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John Wheeler - Session IX
John Wheeler - Session IX
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Interview of John Wheeler by Kenneth W. Ford on 1994 March 4,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
For multiple citations, "AIP" is the preferred abbreviation for the location.
This is one of 22 sessions of oral history interviews with John Archibald Wheeler conducted by Kenneth W. Ford between December 6, 1993 and May 18, 1995. They represent research material for Wheeler’s autobiography, Geons, Black Holes, and Quantum Foam: A Life in Physics (Norton, 1998).
Well, for anyone starting a project today, I have one small piece of advice derived from Matterhorn B. That is: Draw people into a career; don't draw people out of a career. The older people that Matterhorn B was originally designed to get didn't come, and if they had come, why, we wouldn't have had the same drive that the younger people had who were being drawn into a career. This is one factor about assessing Matterhorn B. I confess I've never really sat down in a bar or any quiet place with Carson Mark and Norris Bradbury to get their assessment of what Matterhorn B was and did.
Who was our friend who went to get the things ready for the shot? Who was in charge of the shot? My memory...
Ford: I've forgotten. Was it Al Graves?
Al Graves was one of the people, but there was somebody else who I had the feeling really ran the overseas shot.
Ford: Marshall Holloway?
Well, that might be it. It might be Marshall Holloway. Do you know whether he's still living?
Ford: I don't know.
I'll be in that part of the world for a little while this summer and can try to make a point of seeing him. Could Matterhorn B have been run at Los Alamos? It would have required my taking a degree of charge, administrative charge, that I would not be quite accustomed to do in an environment that already had plenty of people accustomed to taking charge of this and that and where, I suspect, there were turf battles that went on between one and another person.
It would be very interesting to compare what we did in Matterhorn B with what the Soviet group was doing at that time. I have upstairs two Sakharov books, one of which is largely memoirs by Russian colleagues of his who say some things about their project which are $ the degree of secrecy, about the interactions between people, between Zeldovich and Sakharov. My mind is turned toward the Russians, because they realized the value of lithium in a way that I don't remember we got into. In fact, if I recall correctly, our figure for the yield of the Mike shot was less by a substantial percentage—maybe 30 percent—than what it actually gave, largely because of lithium present that we had not figured on. Do you remember that?
Ford: I do recall that figure—that we underestimated the yield by about 30 percent.
The other thing I feel badly about was not having paid more attention to the cryogenic apparatus that was involved in using hydrogen or deuterium. When one saw all that mess and realized the weight and misery it would make for carrying this stuff on an airplane, there would have been powerful motivation to change the thinking from hydrogen to lithium.
One of the people on our project was Pierre Noyes. I had the feeling he was really opposed to nuclear weapons on principle. So I would be interested to assess what he contributed on the project. Do you remember?
Ford: I remember him, but not clearly. Was he affiliated with Princeton at that time, or did he come and join the project from elsewhere?
We brought him from California, and he returned to California. He's at SLAC, but I have a feeling he's simply tolerated there—that the ideas that he works on are so far out of the mainstream that people there realize that he's not adding a great deal to the name of the laboratory and is taking some away from its budget. He's an idealist, and he has to be given credit for his courage. But if you don't have some judgment mixed with your courage, you can get into trouble.
Ford: It's my recollection that his contribution was not as great as that of, say, John Toll or Larry Wilets.
Right. It would be wonderful if we had the bibliography of our reports.
Ford: If the Lillian Hoddeson follow-up project ever gets approved, they may be studied.
Do you know her? Have you met her?
I believe that our final report on thermonuclear weapons—PMB-137, wasn't it?—...
Ford: I can't remember. That's logical. [laughs]
. . . covered a lot of territory, gave a world perspective. John von Neumann contributed some thinking to it. I've been told that it served as a manual at Los Alamos for ten years of the thermonuclear period, a manual for weapons design, but I've never seen that in writing. I'd be interested to know how authoritative that assessment is, whether it's uncontested.
I can't recall whether it was to Smyth or to Lewis Strauss, the Chief Commissioner of the Atomic Energy Commission, that I remarked afterward that I would really feel good if there was some kind of recognition that could be given to the members of the group for the wonderful job they'd done. In the end it turned out—I don't know whether it was by an act of Eisenhower or Strauss or at what level it was decided—that there should be awards. Was it the E pin or E medal? So those were given out not only to the Matterhorn group, but to the Los Alamos group and to others.
Having Bill Bordon and Senator Henry Jackson interested in the Princeton project was a plus that I'm not sure Los Alamos ever won. I think Los Alamos was just as happy to keep Washington noses out of their project.
>MATTERHORN A AND ITS OUTGROWTH -THE PRINCETON PLASMA PHYSICS LABORATORY
Any comments on Matterhorn A? I can't remember really keeping in adequate touch with what was going on there with Lyman Spitzer and his colleagues. Tom Stix: I had a feeling he had been brought into Matterhorn A by the time B finally wound up.
Let's see. Was it Stirling Colgate brought him in? No, it was somebody else I think.
Ford: Ed Frieman was the other very bright young person I remember.
Yes. Ron Davidson is the man who runs it now. There was a meeting, a bit of an anniversary meeting, of Matterhorn A, the [controlled] thermonuclear project, some months ago. I recall somebody who came from a different enterprise speaking up and saying, "You people won't really get money and you won't really get the support you need until you enlist manufacturers in lobbying for your project the way we at NASA have had to do and found successful." I honestly don't know whether that advice has been taken seriously since. It was impressive to read in the paper a few weeks ago about tritium having been fed into the Tokamak, and getting out more energy than was being consumed.
Ford: I'm reminded, John, that the little metal shack in which we worked is still there. It's the only residue of that early period. It might be a good thing to go out and get a photograph of it for possible use in the book.
That would be wonderful. It might be that Bob Matthews has a picture downstairs, although I can't imagine why. He's our photographer; he probably would know if there's any index of pictures.
GETTING INTO RELATIVITY
Beginning in the fall of 1952, with the approval of the physics department, I had begun teaching a graduate course in relativity. So far as I know, no such course had been offered before. Bob Robertson of the mathematics department would have been the logical person to give such a course, and I probably would have heard about it if he had. If I were to look up the copies of the graduate general examination from his time, before I came to Princeton, it would give some feeling for how much was generally expected of students; how much general knowledge they should have, including especially, I'm thinking now, knowledge about relativity.
Ford: I think the answer is zero. At least when I took the general exam in 1950, there were no questions relating to general relativity.
There must have been some on special relativity.
Ford: Oh yes.
At that time—I'm talking the fall of 1952—special relativity, it's ideas, I think were as generally accepted in the recognized physics community as the ideas of Euclidean geometry, although there were always a few individuals who stood out and argued against one or another feature of special relativity. But general relativity did not, so far as I can judge looking back, incite general interest.
I am sorry I was not in close touch with either Pauli or Einstein at the time they did their paper together on the possibility of a particle orbiting a center of attraction without falling into it. It would be interesting to go back and look at that paper and see to what extent they recognized tacitly the looming presence of the black hole, and that [?] trying to escape accepting any such idea.
Ford: When was that Pauli-Einstein work?
I think that was about 1950, but I may be off by five years. If I had to swear where it was, I would say the Annals of Mathematics, but that's a wild guess. The Kaluza-Klein theory must have been on deck at about this time—the idea that there is an additional dimension of spacetime and its contribution to geometry is responsible for electromagnetism. What seminar would have taken up that paper or would have discussed it? I don't immediately think of any seminar that would. It was not as it is today, with a regular group in elementary-particle theory. There was a theoretical seminar, but eventually we set up a special seminar on gravitation and relativity, getting in people who could talk about it.
One great stimulus at this time was the presence of a roughly monthly meeting at the Stevens Institute of Technology, meeting on relativity with James Anderson of Stevens Institute of Technology at Hoboken providing the impetus and various members coming from New York—Peter Bergmann, I can't recall whether Valentine Bargmann was accustomed to go. There is a chap at New York University downtown, of German origin, who was a real contributor there too. I don't recall any other forum where relativity and gravitation got considered. The Institute for Advanced Study—the theory people were very much under Oppenheimer's influence, and he turned the direction of inquiry there toward particle physics largely.
You'd think somebody must be writing a history of the Institute. You'd think there would be some records of what the seminars were, but I'm told that as far as records go, the records of our physics here at the university are in a shambles. The wastebasket is full of stuff at the place up on Nassau Street where the university archives are. So if somebody following up the lead of this morning's paper decides to shred all of those, there will be no earthquake that I know of. I don't know anybody who's working with those papers or organizing them. The physics department, I think, shies away from it, because it would take money to get somebody to go over it. If I had the money, I would get Beth Carroll-Horrocks at the American Philosophical Society to guide it. She has young people she's training as archivists who could do it at a salary less than her own.
Ford: John, I have two questions related to your shift of interest to relativity at that time. The first is: What had been your prior interest? Had you thought about and considered working on relativity? Were you fascinated by it prior to your teaching this course, or was it really a completely new direction?
Was there any special project I had in mind to do that I hoped this course would . . .? I'd have to go back and look at my notebooks to see.
Ford: Had it been a subject that fascinated you in the 1930s and 40s, which you sort of kept on the back burner, or was it a new interest?
Well, ever since I had read the book of Lorentz, Problems in Modern Physics, I had been interested in relativity. And now and again some . . .[end of tape]
EARLY INTEREST IN RELATIVITY
I had always been fascinated in the connection between potential experienced by a particle in a spherically symmetrical potential and the energy levels of that particle, going back and forth between the one piece of information and deducing the other, so that the paper of Schrödinger fascinated me in which he dealt with the energy levels of a particle in a closed universe. There was general relativity coming up, and I'd been interested also in the effect of the spin of the electron in altering the pattern of energy levels. Had Schrödinger taken that into account in his paper?
I had been asked to give a talk at a meeting organized by our Italian friends at Cartona and I thought it would be interesting to consider the interaction of an electron or other particle of spin a-half with the field of force of an atomic nucleus. Was there [There was?] an effective potential barrier, it turned out, that would keep the particle from being swallowed by the nucleus in a singularity. There was an effective barrier between the outer region and this dangerous inner region, a barrier which in principle could be penetrated by quantum mechanical penetration. I figured something on effective lifetime against such a process. I suppose this was a natural tie-in with the work of the elementary-particle physics group. That must have been still going on at this time. Do you remember any interactions with Project Matterhorn and the elementary particle physics group?
I can't either.
Ford: Let me ask my second question, which is: In all your prior work, you had a focus of being close to experiment—theory that had some possibility of confronting experiment. At that time, in the early 50s, I think in the minds of most people relativity no longer had any future experiments to confront. It was purely mathematical. But you must have had in your mind somehow that if that field were mined, new applications and experimental consequences would come to light. Is that correct?
LINKS BETWEEN NUCLEAR PHYSICS AND RELATIVITY
Well, out of the elementary-particle physics work, or associated with it, had been some issues of equation of state of nuclear matter, and how big a nucleus could you have. I can recall that a friend—what's the matter with me? I don't remember his name now—who had muscular dystrophy . . .Well, we set about figuring what nuclei could in principle exist. This was a natural follow-up of the work in the paper of Bohr and myself on figuring nuclear stability, except more factors went into it now. We concluded that there ought to exist some super-heavy nuclei.
The Russian who discovered spontaneous fission, Flerov, entered into this subject more fully using the shell model of nuclear structure and concluded it was not just simply a long peninsula of super-heavy nuclei, but that there was a cut or break in that peninsula that separated the main body of nuclei from an island of stability. He published a book with a lovely picture on the front of it showing that island of stability. There must every year have been one or two experimental physics papers of people purporting to have discovered some bit of evidence for a super-heavy nucleus, but so far none that I knew of had stood. But there's still hope of creating some way or other a super-heavy nucleus, perhaps by pumping neutrons into an already heavy nucleus so fast that it grew before it had time to split.
There's not a great difference between a neutron star and a big nucleus, and there was always the question how heavy can a neutron star be. This posed an issue: What is the equation of state of nuclear matter? I recall the satisfaction I got from showing that despite all ignorance of the exact equation of state, one could draw an important conclusion from the fact that relativity prohibited an equation of state so rigid that the speed of sound would exceed the speed of light. So we found ourselves led to consider the fate of a large collection of nuclear matter.
I found that the invitation to give a paper at some conference provides oftentimes a powerful stimulus to take some little germ of an idea and work it up into something bigger that can be given at the conference. And so it was at the Dallas Conference on Relativistic Astrophysics, there reporting on neutron stars and related issues. The conference required that each participant submit a paper. I didn't have any paper ready, so I got an extension. And the writing up of the paper required not only my efforts, but those of Kent Harrison and Masami Wakano. And there was one other author, Kip Thorne. It came so late and it was so long that the editor at the University of Chicago Press decided to make it into a separate book. And so it's the book called Gravitation Theory and Gravitational Collapse.
It was wonderful that about this time the people at the Naval Research Laboratory, especially Ernest Krause, became interested in trying to detect such a thing as a dwarf star or a neutron star, sending a telescope up above the earth's atmosphere. But then the question was: How heavy can a neutron star be? This book gave some figures on that. But then one of the conclusions in the book was [that] a sufficiently massive object simply could not hold itself up, even with an equation of state at the relativistic limit so rigid that the speed of sound is equal to the speed of light. Such an object will collapse so that the black hole problem came to the fore already at that point. It was impossible to consider the connection between equation of state of nuclear matter and the amount of mass in the star, the distribution of pressure and density throughout this neutron star, impossible to consider it directly without applying general relativity to the equation that Tolman had, connecting pressure change. Then there was also an equation of Oppenheimer. Of course, Oppenheimer and Volkoff had already considered the collapse of an object in the spirit of general relativity; although the object they considered was one where there was no resistance of any pressure of the material, a collection of dust particles you might say.
This work, which grew out of a natural interest in the properties of nuclear matter, tied on with the story of cosmology. I found it hard to understand why there was in the literature so much discussion of alternative cosmologies when the Friedman-Robertson-Walker version of cosmology is so simple and straightforward, a spherically symmetrical distribution of mass, a mixture of dust and radiation, and this whole system expanding, reaching a maximum dimension, then contracting. Some of our colleagues felt that we did not know where the mass was going to come from that would be compatible with this mathematical model. Where was the mass to be seen in the universe?
I first came wholly to realize how inescapable this issue is when I was asked to report at the Solvay Congress on the implications of general relativity for cosmology. The person who invited me was Jan Oort, a grand old man of astronomy whom I had come to know and admire through my days in Leiden in 1956. The impulse to come up with something new and true, the obligation to do it, I have described somewhere in writing about it in my book A Journey into Gravity in Spacetime. Roger Penrose, taking the train in to London one day, having to give a talk to his class, had to figure out something new and true he could tell the members of the class about. That's when he figured out the process of exchange of energy between the particle outside and a nucleus [black hole?], the so-called Penrose process which could subtract energy from a rotating nucleus [black hole?], leave it rotating with less angular momentum and less mass than before the encounter, even though in the course of the encounter a mass was added to the system. I'd be interested to see how many times I had found myself forced into something new by a similar obligation.
RELATIVITY AND THE QUANTUM
In Leiden, occupying the Lorentz Professorship for a semester, I gave a course which was essentially on relativity and particle physics, and things that fall in between the two. That's when, with Charlie Misner as somebody to talk these problems over with, I came to recognize that just as the electromagnetic field everywhere is subject to quantum fluctuations, so the geometry of spacetime must be subject to such fluctuations. And these fluctuations are bigger, the smaller the scale of distances that one considers, until, when one gets down to a distance of the Planck length, one has fluctuations so great that the very ideas of before and after lose their meaning. The paper where these fluctuations are discussed appeared in the Annals of Physics. That was the first use of the term Planck length. Well, Planck himself had introduced the quantity back in 1899, based on the constant of gravitation and constant of radiation and the speed of
light. Planck had introduced constants, which he said are independent of the constitution of matter and have a significance which reaches above all the details of forces between particles. As he said, the meter and the gram and the second are based on our own planet in its time of revolution, its physical dimensions, and the liquid that we drink from its surface, water. But a set of units that would be useful by people on any planet would be these units that he talked about. Well, this was a year before he discovered the quantum. In the meantime the world of physics had found that h bar of your license plate is even more useful than h itself, so that that was a foundation for figuring this set of units, which I took the liberty to call the Planck length, Planck mass, Planck time, and so on.
Well, Peter Putnam was in the class, and he was excited at this idea. Charlie Misner and I had already made progress writing up a paper on geometry as a possible building material for all matter. The idea that we had had been inspired by a paper of—who is the author? A colleague. I think he was at Michigan, an older colleague. He had written about the idea that an electromagnetic field is just a feature of space-time curvature in the sense that electromagnetic field has associated with it a Poynting Vector and an energy density, and these two quantities impose on—[end of tape]
GEOMETRY AS EVERYTHING
(1950s - Leiden)
So the electromagnetic field makes footprints on spacetime so characteristic that from those footprints and the curvature of spacetime one can read back to almost all of the electromagnetic field. In this sense the electromagnetic field could be regarded as just a feature of geometry. Actually it's not quite as simple as that. There is a feature of the electromagnetic field which is left undetermined by the geometry—so-called complexion. Anyway, we thought this is an open invitation to ask to what extent the whole show—particles and fields of force—can be understood to be geometrical in origin.
This was a wonderful opportunity to get a lot of instruction from Charlie Misner about methods of mathematical physics and of differential forms. One key point, one key inspiration, for what we were doing was a remark by Hermann Weyl back in the 1920s, "An electric charge is not a point out of which something showers, but it's a region of space out of which electric lines of force diverge." One could envisage a multiply connected spacetime in which every positive charge is at one mouth of the wormhole in space and negative charges at the other mouth.
Peter Putnam was inspired by a sketch that I made on a blackboard as I was propounding this idea in the class, and he made a sketch of it, took it to a draftsman in town and had it made up into a big, gorgeous poster. I have it somewhere, I hope, in my collection of posters. Where? In France one can buy these wonderful reproductions of paintings, but where do you keep these big sheets? You keep them in so-called carton, the French "carton," which is heavy cardboard, two sheets pulled together with a hinge on the end. I think I've put one of these pictures in there.
The will of Peter Putnam left enough money for various good causes. One of them was money for somebody whose name, if I remember correctly, is Davis—if I remember right, he lives in Salt Lake City—to edit his unpublished papers. Peter had written a lot from the time he was at Union Theological Seminary to the day of his death, and it was unpublished. As a matter of fact, the single biggest obstacle to his promotion at Union Theological Seminary, the reason why ultimately he left, was that he didn't have a publication record.
Thinking back on it now, I realize I didn't do my duty by Peter. I should have realized that he had this shortcoming of not getting things written up. His senior thesis at Princeton was so impenetrable that neither I nor anybody else in the department could make head or tail of it. I recommended the policy we finally followed: that is to give him a grade on it that was the average of his grades in his courses. But I would have done better if I had sat on him sentence by sentence. Well, I'll be interested what this Davis makes out of it all. A tough game.
JOE WEBER AND GRAVITATIONAL WAVES
I have another guilt feeling from that time, that I gave such a feeling of reality to gravitational waves that Joe Weber has devoted himself since then to trying to detect gravitational waves, and taking what I think are instrumental effects as indicating real waves. His enthusiasm has run away with him.
Ford: Are there now other groups with gravitational wave detectors?
Yes, yes. Bill Fairbank at Stanford had a wave detector going. The Rome group have one. And I think—I don't swear the first name is Bill, but I think it is—Bill Hamilton at Louisiana State University felt [?] inspired by Weber's bar detector. There was some talk of a Munich group going in for it, and I know the Pisa people are building a gravitational wave detector, but that's not of the bar type; that's of the type that the Caltech group is planning to use— interferometer.
(Fitch and Tiomno) My 1953 paper on "Mu Meson as Nuclear Probe Particle" I've been told was influential with a lot of people. I remember going to Columbia at the time we were interested in getting Val Fitch here on our staff, talking with him. He had been working in exactly that field experimentally. At about that time, Tiomno and I became interested in the process by which a mu meson interacts with a nucleus. I'm trying to find the paper.
The paper on "The Interaction of Mu Mesons with Atomic Nuclei," the electromagnetic interaction, provided me with an entree to discussions with Val Fitch, which I prized very much then and since. That's the electromagnetic interaction of a mu meson and a nucleus, but there is also the subject of the elementary-particle transformation in which the meson breaks up into an electron and a neutrino, and the process in which the mu meson produces a change in the particle count of a nuclear interior. Tiomno and I analyzed these. One of the features of the analysis was the so-called triangle relation, which compared three interactions with each other, electron, neutrino, and mu meson, and was there a pi meson in there? I can't recall.
Anyway that triangle relation had a lot of resonance in later communications [?] by the community, and I always hoped that Tiomno would get more recognition than he did. He is a man of very great conscience and imagination.
That was 1949. In 1953 was a related paper on the "Mu Meson as Nuclear Probe Particle."
GENERAL TALK IN JAPAN
In 1954, or maybe a year or two earlier, there was in Japan a meeting on elementary-particle physics. I can recall, in the talk I gave—I had been asked to give a general talk—I can recall comparing the tendencies in modern physics to tendencies in the history of Japan. One was Saigo Takemori, who was a great military leader who had helped to overcome the feudal forces in Japan, producing a unified nation back in the 1800s. The other, Sugawara No-Michizane, the Minister of Education back about the 1500s or 1600s, maybe earlier, who had brought the Chinese educational ideals from China to Japan, might be called today a Minister of Education. I compared the tendency in theoretical physics to look for broad overarching principles with Sugawara No-Michizane and the idea of going ahead with experiments without having to think too much about theory. I compared that to Saigo Takemori. I'm afraid it was all too evident to the Japanese audience which side I was on.
GEONS, BLACK HOLES
Already, evidently, in 1955 I had got enchanted with the idea of seeing how far one could get with curved empty space as a building material, because then was a paper on geons, an electromagnetic wave held in a circular orbit by the attraction of the energy of the gravitational [electromagnetic?] wave itself. Such a system, I recognized later, as a consequence of being invited to give another talk at New York University, I recognized that such a system is unstable, like a pencil standing on its tip, and will either collapse or blow up.
There was a paper on geons, later on, recognizing that the geon can blow up, and just this last year I published a paper as a chapter in the Dieter Brill Festschrift of Cambridge University, a paper on gravity waves coming together in an irregular geometrical background to produce by accident a geon configuration collapsing to form a black hole with some spill-off of the radiation that didn't go down the black hole. This is the proposed contribution to try and understand what the source is of the missing mass that closed- universe cosmology requires. (Well I've gone up through paper 163 in 1969. I still haven't found that paper on collapse of a geon to a black hole.)
Ford: John, do you want to mention for the record the circumstances when you coined the name "black hole"? Do you recall when or where that was?
Oh, yes. In the late fall of—was it 1976 or 1967?—the evidence started to come in from Cambridge University of pulsars, Jocelyn Bell and Anthony Hewish. What were these objects? Before the paper had appeared, Vittorio Canuto, running the space agency center on Amsterdam Avenue in New York, had called a conference to consider possible interpretations: vibrating white dwarf, vibrating red giant, rotating object, what? Amidst all this variety of objects, I insisted we should consider likewise objects that have undergone complete gravitational collapse. I had to use the phrase "gravitationally completely collapsed objects." If you use that long-winded phrase five or six times, you look for a substitute. Somebody must have joked and said "black hole," but I took up the word "black hole" immediately. I do not know whether that conference was ever reported in the newspaper, but I do know that I had to give a report a few weeks later. I gave a talk, the Sigma Xi lecture for the American Association for the Advancement of Science, and I put that word into the talk. That talk appeared in two places: the magazine [of] Sigma Xi, and I can't tell you where the other one is. So that was the first use of that term in print that I know of, a term coined in desperation.
THE MESSAGE OF RELATIVITY
The central point of relativity came out more clearly every time I talked about it. I don't know how many times I gave a course in general relativity, but having to write up a book, A Journey into Gravity in Spacetime, forced me to put the message in a single peppy phrase: "Spacetime tells mass how to move, and mass tells spacetime how to curve."
It's so interesting how one always gets letters from people who have some crazy idea of what physics ought to be and what it ought to look like. That surely must give us all a little comfort, knowing that we ourselves are crazy, too. And how to tell—[end of tape]
PUBLIC SERVICE - NUCLEAR POWER
I think I've spoken about the Reactor Safeguards Committee and domes over nuclear reactors.
Ford: You mentioned only one meeting, I think. In October of 1949 you went to a meeting of that committee in England. I don't think you've spoken otherwise about it.
I see. We were very fortunate on that committee to have such a breadth of experience. Abel Wolman, Professor of Sanitary Engineering at Johns Hopkins, who taught me the standard motto of sanitary engineers: "Pollution plus dilution equals solution." And Harry Wexler of the United States Weather Bureau; Edward Teller and Richard Feynman, both so imaginative and lively; and Kennedy, the radiochemist from Washington University, St. Louis. We came up with a proposal that the future reactors should all have surrounding them a dome to contain the radioactive products if the pile ran away out of control and the products caught fire. Then all that radioactive smoke would be contained.
Did I mention about the General Electric Company wanting to put a reactor at Schenectady? That was the occasion for doing this, and we came out with a formula: The distance between a city and a nuclear power reactor should be given by 0.01 times the square root of the power level in kilowatts. That's should give the number of miles of separation. Why a square-root formula? That because the radioactivity spreads out, or a plume of smoke spreads out, through an angle of about a seventh of a radian, so that the distance downstream has to be square rooted to determine the width of the plume. It was quite interesting to ask where could such a strange formula come from, because normally one would think that the diffusion goes in proportion to the square root of the time, and this was at a diffusion proportional to the first power of the time, one-seventh of a radian. The answer is that the normal diffusion outlook presupposes a mechanism which is small in scale compared to the distances involved, whereas diffusion in the atmosphere involves eddies of many sizes, and the greater the distance the larger the size of the eddy that contributes significantly to the diffusion. That's how come the first power rather than the square root power.
We had not got into the question of disposing of the waste products left over from burning uranium or any nuclear fuel. The problem of leakage from the storage at Hanford is often pointed to, but that was after a period of 60  years, and nobody expected the waste to be left there that long. Du Pont had left at the close of the war, General Electric had taken over. It's very interesting that there had been developed there in the Pacific Northwest, if I remember correctly, at the Battelle Northwest Laboratories located on government property at Richland, Washington, a process for taking waste materials and squeezing them into a log shape and coating this log with a glass-like material at high temperature, [which] solidified and left an impermeable coating, the idea being that this put the waste materials in a form where they could be free from interacting with seepage from underground water currents for centuries to come. It's my judgment that that application of that process has been held up not by any technical problem, but by the circumstance that the United States has been unsure whether it wants to put away materials that contain plutonium without processing to get the plutonium out.
The day before yesterday I saw Panofsky visiting here. He was giving a talk, which I didn't have a chance to hear, on the plutonium disposal problem. I asked what was the biggest single issue that he had come to. He said, "The fact the Russians don't know how much plutonium they have within a factor enough to make 10,000 nuclear warheads."
Battelle and Southwest Research Institute
I had been invited to join the board of trustees of the Battelle Memorial Institute in 19-blankety-blank and served there for a little over 30 years. It is fascinating. It's the largest not-for-profit research organization in the world, I think—the organization that had developed the Xerox process. I have written about it in my book At Home in the Universe.
Later I was elected to a corresponding position in the Southwest Research Institute of San Antonio, so I got a feeling of what these two organizations are and contribute to the country. One of the biggest problems is preserving financial stability, so that in good times or bad a staff can be kept and proposals worked out and research done, leading to a future for the organization in spite of downturns in contracts. A typical contract [is] one year to three or five years, mostly with business organizations but to substantial measure with government bodies.
Battelle is the organization that developed the Xerox process. The original idea came from Chester Carlson, an independent inventor. He took it to various companies, tried to market it, but none of them was willing to touch it with a ten-foot pole because it required an unbelievable combination of research skills: ability to work with special optics; to build a piece of mechanical equipment that would work hundreds of thousands of times without failure; and illumination that would be steady and uniform; a method of spraying powder onto the paper and affixing it by pressure plus heat so you get a good record. Nobody felt that they had the ability to carry through in any reasonable amount of time. But when Chester Carlson took it to Battelle, Battelle took it up and carried it on and developed it to a workable stage and got it marketed.
If you give it to a company too big, it falls in the cracks; if you give it to a company too small, they can't push it through. But there was this company of intermediate size, the Haloid Company in Rochester, New York, which had normally been in the photographic business but was facing a bad future because of the competition of existing photographic paper suppliers, and here was something that would be new and promising. So they took it over and got it going.
Whether the organization is Battelle or the Southwest Research Organization, in either case the research center has enough people, it plays a part in the community that's substantial enough, so that it's expected to exert community leadership, promoting things like art museum, music, school. But the biggest benefit I think comes from the individual people serving on these community enterprises.
Frederic De Hoffman had been on the declassification committee at Los Alamos and was familiar with the issues all across the board. He was invited to be a leading figure in an outfit set up, if I remember correctly, by General Dynamics at La Jolla, California, setting up a company called General Atomics. Freddie De Hoffman realized that they would have to have some people who had real experience working with nuclear materials if they were going to do something in this field. I can recall his coming to our house in Princeton, talking about possibilities. At that time I recommended to him Ed Creutz, who had been at Princeton, who had gone to the Chicago Project and then to Los Alamos, and who had that spirit of being ready to do whatever it takes to move the project ahead, whether it's sweeping the sidewalk out in front or turning metal on a lathe. Ed Creutz accepted the invitation and soon had a reactor going at La Jolla. Freddie De Hoffman later became head of the Salk Institute, but he had to have a heart bypass operation and in that operation at the hospital in Boston he was given a blood transfusion which gave him AIDS, so he died a few years ago.
Convair and Lockheed
Through some people I had met, I had learned about some of the ideas of aerospace companies [which] had a future, and was invited to serve on one or another advisory committee. One of the summer study projects that that led to concerned, I think it was Convair, wanting to see about a nuclear propelled airplane, and I argued right from the beginning that we didn't have to go into any detail, that the weight of the shielding would be so heavy that it's absolutely out of the question. So fortunately the work did not stretch for the whole summer. I didn't see why it couldn't be over in a single day. I think Zachariasen of MIT was the person that had pushed for my being on that committee, but I'm not sure he liked the conclusion.
And was it Convair or Lockheed, the board on which I served? We were to consider methods by which Southern California could be rescued, how to get water there, what about enclosing a portion of an iceberg, an ice floe, in a rubber container and towing it north [south?] and then pumping the melt water into the Los Angeles water supply? That didn't work out. Cost plus heat transfer problems.
A Constellation under construction I remember vividly. [This would have been Lockheed. K] Janette had gone with me, and we had gone round, we were taken around, to see the interior of the cabin while it was under construction. There were no floorboards in, and the whole floor looked like spaghetti, with all these colored wires running from one end to the other. Unbelievably complicated. I don't see how it's all kept straight.
Marvin Stern had written a book with George Gamow called One Two Three Infinity, and he had a long term connection with Convair. He knew that as a defense contractor its future depended on what the threats would be to the United States in the future. We had been through an all-out war, but what about a limited war? We were living at the time when the Chinese were making threats on Quemoy and Matsu, and the Korean War had taken place, and Vietnam was a lively topic. So what kind of policy was the United States likely to follow in such a crisis situation? Well, Marvin Stern got Convair to set up an advisory committee consisting of Henry Kissinger, Chalmers Sherwin, Oscar Morgenstern, and myself that met in Southern California a day and a half about every month and a half for a period of about a year and half. We came up with a document called, if I remember correctly, "A Doctrine for Limited War." In the end Convair decided not to publish it, because they feared that it would bring down upon them the wrath of people of the kind who had chanted after World War I, chanted about American defense contractors, "merchants of death." They didn't want to be called merchants of death.
I've got to dig out that paper sometime. I think Henry Kissinger published all that's relevant in it. It was absolutely marvelous to hear his accounts of conditions in earlier engagements—the time when the crossbow first came in, and it appalled people as being immoral because the arrow that killed you could come from somebody you never even saw, so immoral that it was agreed that anybody taken captive who had a crossbow could be put to death on the spot as committing an atrocity. Interesting illustration of how ideas change. And his instances that he knew of past history of open cities, a city declaring itself open to the enemy to avoid the business of being made a target. And then the opprobrium that attached to mercenary forces in European wars, because mercenary forces typically depended for a good part of their pay on the loot that they could accumulate, a scourge to the country through which they went.