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In footnotes or endnotes please cite AIP interviews like this:
Interview of Arthur Code by David DeVorkin on 1982 September 30,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
For multiple citations, "AIP" is the preferred abbreviation for the location.
Discusses his career in astronomy and astrophysics through his student days at the University of Chicago (PhD, 1950, astronomy and astrophysics); and his teaching and administrative positions at the University of Virginia (1950), the University of Wisconsin and Washburn Observatory (1951-56; 1959- ), and briefly with the California Institute of Technology at Palomar and Mt. Wilson Observatories (1956-58). The interview centers on his work in space astronomy, with emphasis on his use of an X-15 airplane for UV stellar spectroscopy, and his role in the development of the OAO series and Copernicus. Also discussed is his work with instrumentation, especially photoelectric photometry, and his theoretical interest in cosmology.
Dr. Code, I know that you were born August 13, 1923 in Brooklyn; but I would like to know a little bit more about your family background. Who were your mother and father? What did they do?
My father's name was Lorne Arthur Code, and my mother's name was Jessie Mae Dodd. My father was a Canadian. He was born and brought up in Ontario, and I believe my mother came from Detroit. At the time I was born, my father had a variety of jobs, and we moved around quite a bit. He had a gas station in Florida, and he worked for Goodyear in Ohio. This is all in the first three or four years of my life.
Did he have training?
He did not. Just through high school in Canada, which is a very good letters training. He knew a great deal of literature, poetry and such from his high school days. That's because he had a very good memory, I suppose.
What was his particular function, running gas stations, or working for Goodyear?
He owned the gas station in Flordia. I don't know what he did when he worked for Goodyear Tire in Akron. When we returned to New York, he worked in a mattress factory, where his father also worked. Then there was a period of time which was during the 1929 depression, for a couple of years there was no employment; and he finally got back into a mattress company, Englander Mattress, and he became the factory manager. Ultimately he went to Chicago to organize and set up a plant there, and finally to Los Angeles much later on, after I had moved to Los Angeles and was a member of the Mt. Wilson-Palomar staff.
But during the time you were growing up and living at home, you moved around a bit. And this was your first recollection.
Yes. I started kindergarten in Portsmouth Ohio. For that year I was living with my grandparents on my mother 's side, and then it was in Brooklyn I actually started school in the first grade. I suppose I got to the order of fifth grade when we moved to Queens, and I went through the rest of school and high school in New York.
These were all public schools?
Did you have brothers or sisters?
Could you characterize your early hone life, as you recall it? What kind of activities did you engage in?
As far as activities were concerned, those were early activities with friends, many in the neighborhood. I think there was perhaps an interest in science involved there. We would hook up telegraphs between houses. And the family life, I guess, made some distinct change from Brooklyn to Queens, because then there was a new house that we had moved into and a new neighborhood. All the family was involved building, gardening and working on our new living quarters. We put in a driveway, gardened and made some furniture. I think the most profound influence was an uncle that lived with us, my mother's brother, who was older than she was, but actually lived with mother and father at the time I was born, and did a lot a baby sitting. He was married for a brief time, and then when we moved to Queens, he moved in with us. He was a high school science teacher.
What was his name?
Russell Dodd. And so he had a great many books, and it was from reading these books that I decided at quite an early age that I was going to be an astrophysicist, not an astronomer.
Can you identify when you moved to Queens? How old were you, and some of the titles of the books, possibly?
I must have been something like 11 years old.
Yes, so 1934.
The books that impressed me most were the ones that were written by Jeans and Eddington.
Any particular titles?
Well, I'm not sure I know what they are now. I guess a book of Jean's was MYSTERIOUS UNIVERSE. (1930)
And STARS AND ATOMS, by Eddington, by any chance?
These are not books like Eddington's INTERNAL CONSTITUTION OF THE STARS?
Oh no, no, but I got a look at those in high school.
Yes. I didn't understand them.
Anything more about your uncle's influence in terms of astrophysics? Did he give you these books to read? Or did you find them on the shelf? Or did he talk to you about astronomy and and astrophysics?
I found them on the shelf, and he encouraged my reading and using the books. But I don't think we talked much about it. I suppose I assumed that he knew everything that was in those books (laughs). He also was quite mechanically minded, and had a rather elaborate wood workshop in the basement. And so I learned something about how to use tools. You asked me if I had any brothers and sisters — I guess he was a big brother, really.
Did you make the telegraph with his equipment?
No, I was a younger and it was independent.
Any memorable teachers through high school that you recall?
By any chance, did he teach in the high school that you went to?
No, he did not.
Where did he teach?
I don't know what high school. I think there was one in Flushing, New York, that was a vocational high school. I know he never considered the students very challenging in the high school were he taught.
Did you ever think of building a telescope after the first readings of these books?
I was somewhat interested in building a telescope, but that didn't seem to be where the action was. It was in the understanding of theory. I remember getting a real kick out of being able to find out how one determined the distance to stars, by trigonometric parallax, and describing it to others in school in class, and that was pretty great, that these distant little spots, you could really find out how far away there were. So it was that aspect, learning about that which was more interesting than building a telescope at that time. I did learn all the brighter constellations as a Boy Scout. I was quite interested in nature as well as astronomy. I did go to a Boy Scout camp every summer.
Did you go to the Hayden Planetarium?
Oh, from time to time, sure
But that wasn't a center of attention?
No, I wasn't in any telescope making classes or anything of that sort. But it was quite common for us to take the subway Saturdays and go to the Museum of Natural History and/or to the Planetarium.
Yes. As you moved into high school then, you mentioned that you saw Eddington's more technical book, INTERNAL CONSTITUTION OF THE STARS. Did you see other books, and where were they? Again, on your uncle's shelves or in the high school library?
In the Public Library. Apparently they were pretty good, because I don't think in our Public Library I would have found Eddington's INTERNAL CONSTITUTION OF THE STARS. That wasn't the high school library, either.
Had you seen Russell, Dugan and Stewart's book on astronomy?
No, I had not. No, I didn't see that until I got to the unversity, I guess.
Okay. First of all, did you make a definite decision to become an astrophysicist?
Yes I did. That is what I wanted to be.
Did you express this to your parents?
Yes, they weren't particularly sympathetic with the kind of interest I had as a career, because they didn't understand it as a possible career; nor my interest in radio.
So the telegraph interest developed into radio?
Did you have a ham license?
I did not have a ham license. I knew quite a few hams, and I listened to the bam bands. I have had a ham license since. But I didn't at the time.
Did you build a set?
I built a receiver. Well, ultimately, when I went in the Navy, I became an electronics technician, and at that stage my family was very pleased about my interest in radio. Then when I got out of the Navy, they thought that electronics was the direction I should go then, because they could understand that as a profession. Going to graduate school to become an astronomer was sonething they only accepted later when they saw that I was going to be successful at it. (laughs)
What was your period of service in the Navy?
I guess it was about three years, 1943, '44, and '45.
You were drafted?
Yes, I was a selective volunteer. You join the Navy before you get drafted. I had just gone to the University of Chicago for one year, and started the fall quarter when I got a draft notice.
Let's back up just a little bit about that. How did you decide, and when do you think you decided that you were going to go to college and that it was going to be the University of Chicago? I thought you went to George Washington University for a while. Didn't you?
That was while I was in the Navy. I started at the University of Chicago, I always assumed I was going to go to college.
Your parents wanted you to go?
Sure. And my uncle was a graduate of the University of Michigan in civil engineering. At any rate, I got catalogs in my senior year in high school, and the decisions weren't based on being very well informed, which I find is true of most students, even graduate students. They go to graduate school for the wrong reasons.
Had you been reading anything beyond the books in the library? Did you find any of the popular magazines, "Scientific American," or "Sky and Telescope," that would have the astronomy articles?
Sky and Telescope, I did see, and I believe "Popular Astronomy" existed at that time. I would see these in the Public Library.
Did they help you find where the centers of astronomy were?
Well, I knew some names at any rate: Otto Struve. I'm not sure who else at the time. But in looking over the catalogs I just looked at courses in astronomy in these catalogs (laughs) and I got the impression Yerkes Observatory was a great place. The mix of courses and the interests of different faculty members sounded to me like the best place to go. I guess I had catalogs from Michigan, Harvard, Berkeley and Chicago.
That pretty much covers it.
So I applied to the University of Chicago and got in. I went there and discovered that there are other things in a college education than taking these astronomy courses. And in fact, I would have to wait awhile and do other things (laughs). I knew nothing about, as a matter of fact, Robert Maynard Hutchins and the Chicago system that existed there at that time. You had to take these four survey courses, and become broadly educated. That's what I meant when I said that I went there with really very little information. I was just aiming at astronomy. Now, even though I was on campus and couldn't start an astronomy program, there was a small observatory on the top of Ryerson Physics Building on the Chicago Campus; and I managed to meet the astronomer who was teaching some courses on campus. John Titus was his name. He is no longer in astronomy. He went to China Lake. He was a dynamic astronomer.
How about Walter Bartky and people like that?
I read Bartky's popular books, too. I do not think that Bartky was the Chairman of the Physical Science Division, but I don't think he was around then. Thornton Page was there, but didn't meet him right at that time when I was a freshman; and he left during that period. I guess Thornton went into the Army. The observatory office was Thorton Page's office. And all of his books were there, and a lot of his father's stuff. Lee Page was a theoretical physicist at Yale. So again I was exposed to a lot of new books.
Could I ask you one thing about funding? Did you get a scholarship to go to the University of Chicago?
No, nor did I ever hear of anybody who had (laughs).
How were you able to go?
Well, I worked. I got some support from my family. I had a variety of jobs. I was a gymnast, and I worked in the Athletic Department, handing out towels in the locker room or doing other things. For student help you were well paid, and for a brief time I worked at the Continental Illinois Bank from midnight until 6 a.m. with a machine that sorted checks for distribution. All these kinds of things interfered with going to class. I had a variety of jobs during that short period of time. Something quite surprising, is that it was only a year and one quarter, and it seems to me that a lot of things happened. That's happened a couple of other times in my life. And I guess it happened to other people, that a lot happens and you can do a lot in a very short period of time; and in other parts of your life, it seems as though it takes forever to get things finished up.
You mentioned that you didn't take astronomy immediately, even though apparently you still read some books in Thorton Page's library in Ryerson. Did you take physics courses your first year?
My only advanced course was in vector analysis. I didn't take the physcial science survey course. I just took the exam for that, although I sat in on some of it. But, no I didn't take any astronomy or physics courses in that first year period; just studied on my own. Going back to this observatory in Ryerson, there was a small telescope there, and also a coelostat to bring sunlight down into a Rowland circle grating spectrograph; and I used that. So I did some photography with the telescope and spectra of the sun.
Did someone instruct you on how to use these?
There wasn't anybody around. But I was given a key to that office, and permission to use it. So I didn't get any significant feedback. I did visit Yerkes during that time with Titus, and met some of the graduate students then. I can only remember two of them now, neither of which are really still in astronomy. Ralph Williamson, later on became a radio astronomer, although he did theory with Chandra at that time. And John Swenson, who did spectroscopy, and went to Liege with Swings, was there for quite a while.
Yes. Swings was around at that time; wasn't he?
He was at McDonald a lot. Did you meet any of the astronomers, Struve, people like that?
I don't think I did there. I think I met Louis Henyey.
Well, had your feelings about doing astronomy altered any during this first year in Chicago?
Oh, I guess just sort of reinforced that's what I wanted to do. There was one other interesting aspect to this observatory. You could look into offices in the Physics Department. And they had set up — well, the project was called Metallurgy for building the reactor in the west stands, which is also where the gym got moved. The actual gym field house had been taken over for Navy training, and became dormitories for some Navy recruits, so the gym was located in the same area where they worked where they piled up the pitchblend.
Really? Did you know what was going on?
Yes, I did. I had read Born and Wheeler's fluid drop model of a nucleus. And earlier there were stories in the popular press about nuclear fuel. So what was going on wasn't much of a secret, because also I had seen pictures of Fermi, Compton, Dempster and so on. And here were these guys going in this office, and they were working in the metallurgy project. It didn't take much guessing. And then, of course, I mean, you could just say to people who were working on it: you are working on a nuclear bomb? (laughs). When they went into a catatonic stupor you knew...
Was this a topic of conversation among you and your fellow students?
Well, there weren't very many fellow students, only one other at the time, I guess. I don't think there were, until recently or ever more than one or two astronomy students. I don't know if the University of Chicago had anything like an undergraduate major in astronomy then.
Who was the other person you would identify as astronomy student?
I don't know, because I don't remember. He never made it.
You mentioned that you got your draft notice, and you decided to go into the Navy. Is there anything else we should discuss about your prewar years that you think would be important in understanding the development of your career?
Of course, I also met my wife as a freshman there at the University of Chicago. And after I was in the Navy, we got married. So I was married quite young, and she was supportive of my ambitions. I mean, it could have been the other way. And she herself was not interested in science. She became a psychiatric social worker. She had started in that direction. She was one year ahead of me in school at the University of Chicago.
What is her full name?
Mary Ella Guild.
So what made you decide for the Navy?
Oh again, my uncle was a lieutenant in the Navy (laugh) and he had continued in Naval Reserve. He had been in World War I right after he graduated from college. Does that make sense? Yes, or maybe right at the end they had an officer training program that he got into. At any rate, the Navy of course was for me. And then when I did get into the Navy and went to boot camp, where the option was electronic technician. I took tests, although again, I got out of most of the boot training, because I attached myself to the gymnasiums as a gymnast, and was helping teach judo and things of that sort so I managed to avoid a lot. So I went after boot camp off to pre-radio school. This was one month, I believe, in which we were taught some math, learned to use the slide rule, and there was a three-month radio materiels school. And then finally an advanced radio materiels school of six or nine months; I don't remember which. I think it was nine. After I got out of that, I taught there, and that was my service. And these were at the pre-radio school in Michigan City. It was a Naval armory off the dunes.
The radio materiels school was in Chicago. I was drafted in New York, because that's where my home was; and I went to boot camp in upper New York State. Ending up in Chicago was accidental. But in this radio materiels school, we lived at Navy Pier in Chicago, and the school was at the Balaban and Katz Television Station in Chicago. That was a movie chain but there was a television studio that was the first in Chicago. The manager-owner of the station was Captain Eddy. And Captain Eddy was a radio officer in the Navy, and had charge of the school then. There are a few such people; and there are books by these people. At NRL, where a school was set up, Cook was the Captain Cook. And there are textbooks on math for electronics, by Cook. It's called a cookbook. (laugh).
That's terrible! To what degree was this new knowledge for you? Were these courses tough, or had you already gotten a lot of this through osmosis?
Not a lot of it. But up until I got to this advanced radio materiels school, there were a lot of neat things I learned that were new and interesting, besides learning about the specific equipment.
Was there any chance that you could have stayed at the University of Chicago on a deferment, or have engaged in more research, or was that not possible?
No, not as a freshman. I might have been able to get into a meteorology program that they had, and gone through meterology school there. There are a few people who went that route. Birms Soumi, who is meterologist at the University of Wisconsin, and got the President's Science Medal of Honor a couple of years ago was very active, still is. He is director of the Space Science Engineering Center; but he was very active in the early meteorological satellite days.
This is the Space Science Engineering Center at the University of Wisconsin?
Yes. One astronomer I know, who came along a little later, but got into that same kind of program, meteorology, is Don Osterbrock.
Yes, but he didn't end up in meterology. But I guess I didn't think that I wanted to do that. I think I had the feeling at the time that, you know, friends back home were going in the Navy or Army, I guess maybe I ought to, too.
While you were in the Navy, did it cause you to rethink any of your career goals?
No. Electronics, as I began to learn it, was just a nice problem-solving tool, and I could even understand some of the stuff and write down differential equations and solve them (laughs) and so on. And so it was just a scientific effort. The Advanced Radio Materiels School was at the Naval Research Lab in Washington; and it may still exist next to the lab there. The other members of the teaching staff that I was in contact with, about half of them had been regular Navy radiomen, and then young fellows like myself; and older regular Navy men, most of them were the chief petty officers, had primarily college educations. They were real bright. They hadn't progressed very far until the war started. They had been men who had gotten out of college in the depression, and where could you go? The Navy was very selective at that time, so that here was a crop of highly educated regular Navy.
Now seeing these people who were well educated and capable people, that didn't draw you more into considering a Naval career then?
Oh no. I wanted to be an astronomer. I had to get back to an observatory, and I had to get the appropriate university credentials. I had a lot more to learn. I was there, however, as an instructor at the Naval Radio Materiels School at NRL.
Were you there for three years?
About two years. So it was during that period of time I took courses at George Washington University. Most of them were offered during World War II at night. There was a large selection. And that's where most of my formal education in physics and math took place. I took a number of courses from George Gamow. I took some other physics courses, too, but I just thought Gamow was wonderful, and he was one of the few physicists left. He was not involved in the Defense Department programs.
Why was that? He certainly was a capable physicist. Was it his background?
I think it was his Russian connections. I think it was security. I think that he felt a little bitter about that. I remember, taking a course in which we discussed nuclear fission. He had said that Monsanto had asked him to write a report on how one can build a nuclear bomb, because he didn't violate any classification, because he wasn't involved in any of these programs. He said: "Well, I suggested several versions, and there was one that they removed, which is probably how they are doing it." So we talked about that. And it was about a week after we had done that the Hiroshima bomb went off. So the newspapers were filled with things, and then shortly after that, of course, the Smyth Report* came out. And so we went through and it appeared that he was right. We could calculate what the critical mass was, and things of that sort (laughs).
Oh, he knew me, and years afterwards he still knew me as someone who had been a student of his, as well as now being an astronomer.
Let me ask one question about his research at that time. He was very interested in stellar interiors, during that period. And there is some evidence that he worked on early shell source models. Do you have any recollection of his interests in stellar interiors while you were a student there?
No, I don't. He had already done some work with Mario Schoenberg, who worked with Chandra on the Schoenberg-Chandraskhar Limit, which it was called then, but is now "The Chandrasekhar Limit." Gamow had already proposed the URCA process for supernova explosions and such. And he had not at this time gotten into element synthesis in cosmology. It seems to me that he was beginning to get interested in biology.
Yes. Could you spell URCA process?
Oh, that's an interesting story (laughs). URCA, all capitals. URCA process is any kind of cyclical process where you start off with something, and you end up with it; and the only net product is neutrinos. And at high temperatures, you can produce a lot of neutrinos which carry energy off. They don't get stopped, and so you don't get pressure balance, so things get out of equilibrium. It cools things off. The star has to collapse more to heat it up. Higher density produces more reactions, and so you get an implosion. And URCA is the name of a gambling casino in Brazil. The energy disappeared like his money did, you see. When he sent the paper in to the PHYSICAL REVIEW, the editor thanked him for the manuscript on the "Un-Restricted Cooling Agent". The editor, I guess, was getting into acronyms or something (laugh).
That's very good. That's marvelous. But you don't recall any of that work of his at the time? It might have come a little later.
Well, just what I'm describing to you now, that he had already done; stellar interiors work, and told us about it in class. So the story I just told you is one that is from Gamow, not relayed and run around. But as I say, I think right at that time he was getting into an interest in biology. He had a wide range of interests. He had done some work on the genetic code. There were just, what is it, 16 amino acids, and you are going to use those to code it; then you can figure out what the word and length would have to be like and so on. Now, I met someone at the Naval Research Lab who currently is an astronomer, and he worked at the Naval Research Lab, not in the school. The is Fred Haddock. Fred was working on antennae for submarines primarily, dielectric antennae, and I met him there when I was still just a sailor. We talked some astronomy. He had some interest, and I apparently knew more about it, and then a number of years later we were suprised to meet in an American Astronomical Society meeting, and he had gotten into radio astronomy. We have known each other ever since.
You hadn't met any of the people who were later interested in upper atmosphere research? Hulbert or Tousey?
Well, I take it then that you had planned all the while, when your tour of duty was up that you would go back to the University of Chicago.
That's right. Yes.
Is this indeed what happened?
Yes. As soon as I got out I went back to the University of Chicago; and by then I had accumulated quite a few college credits. I had taken all of the survey courses, just by taking the tests. One of them I guess I did while I was in the Navy in a correspondence course. But I didn't have quite the right mix of credits to get a degree. I visited Yerkes Observatory at that time.
Was this about 1945, the time you are talking about?
Yes. Struve was very encouraging. He was someone who always gave your morale a great boost. Just what kind of idea you had, the important thing to him, it seemed tome, was you had an idea. And that was great! Well, now let me contrast it with Kuiper. If you had an idea, he could immediately tell you the answer, or what was wrong with it. Kuiper was really bright and knew a great deal; and that was his reaction to anything. He would tell you why you don't have to do it, because it's already been done; or why it won't work, or what the answer would be if you did it. (laughs). And Struve was quite the opposite; at least, if there was something wrong with the idea, I guess he led you around to discovering that yourself and modifying the idea, and so on. But it always seemed worthwhile talking to him. At any rate, Struve was a military man and I arrived there, see, in a sailor outfit. So he really gave me a grand reception, toured me around the observatory, introduced me to everybody, and spent a lot of time. And so, then I went back to campus, because I wanted to go to graduate school. I didn't have a degree.
You didn't have your degree then?
No. I don’t have have an undergraduate degree.
No. And they said, well, if you wanted to be a nuclear physicist, that would be impossible; but if they are willing to take you there at Williams Bay, okay (laughs).
Who said that?
That was Bartky.
Bartky made that decision. Was that something that was made for other people as well.to your knowledge?
I don't know of many people who don't have an undergraduate degree, but it isn't a requirement for graduate work. The prerequisites are different levels of course work, or equivalent knowledge. There is nothing that says you have to have a degree to get an advanced degree.
Do you remember the month of 1945 that you went back to Chicago, to Yerkes then? Was it after August?
During the spring quarter I took courses on campus and then in summer I went to Williams Bay, and became a graduate student there then.
Okay. From the standpoint of our interests here, I'd like to identify whether you knew anything about V-2 rockets at the time, and what their capabilities were?
No, I didn't know about V-2 rockets then. I did almost immediately after when I got to Yerkes, because Jesse Greenstein was involved in a solar program, and I guess at least Tousey was connected with this, but there were two — Durand and Purcell were their names — who were at Yerkes working with Jesse.
They were? I'll be talking with Dewitt Purcell in a few weeks. I didn't realize he spent time at Yerkes.
Well, I think, mainly just for a short period of time.
Did you see his project from afar at all? Did you follow his progress? Did that interest you at any great extent?
No, not at that time. The chance to make observations outside of earth's atmosphere interested me, and it interested other people at Yerkes. Al Hiltner asked me on either my master's or doctor's exam: How would I modify a telescope, if I were going to use it on the moon?
What was your answer?
Let's see, I would use all reflecting optics, so it would get into the ultraviolet. I don't remember now what other answers I gave, or any of that time.
Sure. But you remember that he asked that question.
Yes. Did you know of Greenstein's success, or lack of it with the V-2?
I only vaugely got the impression that Jesse was not particularly satisfied with what he had gotten from the V-2. He was sort of turned off by the whole thing. He didn't continue working on it.
Right, but he didn't do any shouting up and down the halls of Yerkes. Making it a big thing.
I'm looking for the possibility that he may have tried to discourage or encourage other people.
No, no. No, I don't think that he influenced people one way or the other. But I don't know. Maybe, if you would come in to him and say, you have this idea, with these kinds of observations with a rocket, he would have discouraged you (laugh).
Well, you worked with him. Your first paper in 1946 was a paper with Jesse Greenstein on a DC current amplifier for microphotometry.
Yes, that's an old microphotmeter that just had a galvanometer and I was just sort of working as his assistant. Well, at Yerkes, as a student, you really had to put in a tour of duty in each of the kinds of things. Every student, for example, worked with Van Biesbroeck taking plates of comets and asteroids, and measuring them, to learn how to do that. And you had to learn how to take spectra for radial velocities and measure the velocities; learn how to do microphotometry, and each of the kinds of observational task. Every student had to learn, and you worked with the faculty in that area. So you were sort of assigned to them for awhile. And so I said, "I can build an amplifier for the microphotometer."
Were they interested in your electronics experience?
No, not too much. One of the things that I was quite in interested in, and tried to get some enthusiasm and support for at the time was to get the IEEE JOURNAL, what was it called then?
The IEEE JOURNAL, electronics you mean?
No, no maybe it was just the IEEE. I was a member. I also had a First Class Commerical Radio License and such. At that time in the journals were papers on the new image orthicon and what you could do. And it looked as though you could use it as a detector. And I was trying to encourage getting ahold of them and doing some experiments on image orthicons.
It looks as though your interest in image orthicons and image tubes came, at least in your published record, in the mid-1950's; but do you remember when it first became an interest? Was this still in the 1940's?
Yes, the very beginning was. This was as a graduate student at Yerkes, because that was when image orthicons first appeared on the scene, in 1945 or so, in published literature.
What were other people's reactions to the possibility of using this as a detector?
Just interesting, and maybe it will come about sometime.
Did they look to support research in it? Did they ask to actually build a system?
Did you try to?
I just tried to encourage it, to whom I don't remember now, to help me get ahold of one and experiment with it. Of course, at that time I built a scanning spectrograph. I had a small one before I worked with Al Hiltner at McDonald trying to do photoelectric scanning.
You were working with William Hiltner. This was in the JOURNAL OF THE OPTICAL SOCIETY OF AMERICA, Volume 40, 1950, page 149.
That's right, yes. We were picking off a compensating beam, and did this in a Coudé spectrogaph at McDonald. But I had just built a little photocell slit that went into a plate holder, got driven along the back of a small spectrograph that was on the 12-inch refractor at Yerkes.
Oh yes, the Kenwood.
Strömgren had been doing something similar, and just had set up something to make discrete motions. This was a precursor to Strömgren filters.
Right. Strömgren was there, so you went through the transition when Struve left?
Yes, when I started there Struve was the director. And then they had several directors. Strömgren was one. Kuiper was one. Chandra and also Morgan had brief responsibilities.
What was going on?
Well, I think the people that Struve had collected had, for the most part, had a prima donna approach, and Struve was able to hold things together, manage such a group, but not probably without some strain on him. To me it was always a real boost to talk to Struve and I thought Struve was great. I know from comments that I've heard since from people who were there under Struve that he was a very hard taskmaster, and I think he had probably had enough of doing that. I don't know what came first, of course, but I assume the opportunity at Berkeley came along, and he decided he would get out. Then we had to try to find a director, and no one else could really handle the other staff members as well.
Was there any question about what you would be doing for at thesis with all of these changes?
Oh no, there wasn't any noticeable turmoil to students. See, I did a master's thesis with Bill Morgan on the spectra of Cepheid variables. And then I had always been interested in theory. Chandra had started his series of papers on radiative transfer; and my Ph.D. thesis was with Chandra.
Oh you did?
Was your thesis "Radiative Equilibrium in an Atmosphere in Which Pure Scattering and Absorption Both Play a Role".
Right. That was the thesis.
ASTROPHYSICAL JOURNAL; 112, 1950, page 22.
And these are, many of these, just kind of interesting problems, mathematical solutions; and I have written in a few papers on radiative transfer from time to time which is just a problem-solving thing.
But what were you getting interested in, observational techniques, instrumentation, or theory? Did you have any conscious feeling of what direction you wanted to go?
I didn't see, really. What I was interested in, I guess, about that time was that one should make physical measurements of the radiation from stars. You ought to know how many ergs/cm2/sec/per angstrom were coming down, and not magnitudes or relevant color-indices; and that those physcial measurements are the things you need to have to compare with the theory of stellar atmospheres, it seemed to me. At that time, stellar atmosphere theory was far ahead of observations. That's why I wanted to build photoelectric spectrographs, and try to make energy measurements of stars.
From your vita, it looks as though you spent part of the year at least as an instructor of astronomy at the University of Virginia. Was that taken before you completed your dissertation?
No. When I finished at Yerkes, I had only one job offer. I had fellowships. I had a fellowship at Princeton, but I thought, "gee, I want to get started." I had visited Charlottesville, and I had heard that they really wanted to do something. They wanted somebody who could build a photoelectric photometer. And so I went there instead of going to Princeton.
What did they want at Princeton. Any idea? Just someone as a postdoctorate fellow?
Just a postdoctorate fellow. I forgot what the name of it was. And I had always thought that Wisconsin was the place I would like to go to.
You mean the University?
The University of Wisconsin, yes.
And why was that?
We had an American Astronomical Society meeting there where I met Stebbins and Whitford. They had forgotten about the photographic plate and gone on beyond that right away. I thought they were both fine observational astronomers who were doing things thats nobody else was doing. And I thought the town was very attractive, so that when I got an offer from the University of Wisconsin after I had been at Virginia for nine months, I took a transfer.
Did you seek out the offer? Or was it known that you would like to go to work there?
I didn't seek out the offer, but Whitford certainly knew of me. I don't remember now exactly the details of that; but Charlottesville was interesting to have been in, but the astronomical future didn't seem nearly as bright as I had thought it would be when I accepted the job. The director then at Virginia was Harold Alden. He was really a very timid man. He wouldn't do anything that the administration might not like or approve like fix up a telescope. Or having the audacity to ask for money was something that inconceivable. But I did make a photometer, got it working and left there.
You taught classes during that period?
Then you went to the University of Wisconsin with what particularly in mind? They didn't have a large telescope — a 15-inch refractor.
Oh, but every summer the Mt. Wilson observatory was available. Almost all of their observations were made at Mt. Wilson, and I knew that. And I intended that we'd go there every year.
So that was known to you.
Yes. I remember driving from Charlottesville to Madison, Wisconsin, thinking about the new job. One of the things I was going to do was solve the problem of the Stebbins-Whitford effect. Which in fact I did (laughs), but I had thought it would be a more interesting answer that it came out to be.
Other than it didn't exist.
Did you announce this to Whitford when you got there?
No, I don't think so.
Again, from your papers, it looks like you worked with a number of different people on a combination of spectrophotmetry, atmospheres, and you certainly worked with Whitford, but also with W.W. Morgan on the red S-type stars. Now this was in a period when Morgan was developing his spiral arms observations. Is that correct?
Yes, that's right, but it may have been a little bit later.
1953? This is 1952 that you wrote that paper.
Well, Whitford, Morgan and myself, had this joint program of getting photometry and spectra of these stars, and went to South Africa to get some observations of Southern Hemisphere objects. And that particular "reddest" is just a paper on some of the reddest objects we picked up on that survey.
There was a publication 1360 B stars, or 1320.
1270 blue giant stars. That was in 1955 already, ApJ Supplement.The first paper in that series was "Studies in Galactic Struture I-A Preliminary Determination of the Space Distribution of the Blue Giants." That certainly seemed to be a paper that led one to spiral structure.
All right, I was thinking of something different when you mentioned spiral structure. Yes, certainly, what we were interested in was delineating spiral structure. Later on, Morgan got into the morphological classification of spiral galaxies from their spectra. That was what I thought. (laughs).
Oh, I'm sorry.
No, what you said was quite right. I just jumped ahead to spiral arms and other galaxies.
What I would like to have is your recollection of the period of time during which Morgan was adding evidence to his Gray Wall map. To what degree were you involved with the delineation of a structure? Did Morgan always have the feeling that it was always there, and was it just a question of finding it? And was there a sense of competition with the radio people?
No, I don't think there was a sense of competition as far as Morgan was concerned, because indeed for quite a while he knew it was always there, and had delineated it. He didn't get too far; but we understood the structure and the tilt of the arms, and the separation. So then later on, 21 cm. observations didn't yield the same pattern; and that was a concern to many of us, Morgan, Strömgren, Whitford, myself, and Nelson Limber. We had a couple of meetings on just that subject. We'd come down to Yerkes and spend a whole day trying to induce arguments. Guido Münch was also working on distant stars. And one of our students at the University of Wisconsin, John Bahng, who is now at Northwestern, did some analysis. The starting point was this: How come the zero-point for the Cepheids has changed?
Now the luminosities of early type stars have gone up; and Jan Oort still gets 20 kilometers per second. Oort's A is still 20. Why shouldn't it double the distances? Why should it be 10? So we just set students to redoing the calculations with modern distances. And the early type stars seemed to yield between 10 and 15 for Oort's constant of rotation. Well, Oort (as I say, he was just visiting Yerkes then) of course, said that could not be right, and that's something that someone has to be careful of when they become senior. He didn't mean anymore than he just didn't think it was right; but I mean, that carried enough weight that Johnny Bahng's work was not right; and that was the end of that effort, essentially. There was a conflict between 21 cm. and visual stellar arms, and Morgan was interested in it. But it certainly seemed that the velocity fields were not the same. And the arms today are no longer circular.
At any rate, that was something I don't think Morgan had too much of a problem with. Stars are right, and you had to explain the 21 cm. some way or other. And ultimately, that's the way it shakes out.
You’re still trying to explain the 21 cm. observations?
Through the mid-1950's you seemed to have a combination of interests: a lot of observational work, spectrophotmetric work, and you were also building equipment. And it looks as though you were building equipment with different people. You were working with Kaj A. Strand on a multiple exposure camera. Later you worked with Bob Hardie in 1955 on comparison of image tube systems. And I would be very interested to know if you developed instrumentation at this time, in response to specific needs that were perceived; or whether you were interested in looking generally at better instrumentation for a lot of needs?
It's both. In the case of Kaj Strand, he was a very good friend. He was a neighbor at Yerkes. And in fact, his wife introduced me to my wife, and I introducted Kaj to his wife later on, so we are good family friends. Kaj had just mentioned the advantages of having an automatic plate holder, and what it does when you put your hands on it and such. All this really was, a timer to time the sequence of motion.
This was a camera that would take an exposure, then shift the plate a little bit, take another exposure, and then shift the plate again? For double stars?
Yes. And so here was a need or desire that he had. He wanted something to replace turning it by hand. So I built it for him; that's all. At one time there weren't too many people in astronomy that had electronic experience. Bob Hardie was one who also had electronic experience; but this goes back to the interest I told you I had in image orthicons at the beginning.
Was Bob Hardie’s experience in electronics also from World War II?
Yes. He was in the Canadian Navy.
How did you develop your interest in image orthicons and in comparing various image-tube systems?
Well, it was just that Bob had been active in working with image tubes, and gotten connected with a program that Hiltner had started, I believe; and just discussing the comparison systems. We thought that the comparisons should be on the basis of the theoretical limits that you can set, how the systems measure up to it, and what represents a really fundamental limitation. If one says this system is better than another do they really mean that, or is it the way that it's being used? If your quantum efficiency is very low, you can't count photons. You can't reduce noise below the square root of a number of events you are measuring, and things like that. What additional noise do various systems produce? How do they measure up with perfect detectors? This is what we talked about a lot, and we decided to write it down.
Which detectors were you working with at that time? I haven't seen the article; but did you go as far as looking at the experimental ones of Lallamand?
Yes. But we tried to formulate it in a more general way. If you get an event, a photo event, how do you use that? And if you are going to pick it off of a beam that has a certain beam current, that adds to the noise. But it was just an interest.
It doesn't seem that you continued at that time. Did you continue?
No, because we weren't into any big program. Starting up elsewhere, the most concerted effort was the Carnegie effort that Merle Tuve got going.
Did you have any of his early tubes?
Yes we did. Ted Houck worked on the Carnegie program at Lowell for about two years, and brought some of those tubes back. And when Kent Ford started to distribute them, we got one of the first ones.
Moving through the 1950's you were progressing at the University of Wisconsin, as an instructor and then assistant professor. Then you left and went to Caltech and Mt. Wilson in 1956. You had been going out to Mt. Wilson every summer. Certainly, you had a lot of contact there. What was your decision, and what was the opportunity that allowed you to make the transition? And was this thought to be permanent by you?
The opportunity, of course, was first of all an Associate Professorship, a tenured appointment at Caltech.
You didn't see that coming in Wisconsin?
Ultimately, sure, but a permanent staff member of Mt. Wilson Palomar Observatory, and a chance to use the 200-inch telescope on a regular basis — at that time that was the ultimate that any astronomer could look for. Jesse Greenstein offered me the job. It wasn't very difficult to make the decision, and it was a permanent decision. The thing that changed was Sputnik and the possibility of making observations from above the earth's atmosphere. And lots of people were using ground-based telescopes, and nobody seemed to be interested in doing space astronomy. It's going to be done. There had better be some good astronomers involved in the program. I could go back to Wisconsin as a professor or director of the observatory; and start such a space program. That part of the country is just as good as California for it.
You just told me an awful lot. I'd love to have you expand on that.
I was the first person to ever quit Mt. Wilson-Palomar. And it wasn't too comprehensible. I mean, this took a lot of wrestling with. Whitford was leaving to become director of Lick Observatory, and they were looking for a new director in Wisconsin. I was offered the job. I would not have accepted it on just that basis. I wasn't looking for being a director of an observatory. But at the same time, there was this letter that Lloyd Berkner circulated in academic circles, that if you had a 100-pound satellite, what would you do with it? I thought about that and responded to that letter.
Do you think you have copies of that correspondence still in your files?
I don't think I have a response, but I might. I certainly could go back. I'm sure I can find material on the first meetings of the panels that were — I guess they called it initially, right from the very beginning, the Space Science Board. That was set up to look at these proposals. I'd probably find correspondence that far back.
At the Academy? And we could find your correspondence possibly at the Academy in Berkner's papers.
Okay. We'll talk about that later. I want to ask you a million questions about this period. I mean, why did you see Sputnik as a chance to work when so few astronomers did? And did you make this a stipulation at the University of Wisconsin, that if you came back, you would work in space science?
Maybe this is a good place to start up next time.
Okay. Those are the kinds of questions that I certainly want to talk to you about next time. Great.