —
Weart:— in the area of what?
Greenstein:Of compositions. After all, it there are no metals, thats the ultimate in peculiarity of composition. In fact, right now I am interested, and Preston and Schectman are active, in looking for stars with essentially no metals, to see if there are, in fact, stars where the element-building game was played up to carbon, but never beyond in space, or in older stays that sprayed space with elements they had synthesized.
Weart:I see.
Greenstein:When the star formed, that is. You might call them first-generation stars. Ideally, thered be stars with nothing but hydrogen and helium.
Weart:Or maybe even no helium?
Greenstein:I believe there was no, or low, helium in population II. I seem to have been wrong.
Weart:Also, at the same time, you were making a lot of observations of white dwarfs. I dont know what the figures are but you must have doubled the number of white dwarfs that had been observed, or something like that. How did you get into the white dwarfs? How did that start?
Greenstein:Technology leads science by the nose. We had a big telescope, we could work on faint objects; if you wish to exaggerate, nobody else could. What better problem? Other people could do Coude spectra of interesting, even fairly faint stars. But very faint stars, nobody else could do. And the equipment developed for the red shifts, the nebular spectrograph, was a high quality, fast instrument. You cant resist the fact that youve got an unbeatable gadget that nobody else has. And you cant resist, in this particular case, the fact — again, Im making it a little over-simple — that the white dwarfs are the only objects whose structure is completely understood. The theory of the white dwarfs as developed by Chandrasekhar, for cold degenerate matter, gives, for a given mass and composition, the size and the temperature as a result of a simple cooling — so everything is known. Of course, thats a terrible exaggeration. Theres an enormous amount thats been found and theres an enormous amount thats been surprising. But the straightforward mass, radius, luminosity, temperature relations are perhaps the best parts of stellar interiors [theory]. And here, one is able to look at the atmospheres. To me, from the abundance point of view — I had this theoretical background, which dates back to about 47, that there cant be any hydrogen in a white dwarf. And yet, 90-odd percent of the know white dwarfs at the time had nothing but hydrogen in the surface layers. Its still a problem. It was an odd subject, one Im glad I am still in — frustrating, chasing them fainter and fainter and colder. They are extraordinary objects. They have all the romance astronomy should have. A force of gravity 100,000 times that on the earth. —
Weart:This romance appeals to you?
Greenstein:Always. I find extraordinary, extreme, objects interesting, and dramatic and romantic. I have never been interested in Bug Eyed Monsters, but any bugeyed star will get me. Even galaxies would get me, if I had time. You have just some of the most interesting possible quantum physics phenomena going on. In a very cool degenerate star, made of helium only, recent theoretical computations indicate that the bottom of the atmosphere, which is about two meters deep is degenerate. So you can actually see degenerate matter.
Weart:You c see through those two meters.
Greenstein:Yes, just about! At 4000 degrees, in a helium atmosphere. We have no knowledge of such a star, yet.
Weart:During this period, lets say from the early fifties on there were white dwarf models being made and refined by Opik, Osterbrock and so forth. Did you see that what you were doing had anything to do with checking these models, providing input to the models, or any kind of interaction with the model makers?
Greenstein:The theorists, on white dwarfs?
Greenstein:Well actually, there werent all that many. Thered been a terrible frustration, when a good physical approach to the companion of Sirius had failed, Bob Marshak. That left the problem even more interesting; of course, unfortunately it turned out that the mystery came from a bad observation at Mt. Wilson. The theory was held back by observation. We later went and killed off the old Mt. Wilson spectra pretty well. They were not good.
Weart:Did you see yourself as having an important interaction with theorists?
Greenstein:Well, yes, because there was nobody else doing observations of white dwarfs in any detail at the time.
Weart:Did they sort of come knocking at your door?
Greenstein:Oh, yes. There were two theoretical problems that came up very early, soon after I looked at them. One, thats unsolved, is why you have two groups the hydrogen-rich and the helium-rich atmospheres. Theres a lot of speculation and argument; I dont think anybodys right, yet. In the abundance project time, which was a long time ago already, I had one visitor, Volker Weidemann in Kiel now, a pupil of Unsolds, whos been worrying about it and worrying it to death. There are problems, I think, in the physics of convection, and the separation of the elements by gravity, which are not solved. Also Schatzman. Schatzman was then the real white dwarf theorist. He also visited here, in the abundance project time, and we discussed this.
Weart:All this would encourage you to keep on -
Greenstein:Yes. And the other thing was, as I said, that technology leads you. You can do it. You dont know what the scientific result will be, but since so far every improvement of technology has led to a major astronomical discovery, why not in white dwarfs? And I did it, Im still doing it. Now its a very competitive field, and people are chasing me and criticizing the work I did 10, 12 years ago. I feel pretty ashamed of it, because it was pretty primitive when I first started. But it did lead me to more and more dark-time observing, which was a difficult.
Weart:You mean difficulty in getting the time for spectroscopic work?
Greenstein:Getting it, yes. Its hard to say that observing some new peculiar-atmosphere white dwarf is as important as another red shift of a faint object. Ive been able to keep it up. Its pretty tolerant institution. The question is, when does it get not to be worthwhile? By the way, the list of those Ive observed is now up to 460. And theres a paper in press, with the next 50 or so. Ive observed about 460, lets say, of the 650 tabulated about which anything substantial is known. Except for moving objects that are blue; we know thousands of those.
Weart:— yes, but of the ones that are known to be —
Greenstein:— ones where you see peculiarities get the luminosity, Ive observed most of them. The new discoveries about magnetic fields were not mine, but Im working on that. They involve the new technology of photoelectric polarimetry. They found high magnetic fields. I have two papers in press on those subjects, now. Its a very exciting field. The deepest physics part of it, I think, is connected with the solid-state aspect of the white dwarfs; there are cool surface objects which have cool interiors, below 4 or 5 million degrees.
Weart:This came along later.
Greenstein:Yes, it came much later. But oddly enough, in the first observed group, among those found maybe 50 or 60 years ago for which parallaxes existed, there are two of these cool ones. Eggen and I collaborated on three papers[28], and I have seven by myself since, lists and descriptions. But when Eggen and I finished there were about ten, instead of the two cool ones. And the real problem of the cooling, and whether there are any really cold degenerate stars, is not yet solved. There may be none I think there arent enough, others think there are. I think my last paper on the white dwarfs will be on that topic.
Weart:Your final paper?
Greenstein:Yes, there are actually pieces of it. I changed topics quickly for a week or two.
Weart:Have you ever felt there were many other people working on white dwarfs?
Greenstein:There werent, but now there are. Oh yes, now were fine.
Weart:But at one point, you were just sort of there by yourself.
Greenstein:Thats right.
Weart:Did you wonder, was it simply because you were the only one here, with this telescope?
Greenstein:I wasnt scared because I was alone. I didnt think it was a bad idea not to be fashionable. Nobody else cared, because obviously, nobody else knew. Well, Lick could have. But they just happened not to. My only good competition, I will say, is a first year post-doc who got his degree at Lick last year. He is good, and hes shown me wrong in a couple of cases. And recently down in Australia, a Hindu who worked in England and an Australian are doing good work with the Anglo-Australian telescope. But it takes at least a 100, 150-inch size, and the new electronic spectrographs. You cant do it photographically any more.
Weart:OK. Before we get into your survey of stellar compositions, I wanted to ask you about government funding in general. Shall we start with your chairmanship of the NSF panel of consultants for astronomy in 52? Thats the very beginning of NSF government support. How did you come to be chairman of that panel?
Greenstein:I dont know what change happened to me. I had bad luck, in one sense. With the good things Ive told you about came some calls like that to take on national responsibilities. If Id had any brains I wouldnt have done it. Looking back I was mistaken, as far as my scientific work went. Let me just look this over. I told you that a top secret, still classified project called VISTA occurred. This led me into the federal government — the military — deeply, and I stayed in a long time.
Weart:Yes, I had some questions about this.
Greenstein:Let me show you this while I talk [Looking through papers]. In any case, I got into Washington, if you may call it that. I notice that on my oldest biographical list, which begins in 52, Consultant of Operations Research Office, Office of Ordnance Research; National Science Foundation, 52, chairman, Consultant, 53-55; Scientific Advisory Board, US Air Force, 56 to 60; RAND [Corporation], 57 to 61; Astronomy Panel, NASA Steering Committee, 61 to 64; Ramsey Committee, thats the thing that led to the space telescope, 66 - I got elected to the [National] Academy [of Sciences], I was on the Samos committee — you dont know what Samos is, I hope.
Weart:Samos? [Makes circling gesture: A satellite].
Greenstein:Yes. Well, that was another thing.
Weart:That was one I didnt know about.
Greenstein:Yes. They fired me — I have the letter here, I found it — in 1960, saying theyd got set up and didnt need us any more. And what it meant was, they didnt think we were good enough to keep the secrets. So from, really, the Korean War, thats this [Vista], and afterwards till 61, I was very much in Washington. As far as the NSF goes, its a little different. There —
Weart:That was a separate thing then?
Greenstein:Oh, yes.
Weart:The fact that you were in NSF had nothing to do with the —
Greenstein:No, nothing to do with the military, but —
Weart:I want to ask you about both of those things, and I wonder which one should start with.
Greenstein:OK, there was a kind of connection, and that is my far seniors the people who ran science during World War II, knew me. And that is about it.
Weart:Knew you simply because of your work at Yerkes?
Greenstein:Some because of Yerkes, some because I was at Caltech. Vannevar Bush, you know, people like that it they needed a universal astronomer there was Leo Goldberg, Martin Schwarzschild, or me. It got a little bit too much. That, mixed with the military, got to me emotionally, eventually. Its rather frightening how much time — and that at the expense of my work. I really felt, till a few years ago, that Id lost a great deal of my scientific potential by coming to Pasadena, and becoming a semi-public figure. Its fun, and its necessary, but I would rather have been Einstein than Greenstein, and I dont have a prayer. Im just not even a Sandage. So theres some emotion, how the hell did I ever get into this. Heres a report to PSAC[29] why does PSAC call on me? Because Im at Cal Tech, I know radio, I know optical astronomy. Ive been an advisor to the government. PSAC calls on me, therefore NASA calls on me. I was an advisor to Jim Webb for six years. Personal. Three people in astronomy, on the non- planetary program, three people: Goldberg, Schwarzschild and Greenstein; it was a bore. I got out. As I told you, I just literally dropped out of all of this, at a certain time. But while I was in it, it feeds on itself.
Weart:Once youve been on one, people get to know you. Well, how did it begin? Was it Vista that it actually began with?
Greenstein:No, that got me back in the military.
Weart:But until Vista, you hadnt been in anything connected with the military.
Greenstein:No, there had been a quiet period. But on the other hand, when ONR[30] started its first grants program, I was on the committee. Whatever year that was, 47 or 48.
Weart:47, would that have been under Mannie Piore?
Greenstein:Well, maybe it was, maybe it was Joe Weil — I sort of remember Joe Weil. But its first year, I was on it. Partly I represented the Mt. Wilson-Palomar Observatories. That gives you clout, if its about astronomy. And partly Cal Tech, and partly, as I said, the Washington scene. I cant find the NSFs little brochure about all its committee members, but it sure used me. I remember, this is probably a thing youll hear from nobody — Bob McMath told us that he knew the director of the Office of Management and the Budget when the NSF was established, and that McMath was there his hand out for astronomy, before anybody else. Leo Goldberg says its not true, but I think Leo may be unfair to Bob McMaths memory, he doesnt remember it that way. I think its true. The first committee of the NSF was a little group of astronomers including McMath, myself, Schwarzschild, Whitford, and maybe Goldberg (Im not sure, but certainly the nest year, Goldberg).[31] Bob McMath crowed at how he had pushed the NSF to give its first real grants in astronomy, bypassing all the other sciences. Well, I think he deserves credit. It was an interesting time. I was on the so-called divisional committee of the NSF a few years after. Id been for four year in the advisory panel, and then the divisional thing, mathematics, physics and engineering I was on that committee 57 to 60. That was about the end of my direct NSF involvement, until recently.
Weart:How did the panels function?
Greenstein:In those days, we gave away the money. We recommended the breakdown.
Weart:You had the choice.
Greenstein:They had almost no staff. They had one man to do two or three sciences with $100,000. For ONR that little committee had $80,000 to divide over some 20 or 30 people, two or three thousand dollars a grant average.
Weart:Did people come in with proposals, or did you go —?
Greenstein:People had come in. And the committee looked them over all together, and decided on their order. Then of course the NSF or ONR, whoever was legally responsible, did the final budgeting. But in the early days, it was very much an advisory committees also in the direct responsibility live. Now theyre just advisory. Its weakened.
Weart:Though they still have some clout.
Weart:I presume they still have a lot to say about who gets the money?
Greenstein:No, not who gets the money. Its the general balance in an area, or the general performance of, say, the astronomy or the physics section, thats reviewed.
Weart:Oh, I see.
Greenstein:The advisory committee doesnt even see a proposal.
Weart:Oh, is that so? When did this change?
Greenstein:I have no idea. Between now and 1960. I dont think the [astronomy] advisory committee has a real function, because Ive heard so many complaints about even its general policy advice not being listened to. I dont think its had much function for 15 years.
Weart:I see. Its strictly the program officers.
Weart:Whereas back when you were in there, you were in effect the program officers?
Greenstein:More or less. There was a guy, who probably is retiring now, and could rise to associate administrator or something like that, whatever theyre called, who would do all of the grants. For contracting, a business officer and a lawyer.
Weart:I see but in terms of the real decisions?
Greenstein:Perhaps Im overdramatizing an idealized past. But policy decisions were originally in the panel, with discretion as to details of budgeting left to NSF staff.
Weart:Would you go and say, Theres not enough proposals in this area or that area? Would you ask somebody to submit proposal, advertise in some sense?
Greenstein:I dont remember that. There were always too many proposals, too little money. Nothing has changed on that.
Weart:Even right from the beginning. Were there any differences of opinion, conflicts, changes as to what areas should be supported, in philosophy of —?
Greenstein:Oh yes, sure. That is what a good advisory committee ought to be doing, saying, Well, too little money for solar physics, or, Close solar physics.
Weart:Back in the fifties, what was it?
Greenstein:In the fifties, I think we were much more interested in the NSFs growth in support of research, as one of many agencies, than worrying between fields. But it was certainly true that we did have, very early, the problem about radio astronomy. From what you tell me — and I didnt remember it — when I left the NSF regular advisory panel. I got into this radioastronomy advisory panel.
Weart:I think they were overlapping.
Weart:The problem being how and where it should be supported?
Greenstein:Where. And how much was required. One of the things, of course, was a sort of conflict between astronomy and physics. Physics never got, when I was at NSF, to be a terribly strong group. I think astronomy and its program officers were pretty powerful. They had good ones, borrowed from universities for a year or two at a time. Jeff Keller did it, Frank Edmondson did it. They were people who were on loan and had some scientific standing. I think astronomy has done remarkably well within the NSF, in getting —
Weart:Do you think radio astronomy has some through the astronomy part of NSF because of the great strength there?
Greenstein:You know, theres an incredible amount of money going to radio astronomy, altogether, from the NSF. Its problem is how to close down in an orderly way some university observatories which are, perhaps, scientifically defunct.
Weart:In the early days of NSF funding, were there strong feelings in the astronomical community about government funding, not only at Carnegie but in general?
Greenstein:Yes, there was a general concern — whether it was safe, for one thing. Because it didnt have any assured future. And whether it was good. Whether government money, soft money, wasnt immoral. Military —
Weart:What do you mean, soft money?
Greenstein:Soft meaning you dont have it, its from the government. Hard money means if you raised $50,000 dollars by begging from a millionaire or a company. For one thing, if its soft you cant rely on it for the next year. If youve got an endowment, you can. The older school was upset and when I say I knew the older school, it might be the generation of Conant and Bush, Lloyd Berkner who was not that old, one of the war science leaders — their attitudes after the was were mixed. Bush pushed a great deal about the NSF but there were conflicts in the scientific community about the NSF.
Weart:You mean generally?
Weart:The astronomical community more or less was one part of that general thing?
Weart:A curious thing about the astronomical community before the war, it was the one community that had operated very large and expensive facilities, and somehow one would expect them to have a unique viewpoint towards this funding.
Greenstein:It should have. I can tell you in my own institution, I found it very difficult to ask for Federal money myself its embarrassing to be an advisor, the way I was, and to ask for money. Thats one part of it. The other thing was strong opposition from people I respected and liked. As I said, I wrote a letter saying that unless I could get a good group of young people working in my general area, that I was interested in, I would leave.
Weart:The survey of stellar composition.
Weart:And this was a letter to the —
Greenstein:— to the president of Caltech. To my friend, DuBridge.
Weart:The opposition came from Carnegie?
Greenstein:Well, it came in part from Carnegie; it came from within the division, in part. You know, it seems unbelievable now that government money should be viewed as dangerous, but —
Weart:— oh, I dont know —
Greenstein:It is dangerous.
Weart:It is dangerous, sure.
Greenstein:I had sold my soul to the government, and they owed me that money, damn it. The Air Force owed me that money.
Weart:Yes, I noticed it came from OSRD[32].
Greenstein:OSR. Yes. Well, Id been on the [Air Force] Scientific Advisory Board; I dont know if anybody in the Office of Scientific Research knew that. On the other hand, had I not got the money, I would have called somebody up. Oddly enough, it went the other way. The contracting officer for the OSR, a physicist, came out. There was an Office of Naval Research Center near (maybe it still exists, I dont know,) which ran clearances and stuff like that, and I guess the OSR man came out and he wanted to know who the scientists were at Pasadena. He came and saw me and said, Why didnt you ask us for some money? I said, What would the Air Force want to do in astronomy? He said, Oh, we have a lot of interest in astronomy. I said, Well, how much do you think you have? He said, Oh, I dont know, start with a hundred thousand dollars. I said, Oh great. Ill look into it. And then I ran into all the trouble.
Weart:You ran into the trouble here.
Weart:This guy had no idea what you might do with the hundred thousand dollars?
Greenstein:Not in detail. He just said, Do you want a hundred thousand dollars? He wanted to support science I guess, a prestige science, astronomy, and a big observatory. You know, the Office of Naval Research invented government support of university science and did a marvelous job, and except for Senator Mansfield I think would still be at it.
Weart:Now, why would the Air Force support astronomy? Youve mentioned raising funds from rich people and so on, but why did this guy want to offer you a hundred thousand dollars?
Greenstein:I never saw him again, incidentally. A man named Lloyd Wood, who ran the OSR office, got interested in specifics. In those days, there were several possibilities. The Air Force was not sure whether it had cognizance, as they called it, over space, or not; whether space research belonged to the Air Force was not clear. Operations in space were its responsibility. Therefore, if an astronomer was working with the Air Force — good. A lot of scientists who worked with the military developed their pet services. For most scientists I think the Navy was the pet service, the gentlemans service, and the Air Force wanted a bit of that cooperation. But I think they wanted to know more about phenomena in space. I must say that, oddly enough, I gave two kinds of lectures for the Air Force, in later years. One was about the results of the project on stellar abundances and nucleo-synthesis; the other was about tactical nuclear warfare, and reconnaissance, a very mixed bag.
Weart:Was there some interaction in the sense that the Air Force was glad to have you aboard because they needed scientists to —
Greenstein:— I think so. The Army never had any decent scientific backing, and when they had a technical problem, they were in the soup.
Weart:They didnt know who to go to, you mean?
Greenstein:They did not. I would et even now if some senior naval officer called on me and said, You know, weve got a problem of so and so, I would drop things and try and think of something.
Weart:— excuse me, I have to switch the tape.
Greenstein:I developed, and a lot of people of my age developed, a great respect for senior people in the armed services. They were the only people except scientists who had, it seemed to me, a reason, a cause other than their own interest, for living or working. They worked very, very hard, and you know, many had risked their lives. But they all worked, and there was some kind of feeling on their part maybe patriotism that made it easier to have a link with such a person than with a person whod spent his life in a Washington planning office. The service people, especially those in responsible positions, were in general, like very wealthy people, reachable and intelligent. At least those I had to deal with. And while they threw you out when they thought your ideas didnt agree with theirs, they were used to having conflicts, and I got along all right with them. I was very upset, for example, when the Mansfield Amendment cut the services out of support of science. I was upset for science, not only for the money but for the contact. The Services put all the research money after that into the industrial world. Scientists would see research supposed research — being done in industrial research laboratories for the military, at an incredible cost, producing no tangible result either scientific or military. I must say that [as to] how you get money for science, whether you have a sole agency or many agencies, to my mind theres clear answer: its got to be multi-agency funding. And Ill take money from bombardiers or anybody, for astronomy.
Lets stop at this point.
[1]G. Reber, APJ. 91 (1940), 621.
[3]J. J. Hopfield and H. E. Clearman, Jr. The ultra-violet spectrum of the sun from V-2 rockets, PHYSICAL REVIEW (2) 73 (1948), 877.
[6]APJ 107 (1948), 151; See APJ 109 (1949), 121, 265.
[7]At that time called the Federation of Atomic Scientists
[8]Metallurgical Laboratory, code for the Chicago labs.
[9]Baade was on the staff continuously 1931-58.
[10]i.e., ANNUAL REPORTS of the Mt. Wilson observatories (in Carnegie Institution YEARBOOKS).
[11]In 1953
[12]Humason, Mayall and Sandage, ASTRONOMICAL JOURNAL 61 (1956), 97.
[13]Teachers Insurance Annuity Association of America.
[14]By J. Ostriker
[15]I. E. with Babcocks retirement
[17]Yes, from 1951 to 1960
[18]Associated Universities, Inc.
[19]Caltech faculty club
[20]Campus Cafeteria, mostly populated by students.
[21]The Natural History of a Star, Sept. 24, 1959.
[22]Exploration of the Universe (1st ed. in 1964)
[23]AP. J. 113 (1951), 531, 536; 119 (1954), 113; etc.
[25]W. S. Adams, A. H. Joy, M. L. Humason and A. M. Brayton, Ap. J 81 (1935), 187-291.
[26]The Abundances of the Elements in G-Type Subdwarfs. AP. J. SUPPL. 46,5 (1960), 139-186.
[29]Presidents Science Advisory Committee.
[30]Office of Naval Research
[31]Goldberg was not on the astronomy panel, but represented astronomy on the Mathematics, Physics and Engineering Divisional Committee, 1952-1955.
[32]Office of Scientific Research (later: and Development).
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