Seth Neddermeyer – Session I

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ORAL HISTORIES
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Interviewed by
Charles Weiner
Location
University of Washington, Seattle, Washington
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Interview of Seth Neddermeyer by Charles Weiner on 1972 May 30, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/31786-1

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Abstract

Topics discussed include: his education, Robert Millikan, Carl Anderson, his dissertation on energy losses of certain high energy electrons, his time at California Institute of Technology (Cal Tech), Bethe-Heitler calculations, his discovery of muons, Yukawa's theory, and his work with the Manhattan project at Los Alamos.

Transcript

Weiner:

Today is the 31st of May. This is Charles Weiner talking to Professor Seth Neddermeyer in his office at the University of Washington in Seattle. Since we have limited time, what I'd like to do is to pick you up in your college days with a few preliminary questions. I know that you got a BS from Stanford in '29, but I don't know whether it was in physics, and I don't know if that's the case what got you interested in physics. I'd like to know that.

Neddermeyer:

Well, I went to Oliver College in Michigan for two years, freshman and sophomore years, transferred to Stanford from there. There I had some rather — some very good teachers, Professor Stowe in chemistry, Professor Skinner in physics who was not what many people would call an outstanding teacher, but in my book he was actually a very good teacher. I took calculus from him and physics, and he gave us a very nice little short course in what he called theoretical physics, which was some classical theoretical physics, some treatment of the (???) like Law and so forth, and a little bit of hydrodynamics and some free analysis, vibrations of plates and conduction problems. It really — I got quite a good feeling for some of those problems. Sans rigor, without any rigor, but we got the ideas, learning how to manipulate these things. He was the one who pursued me to major in physics. I'd already decided to major in chemistry, because I was very excited after having read various popular accounts of chemistry. It looked like a terribly exciting field, synthetic chemistry of various kinds, especially. So he encouraged me. He wanted me to go to my chemistry professor wanted me to go to Cal Tech because of Millikan. My physics teacher suggested I should go to Stanford, because he himself was interested in X-rays and was doing a thesis on diffraction of X-rays in liquids, and Ross and Webster were at Stanford and he felt that that would be a better slot for my level of ability, a slightly less competitive situation, and I might make out there. So I went to Stanford, without any trouble.

Weiner:

To backtrack a minute, before your entrance into college, and your course in chemistry — you mentioned you did some reading of popular works. What other scientific interests had you had? Were you a tinkerer, as a kid?

Neddermeyer:

Oh, I built model airplanes, not very successfully. I was a radio amateur for several years. Not a very good tinkerer really.

Weiner:

But you had the interests.

Neddermeyer:

Oh yes.

Weiner:

Did this reflect anything from your family background at all?

Neddermeyer:

No, not too much. Well, my father was a businessman with no college education. My mother was a graduate, also of Olivette (?) College. That's why I went there. And I had an uncle who was something of a classical scholar and liked to read Hebrew, Greek, Sanskrit, German and French. However, he wasn't able to pursue this because of economic reasons. He had to go back home and go into business. So he was lost to the academic world for whatever he might have been worth. But he had a tremendous book collection that he left in town, and I didn't make nearly the use of that that I might’ve. I've often regretted this. He had things like Hamilton's Katurnians in Simple Tongue" and astronomy and things like that. Oh yes, he had an Olney's calculus, and I studied in that before I went to college, and then got into trouble, a little bit of trouble, because I happened to remember some of the definitions out of Olney instead of from the book we were using. But I wanted books on current science, and somehow I didn't get access to those. Of course I could have made access. I could have been creative about it and gotten access to such books, but I didn't. Well, I wasn't in any sense precocious at all. It was just my own curiosity. I was next to the top of the class in high school of course which wasn't too much. I was a B plus student in college, A's in math and physics for the most part and chemistry. At Stanford, I couldn't get too excited about pursuing X-rays. Webster and Ross had a good program going there, but I'd heard about other things that more appealed to me, so I decided not to stay. I had an assistant ship for the next year if I wanted to stay, but I decided to go to Cal Tech. During my — I took two independent reading courses, one an advanced course, one just a general reading course, and during that term I spent many hours in the library reading the controversies of Jeans and Eddington, problems of constitutional behavior of stars, and I read Eddington's book on the internal constitution of the stars. I got that book and pursued it quite avidly. Of course, I didn't get everything in it by any means, but I wrote a paper on Eddington's work on the radiation inside of stars and thought it was very exciting. So I decided to go to Cal Tech to go into astrophysics.

Weiner:

You got your bachelor's in physics.

Neddermeyer:

I got my bachelor's in physics at Stanford, and— well, ltd already gotten interested in astronomy through my uncle. He was interested in ordinary observational astronomy, and so I learned the names of many of the first magnitude stars and how to recognize them and so forth when I was at home.

Weiner:

You went to Stanford, it must have been ‘27 then, right?

Neddermeyer:

‘27, right, '27. I graduated from Stanford in April, '29, stayed there for one quarter of graduate work through June — but I couldn't start Tech that fall because of a shortage of cash and my dad needed my help at home, so I missed that quarter. Consequently in January, 1930, I started a full schedule of graduate courses in the middle of the courses at Cal Tech — Smythe, optics, and Halston's theoretical physics, and of course it was a little rough, and I didn't exactly cover myself with glory. However, I managed to survive. I also managed to pass Swiggy’s exam without taking his course.

Weiner:

This was in astrophysics?

Neddermeyer:

No, it was in mechanics.

Weiner:

I think of him as getting involved in —

Neddermeyer:

He taught the course in classical mechanisms for many years. He passed me through the first two terms, and later when I had all the other requirements gone except that one, he finally gave me an oral for the third term, so I cleared mechanics. However, I had to drop out again, and I can't remember the dates exactly. I went back in — I guess it was in January of 1932. I really don't remember these dates for sure. And finished getting off my candidacy requirements. No, that strung on a little longer than that, but anyway I started poking around for a research problem in March, — no, I was still there in March of 1931 because I remember giving the first colloquium I had ever given, and I gave one of the first colloquia in nuclear physics there, — the title of the seminar was "Beta Rays and Gamma Rays." It was based mostly on the Rutherford - Ellis Chadwick-Ellison book, you know, among other things I read. I remember the thing that was most exciting to me was the beta ray spectrum, the experiment that Ellis and Worcester, on radium-E spectrum, showed that there was a difficulty with conservation of energy, and I was concerned about trying to hatch up a research problem to perhaps check that. For a while I had some idea of the possibility that maybe two electrons came off at once, but I discovered that that was pretty well taken care of by the chemistry of the situation, and besides T. Iguchi had already anticipated me, I realized, on the experiment. So of course that was already Pauli postulated the neutrino, of which I was not aware.

Weiner:

He had done it at Cal Tech, 1930.

Neddermeyer:

And I had missed that talk.

Weiner:

It may have been the summer of '31, I don't — I'm not sure, but anyway you don't recall that.

Neddermeyer:

If it was 1930, I was at one of his talks, but it seemed to me I missed that Pauli's — Well, I don't know. No, I don't think I could claim that I was at all close to being able to make the neutrino postulate, but I was keenly aware of this difficulty and very interested in it. Well, let me sew. I think there were two gaps, and I dropped out again in'31, and then I got back in '32, and I forget whether it was January or April. Maybe it was April. Yes, it was April, and I had talked with Anderson. I'd seen what was going on. And l’d talked with Millikan about a research problem. I hadn't done as well as I might have in my courses and Milliken wasn't willing to trust me to start a research problem on my own, so he said, "There are two possibilities. You can measure the viscosity of air, continue Bleeke's experiment” and the reason for this will be obvious to anybody. It was related still to his old determination to "Or you can work with Anderson. He needs some help on his cosmic ray experiment." Well, I had already talked with Anderson, and so it was pretty clear what I was going to do. So I registered that spring term. No, I didn’t register. I started doing research with Anderson and later Dean Watson discovered that I was at school working on a research problem without being registered, so he lowered the boom. I forget when I raised the money. Anyway I was always in a very precarious Situation. Finally Millikan rescued me by giving me an allowance of $25 a month to survive on.

Weiner:

Some kind of assistantship?

Neddermeyer:

Research assistantship, yes.

Weiner:

$25 a month?

Neddermeyer:

Yes. I later got a raise to $35 a month, then to $50, so I survived that way through my graduate career. Well, the problems, at the time I started working with Anderson, it was in that spring term of 1932, there were some very interesting difficulties that had appeared already with the cosmic ray data, and I'm sure that Anderson has discussed these and it's probably superfluous for me to go into them.

Weiner:

Well, one thing that he had forgotten, I found a letter that he wrote to Millikan in October of '31, when he had first gotten some stuff and Millikan was in England, and lectured on these results. This was the beginning of the work that led up to the ultimate position photograph. So I know the general outline of what he saw as the line of research.

Neddermeyer:

Well, the first thing I did was, with Anderson, was to help him run the apparatus and also measure tracks, so I got involved in the track measuring business, and it was pretty clear that — I'll skip those difficulties that already existed, but it was evident that there were some of these particles that were pretty high momentum, that is well above a billion electron volts, and even one that could have been as high as , you know, something like tea, although that was really beyond the limits of the measuring capacity of my chamber. I remember how difficult it was to convince Millikan of the existence of the very high momentum, very high energies. He simply wouldn't buy it, because they were way above the range that he could explain in terms of his ideas about the origin. And I remember having a long discussion with Millikan about the measurements I'd been making, and had no feeling that I'd made any impression on him particularly, but I found out later that maybe it was my argument that convinced him finally that particles with momenta above that actually existed. So that was one thing. Well, the other thing having to do with this difficulty about the protons and the electrons — many times. When you saw a particle coming in that you assumed was going down, because the cosmic rays were generally going down, you'd sometimes find that the particle indicated a positive sign, which showed excess heavy ionization which was characteristic of what you would have expected from a proton. And particles, negative particles showed generally the light ionization that you would expect of an electron. Of course, the extremely high momentum ones, there would be no, very little difference. But there were many cases that Anderson had found very early of particles which, if you interpreted them as going down, were positive sign and showed the characteristic ionization of light particles like an electron. So the thing was, you interpreted them as electrons going upwards. But then this became difficult, because you'd find groups of particles, or there was a center they were coming from, both positive and negative, and there those simply couldn't be interpreted as protons, and still they showed the characteristic ionization of electrons. So the crucial saw Anderson decided, the only way to test this was to take a plate of material, let them undergo momentum loss or an energy loss, and that will hang a vector on the particle effectively and tell us which way it's going. So one of my early jobs, apart from measuring tracks, was lead to machine the lead plate that went in there for that purpose. And very soon after, this famous picture occurred, which showed a loss of momentum, and corresponded to a particle with positive sign and showed the light ionization characteristic of an electron. The amusing thing is that that was a positive electron going up. So — well, Anderson had that interpreted Wile the film was still wet. He looked at the film — "My God, it's a positive electron," and that was that. Now, the discussions and ideas that were kicking around were, in retrospect, very interesting. Oppenheimer was following this work very closely, and he would come in very frequently, and I remember how interested he was in this weird track we had. Oppenheimer who is — he was an expert at Dirac's theory, of course. He had followed it very closely, and after Dirac had made the hard effort to interpret the empty negative energy states as protons instead of electrons you know, forcing it very hard— his argument was, "Well, positive electrons haven't been observed, therefore presumably this has to be — you have to find a way of interpreting the proton." Well, of course it was a very forced thing and very un-Diracian, perhaps, although I couldn’t understand the paper by any means.

Weiner:

Had you seen it up to that time? Had you been aware of that paper at that time?

Neddermeyer:

I’m not real sure, but — well, no, we knew we knew about the negative energy states. I'm almost certain that we knew about the negative energy states, and the possibility of their being interpreted as positive electrons. I'm almost certain that we knew about it at that time. However, of course, Oppenheimer then wrote a critical paper demolishing Dirac's attempt to have made the proton.

Weiner:

— to show that it couldn't be protons —

Neddermeyer:

But then, I remember it clearly, and Anderson supports me in this, a remark that Oppenheimer made in regard to this picture. "One thing certain, it has nothing to do with Dirac's theory." Now, I never was able to understand this. I never pressed him on it. Norma Philipps told me once that she thought that Oppenheimer really didn't particularly like Dirac's theory, and she said also that there might have been some influence from Bohr involved. I don't know.

Weiner:

Oppenheimer had had no contact with Bohr at that time as far as I know.

Neddermeyer:

I thought he had.

Weiner:

He wasn't in Copenhagen.

Neddermeyer:

Are you sure of that?

Weiner:

No, I'm not, but I can't

Neddermeyer:

Oppenheimer wasn't — see, he was —

Weiner:

— he was in many places. He wasn't in Copenhagen at all. He was in Cambridge.

Neddermeyer:

Yes, but wasn't — but Bohr also spent some time in Cambridge, didn't he?

Weiner:

I'll check it out.

Neddermeyer:

It seems to me — well, at the time when Schroedinger's wave mechanics came out, there were these meetings with Schroedinger and Bohr and Heisenberg and all, where was that? That was at Copenhagen. I don't know whether Oppenheimer was there or not.

Weiner:

He never met Bohr until '33 when Bohr visited the US.

Neddermeyer:

Is that really true? I didn't realize that.

Weiner:

Tremendous thing, the visit with him, but that was the first –- that is not —

Neddermeyer:

Yes, well, this is the bad thing about trying to do this, you know, from memory, so far back.

Weiner:

But in this case it could very well be that he was influenced by Bohr, just taking what it says, because Bohr wrote

Neddermeyer:

Yes, all right, of course, but I was under the vague impression that —

Weiner:

— it's something I can check, I may be all wrong. Anyway, you're saying that Anderson recalls that Oppenheimer looked at the certain, photograph, the important one, and said, “Well, one thing is certain, this has nothing to do with Dirac's theory."

Neddermeyer:

We were both there when he said it.

Weiner:

Do you recall that as well?

Neddermeyer:

Oh yes, yes. I remembered this and I was so sure, and I asked Anderson, and he said, "Absolutely.” I You see, this is a very interesting thing. It's too bad that we didn't press him on this, to find out — So, well, so...

Weiner:

Anderson said in his published paper that there were several intensive discussions among colleagues — you know, we've finally come to some decision — so are these the same discussions you're mentioning? You were saying that there were lots of discussions going around. On the certainty of what this thing was, and to eliminate apparently in a conservative fashion every other possibility.

Neddermeyer:

We kicked it around and around, trying to interpret it as a change in depth angle, you know, getting a bad projection because of a scattering into the of the chamber, or, you know, just nothing , nothing — it really had to be, as long as you bought conservation of energy, and the electrodynamics of such things, you really couldn't get around it, it had to be a light particle. And Anderson was able to show, just on the basis of arguments about the ionization, you know, that the mass had to be less than 20 electron masses approximately. In other words, far, far less than a proton. So that was really —

Weiner:

— did Millikan get involved in those discussions? After the photograph did he get involved?

Neddermeyer:

Oh yes, yes. It was just, for a long time it was the funny picture or whatever we called it. But then of course other cases came along that really sewed it up.

Weiner:

Did you participate in the taking of the plates?

Neddermeyer:

Yes. I was involved in running the apparatus, yes. The design and construction of that apparatus was a real stroke of genius by Anderson. Well, he made a few minor mistakes, but basically it was a very, very fine piece of apparatus, and the remarkable thing is that he was able to do it in such a short time. In one year he he got this thing built and working. Of course, you did have the help of an excellent shop, a new shop that was built for the 200 inch telescope was the shop that built that apparatus. Otherwise it probably couldn't have been done. But even with all those facilities, it was a remarkable thing to get it done so fast, and have it go.

Weiner:

This picture was August. The paper?

Neddermeyer:

Oh, the letter was in September, in SCIENCE in September, and then the main paper in the PHYS REV was the following April. Now, that later paper wasn't sent in I guess until – gee, now, I can't remember, whether that was published after the first paper of Blackett or not.

Weiner:

I think I may have a reference.

Neddermeyer:

I sort of thing it was, but — this really gets to be embarrassing. This is a bad way to write history.

Weiner:

No, it's a line of evidence here. Let me — here, yes, I have it in my note here, SCIENCE publication in September, '32, and I didn't talk about the later developments so I can't give that, but the point is, the thing that this leads me to is that in this period, from August and September of '32 to whenever it was in the, early '33, had either of you been in contact with other people like Blackett and Occhialini? Letters or anything like that?

Neddermeyer:

No.

Weiner:

Was there any response to the publication that you recall, from outside people? After all the first letter didn't include any photographs.

Neddermeyer:

Right. No, well — I heard long afterwards that it was read very seriously. For example, Rufus Prince of Hofstetter told me that the group at Princeton read that paper and reported on it in a seminar and took it very seriously, the SCIENCE paper, really thought about it. But you know, it's hard to appreciate how difficult it was to believe that result. Anderson himself was terribly worried about it. You know, he just couldn't believe it. He even talked about withdrawing the letter. But fortunately he didn't.

Weiner:

The follow-up work must have been rather intensive, in other words, to get better photographs.

Neddermeyer:

It wasn't as intensive as it should have been. I'm trying to remember now, the date of work on the gamma rays, for pair production by gamma rays. Of course, as soon as one recognized the Dirac interpretation, then this possibility of producing pairs with all thorium zeta prime gamma rays — I forget now — what the full designation of that substance is, but 2.6 gamma rays, you would expect to be able to create pairs. Well, so we decided to do that, and I set the thing up and got the experiment going, and it wasn't too long before we got some pairs. We had a rather — this took us way too long after the initial not discovery. I forget what the date was, but the work was not published until maybe 1934, I'm not sure, I don't remember it. It might have been '33 but I don't think so.

Weiner:

Why the delay? Was it other things that interfered?

Neddermeyer:

Oh, I don't know. I don't remember, you know, just —

Weiner:

You’re saying that in this period, after the publication of the letter, this period where there was some uncertainty, even to the point where Anderson had his doubts, and it was a period of not as intensive follow-up as one would expect — was it because there was no appreciation of the significance of this, of the discovery?

Neddermeyer:

No, I don’t think so. Of course, what we should have done was jump in right away, bang, and do this thorium C double time experiment. We didn't, and I can't remember how long that took to do that. Well, anyway, we did it and we got a distribution, not as many observations as we should have had, but we had some 20 or 25 cases, something like that, with a distribution that definitely cut off very close to 1.6 NEV (?) and… Then not long after that, Blackett published a much more extensive distribution.

Weiner:

What about the photographs? It seems that the Blackett and the Occhialini photographs were very good. Did this serve as a stimulus then to improve — ?

Neddermeyer:

Yeah, we went to counter-control after that. That took a fair amount of time out to do that. We got that going, got counter control rig going I think in the fall of 1934 or something.

Weiner:

Was there a consistent program of cosmic ray research that you and Anderson were involved in ? Was it quite clear that you’d carved out through a certain field and that you were consistently working your way to it?

Neddermeyer:

Well, we were continuing to work on the behavior of these particles. For instance, I picked up the problem of the scattering of the cosmic ray particles on electrons, that is electrons ejected from various targets, and I analyzed this scattering distribution, which was part of my thesis. We were also measuring the minimum losses of these particles on plates of various materials. I mean, that was going on all the time. In fact, that really was the main work that was going on in the interim between the discovery, between this picture and the time when we took time out to do the thorium C over prime gamma ray experiment. So we had — yes, really there were several things. And these are all kind of scrambled up, because, well, there's the question of the interpretation of these scattering distributions. There was the question of the interpretation of the Mundamoss (?) measurements, and of course the, pushing again still on the momentum distribution of the particles, and then then there was the question of the character of the particles, of the main bulk of the particles that were coming in. Now, you see, with the discovery of the positive electron, it suggested that, well, that the bulk of the particles coming in were electrons, electrons and positrons. This was the assumption, electrons and positrons. And the work on the scattering supported this if hypothesis, because the bulk of the particles, the, even the positive component, were all protons, — see, this is just terribly rambling. I guess I should have made notes. Tried to follow a well, of course, my rambling talk, I mean, it's like an old man rambling.

Weiner:

You’re trying to unravel something.

Neddermeyer:

Well, it's sort of like the events actually were, I mean, it was a helter-skelter crazy situation with all sorts of things going on that we didn't really understand, and there were some questions, should we do this or should we do that or what, you know. Well, of course in retrospect, it's easy to say that we should have done with the gamma rays, now. Well, it wasn't so clear then that that was the thing to do.

Weiner:

How were the decisions made?

Neddermeyer:

Anderson and I just talked about it, argued about it and decided.

Weiner:

It was your collegial kind of relationship.

Neddermeyer:

Yes. Right.

Weiner:

What kind of influence did it have on you that you had to select a thesis problem which could be done in a reasonable period of time? When did that decision force itself on you?

Neddermeyer:

Well, I don't know. I didn't get assigned a thesis problem. I just took one and worked on these things and wrote it up as a thesis, and my thesis was just a little thin thing, 20 pages, sort of sophomoric , that kind of effort — obtained the distribution of the scattered e1ecnrons and the interpretation in terms of the data. The scattering formulas, and the measurement of the momentum losses of these particles. Now, the question — now, this was in 1934 perhaps, that Bethe and Heitler's first papers came out on the radiative losses of high energy electrons. Now, there was a difficulty from the very beginning, because if these particles, if the bulk of these particles were positive and negative electrons, then they should have lost momentum very, very rapidly. For example, in a lead plate, specially a material of high atomic number. They didn't. On the other hand, some of them did. And so I had a distribution which just included all the measurements that I could make, willy nilly, and all of them on lightly ionizing particles. And they showed a rather marked fluctuation. That is, the — at the lower edge, the energy loss seemed to increase with energy, but then as the energy went up, it seemed to just fluctuate around, it showed a marked leveling off. Now…

Weiner:

Let me ask a few questions about the dissertation. It was done in 1935. At least you got the PhD in 1935. So for the piece of work which you distilled out of the overall project that you were doing, can you put a time period on that, when you had identified that as the piece that you would do for your dissertation? How soon before 1935 did you start on that chunk?

Neddermeyer:

Well, I just took as a general problem the energy losses of certain high energy electrons, so that included the business of looking at the scattered electrons that came out of these various absorbers, and also measuring the direct momentum losses by magnetic deflection.

Weiner:

When did you take that problem up, was it ‘34?

Neddermeyer:

It was finished in December, '34. That’s when I took my exam. So I had been working on that from — well, actually that started shortly after the positive electron discovery in '32. Well, it strung along —

Weiner:

— yes, I know, all through '33 —

Neddermeyer:

In fact, in the autumn of '34 there was this international conference in London, at which the first of these measurements were published, and then I just continued with them and took that as my thesis problem. So there were two aspects of the thesis problem. One was the scattering of the electrons, and the other was the close collisions of the particles with electrons; the other was just the overall measurement of the momentum losses by direct curvature measurements on particles before and after traversing the absorber.

Weiner:

The conference was October, ‘34, and Millikan presented the —

Neddermeyer:

— Millikan presented the paper. I remember the summer of '34, yes, the summer of '34, when Anderson and I were sitting at one of the big tables in the freshman laboratory working on that paper. We got a first draft done and sent it over to Millikan. He criticized it, so we rewrote it. Then he said, well, he didn't really intend such a massive revision. But at that time I remember — well, in that paper already there is the suggestion of the possibility that there may be some new particles involved, that was in the fall of 1934. And that appeared on the basis of the scattered electrons. You see, one could argue that if the incoming particles were photonic mass, and if you measured their momenta, then you could place an upper limit place a maximum value on the energy on the maximum value on the energy or momentum of the scattered electron, and we had many particles of too high energy to be accounted for by the assumption that the incoming particle was a proton. On the other hand, there were already some — so we could make a fairly good argument about that, that the particles could not be protons, but the question is, what were they? If they were electrons, they were —

Weiner:

This was in the '34 paper? OK. I have in mind in a few minutes — just to get some dates established anyway, that will help me with my homework a little bit. Forgetting the details of the problem now and the date of its origin, but you're saying that this is a problem that you finally presented as your dissertation, and in December of '34, and you said you had an oral. I'm curious about the oral, what kind of procedure that was, who was involved in it?

Neddermeyer:

Oh, well, there were — the details of the procedure were somewhat varied. There was a committee. Millikan appointed a committee consisting of Tolman, Betman, Anderson, and himself, and Hofstra, that was it, and Anderson. Tolman Betman, Bowen, Hofstra , Anderson, and Millikan, six — oh, there were seven.

Weiner:

Zickie?

Neddermeyer:

No. Epstein. It was customary for Epstein to give a list of topics that he might ask questions on, Betman the same, so I handled Epstein's all right, Betman’s, I managed Betman's. But otherwise I did all right. My record wasn’t very good. I think the committee expected me to flunk, I found out afterwards. They gave me intermediate honors, gave me a magnum, so I passed it. But I was anything but a brilliant student.

Weiner:

Then you stayed. On what basis did you stay?

Neddermeyer:

Post-doc.

Weiner:

From what source of funds?

Neddermeyer:

Carnegie funds.

Weiner:

So this was the grant for Millikan's cosmic ray research.

Neddermeyer:

Yes, right.

Weiner:

That sort of — Robley Evans for example did some of his work on it while he was there.

Neddermeyer:

Perhaps.

Weiner:

Even though his papers are on different subjects, they credited it to that. And how long did that fellowship last? You were there until the war.

Neddermeyer:

I was there until February, ‘41. The question of my promotion had come up. I was in competition with Fowler. Of course, Fowler got it because Fowler was just, you know, way ahead of me. He's a bright guy. So properly Fowler got —

Weiner:

— in a completely different field of work.

Neddermeyer:

Oh yes, but I mean, no, it's one of those decisions. However, I could have gone back there after the war, but I decided in fact, Oppenheimer was being considered for the presidency of Cal Tech. He finally turned it down. He approached me, in case he got that job, he wanted me to go to Tech. Well, then later I had another chance, but I decided that I should stand on my own feet more, and finally decided to come here.

Weiner:

Your status at Cal Tech after the PHD, at first you were this Carnegie fellow, then —

Neddermeyer:

No, there was no particular title. I don't know, I guess it was research fellow or something, I forget.

Weiner:

I think you were a research associate probably.

Neddermeyer:

Research associate. I don't know what the title was.

Weiner:

It was a research position. Did you have teaching responsibilities?

Neddermeyer:

Yes, I taught some undergraduate sections. But well, the students were displeased with me and complained, so —

Weiner:

Why?

Neddermeyer:

Because I didn't stick close enough to the material, you know, that they had to pass examinations on. So they complained and I got ditched from that, to research, so — I'm a failure as a teacher.

Weiner:

Do you enjoy it? Enjoy the process of teaching?

Neddermeyer:

I can enjoy it, but I don't very often. Sometimes I connect with the students and have an enjoyable experience. You know, I’m not a very orderly guy, and what they like is a nice organized package that they can gobble.

Weiner:

Depends. Some students are turned off by that too.

Neddermeyer:

No, I'm just not a brilliant teacher, that's all. No hard feelings about that. I mean, teaching is just not my bag of fish, that's all.

Weiner:

I think I'll just take a minute now, as you have to go, to outline the kinds of things it might be good to think about. If we do manage to get back to thin – that is, to unravel a little bit the sequence of events in the research that led from the positron through your dissertation to the meson work, in the context of the overall cosmic ray problems. This is something that we’re going to do and I can bone up on it a little bit. I’m really totally unprepared on that. And to take it in terms of also the whole overall unprepared at Cal Tech in the thirties that was developed. I’m very curious about the relationship of your work to work going on elsewhere there in the physics division –- some of the nuclear physics work that was developing, any contact with Oppenheimer, the kinds of colloquia and so forth. That’s sort of a general matrix of this specific cosmic research that we want to discuss. So, that’s to think doubt?

Neddermeyer:

Ok. When do you want to come in again?