Otto Stuhlman

Kuhn:

Professor Stuhlman, what was physics education, graduate education particularly, like at Princeton in the years you were there.

Stuhlman:

I’ll show you a photograph. Can you identify them? Stuhlman, Charlie Heebs, K. T. Compton, and this man I think would be Crandall; and there’s a little red-headed fellow back there. I don’t know what happened to him, he disappeared. These were the fellows at Palmer lab in 1911. Those are just incidental snapshots. Now this is a graduate school group. There’s Dean West, and Karl Compton, now Arthur hadn’t arrived yet. You see, he came the next year. And most of these are chemists and biologists and what have you. They’re the graduate school members. All the graduate students in the entire school…

Let’s get back to Jeans.

Kuhn:

You were telling me that he was lecturing on electricity and magnetism.

Stuhlman:

Yes, lecturing, and he was very boring. And I told you what happened — he said if you don’t care about it, if you don’t like these lectures, please get up gentlemen, and go out. So they went out. And he was very much astonished. It couldn’t have happened, you know, in an English school.

Kuhn:

That included Karl Compton and Davisson and yourself?

Stuhlman:

Yes. And a couple of chemists, physical chemists, who came in. Then there was O. W. Richardson. I think one of the most characteristic of the stories that pertain to him is that he always came around around two o’clock in the morning to see if we were working. And when Karl Compton and I did that double headed paper on the value of h and checking the value of h to prove that our interpretation was correct and everybody else was wrong, he came around about two o’clock in the morning and said, “Why haven’t you solved the problem?” And so he suggested that the value of h was so high simply because of the greasy films and the dirt in the apparatus. We cleaned it up and found out that h came to its proper value. And that was done during the vacation period between Karl Compton and myself and Richardson, during the vacation period. And my wife — we were just married then — took all the data, as fast as the three of us could call it out. We had solved the problem. One of the interesting things about O. W. Richardson was that he could do mathematical research at the blackboard. That was a remarkable thing. We always marveled at it. And when he wrote his book on electron theory, he took our notes. He took mostly Karl Compton’s notes. He kept no notes at all. He just went up to the blackboard and just began working. And we just sat there and watched what was coming out the other end of the horn. And it was perfectly astonishing. He was small, shriveled, pipe-sucking. He would suck his pipe. He didn’t smoke his pipe, and it would go in every once in a while — you could hear it go “sip.” Small middleclass Englishman. His wife was a large blonde, about a head taller than he was.

Let’s see, who else was there. Oh, McGee was head of the department, Billy McGee. Now he worked in thermodynamics and heat, and Arthur Compton worked with him for his doctor’s decree. Then there was Trowbridge. Trowbridge was an experimentalist also. McGee was an experimentalist. Trowbridge was an experimenter in optics. I don’t know whether you recall, they repeated the Michelson-Morley experiment?... They didn’t get anywhere with it either. But he was an experimentalist. And then there was Loomis, who was the undergraduate teacher and had nothing to do with any of the research problems. There was a man — Cook, Cook was brought over with Richardson from England — imported. And they were the fair-haired boys. And Richardson was the only one that had fair hair because he had very little hair in the first place to start with. Now Cook was an experimentalist also, but he didn’t do so very well. But he stayed there. He was doing fairly well the last time I saw him. So you see it was a very small group.

K. T. Compton was assistant in the laboratory. I had the class of 1860 experimental science fellowship. Charlie Davisson — I don’t know what he had — he had $500 from some source. I don’t know. Some scholarship or something… He married one of Richardson’s sisters. And he had another sister. When I arrived they imported her, and we had to take the other sister to the various dances and parties. But it did not materialize. The English method of propagation of species! That’s about what it amounted to. The laboratory was the same Palmer laboratory as present, the front of it. The statues weren’t up at that time. Theoretical physics was taught — Jeans’ Mechanics, Jeans’ Electricity and Magnetism, which I fell in love with and I started teaching it myself, but the book became unwieldy, pretty near a folio.

Merzbacher:

Why was the English influence so strong and the German apparently not existent at Princeton?

Stuhlman:

The English influence was brought on by Dean West. He was the dean of the graduate school. And he also controlled the money with which the graduate school was being built up. Remember that controversy between Wilson and West as to where the graduate school should be built? West wanted it off the campus; Wilson wanted it on the campus so that the undergraduates could mix with the graduate students. And West suggested that if he could get the money he could build the school where he wanted it. So he got the money by hook or by crook from a Boston friend who had a couple of million dollars in real estate. He sold that and bought a couple of farms down at Palmer Lake — I think that’s Palmer Lake. Palmer Pond or something like that. And then since he had the money, we were the experiments with which he experimented. So he put us in a small dormitory which was a private residence, and we experimented how to run a graduate school, cost of room, cost of board. We had a house committee, we had a Master of the house. Now there you see comes in the English influence. The Master of the house was an archaeologist, an art and archaeology man. West’s idea was not a specialist’s knowledge of physics but a good ground education plus physics. So we didn’t specialize in mathematical physics. Neither did we specialize in experimental physics. We were all experimentalists plus what we could get as theoretical or mathematical physicists.

Kuhn:

You speak of using the two Jeans books. Were these just books you happened to use or were they used by the whole group?

Stuhlman:

They were used by the whole group... We had Jeans’ Mechanics, Jeans’ Electricity and Magnetism. We had Lamb’s Hydrodynamics. We had German optics, Drude’s Optics. And the rest of it — they just let us do what we wanted to do. That is, we could go to lectures if we wanted to, or we could stay away if we wanted to. The English system. If we didn’t care about the lectures, we just didn’t go.

Kuhn:

Now how much mathematics were you expected to know?

Stuhlman:

Let’s see. My requirements were through the Master’s degree. I had my Master’s degree at Illinois, and there we had a requirement to take mathematical physics. They called it mathematical physics, not theoretical physics. And there, there were lectures on electricity and magnetism, on acoustics and what have you. That went through calculus, differential equations, partial differential equations, spherical harmonics, and I had elliptic harmonics. Well, I had some of that before I became a candidate at Illinois for my Master’s degree.

Kuhn:

Would that mean that you probably had more mathematics than —?

Stuhlman:

I had a little more, yes, but the other fellows were smarter than I was. Karl Compton was a smart man, as a smart man can be. And Davisson was a smart man. The rest of us were just not quite so smart. And the mathematical physics was just not theoretical physics — mathematical physics. Jeans assumed — his book assumes — you know differential equations. And of course his elementary book in mechanics, that’s probably called senior work now, or junior work. We had it as graduate work. Now that’s about the set-up.

Kuhn:

Do you suppose, just in formal terms, what — three years of mathematics is the most the other people would have had? Or more than that?

Stuhlman:

I think we were all about the same. I repeated differential equations with Birkhoff. And the others took differential equations with Birkhoff, while I repeated it. Now that gives you some idea. I was just, you might say, one course ahead of the group. But they caught up with ne in the second year I was there. They had had the differential equations by that time. And that was their first year in the graduate school — differential equations. I had had it simply because I wanted to be a mathematical physicist and couldn’t. I was more interested in experimental physics. That’s the reason I have always been in experimental physics.

Kuhn:

My impression is that in this period if you wanted to be a mathematical physicist, you must have been one of the very few people in this country who did pick that.

Stuhlman:

That’s correct. That is correct. One of the few…

Kuhn:

How did people feel if you said you wanted to be a mathematical or a theoretical physicist?

Stuhlman:

Well, they want me to be a mathematician. For instance, I took spherical harmonies with Harris Hancock. He said, “You want to be a mathematician, not a physicist.” I said, “No, I’m going to go into experiment.” He said, “You’re making a big mistake. You ought to be an applied mathematician or engineering physics.” Now Louis (Brange), who was a classmate of mine at Cincinnati, in order to teach mathematics and theoretical physics, he became a major in engineering mathematics. You see, that’s where we got some of our mathematicians. They had structure of material, which they didn’t give in the physics department. They had hydrodynamics, which you didn’t get in the physics department…

Merzbacher:

With whom would you have worked if you had become a mathematical physicist?

Stuhlman:

I worked with Jeans. And that’s what I didn’t like… But he left in the summer when I came there. So I never really had any work with him at all.

Kuhn:

Now there was nobody else really in that department who was doing that sort…?

Stuhlman:

Nobody — yes, E. P. Adams. E. P. Adams was professor of mathematical physics, I just happened to think. I hadn’t thought of that for years. And we took our mathematical physics from E. P. Adams. He taught Jeans’ mechanics, Jeans’ lectures in magnetism. You see we had that. That was kind of a follow-through. He sat on my doctors’ oral examination. He examined me on mechanics, classical electro-magnetism, and theory of functions — I think. I’m pretty sure, theory of functions. Well, that’s about the line of work. E. P. Adams and Jeans must have been there simultaneously. Now if you know Richardson, well he was just as good a mathematical physicist as he was an experimentalist. He was there primarily as an experimentalist.

Merzbacher:

Was anyone else there who did work with Adams in mathematical physics?

Stuhlman:

No, nobody majored in mathematical physics. They were all experimentalists.

Kuhn:

Was Adams himself doing any research to speak of at this time?

Stuhlman:

I never was impressed by him, I mean whatever he did, it just didn’t register with me at all. Even now, looking back, it just doesn’t register with me. The same as with McGee. He was just typical, a generation ahead of us, a typical experimentalist. Heat and thermodynamics. I think that sort of gives you a picture of the situation.

Kuhn:

How conscious were people, when you were in graduate school, of the revolution that was brewing in physics?

Stuhlman:

Yes, we acknowledged and accepted it. We accepted it.

Merzbacher:

When you spoke of the experiment to determine h, did you mean Planck’s constant?

Stuhlman:

Yes, by the photo-electric effect. We published a long paper, about 20 pages, to prove that it was a measurable quantity, and we determined the precision of our measurement. Because you know everybody was getting all kinds of values for hand disproving it and proving it. The Physical Review was just full of that sort of stuff until we sat on it. And then that clinched it.

We were not consciously conscious of quantum mechanics. I don’t think I was except through Millikan’s experiment of e/m, and the thermionic experiments which were going on with Richardson, and the photo-electric experiments I was doing with Richardson. We had no explanation for them. You know, this doesn’t appear in the literature, but you remember Richardson published a paper on the specific heat of electrons?... Well, that gives you some clue as to how we looked at the problem.

Kuhn:

Ja, that one was bothering quite a number of people all over the world at this point, I think.

Stuhlman:

I think the German school was doing exactly what we were doing. Max Planck. What was Max Planck doing about that time?

Kuhn:

Well about this time he was developing the second version of the quantum theory. Did people —?

Stuhlman:

And it didn’t make any impression on us.

Kuhn:

Were you still at Princeton when the Bohr atom —?

Stuhlman:

Yes.

Kuhn:

— came out? How’d people feel about that?

Stuhlman:

Oh, we accepted it. We accepted the Bohr atom.

Kuhn:

Didn’t it bother you?

Stuhlman:

We accepted it as one of the outstanding new contributions of physics.

Kuhn:

Did it bother you what happened to classical mechanics and electrodynamics?

Stuhlman:

It just kind of disappeared! The last time I taught Jeans’ lectures in magnetism was in 1914 or ‘15 when I was at the University of Pennsylvania. And I was a junior instructor in the department and I came in with Jeans’ lectures in magnetism. That’s the level. It was a very poor department. You know, teaching engineering school, you know. Nobody did anything at all, I developed the thin film idea right there.

You might be interested in this reaction. It might come in handy sometime. At the University of Pennsylvania — a typical case. I wanted an ultraviolet, monochromatic illuminator. (Goodspeed) said all right, order one. So we got $1200 together and I ordered one. And when I returned in September, there was a small box on my office desk. I opened it up, and there was a high school student’s spectrometer in there — a high school student’s. You know, the kind that’s about this big. I took it down to (Goodspeed) and said, “Look here, there’s some mistake about this thing, some express has balled things up.” He said, “Well that’s funny, let’s look up the order.” It said a spectrograph. So he called the purchasing agent. The purchasing agent said, “Oh, you didn’t know what you wanted. I saved you $1800 by buying that nice piece of apparatus!” That was the level of technicians and purchasing agents. So you see the sort of fight we had on our hands. Now you spend that much money overnight every minute…

Merzbacher:

How about the Compton effect? You asked about that yesterday. What sort of impression did that make?

Stuhlman:

It just didn’t make any — a billiard ball impression, that’s all it was, a billiard ball bouncing around.

Kuhn:

Wasn’t this a little hard to take for somebody who was teaching Jeans’ electricity and magnetism?

Stuhlman:

Well, you remember I had Richardson’s electron theory. And it wasn’t in book form yet — from the raw notes. So my training in that phase of the work was what Richardson used to put on the blackboard with Compton getting the same thine – K. T. — and Davisson getting the same thing. Now Davisson was smart, he was a boy that had used this stuff. He was very much smarter.

Karl Compton’s great contribution to physics was his administration ability. He didn’t ask me personally, but I advised him personally not to take the job at M.I.T. I said we’re going to lose a physicist who’s on the verge of being a Nobel laureate. And he said, no, he said he thought he could do better there. Well, I guess he could, tripling his salary from $6,000 to double that or triple that. But he became an administrator, which is one of the fallacies of the present age. All good physicists are good administrators.

Kuhn:

As you say, you must have been one of the very few people who even wanted to do mathematical physics. Perhaps one of the few who recognized this as a possible field of work. Where did that begin to happen? When did it begin to happen? What is it that caused that transformation?

Stuhlman:

It happened as a junior at the University of Cincinnati where I majored in mathematics. There was Harris Hancock. Now I don’t know whether you know Harris Hancock’s work or not — on elliptic harmonics. He was working on that. We had a small class in the junior year in which we had differential equations, method of least squares, theory of functions, spherical harmonics. And from there Hancock said, “Well, you’ll make a mathematician.” I said, “No, I’m interested in physics.”

Kuhn:

Well now what took you back to physics?

Stuhlman:

The experimental end of it… I’m an experimentalist from the word go. I even do a little watercolor painting as experiments. I’m an experimentalist. I just can’t think enough mathematical physics to make it worthwhile. I majored in mathematics because I liked the manipulation, the pencil-pushing.

Kuhn:

Now having watched the development of the profession in this country since the time that you took your own degree, at what point do people stop thinking of physics as so largely experimental a subject?

Stuhlman:

Around 1912, ‘13, to my recollection. I think maybe the Physical Review would give you the clue to it — the papers published in a certain number of years, say from ‘10 to ’14.

I'll tell you the man I thought was quite a prominent theoretical man, was our friend from the Bartol Foundation, Chuck Swan. I knew him very well, and I always admired his skill at the blackboard with his crayon — giving papers to the American Physical Society. I always admired that sort of skill. But I never could achieve this skill, and I was envious of that situation. So I went into experimental physics. I was originally, for a master’s degree, in architectural acoustics, which was an experimental field. At the University of Illinois where I was we had captured the biggest echo in reverberation in the world, right underneath that dome. It was made for the purpose. Terrific auditorium. Seat two thousand people. This reverberation from these mirrors on each side and in back. You could drop a pin on certain places on the stage, you could hear it way up here in the audience by just pure reflection… My master’s thesis was on architectural acoustics. Saunders got started in it and he blew it wide open. Well and he was interested also in another phase of it, which was a musical phase. And so was D. C. Miller.

Kuhn:

When you say you think the breakover came and the date is one we can determine sometime in the early part of the second decade of the century, what do you think was responsible for it?

Stuhlman:

The German school was responsible, to me I mean, personally. The German school.

Then of course the Bartol imported Swan. And I remember very distinctly he’d be the only theoretical paper in the whole physical society meeting. But that’s classical.

Well so far as I know Max Planck was an experimentalist.

Kuhn:

No.

Stuhlman:

I was at Berlin, and the first thing he asked me was about experimental physics.

Kuhn:

It interests me that he should have. What sort of question did he ask you about?

Stuhlman:

What I was doing, and what we were doing at the University of Penn, where I was at the time… They were working on optics there, I saw the equipment.

Kuhn:

But I think not Planck.

Stuhlman:

Now I had the impression that he was. It may not, it may be somebody else in the department. He took me all through it, and I spent a whole afternoon… I was over there one summer… Somewhere around ‘35 or something like that.

Kuhn:

Reiche took his degree in 1907 and spent the next two years in Breslau, in part trying to do some experimental work, of which he’d had none as a student of Planck’s in Berlin.

Stuhlman:

Now that’s a new one on me. I always had the impression that he was an experimentalist who just did theoretical physics on the side.