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Oral History Transcript — Dr. Arthur von Hippel

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Interview with Dr. Arthur von Hippel
By S. T. Keith
At MIT, Cambridge, Massachusetts
October 6, 1981

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Arthur von Hippel; October 6, 1981

ABSTRACT: Topics discussed include: family background; von Hippel's time at Gottingen and lectures by Max Born and James Franck; his fellowship at Berkeley; Leonard Loeb; work on his dissertation on charge phenomena in gases and discharge phenomena in solds and liquids; Richard Pohl; Edward Teller; Niels Bohr; Karl Compton; Herbert Frolich and the development of dielectric data for radar; Frederick Seitz; Massachusetts Institute of Technology; John Slater; R. J. Seeger; solid state physics.

Transcript

Keith:

You were born in Germany. Have you got any particular memories of your childhood that stick out, maybe that contributed to your future career?

von Hippel:

In my family, the tradition was, in one section, to go to the army mainly, and in the other one, to go to professors of universities. Now, there had never been a scientist in this second group, but medical people, and my father was professor of law, my two uncles became professors of law, so in my case, it was really a breaking away from family tradition, and going into science. You know, our generation has been especially — saw difficult times, because we came from World War One, there was still several years during the war, then, suddenly, revolution came, we went again, twice, to defend whatever was left of Germany in these revolutions, but simultaneously there was enormous joy of living there. We had survived somehow, and it was — artistry was lovely in Munich. I really made up my mind to become a scientist. Now, since I was the son of a professor in Gottingen, Davis lived very near to our house, and we got to university, walking to school along this road. I knew him very well, his eccentricity was one of the things, so, I remember, the other scientists, I remember seeing a number of the other scientists. This was practically one of the outgrowths of greater — a question, how far you could fit into this. Now, I mentioned in this memorandum that the famous who served up here, I think it was 1921 or so, gave me an inkling of the real genius in theoretical physics. I decided that I ought to become an applied scientist. As I mentioned here, I took a project which was at that time important, in which my performance could be useful. I worked for broadcasting. Public broadcasting was right at the beginning. I myself was somewhat involved in the early stages of electronic tubes, because I had been in the army for a while, the officer in charge of the communications system of the division; because this was the form of control, so I had seen the early electronic systems at the beginning, like many of the plans of our detection devices, directing the French [???]. So I knew a little bit about this, but [???]. Coming out of the war, having a tremendous joy of living, and I was a member of the youth movement, which at that time in the early days, was wonderful. We tried to create a new type of person, different from the Victorian.

Keith:

Yes. What kind of person did they try to create? What kind of image did they have?

von Hippel:

Well, the youth movement which went on — it’s a meeting — purity of light (?), new understanding, trying to bridge between social classes which were very strong in the Victorian age, and unfortunately, the youth movement during the war lost about half its membership. But I found it, and others, a student group in Gottingen which continued this, and used the church tower, the church, for this purpose Blucher (?). But then, these kinds of studies were interrupted by revolutions. We had to leave for a few weeks to try to do something about it. I was twice in some of these fights, but it was not anything that ended up changing the development of history.

Keith:

Are there lectures that stand out from your Gottingen days? You went to Paul's lectures while you were there, did you?

von Hippel:

The lectures of Max Born, of James Frank, of Robert [???] in physics were really decisive. Besides, there was a wonderful philosopher, Professor Nowel (?) who was very influential, lecturing to young people, before and after World War I. Pater (?) also carried on his work until it was suspended by the Nazis, and was very decisive in creating a large group of people who did social work very effectively in Germany, quite free from Nazi ideology. So, in a way, I was lucky to have so many human contacts. Then, to make it not too long for you, I decided at last that it was high time to get my doctor's degree, and I left and got my degree fast and became an assistant of Max Wien in Jenna. He was the inventor of the [???] which was, at that time, a detour allowing you somehow to get the energy from an oscillator into an antenna with that it came back without that it came back. His [???] cut off the primary circuit, and the energy made the first contact and transmission contact. Besides he was a great gentleman who was later working on conduction of very high fields in liquids. This is called the two Wein effects. But when you come to such a situation, at last I was quite cocky at that time and wanted my own research, to work on [???] spectrograms, I mean, what really was going on in the process of the [???] spectrum. Of course it has since been used for many purposes. And then simultaneously I worked on [???] research, introduction by a year in Berkeley as a Rockefeller fellow.

Keith:

That was in 1927.

von Hippel:

That was in '27, in Berkeley.

Keith:

Why did you go to the United States? At that time?

von Hippel:

They offered me a fellowship. I was always interested in coming to other countries. I had gone to Sweden and Italy, up through the Alps to Italy, etc. So I mean, every year I had the feeling I should try to enlarge one's knowledge of surroundings, and so, Berkeley was the farthest away, I took Berkeley.

Keith:

Were you in the electrical engineering department at Berkeley or physics?

von Hippel:

Physics.

Keith:

Who was in charge of physics at Berkeley at that time?

von Hippel:

There was no great name at the moment. Leonard Loeb was there, and some others, but the real great genius was in the chemistry department. That was Herbert Lewis. The chemist. So one was quite on one's own. On the other hand, I found many friendships there. I got to know Oppenheimer at that time. He was teaching in Berkeley. I had contact with him.

Keith:

What kinds of problems were you working on at Berkeley?

von Hippel:

Much too difficult problems. To cross an electron beam with an ion beam, measure the ionization from [???] atoms. It succeeded at the last moment before I had to leave for Germany. But it was a year's research — too hard — because Berkeley at that time was completely cut off from any industrial supply centers, as one would have on the East Coast.

Keith:

It was — was it in Berkeley where you first met James Frank?

von Hippel:

No, no. James Frank I knew from his lectures in Gottingen.

Keith:

But was this the first time you got to know him on a personal basis? I met his wife through bicycling?

von Hippel:

No, because I went with his wife bicycling, and saw his little dog also. So, no, I knew him somewhat, but we became really very close friends when I knew him in Berkeley.

Keith:

Did you discuss problems in physics with him?

von Hippel:

Well, we talked physics, certainly, problems were discussed. We had a lot of fun climbing together on Mt. Hamilton, Mt. Wilson and so on. No, it was really one of those wonderful friendships where you could really talk on an equal basis, there was no false about it, spontaneous he had a very, very great intellect, wonderful.

Keith:

Would you say he was an influence on your own physics?

von Hippel:

Certainly a man like that has always an influence on your own physics. Any real great personality has, in that sense. But, I had the feeling that really physics at that time was my dish, until I later came to Gottingen and —

Keith:

— yes — when was that then? Why did you not think physics at that time, of that kind —?

von Hippel:

(crosstalk) ... My wife died. I waited for her very long. She was very much on my mind. She was, her very good friend was a daughter of [???] Swan, and child [???] — there was no necessary — and this sort of, if somebody got really very difficult, you can't expect of a child — in particular, she was... (This is virtually inaudible here —) Well, I went to [???] after this, came to the [???] Institute.

Keith:

What particular problems were you working on? Was that the period when you became interested in breakdown, in gases, liquids and solids?

von Hippel:

That's right. That was one of the main issues. It was not in liquids and solids only, but also in gases... thunderstorm...

Keith:

Yes ... yes... (crosstalk) Did it start from gases? Was that the first thing you became interested in, in that area?

von Hippel:

No, I don't think actually, when you begin to think about it, the applications of this work are so important for our understanding.

Keith:

Yes. The gases were the easiest ones?

von Hippel:

At that time, I thought just a negative spark — nobody had seen them before — I could make them into a lamp, by special technique. I was very amused when I met Einstein, about 20 years later, and they passed this out, and they got this spark — he was very interested in it. So I did my dissertation on charge phenomena in gases, and did research on discharge phenomena in solids and liquids, and condensed...So this whole field became one of my great fields of interest.

Keith:

What was the attraction of that area to you?

von Hippel:

Well, it was wonderfully unknown, and I was obsessed with understanding the interaction of the electrons in with molecules, etc. It's one great entrance wedge into modern physics. From that standpoint, I have a series of figures in which, in addition to figures, in which there are many more so, and just as you are trying now to put together a book of all these unpublished things. Keith — yes —

von Hippel:

There are some, they are really quite beautiful.

Keith:

They're very attractive. Do you think this was sort of a combination of your professional interest in science, and obviously what was a previous interest in art?

von Hippel:

Perhaps, I see, this kind of thing, in order to become intrigued again…all these things, I have at least, right along, when you see this kind, of Corning (?) what is it now, mollusc or something like that, you see that science and art can mix, and then that makes the process especially interesting.

Keith:

So that's what attracted you to that area, probably.

von Hippel:

Partly, yes. But I mean, — anything that is really unknown challenges you. Because you somehow have the feeling, for heaven's sake, it should be possible to understand it.

Keith:

Yes. And how do you go about understanding it?

von Hippel:

Well, you try to make some decisive experiments, and then to analyze what you see. This has gone on now throughout my lifetime, more or less. When I make a — (or) here is the last lamp, which I made a molecular design into devices on the lamp. Of course it was a very hard struggle. New ideas, that my colleagues know several years, whereas I, new ideas are despised, maybe, because they shake old beliefs, until they are put over.

Keith:

I mean, I don't think it's just old beliefs. Its old institutions, particularly in an area where you're dealing with engineers, applied scientists, people who categorize themselves.

von Hippel:

Yes. You see, when I came for instance, in my teens, there was no physicist in the department, and In order to go out as an electrical engineer, it's the electrical engineering department. They are all somewhat scientifically oriented. So the empirical style, for instance, when you want to learn about the breakdown strength of gases, you make a hundred shots statistically instead of doing one shot so that you can see everything , in a…

Keith:

— yes— so, going back, what were the experiments you started doing in Gottingen, to look at the discharge phenomena?

von Hippel:

You see, I tried, for instance, to isolate the negative and the positive discharge. I took soapstone on the one side, as an electrode, and shot now from the point of electrode, a positive or negative discharge on the soapstone, and on the soapstone the so-called [???] figures developed, and then you could judge it must have been positive or negative. Now, certainly, they transfer this to photographic plates, and [???] like which this compare to the process today…practically from gases to liquids. Again, when you try to understand liquids, the solids give you no problem because there's order. So I think this all develops logically, one from the other, when you think about it, until you say, for heaven's sakes, the molecular designing of materials is the wisest — what are the molecular phenomena which we have to understand to design properties?

Keith:

Yes. So it was during this period in Gottingen that you thought out this concept of electric breakdown in a solid for the first time, was it, that that concept really was established?

von Hippel:

I think so. It really established the ideas, what electric breakdown was. Here, when I carne later to America, I found that the Bell Telephone Co. had my papers translated into English, so that they could make it available for their own interests.

Keith:

Yes. Were there any other people working in this area at that time?

von Hippel:

In England there was somebody. I've forgotten his name. It's mentioned, discussed in my paper on [???]. But I've forgotten his name. See, in the course of this kind of running round, in science, from gases to liquids and solids, from insulators to semiconductors in metals, that's been in a way unusual. People stuck to one or the other field. But when you are determined to find these things and you've got to understand the state of [???] and how they affect you will go then later in the direction of breakdown in crystals and what they show you, the injection of electrons into crystals. [???] centers and all this kind of thing.

Keith:

You were very much in contact with the work that was going on in Pohl's group?

von Hippel:

Pohl, yes. You see Pohl was an empiricist. He was an excellent experimenter. But he had no inner urge to — maybe so much — to understand our field. But he was a wonderful lecturer. But, see, Frank was quite different. Frank was a thinker, who was not an excellent experimenter, but he was a thinker about what would go on now in, up to living systems.

Keith:

Pohl still was very, I mean, one would call him very much a solid state physicist. He was interested in the solids.

von Hippel:

He was an experimenter, on these things. Frank very much talked with him also, but Frank was much more a thinker than Pohl. Pohl was much more the experimenter. His lectures were always spectacular.

Keith:

His demonstrations were renowned.

von Hippel:

They were, in Pohl's circles at that time.

Keith:

Were there any other people at Gottingen at that time that you had close contact with? Max Born.

von Hippel:

I knew Max Born, yes. He had a brilliant group of theoretical physicists around him. At that time, Heisenberg was coming into — Pauli was there —

Keith:

Was Edward Teller there?

von Hippel:

Teller — Teller was not with Born. Teller was there at the time with Altman? Teller was there at that time, yes. Altman, a very good man, in many ways [???] and his successor, Telam (?) He was one of the great figures in physical chemistry. He was the successor of Nash in England? I knew [???] boy [???] and Nash was in Gottingen, when [???] invented the lamp — and so, was the first professor who became a millionaire, in chemistry. Half a year later, the incandescent lamp was invented, and his invention was practically useless or used only for specific purposes. But Nash was a wonderful character. Went hunting with my father, and they had the first automobile — my father was standing in it and blowing the trumpets of victory, "out of the way,” [???] was steering this thing…

Keith:

That period you spent in Gottingen was really the last of the golden years of Gottingen. Did you have that feeling then? That you were really in at the end of something very special?

von Hippel:

It was something very special. The contact between — I mean, when the Nazis came in, there was still the question, whether Professor Planck should come to Berlin and start a new institute there. I knew Haber also [???] and so on. This was a great period for science, in Gottingen and in Berlin.

Keith:

Yes. When you left Gottingen, you went to Istanbul?

von Hippel:

One thing I must mention, that was wonderful. [???] came to Gottingen. It was really very lovely to meet him. He climbed with me to [???] and was very interested.

Keith:

That was just a few years before he died. He was a very old man by then.

von Hippel:

Oh yes, but very alive, he was … (off tape)... gave a lecture at Gottingen... and Frank introduced him, and suddenly I saw that Frank had forgotten his name – he said, "This man whom we all know, etc.” "damn, what is your name?”

Keith:

Yes. I'm sure Rutherford got his own back —? [???] came back then when the Nazis took over, took up his position in England, but —

von Hippel:

I came back then when the Nazis took over, took up my position in England, but I was not very happy to begin with because I had my wife, that certainly made me a [???] for the Nazis, but simultaneously I had so many other things to do that they left me alone for a short while. Then you remember that James Frank was exempt, of course, first class. He refused to accept the exemption, and made a very dignified declaration which was published in Gottingen [???] (a newspaper?). The Nazis were furious. They took over the Gottingen (a newspaper?) under the title [???] So the situation became dangerous. I was called into both the college and the [???] (more German here) called in to the Nazi machinery and disappeared. So, [???] to join a group which [???] at the university there. This was one of those nice adventures, to take you out of adventurism. Really it was hard for my old colleagues, but it was an amazing kind of experience, to see a country, that was guarding itself? He was a very astonishing personality. He had been a general, as you know, a general in World War I. One of my uncles had had been a commander of the German army in that area. Of course it was a very difficult — for the general — because he had thought already that he was destined for great things, and he learned in a day or so that accidently (?) — I got as my [???] accidentally institute (?) a Palace of the Sultan (?) which was quite unnerving. There was nothing in it that you could use, besides a map of Paris. With a lovely lady standing there and some tours of stuffed animals. That was the kind of thing. So I had to build up something completely from scratch. It was very nice, in a way. My friends in Germany were furious that I had to leave. I got 18 boxes of instruments from [???] industry, donated to start the — but it didn't help a bit, because the Turks had no idea how to handle the entrance that had taken place. Swiss code of how to pay duties, they couldn't understand it. My instruments stayed in — on lighters in the harbor until I left there.

Keith:

They basically, you basically had no equipment to do experiments with.

von Hippel:

Well, I had one other machinist, and we would go into the Turkish bazaar in Istanbul, and ask for the [???] of Alexander the Great and somebody would say, "This is the [???] of Alexander the Great." You would find so many strange things there, but we did make equipment and try with one other machinist, Mr. Rober who came from [???] and we did things. So my laboratory was the first one which was ready to open.

Keith:

Yes. What particular areas were you hoping to develop in your laboratory?

von Hippel:

Well, I had two contracts. That was the difficulty. One day, I was professor of physics...that I knew well...then I was professor of electrical technique which I didn't know so very well. But I knew something. You know, as soon as you are successful, you find some people want to take over. This ended my Turkish adventure, in the sense that I did this research, and I, in one of my lectures here I was talking about the big generators, you need not study in detail because you need only one or two at the moment, to justify the [???] product of your country. That seemed to be a reasonable statement, but my assistant translated it, "The professor says it's foolish to understand it,” and “it is much better to buy these instruments and these machines." You can imagine what happens when such a situation arises in a country that [???] Stumlitz (?) looked at me as if he wanted to cut my throat. I was very astonished because I didn't speak enough Turkish to understand properly what had happened. So the [???] was shut down, and the prime minister, everybody, came and the newspapers wrote that I had never been a physicist, but had (?) clothes. And so I departed. But I shouldn't bother you with all these details.

Keith:

Did you actually manage to do any research while you were there?

von Hippel:

I had the [???]. I wanted to use it but I never had a chance to use it there.

Keith:

So when things became difficult for you in Istanbul, you moved elsewhere. You went to Copenhagen.

von Hippel:

Niels Bohr was one of, he had invited me for a lecture in Copenhagen, so I went to Copenhagen. They liked what I had to say, and I was — and so they offered me a job in Copenhagen, so I went there, giving up my [???].

Keith:

You — Who was there, apart from Bohr, at Copenhagen during that particular year?

von Hippel:

I was there for one and a half years. At that time I developed and furthered my ideas about breakdown in [???]. There are some papers from that period.

Keith:

Yes. Who else was in Copenhagen at that time? That you came into contact with?

von Hippel:

Who was not in Copenhagen? So many people had left. I think Teller came, Weisskopf came, a number of other people. James Frank was there. Everybody came through there in this period as long as the Nazis had not started the war, still one must realize, great development of German physics.

Keith:

It was a place where people would spend a few weeks, a few months.

von Hippel:

Well, simultaneously, Neils Bohr was not only a genius, but one of the first — his family we became close friends, and I'm still, I have contact with his family now. So it was on the human side also a very rich time. I was in my own world of developing this molecular designing, etc., of further understanding of materials, and I was quite alone. I was sitting in the basement of the [???]

Keith:

When did you first become interested in this idea of design of materials? Was it just gradually growing in your mind?

von Hippel:

It was developing all the time, because I saw this completely classical approach of electrodynamics to the behavior of matter — and that physics had not yet come around to it, to be interested in these phenomena from the standpoint of molecules and structure, because the development, you know went through the gases.

Keith:

— yes —

von Hippel:

Not to mention in the condensed stage, it was not very well understood, so that was the challenge. One of the great accesses to the understanding of the solid state, the liquid state, was through electrical phenomena. Obviously, from my standpoint obviously…

Keith:

Yes. So you came to the USAS at the invitation of Karl Compton.

von Hippel:

I came to [???] somewhat for that, certainly. He was a wonderful person, one of the great human beings I met in my life. He talked with me, and after we knew each other a little bit, gave me five fellows and told us to start a lab. So they put in less than, [???] got more than a million dollars back. And I was on my own.

Keith:

What starting point did you wish to make in the laboratory that you set up here? What did you see as the important problems to solve, to be able to carry forward this ambition you had?

von Hippel:

Well, certainly high field stress phenomena. This came from my interest in some of the situations I just studied it and simultaneously I saw, not only going up to very high fields and looking at not only gases but also liquids and solids— in solids, I had discovered the way which centers, the direction breakdown which was quite unknown when I started, and the [???], this kind of thing. On the other hand, high frequencies, which were also an unknown field — what happens at higher and higher frequencies? We developed some techniques which went to 10 centimeters and a continuum, there's a theory, to this great theory to — the theory of understanding of wave phenomena in solids, and the dielectric losses We had developed an instrument which went to 10 centimeters, the so-called MIT instrument which later was developed more and more, in a number of copies, and (inaudible) other laboratories. So we were more or less, when the war broke out, GE Labs, which had developed techniques to measure, where radar was so important, therefore we automatically were assigned the responsibility to go into this field, and the lab became very large, had about 50 people at last, trying to develop the dielectric data for radar.

Keith:

Before that, you had started some research in England on dielectrics, particularly at Whiteshead, at the Research Association, and directly through their initiative, Herbert Froelich's work. How did Froelich's theory of dielectric breakdown differ from yours?

von Hippel:

Whose theory?

Keith:

Froelich.

von Hippel:

Froelich. Let's see, if I remember right, Froelich and I had not any special arguments about anything. He came from the theoretical side and I from the experimental side. We were quite good colleagues. He stayed in his part of theory. I stayed in my part of finding out what was going on and trying to make a picture which fitted it. So —

Keith:

Did you ever meet him in that period? Did you meet Froelich in that period?

von Hippel:

I don't remember when I met Froelich! But we met later several times, and he was a very nice man.

Keith:

Do you know when he first started work on dielectric research, solid state, he solved theoretical problems for them, and they gave him the nickname of "the Wizard." I always called him the Wizard after that, when he came to see us again. You know, Froelich became interested in dielectrics through Electrical Research Association in Britain, which was headed by White head. Whitehead rather earlier had become dielectrics, and they had a particular theoretical problem, and they asked Froelich's opinion, and he told them that they would get from their experiments something totally different from what they expected, and as a result of his prediction, they did the experiment, and they found this and they were so impressed with him as a theoretician that they called him the Wizard.

von Hippel:

I didn't know that. I didn't know that at all. He's a very good man, and we remained on very friendly terms. We worked quite independently. Our approach was to develop the theoretical ideas through our experiments, and he came from the theoretical end. I think we have — I don't know how far we have influenced each other. But I think, until, well, for one or two, whether we had met, I'm not sure...How is he, by the way?

Keith:

Very fit, for his age. Very fit.

von Hippel:

Is he? Oh, I'm terribly sorry.

Keith:

No, he's fit. You know, he's very healthy.

von Hippel:

Oh, I see, oh. I thought you said sick. That's wonderful.

Keith:

He has an office on the 6th floor of the building, and he insists on going down the stairs and he does this remarkably quickly.

von Hippel:

How old is he now?

Keith:

I would think, —

von Hippel:

I think he's quite a bit younger than I.

Keith:

Yes, probably about in his seventies, I would think. I would imagine about 75.

von Hippel:

I'm nearly 83 now. Very good.

Keith:

Are there any other people of that time, in your field? Would you say the two of you were mainly the two people who were most interested in dielectrics?

von Hippel:

Then Seitz came in from the sideline, from the theoretical end. We were left quite alone, until it really became fashionable. You know that's always the case, until some new insight, some new development of a field, first they are not interested, then they ignore it, and at last, when it becomes fashionable, then everybody comes up to the bandwagon.

Keith:

Is there a reason why it became fashionable? Is it very much a technological reason; was it development of electronics devices in the Second World War?

von Hippel:

Slowly people became convinced, what we said all devices along; that it's the molecular designing of materials and devices was the way to do it, not empirical ones. This understanding of the phenomena which were involved in the structure of matter — that was at issue. We tried to put it over in a number of summer sessions, and 1959 or so, everybody got on the bandwagon. Before...there were a number of groups like that were very active, very interested. But in general the scientific community was still not convinced, until about that time.

Keith:

There was no industrial interest?

von Hippel:

Oh yes. The industrial interest was there, at Bell Telephone and so on. My first contact with industry was Bayne of AT and T, who came to my lab and brought electrifiers and said he couldn't make them anymore because the Germans had taken his data practically away and, with it the whole knowledge how to make them. He made them in New York, had other factories, and unfortunately, between the soap factory and a chocolate factory. The process took about three days, if I remember rightly, and half the time, when the wind blew from the chocolate factory, the chocolate properties...? He had this it was practically 95 percent of his production — so he came to me and was sitting in the lab and asked me, if we had any. It was one of the entrance (?) for us at the factory. I asked him, why can't this be electroplatting? He said, "It can't be electroplatting." We developed a method of electroplating it, a modification which was insulating the [???] which was conducting. I had to figure out how to make the grate, the modification of electroplating, so we could later make rectifiers electrifiers in about 20 minutes instead of three days. I think he got the patents for it and MIT got the patents for solar energy at that time. But it had never been...

Keith:

Going back to your, to the group at MIT, how big was your group when the war broke out?

von Hippel:

Oh, I would guess about 15 or something. Mostly students. Later came maybe 80 people or so.

Keith:

So how big was it? How long was it before you reached the figure of 80?

von Hippel:

This did not take too long, because the emergency was on, and we became responsible for radar dielectrics. We developed techniques that were used.

Keith:

And you became a major clearing house, for information.

von Hippel:

Not only on that, but on some instruments which were needed particular in England, for industries etc. — dielectric materials became the basis for using dielectrics.

Keith:

Yes. Were these the first comprehensive tables of dielectrics that were produced?

von Hippel:

Oh yes. There was nothing in the field. Nobody could go to [???] at that time, and this whole idea of having the total [???] frequencies — you ought to see those tables, they're somewhere — we brought it about from DC to microwaves, dielectric constant [???] and other data which were needed. Then our instruments were also sent to England, to industry etc. in England. We became more or less a clearing house for dielectrics during World War II.

Keith:

Yes. How about contacts you made at MIT? Did you have many discussions with John Slater for instance about particular problems in the solid state?

von Hippel:

I was later on a committee on dielectrics in Washington, Army-Navy War Production Board, trying to clear up lots of knowledge, of the needs and difficulties in general, I probably mentioned somewhere, like the first war? Nepini (?) breaking down practically on account of fungi, eating everything what the people had, [???] as well as [???] and at that time we told them, for heaven's sake, you have to [???] materials which cannot be eaten, and then it turned out, the quartermaster corps had contracted for years ahead for the other materials — until the government machinery found that they really started the [???] world wars…it took quite a while...

Keith:

Yes. Did you have many conversations about particular problems in solid state with John Slater at MIT?

von Hippel:

Not much. Let me think.

Keith:

He particularly points out in his book discussions with you regarding excitons in alkili hallides, before the war.

von Hippel:

John and I know each other quite well. Certainly we talked shop. But I can't think that we depended on each other's knowledge very much. He was one of the theoretical men, very understanding, and we had good discussions. Unfortunately he died too early. But no, we were good colleagues.

Keith:

Also before the war, I wrote that Edward Teller did work in dielectric breakdown with R.J. Seeger. He did a study of breakdown in alkili hallides with Teller when, Edward Teller, when he was at George Washington University.

von Hippel:

I knew Teller from Gottingen. Teller was a genius in a great many ways. I can't remember that he had anything to do with breakdown. He —?

Keith:

He did one paper. It was a paper on dielectrical breakdown in the alkili hallides and in that...

von Hippel:

I had completed in this kind of thing.

Keith:

Yes. I would imagine, judging from the paper, you possibly super — the main person working on it was Steeger — R.J. Seeger?

von Hippel:

Seeger. Yes, Seeger. Was that in Gottingen still or…?

Keith:

I don't think so; I think the paper was in the PHYSICAL REVIEW in 1938. It's in English.

von Hippel:

I see. Oh yes, No, I have completely forgotten that. I don't think I was influenced by it in any way, but I knew Teller, respected him very highly.

Keith:

Who were the most outstanding students that worked with you in the early years, in the laboratory (?) the students and assistants (?). I mean, there were a few people who collaborated with you on papers, J. W. Davidson.

von Hippel:

Oh, Davidson was a doctoral student. He was the son of Davidson from over there in Bell Telephone.

Keith:

Yes.

von Hippel:

He did his doctor's thesis in the lab. And then I hope he's alive, I haven't seen him for many years now, he was very nice. But not a man to influence me. It was more, he tried to get in to get his doctor's degree, and —

Keith:

Yes. And Robert Mower?

von Hippel:

He was a very lovely man. He's still working in Urbana.

Keith:

Yes, I'll be meeting him in the next few days, I hope.

von Hippel:

Please give him my best greetings.

Keith:

Will do. He was a student of yours?

von Hippel:

That's right, and got his doctor's degree with me. He's a very good man. Went to Urbana and has a big lab there, I think. He has a big laboratory.

Keith:

I think so, yes.

von Hippel:

Yes, he's advanced there. No, I haven't seen him for years now, but he's a very nice person.

Keith:

There's a paper you wrote with him on the effect of all the disorder on breakdown strength.

von Hippel:

Papers done here more or less were, when he was a student then. It may have been he wrote a few others. Professors tried to put the input in as far as new ideas are concerned, but certainly we should not underestimate what the students contributed, but at this date I couldn't say anything about it.

Keith:

E. T. Mathias, who went to Bowdoin.

von Hippel:

He was the best man I ever saw, Mathias. He came to us after World War II from [???] lab in Switzerland. He was very attracted to our work, to our dielectric work.

Keith:

Yes. He'd already started working in dielectrics by then…

von Hippel:

Yes, during the war, yes. [???] systematically, by going from [???] to [???] to see what changes took place in this case, the response of dielectricity of [???] strontium (?) in the properties, in this project too, more or less, but then he was the one who was getting down with the chemical dictionary and trying to find substitutes for [???] and [???] He developed dielectrics, with the ferro electrical and magnetic properties, etc. He was absolutely excellent. Unfortunately he died too early. He went from here to go to [???] and later went to Berkeley, to California. Unfortunately he died. He was the most outstanding man I have ever seen. Very good.

Keith:

He did a lot of work on superconducting materials.

von Hippel:

Yes, and magnetic materials. He was excellent.

Keith:

He must have been. What were the particular hopes that you had for ferro-electric materials at that time? Did you think that they would become very important?

von Hippel:

Yes. I mean, to be able to control the dielectric properties, by its strengths and by its stress conditions and produce very high storage possibilities, etc. See the breakdown strength of these things and what happens now, with sopping up electrons etc. on it, this was all terribly interesting. One aspect of our whole thing on dielectrics. We wanted to go to ferromagnetics and [???] which is a little bit like, you will see it in the paper. That was done at that time....

Keith:

Yes. Ellis Alger, was he a student of yours?

von Hippel:

Yes, certainly he was a student of mine. Alger. — I haven't seen him for two years or so, but he has founded his own company in the area and I hope to see him soon again. He was very nice too. He came, I think he came from government of — Hitler put him out of there — no, he was very nice. There were so many students. Alger was one of the ones who also did some work in [???]. There were some outstanding groups, for instance [???]. The — which came out of the lab. Three of my students from the Central [???] Lab, who are the ones, you know, putting out the robots for the handling of nuclear devices. So you might like when you go west some time to see them. They are in Minnesota out there, three very, very nice fellows, good friends of mine. They came out of this war research business.

Keith:

Did a very large proportion of your students go into industry?

von Hippel:

Yes. Yes, sure. You'd expect that, after all. [???] at MIT, but now I [???] with names. He later became practically director of Bell Telephone. Unfortunately he died just when he took over. But there are quite a lot. We had several reunions, sometimes, but now you see everybody is so busy this is the [???] lab is not existing any more. This is now more or less a sort of goodbye situation.

Keith:

Yes. You mentioned a few of the students. Can you remember any — what was the structure of the laboratory in the period just after the war? I mean, with yourself as director? How many students would that mean?

von Hippel:

All in all, in detail...more or less (inaudible...) It was a big lab...technical department, went up to 16, something like that…and started the new line, which went up to 20, with the smaller line here. I think you'll find all that stuff here, with the students and everything. This is easy to control again. I sent one of those sets to the American Physical Society in New York, you know, so if they haven't thrown it away, they have it.

Keith:

Yes. What do you think during the forties were the most important parts of your own personal research? Did you get much chance to do your own research?

von Hippel:

Well, you see, as you know, I was a there, partly, of the operation.

Keith:

You had that position in the early fifties.

von Hippel:

And the dielectrical materials applications. Molecular science. Molecular engineering. Molecular designing of materials and devices. I don't know if you've seen those things?

Keith:

Yes. I've seen three of them. I think there's one...

von Hippel:

Here's one, here. The start of this — this was for a book which I wrote at that time.

Keith:

Yes.

von Hippel:

And I came to this ... then developed the theory...

Keith:

Were these books the basis of cinescopes?

von Hippel:

Yes, but this was written for the [???]. This arrangement, more or less, I made the basis of summer school, to put the ideas into industry and also to other universities.

Keith:

Yes, and how successful were those summer schools, in your own mind?

von Hippel:

It was lovely.

Keith:

Yes. Where were they held?

von Hippel:

Here. MIT. That was really an exciting time. Everybody enjoyed the sessions.

Keith:

How many people would attend those sessions?

von Hippel:

Oh, I suppose 90 people, something like that. A number of my colleagues. There were also some from England, from Germany, and simultaneously I was trying to bring the colleagues themselves together.

Keith:

Yes. So they were influential, do you think, in changing people's attitudes?

von Hippel:

Oh yes. Sure. Sure. Because industry caught on to it. So I was then…somewhat at the Boeing labs, the Air Force labs and the rest, trying to get out materials research — all the aircraft industry was completely empirical at that time.

Keith:

Yes.

von Hippel:

So they began to understand. It was a very good contact we made at that time, it was one of their directors. So I mean, I talked quite a lot to industry, and to universities. You have to do some proselytizing to get these ideas in circulation.

Keith:

Yes. In the 1950's it was very much beginning, when people started thinking of material science as almost a discipline on its own.

von Hippel:

Yes. That was the end of our activity in that sense. Because '64, I became professor emeritus, and I was for a year the science advisor of the research labs, and then I started small again, here, a group going to the life sciences. The material sciences were rolling, and the connection to the life sciences was missing. So I tried to get that started.

Keith:

Yes. Taken in very general terms, how important do you think was the development of theoretical ideas in solid state physics, in transforming a lot of traditional areas like metallurgy into this newer area of material science?

von Hippel:

You see, because partly, an experimental approach which opened up the way to the theorists to talk about something, they had no data on it these kinds of phenomena like dielectric breakdown, electricity and so on — came out of experimental work, and then, —

Keith:

Yes. From the other side, though, one can look at the way that the electron theory of metals, which was a theoretical development, the idea of dislocations, which is a theoretical development, which had a —

von Hippel:

— no, dislocations were not a theoretical development. You see, you saw them in your experiments.

Keith:

Yes. Admittedly the problems did obviously come from experimental, empirical work on plastic deformations. I mean, I would accept that. But in themselves, they were as theoretical, to some extent they were developed in a kind of theoretical vacuum for a while, and then had a tremendous impact in metallurgy, in physical metallurgy, and so transformed that subject almost until it becomes the materials science. I mean, people suddenly stopped thinking in terms of a metal, metallurgy and started thinking in terms of materials.

von Hippel:

No, I don't, not quite right. We always worked from insulators, to metals, to semiconductors. As you know, this kind of (phone rings)

Keith:

We were talking about the way…talking about the way that material science emerged, and I suggested that initially people started thinking of , in terms of materials, of metals, and they moved onto a general concept of materials. And you said that wasn't quite right. You were elaborating it.

von Hippel:

No, I mean, from the other standpoint, namely, we came from the other side, from insulators, saw the conducting halides electrons running into our and all this stuff, and then, we came to semiconductors and to metals from that side. During the war, we had made strong non-metals into metals, in the sense of taking titanium, titanates, and taking the oxygen out, etc., from the semiconductors, and then trying to reach the metallic state. So, this was a logical development, and certainly, what we did and what others did, very often we knew each other — sometimes we didn't know each other — and everyone followed his own course, and each developed what concerned him. Then ask each other [???] all one needs to I think every original scientist has his own spirit that guides him.

Keith:

Yes. How important was technological need, in guiding emergent material science? I was thinking of the material needs of the nuclear industry, the micro-electronics industry, the needs of the aircraft industry, where there were great demands for materials with extremely precise properties.

von Hippel:

Yes. that's right. As far as we were concerned, our course on dielectric materials elaborated the properties and gave the characteristics were one entrance wedge into the field. Now, in our books etc. and research, it was all one field, from insulators to metal [???] in semiconductors, by for instance taking oxygen out of materials, oxides of titanium, of silicon, or whatever. As you know, at the Bell Telephone Labs, they were working on these important developments which led to the semiconductors used in industry. They based their approaches on silicon dioxide and we had produced the selenium, the siluriun approach, which automatically came in on account of the selective [???] but not as guiding the line as the silicon dioxide line was. The transistors came out of the silicon dioxide business. So, this — there were many ways to go, with many good people at work. Mostly we knew each other, but we didn't — our existence certainly has mutually influenced each other. Also, many of those, on the other hand, there were — every good scientist likes to go along his own way of thinking and interest, without suddenly breaking into somebody else's field. But, it is more or less the illumination of something in your brain that is doing that.

Keith:

It also guided you — the illumination of something in your mind.

von Hippel:

That's right. That is the way normally people grow, when they are not copying each other.

Keith:

Yes. Looking back in retrospect, are you satisfied in the way that the laboratory research developed?

von Hippel:

Certainly. I mean, you must always think — the joys in trying to find something, and learn — in principle, the joys are not in being important. What comes out, out of your life's work, well, you more or less thank God that you have such an interesting life. But I mean the acknowledgement is not important. Lots of people, later, when something's finished, jump on the bandwagon, and so on, and, who does what becomes standard, etc. and, as long as you do science because you want to know, look for it and to see. That's important, that you honestly try to go forth and to see.

Keith:

Yes. That's very much the attitude of an experimentalist.

von Hippel:

Yes. When you are an experimentalist, an experimental physicist, you can't help but to slowly come up with a lot of the theoretical ideas also, which have been so successful, as you [???] call it, and you come back from the theoretical side, and that constant back and forth, this becomes a unified field, and again, you depend on them they get ideas from you, you get ideas from them.

Keith:

Yes.

von Hippel:

It's just the advance of science, in this case, not the individual personalities.

Keith:

Which piece of your own academic work do you think gave you the most satisfaction, looking back? Which gave you the most pleasure?

von Hippel:

I mean, this whole development is of one piece, so…

Keith:

Don't some things stick out, in which you felt particular joy at the time, achieving it?

von Hippel:

I think, certainly, you're delighted when you see new things. Like the direction of [???] and all this kind of thing. You're delighted to understand. But it develops slowly in your mind, the concept of nature — that's so important — slowly seeing large fields intersecting, and in this case, the feeling of, well, here we are now, we developed this in the non-living nature, and what is going on in the living nature? Therefore, when I retired, in the sense of becoming professor emeritus, I went from the non-living systems to the living systems, because that was the great challenge then. The question was again, how to come to the living systems? And then you could ask: without water, nothing could be alive. So what is going on in water?

Keith:

If I may say so, I find it very fascinating that you yourself have gone on to biological systems, because that's exactly what Froelich has done. He's been looking at the biological systems.

von Hippel:

We came probably both from different directions I was interested in, why is water? Why is water necessary for life? Then the question came up, what is water anyhow? Then the question was, how is ice and water, and water vapor, such, how are they interacting, now and so, the whole story of the life after I retired comes down just to this subject, up to the burning of materials on account of water. And what is going on in solutions, and what is the role of water for life? There, the biologists have now long [???] disappeared, they and I am out of it. I just start something, but this is a long lifetime for somebody else.

Keith:

What has been your main interest outside science in that time? Have you maintained your interest in art?

von Hippel:

Yes. But no, I have always liked to see it, to understand it. My first wife, who died [???] was one of the [???] and was an artist, created sculpture. So, I've always kept interested in art. My children hopefully will continue something in that direction. Most of them are now... (off tape) My children are now in the widest kinds of professions. One is in a big institute in the life sciences. Another one is a heart and lung surgeon in [???] He was the first public scientist in Princeton to try to [???] at bombs. He's here at MIT as a professor of innovation, and my daughter is in social work, so I mean, they are all somehow in something with challenge. Your life is rich when you look and you see now your children and grandchildren coming along, and I have ten grandchildren who, they have become very amusing now, they are at different universities. So, you have to work out some good…

Keith:

Yes. That's a future responsibility. OK, you had a long career in science. What are the greatest changes in science that you can point to?

von Hippel:

I think the greatest change is, nobody creates his own equipment any more, what he can buy. He can buy the most sophisticated equipment, so that he's directly free to make experiments. We always had to make our own, oscillograph — no, the oscillograph you could buy, but I mean, we had to build our spectroscopes, and it took an enormous amount of time to build equipment for specific purposes.

Keith:

I think it was J.J. Thompson who said; in the period before you were a student, that in his day you got a PhD for building a piece of equipment, not what you could do with it — if you managed to build it, they gave you a PhD.

von Hippel:

It was an achievement. To build a spectrograph that really was good — you know. I mean, in retrospect one has to judge a little bit differently — also, it was an approach which slowed us down very much. Every time, you had to develop the new equipment.

Keith:

Yes. But this must have given you very versatile experimental skills.

von Hippel:

Well, some experimental skills, certainly, and on the other hand, there are many people who are really destined to be skillful experimenters. My kind of approach was the thinking approach of — the building of equipment for doing just what you wanted to achieve.

Keith:

Yes.

von Hippel:

So many people were with us in experimentation. Certainly I was good, but I was not outstanding in that sense. Other people were.

Keith:

What about the expenditures? I know in those days as a student, the expenses weren't very great. But in the postwar period, for instance, in your own laboratory, the expenses must have been considerable.

von Hippel:

They were very high. It was very high, but fortunately we had the confidence of the armed services. We got the first contract then from Army, Navy, Air Force, when it started on a peacetime basis, and they were very nice to us, and set us up for — kept it up for ten years or something, like that, so systematically we could develop things without worrying too much about it. But certainly it was always tough going.

Keith:

Yes. Did they give you any specific guidelines as to what kinds of areas they were interested, when they gave you the funds?

von Hippel:

No. Only, they trusted us. They saw that something would come out of it that was really an important contribution.

Keith:

Yes. Has anything else changed? In that postwar period, funds for basic research from military sources were much easier to come across?

von Hippel:

Yes, — no, at that time, everybody had an obstacle anyhow, and peacetime projects were very essential to the further development. After all, we had used up everything for science during World War II. To get new ideas, develop new fields, was very essential, and I think the Army, Navy, Air Force contracts were very enlightened in their way to allow us complete freedom to do what we thought was necessary to field push this materials field thing along.

Keith:

Yes. I think I've just about exhausted the questions.

von Hippel:

Yes. I hope I have not painted a picture which is too one-sided. I mean, everyone knows his side better than the other's.

Keith:

We have the advantage of interviewing many people, so we lots of sides. Thank you very much.

von Hippel:

It was very nice to have you here.