Oppenheimer on Bohr (1964 UCLA)

I came across this 1964 UCLA talk by Oppenheimer, on his hero Niels Bohr.

Oppenheimer: Mathematics is "an immense enlargement of language, an ability to talk about things which in words would be simply inaccessible."

I find it strange that psychometricians usually define "verbal ability" over a vocabulary set that excludes words from mathematics and other scientific areas. A person's verbal score is enhanced by knowing many (increasingly obscure) words for the same concept, as opposed to knowing words which describe new concepts beyond those which appear in ordinary language.

Is it more valuable to have mastery of these words: esoteric, abstruse, enigmatic, cryptic, recondite, inscrutable, opaque, ... (all describe similar concepts; they are synonyms for not easily understood),

or these: mean, variance, standard deviation, fluctuation, scaling, dimensionality, eigenvector, orthogonal, kernel, null space (these describe distinct but highly useful concepts not found in ordinary language)?

Among the simplest (and most useful) mathematical words/concepts that flummox ordinary people are statistical terms such as mean, variance, standard deviation, etc. One could be familiar with all of these words and concepts, yet obtain a low score on a test of verbal ability due to an insufficiently large grasp of (relatively useless) esoteric synonyms.

See also Thought vectors and the dimensionality of the space of concepts , Toward a Geometry of Thought and High V, Low M. 

Added from comments:

I'd like to clarify something that was probably confusing in the original post and my subsequent comments. 

One of the things I noticed in the SAT reading comprehension sections my kids were looking at is that one is NOT being asked to making subtle distinctions between nearby concepts/words. One is merely being asked to know that X (esoteric word) is a synonym for Y (common word), without having to know the subtle difference between X and Y. 

So, if my kid didn't know that "Brobdingnagian" is a synonym for "big" they might not be able to answer a multiple-choice question about a paragraph containing the sentence: "But of course the error was of Brobdingnagian proportions." To answer the question doesn't require knowledge of Gulliver's Travels -- I could un-befuddle my kid (allowing him or her to easily answer the question) just by saying "Brobdingnagian means big"! 

So, at least this psychometric exam (the SAT) isn't even testing fine distinctions -- it just tests whether you know that X1, X2, ... , XN are synonyms of a very primitive concept like BIG. What is the value of taking N larger and larger (in this sense; not the fine distinction sense)? Surely there are diminishing returns...

Einstein and Oppenheimer on detachment

These are excerpts from Sam Schweber's Einstein and Oppenheimer: The Meaning of Genius.

Perhaps they can provide some solace as we near the end of this ridiculous election season.

Einstein: He never looked “upon ease and happiness as ends in themselves.” The trite objects of human efforts—possessions, outward success, luxury—always seemed to him “contemptible . . . [and] without the kinship of men of like mind, without the occupation with the objective world, the eternally unattainable in the field of art and scientific endeavor, life would have seemed empty” (Einstein 1954, 9). In his tribute to Max Planck on the occasion of Planck’s sixtieth birthday, Einstein stated that, like Arthur Schopenhauer, he believed that “one of the strongest motives that lead men to art and science is escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one’s own ever shifting desires. A finely tempered nature longs to escape from personal life into the world of objective perception and thought” (Einstein 1954, 225).

Oppenheimer: In a letter to his brother in March 1932 Oppenheimer declared that “through discipline, though not through discipline alone, we can achieve serenity, and a certain small but precious measure of freedom from the accidents of incarnation, and charity, and that detachment which preserves the world that it renounces. I believe that through discipline we learn to preserve what is essential to our happiness in more and more adverse circumstances, and to abandon with simplicity what would else have seemed to us indispensable; that we come a little to see the world without the gross distortion of personal desires, and seeing it so accept more easily our earthly privation and its earthly horror. . . . [I]n its nature discipline involves the subjection of the soul to some perhaps minor end; and that end must be real, if the discipline is not to be factitious. Therefore I think that all things which evoke discipline: study, and our duties to men and to the commonwealth, war, and personal hardship, and even the need for subsistence, ought to be greeted by us with profound gratitude; for only through them can we attain to the least detachment and only so can we know peace. (Smith and Weiner 1980, 155–156)”

My favorite quote from Marcus Aurelius:

Marcus Aurelius

"Or does the bubble reputation distract you? Keep before your eyes the swift onset of oblivion, and the abysses of eternity before us and behind; mark how hollow are the echoes of applause, how fickle and undiscerning the judgments of professed admirers, and how puny the arena of human fame. For the entire earth is but a point, and the place of our own habitation but a minute corner in it; and how many are therein who will praise you, and what sort of men are they?"

The Day After Trinity

This was released in 1980 and includes interviews with Rabi, Ulam, Bethe, Frank Oppenheimer, Robert Wilson, and Dyson.

Feynman's cognitive style

Some interesting finds in this 1966 AIP oral history interview with Feynman.

I have always felt that Feynman was cognitively a bit "lopsided" -- much stronger mathematically than verbally. This might be partially responsible for his way of learning -- it was often easier for him to invent his own solution than to read through someone else's lengthy paper. (Personality factors such as his independent streak, and his strong creativity, also play a role.) But this sometimes left him with gaping holes in knowledge. In contrast, Schwinger had at age 17 an encyclopedic understanding of what was known about quantum electrodynamics -- he had read and mastered all of the literature as a high school kid!

This excerpt reveals that Feynman did not understand the conventional formulation of QED even after Dyson's paper proving the equivalence of the Feynman and Schwinger methods. (When someone explained the action of a creation operator on the vacuum, Feynman reportedly objected "How can you create an electon? It disagrees with conservation of charge!" :-)

... I was struggling gradually to learn. I mean, I had to learn something to prove the connection between my thing and the same thing. Dyson had done a great deal in that direction. That didn’t satisfy me because I couldn’t follow that. Dyson told me, when he wrote his paper, “Don’t bother to read it, there’s nothing in it that you don’t know, except that it proves it’s the same as what everybody else knows, but it doesn’t say anything different or do anything different than is in your paper. Nothing more in it,” he told me.

... Yeah, because I remember him telling me not to worry about the paper. It hadn’t anything in it, you see. ... But then I thought I had to understand the connection, for publication purposes and others. And I had a good opportunity, because Case sent me his theorem — the manuscript of a big paper that he was going to publish in the Physical Review, which had all the steps of the theorem. Now, I argued in the meantime with myself, in my usual physical way of arguing, and concluded for several physical reasons, by some examples and other things — simpler examples that weren’t so elaborate as the calculations I made — that it couldn’t be true that the two methods would give the same result. ... I prepared a letter in which I wrote the physical arguments. Then I decided, that isn’t going to convince him. Nobody pays any attention to physical arguments, no matter how good they are. I’ve got to find a mistake in the proof. But the proof has creation and annihilation operators and all kinds of stuff. So I went to some students, in particular Mr. Scalator who was only fair, but he understood. He had learned in a pedestrian way what it all meant, and he explained to me what the symbols meant. So I learned like a little child what all this was about, so I understood what the symbols that he was using in the paper meant, and I tried to follow the proof, and I learned enough to be able to do that kind of mathematics, see — for the first time. So I followed the whole thing through, and I found a mistake, a very simple algebraic error, in the proof. He commuted some things that didn’t commute and so on.

Feynman never carefully read either Schwinger or Tomonaga's work:

Weiner: How about Tomonaga’s work? When did you first hear of it?
Feynman: I don’t know when I first heard of it. The work itself, I never knew exactly what it was, and I don’t yet know precisely what it was.
Weiner: You read his paper?
Feynman: No.
Weiner: I mean, there’s one paper that is often cited —
Feynman: No. No. I don’t think I read the paper. But this must be understood — I don’t mean anything disparaging. If Schwinger hadn’t been in the front yard at Pocono, or next to me, I wouldn’t have known what he did either. I got the same as everybody else. If you can do it yourself, why learn how somebody else does it? So I don’t know precisely what the relation of Tomonaga’s and Schwinger’s work is or the relation of his and mine. I think the relation of Tomonaga’s work to my work is very small. I mean, I think he’s gone around much closer the direction that Schwinger went.
Weiner: I think it’s the general impression.
Feynman: But I don’t know the precise relationship of their work. But I believe, if I’m not mistaken, although you’ll have to ask Schwinger, that everything that Schwinger did he did without knowledge of what Tomonaga did. I hear, but I don’t know, that Tomonaga did a very great deal, and did essentially what Schwinger did, except perhaps for working on certain practical problems. I don’t know. That’s what I hear. But I don’t know. I’m sorry, that sounds stupid, but I have never looked into it, and I never read Schwinger’s paper in a comprehensible way. I don’t know what’s in that paper of Schwinger’s.
Weiner: Haven’t tried to read it?
Feynman: Never. Tried in the sense that I looked at it and I flipped the pages, because it’s too hard. I read it at a time when I didn’t even know what a creation-annihilation operator was. I read it — you probably can prove that by the fact that I refer to it in various places, and get certain formulas out of it — I read it in the same way that I talk to him. When something looks like something, I know that’s it, you know? But I didn’t follow all the steps. I never followed all the steps.
Weiner: But you did know, when you talked to him at Pocono, and then —
Feynman: I know Schwinger — that’s what I say, I must have read it in pieces and bits. I know what Schwinger did; I know more or less how he did it. ...

Feynman: Yes, because we talked together, we had the physical idea of what starts it, but there’s a difference from that and checking all the equations, ... I don’t know whether he really read mine in detail or not. But he knows what’s in it, and I know what’s in his, but I can’t tell you. Perhaps if I look at his paper carefully, I can see that I really did read it, you know? I mean, I’d have to have it and look at it and see if I did read it. That’s a good way to look. I doubt that I read it in detail. I doubt that I looked at all of the various complicated sub-things that he had to worry about, like what to do with the longitudinal waves — because I don’t think there’s any problem with the longitudinal waves. I couldn’t pay attention to such a thing, see? So I doubt that I’ve ever read the paper in any careful way like a student would try to learn it. I don’t believe I’ve ever done that.

Finally, an interesting conversation between Feynman and Oppenheimer concerning the covariant propagator and positrons as electrons moving backwards in time:

So I went to the Physics Society and gave this paper, and I wanted Professor Oppenheimer to hear it, and other people like that. I particularly wanted Oppenheimer to hear it because he often said that there wasn’t anything to it. He understood Schwinger’s and he didn’t understand mine. And I thought he would be at the meeting. I’d kind of half thought about him when I prepared it. When I went to the meeting, he wasn’t there, but I gave the paper, and then Weisskopf got up and said, “This paper is so important and unusual” and so on “that we ought to give the man more time to express his ideas.” ... Then I stepped down, and just at that moment, Oppenheimer came in and sat down in the chair just ahead of me. And he turned around and said, “What did you talk about?” I said, “The idea of electrons going backwards,” meaning positrons. He said, “Oh, I heard all that. Oh, yes,” he said, “I heard that stuff, right? That stuff I heard.” I said, “Yeah, you’ve heard it, but you’ve never understood it.” Now, the response to that was an invitation I found in the mail when I got back to Cornell, to come to Princeton to the Institute and explain all my ideas, in as many lectures as I wished, two a week, as long a time as I wanted, expenses to be paid by the Institute, and so on. He’s a very great man, I know. I mean, I understand him. We’re good friends. You know. I mean, it’s not enemies. I said that because I was trying to get something across to him, that he didn’t understand it. That was honest. He knew that if I were driven to say that that was true — you know what I mean — and it was worth learning. So I said that, and his response was very generous — any length of time I want, any conditions. So I went to the Institute of Advanced Study.

In his eulogy, Schwinger described Feynman as "... the outstanding intuitionist of our age ..." :-)

Note added: I recalled another anecdote related to this post. At his Pocono talk Feynman was repeatedly asked by Dirac "Is it unitary?" (referring to Feynman's diagram method deduced from the path integral). Unfortunately, Feynman did not seem sure what "unitary" meant and responded "perhaps it will become clear as we proceed..." (a trick he learned from an earlier Schwinger talk). Feynman also did not seem to know what an S-matrix was!

But is it unitary?  :-)

See follow up post: Feynman and the secret of magic.

Sitzfleisch

Freeman Dyson reviews the new biography of Oppenheimer by Ray Monk. I discussed the book already here.

NYBooks: ... The subtitle, “A Life Inside the Center,” calls attention to a rarer skill in which Oppenheimer excelled. He had a unique ability to put himself at the places and times at which important things were happening. Four times in his life, he was at the center of important events. In 1926 he was at Göttingen, where his teacher Max Born was one of the leaders of the quantum revolution that transformed our view of the subatomic world. In 1929 he was at Berkeley, where his friend Ernest Lawrence was building the first cyclotron, and with Lawrence he created in Berkeley an American school of sub-atomic physics that took the leadership away from Europe. In 1943 he was at Los Alamos building the first nuclear weapons. In 1947 he was in Washington as chairman of the General Advisory Committee of the United States Atomic Energy Commission, giving advice to political and military leaders at the highest levels of government. He was driven by an irresistible ambition to play a leading part in historic events. In each case, when he was present at the center of action, he rose to the occasion and took charge of the situation with unexpected competence.

... In 1939 Oppenheimer published with his student Hartland Snyder a paper, “On Continued Gravitational Contraction,” only four pages long, which is in my opinion Oppenheimer’s one and only revolutionary contribution to science. In that paper, Oppenheimer and Snyder invented the concept of black holes; they proved that every star significantly more massive than the sun must end its life as a black hole, and deduced that black holes must exist as real objects in the sky around us. They showed that Einstein’s theory of general relativity compels any massive star that has exhausted its supply of nuclear fuel to enter a state of permanent free fall. Permanent free fall was a new idea, counterintuitive and profoundly important. It allows a massive star to keep falling permanently into a black hole without ever reaching the bottom.

Einstein never imagined and never accepted this consequence of his theory. Oppenheimer imagined it and accepted it. As a direct result of Oppenheimer’s work, we now know that black holes have played and are playing a decisive part in the evolution of the universe. That is the historical fact. The mystery is Oppenheimer’s failure to grasp the importance of his own discovery. He lived for twenty-seven years after the discovery, never spoke about it, and never came back to work on it. Several times, I asked him why he did not come back to it. He never answered my question, but always changed the conversation to some other subject.

It is true, as Monk demonstrates, that Oppenheimer’s ruling passion was to be a leader in pure science. He considered his excursions into bomb-making and nuclear politics to be temporary interruptions. My interactions with Oppenheimer confirm Monk’s picture of him. I worked at the Institute for Advanced Study for almost twenty years while Oppenheimer was director. He rarely talked about politics and almost never about bombs, but talked incessantly about the latest discoveries and puzzles in pure science.

... Oppenheimer continued for the rest of his life to be proud of his achievement at Los Alamos. ... Monk expresses his opinion, with which I agree, that Oppenheimer’s anger arose from his deep loyalty to America. For him, expressing regret for what he had done for his country would have meant joining his country’s enemies.

... Oppenheimer was above all a good soldier. That is why he worked so well with General Groves, and that is why Groves trusted him. I have a vivid memory of the ice-cold February day in 1967 when we held a memorial service for Oppenheimer at Princeton. Because of the extreme cold, attendance at the service was sparse. But General Groves, old and frail, came all the way from his home to pay his respects to his friend. ...

The real tragedy of Oppenheimer’s life was not the loss of his security clearance but his failure to be a great scientist. For forty years he put his heart and soul into thinking about deep scientific problems. With the single exception of the collapse of massive stars at the end of their lives, he did not solve any of these problems. Why did he not succeed in scientific research as brilliantly as he succeeded in soldiering and administration? I believe the main reason why he failed was a lack of Sitzfleisch. Sitzfleisch is a German word with no equivalent in English. The literal translation is “Sitflesh.” It means the ability to sit still and work quietly. He could never sit still long enough to do a difficult calculation. His calculations were always done hastily and often full of mistakes. In a letter to my parents quoted by Monk, I described Oppenheimer as I saw him in seminars:

He is moving around nervously all the time, never stops smoking, and I believe that his impatience is largely beyond his control.

In addition to his restlessness, Oppenheimer had another quality, emphasized by Monk in the subtitle of his book. He always wanted to be at the center. This quality is good for soldiers and politicians but bad for original thinkers. ...

I have to admit that my own Sitzfleisch, while well above average for a normal person, is probably less than required for true excellence in theoretical physics. (This might have something to do with my being less aspie than the typical theorist ;-)

The life of the mind

From Sam Schweber's In the Shadow of the Bomb:

It was part of Oppenheimer's tragedy that, after World War II, he felt that he no longer was a creative scientist and that he therefore had lost part of his "anchor in honesty," and hence integrity. George Kennan, who got to know Oppenheimer after the war and became his colleague at the Institute in 1951, made some of the most insightful observations of Oppenheimer's personality. Kennan described Oppenheimer

as in some ways very young, in others very old; part scientist, part poet; sometimes proud, sometimes humble; in some ways formidably competent in practical matters, in other ways woefully helpless: . . . a bundle of marvelous contradictions . . . His mind was one of wholly exceptional power, subtlety, and speed of reaction . . . The shattering quickness and critical power of his own mind made him . . . impatient of the ponderous, the obvious, and the platidinous, in the discourse of others. But underneath this edgy impatience there lay one of the most sentimental of natures, an enormous thirst for friendship and affection, and a touching belief . . . in what he thought should be the fraternity of advanced scholarship . . . [a belief that] intellectual friendship was the deepest and finest form of friendship among men; and his attitude towards those whose intellectual qualities he most admired . . . was one of deep, humble devotion and solicitude.

The greatest tragedy of Oppenheimer's life was not the ordeal he went through over the issue of his loyalty, but his failure to make the Institute for Advanced Study a true intellectual community. As Kennan noted, Oppenheimer was often discouraged, and in the end deeply disillusioned, by the fact that

the members of the faculty of the Institute were often not able to bring to each other, as a concomitant of the respect they entertained for each other's scholarly attainments, the sort of affection, and almost reverence, which he himself thought these qualities ought naturally to command. His fondest dream had been [Kennnan thought] one of a certain rich and harmonious fellowship of the mind. He had hoped to create this at the Institute for Advanced Study; and it did come into being, to a certain extent, within the individual disciplines. But very little could be created from discipline to discipline; and the fact that this was so--the fact that mathematicians and historians continued to seek their own tables in the cafeteria, and that he himself remained so largely alone in his ability to bridge in a single inner world those wholly disparate workings of the human intellect--this was for him [Kennan was sure] a source of profound bewilderment and disappointment.

G.H. Hardy, A Mathematician's Apology:

I still say to myself when I am depressed and find myself forced to listen to pompous and tiresome people "Well, I have done one thing you could never have done, and that is to have collaborated with Littlewood and Ramanujan on something like equal terms."

Spies like us

Click the link below for the MP3 interview with Haynes and Klehr (New Books in History podcast).

Spies: The Rise and Fall of the KGB in America
JOHN EARL HAYNES, HARVEY KLEHR, AND ALEXANDER VASSILIEV
YALE UNIVERSITY PRESS, 2009
by MARSHALL POE on JULY 10, 2013

For decades, the American Right and Left argued about the degree to which the KGB infiltrated the U.S. political and scientific establishment. The Right said “A lot”; the Left said “Much less than you think.” Both sides did a lot of finger-pointing and, sadly, slandering. Things got very ugly. At the crux of the problem, though, was a lack of reliable information about exactly what the KGB had done and how successful (or not) they had been in recruiting Americans.

That changed in the mid-1990s. The United States de-classified the results of the “Venona Project,”–an intelligence initiative that involved the surveillance of secret Soviet cable traffic during World War Two–and Alexander Vassiliev, a Russian journalist, made his notebooks on KGB activities in the U.S. available to researchers. For the first time, scholars such as John Earl Haynes and Harvey Klehr could measure the success of KGB spying in the U.S. during the Cold War.

The results are eye-opening, as Haynes and Klehr explain in Spies: The Rise and Fall of the KGB in America (Yale University Press, 2009). Though it’s probably unwise to speak of “winners and losers” in the debate over KGB spying in the U.S., Haynes and Klehr show that the Soviets, though often bungling, had done a pretty fair job of tapping sympathetic American Leftists and stealing American secrets. That said, they also discovered that some of those the Right had accused of spying (e.g., Robert Oppenheimer) were in fact innocent.

Strange gadget: Robert Oppenheimer

This is, in my opinion, the best biography yet of Oppenheimer. I think I have read all of the dozen or so major ones. See also The Christy gadget.

Oppenheimer's near breakdown while at Cambridge: the story that Oppenheimer attempted to poison his tutor Patrick Blackett (with a cyanide-laced apple) is well known; his erratic behavior in Paris and an attempt on the life of his Harvard friend Francis Fergusson are also described.

(p.102) [Oppenheimer's mother] insisted he see a Parisian psychiatrist. The diagnosis was sexual frustration and the prescription, accordingly, sex with a prostitute [However, this was unsuccessful, see footnote.]

... Fergusson went to see Oppenheimer in his Parisian hotel room and discovered him to be in "one of his ambiguous moods." He showed Oppenheimer some poetry written by his fiancee ... "I leaned over to pick up a book, and he jumped on me from behind with a trunk strap and wound it around my neck. I was quite scared for a little while. We must have made some noise. And then I managed to pull aside and he fell to the ground weeping."

Norris Bradbury (Oppenheimer's successor as Los Alamos director):

(p.419) Oppenheimer could understand everything, and there were some hard physics problems here to understand ... Don't forget what an extravagant collection of prima donnas we had here. By his own knowledge and personality he kept them inspired and going forward.

Robert Serber:

(p.419) He could understand anything ... One thing I noticed: he would show up at innumerable different meetings at Los Alamos, listen and summarize in such a way as to make amazing sense. Nobody else I ever knew could comprehend so quickly.

Schwinger on Oppenheimer losing touch with real research after too much time as an administrator:

(p.299) [Oppenheimer's grasp] became more and more superficial, which I regretted very much. It was a lesson to me, never to lose completely your touch with the subject, otherwise it's all over... He [Oppenheimer] did have a quick brain. There was no question about that, but I think the brain must be supplemented by long hours of practice that go into the fluidity and ease. Without the technical practice, sooner or later you get lost.

Here's an Edward R. Murrow interview with Oppenheimer mentioned in the book.

He is a second Dirac, only this time human

Another historical letter sent by a reader. My understanding is that Feynman was not appointed at Berkeley because of Birge's anti-semitism: "One Jew (Oppenheimer) is enough," he is reported to have said.

CONFIDENTIAL

November 4, 1943

Professor R. T. Birge
Chairman, Department of Physics
University of California
Berkeley, California

Dear Professor Birge:

In these war times it is not always easy to think constructively about the peace that is to follow, even in such relatively small things as the welfare of our department. I would like to make one suggestion to you which concerns that, and about which I have myself a very sure and strong conviction.

As you know, we have quite a number of physicists here, and I have run into a few who are young and whose qualities I had not known before. Of these there is one who is in every way so outstanding and so clearly recognized as such, that I think it appropriate to call his name to your attention, with the urgent request that you consider him for a position in the department at the earliest time that that is possible. You may remember the name because he once applied for a fellowship in Berkeley: it is Richard Feynman. He is by all odds the most brilliant young physicist here, and everyone knows this. He is a man of thoroughly engaging character and personality, extremely clear, extremely normal in all respects, and an excellent teacher with a warm feeling for physics in all its aspects. He has the best possible relations both with the theoretical people of whom he is one, and with the experimental people with whom he works in very close harmony.

The reason for telling you about him now is that his excellence is so well known, both at Princeton where he worked before he came here, and to a not inconsiderable number of "big shots" on this project, that he has already been offered a position for the post war period, and will most certainly be offered others. I feel that he would be a great strength for our department, tending to tie together its teaching, its research and its experimental and theoretical aspects. I may give you two quotations from men with whom he has worked. Bethe has said that he would rather lose any two other men than Feyman from this present job, and Wigner said, "He is a second Dirac, only this time human."

Of course, there are several people here whose recommendation you might want; in the first instance Professors Brode and McMillan. I hope you will not mind my calling this matter to your attention, but I feel that if we can follow the suggestion I have made, all of us will be very happy and proud about it in the future. I cannot too strongly emphasize Feynman's remarkable personal qualities which have been generally recognized by officers, scientists and laity in this community.

With every good wish,

Robert Oppenheimer

"For the historians and the ladies"

The excerpts below are from interviews with Benoit Mandelbrot.

On the birth of molecular biology under Max Delbruck at Caltech:

I would say the more important event was quite outside of my life's work, the arrival of Max Delbruck. Now Max Delbruck was, I think, one of the great personalities of those times. He was a physicist by training, a man belonging to one of the very highest families in Prussia, in many ways a great liberal, in many ways a great authoritarian. 

Max Delbruck had been told in the '30s, according to rumour, that he was just not good enough to be doing physics as well as he hoped; that while Bethe would spend a few hours and write seventeen pages of flawless mathematics, and Weisskopf wrote only fifteen, but equally flawless - and Pauli always preferred Bethe to Weisskopf because of this difference - well, Delbruck only wrote five and there were bugs to fix. He was not up to this competition, which he was finding himself in. 

But he had branched into biology, the first physicist (to do so). Schrödinger had written about him in his book What Is Life? Delbruck had suddenly become a challenge. And the challenge was met by an equally remarkable man named Beadle who was a farmer from Nebraska who had gone to university to learn more about corn to improve the yield of his farm and moved on, and by that time had become the chairman of the Biology division at Caltech. Beadle was a very bold person. He hired Delbruck, who knew no biology, and told him, "You go and learn biology by teaching Biology One to freshmen, and then go on and do your thing," - which was to introduce quantum mechanics ideas into biology. 

Now, I never knew what they were doing. They were very - I wouldn't say secretive, they were just a little elusive. They never said what they were doing. Well it was clear they were doing something extraordinarily exciting which for me was again this very strong hope of bringing hard mathematical or physical thinking to a field, which had been very soft before.

"For the historians and the ladies"; saved by Oppenheimer and von Neumann:

... I met Oppenheimer now and then, and then saw him in a train from Princeton to New York. We chatted. He asked me what I was doing, and I explained to him what I was doing. He became extraordinarily excited. He said, "It's fantastic. It's extraordinary, that you could have found a way of applying, genuinely thinking of applying thermodynamics to something so different, and that you find everything will be decided upon analytic properties like partition function," and of course he understood instantly. 

And he asked me to give a lecture, and he said, "Make it a lecture in the evening, for the historians and the ladies." Those were his words. "Make it easy." 

So one evening, which was fixed with his secretary, I came up and I was expecting to find "historians and ladies." To my surprise, Oppenheimer was there. I tried to block his way, and he went, "No, I'm very much interested.' And then Von Neumann came. I said, "You know my story completely. I didn't prepare a lecture for you." "Well," he says, "perhaps not, but I'm the chairman and the discussion may be interesting." Now, the lecture was, again, to explain to this group that the kind of thinking represented by thermodynamics, as Tolman had made me understand it, could be applied outside and that in a way the abyss between, how to say, humanities and sciences was something you could bridge. That was Oppenheimer's idea, or something like it. 

Well, I saw all these great men and their spouses arriving, and my heart sank to my heels. I became totally incoherent. I had prepared a very simplified lecture, which I could not do at that age - I could do it now, perhaps, but not then. I tried to change it into a lecture for them. They started falling asleep and snoring. It was a horrible sight. I stopped after forty-five minutes saying, "Ladies and gentlemen, thank you for your attention," etc., etc. Mild applause. Von Neumann stands up and says, "Any questions?" Dead silence. Then a friend asked a question. "Any other question?" Dead silence. Another friend asked a question. And when Von Neumann was about to close the lecture, somebody named Otto Neumenbour stands up in the last row and says, "I have, not a question, but a statement. This is the worst lecture I have attended in my life. I have not understood one word the speaker said. I don't see any relation with the title," and he went on like that, until Oppenheimer stopped him. "Otto, Otto. Please, let me respond, if Dr Mandelbrot would be so kind as to allow me to respond instead for him. The title is very unfortunate. I gave it to my secretary. Dr Mandelbrot should have changed it to be more appropriate. As to the content, well, it may well be that he didn't make justice to his own work, but I believe I understand his every word, and he has a point." 

Now he went on into the celebrated Oppenheimer lecture. In fact he was the fear of any lecturer in physics - after he had struggled for an hour explaining things, Oppenheimer would stand up and say, "Well, if I understand correctly, this is what you said." In ten minutes he would speak flawlessly - finished sentences and everything! At that time everybody woke up. They said, "That miserable lecturer, he was trying to say these things!" Well, then when he sat down, Von Neumann stood up and said, "Well, I too have some comments to make about Dr Mandelbrot's lecture. We've had a number of interesting discussions and it may well be that he didn't do much justice to his work." Well, it was an abominable lecture, and he went on in his style which was very different, explaining what he saw in my work and why it was interesting, why this and that. Well, needless to say, I was taken in time by my friends to the only place in Princeton that served beer at that time. 

Next day I went to see to Neumenbour, when I entered he said, "Oh, I'm very sorry. I made a fool of myself yesterday. Please excuse me," etc., etc. (I replied) "No, I am coming to thank you. It was you, in a way, that started the real lecture." Well, so you see what was happening was that Von Neumann - and Oppenheimer, I think- understood what I was trying to do, and Von Neumann wanted to encourage me very strongly.

Note added: In this Caltech oral history, Delbruck recalls that at one point he was studying Fisher's The Genetical Theory of Natural Selection, and mentioned this to a visitor from the Rockefeller Foundation (the sponsor of Delbruck's fellowship at the time). He was immediately offered the chance to work with Fisher, but decided to go to Caltech (as a postdoc; he was hired back as a professor some years later) instead. Also, see comments for corrections to Mandelbrot's story from a biologist.

Theory and experiment

From the autobiography Alvarez: Adventures of a Physicist. See also Alvarez quotes, and related posts.

Chapter 4: I learned about the discovery of nuclear fission in the Berkeley campus barbershop one morning in late January 1939, while my hair was being cut. Buried on an inside page of the Chronicle was a story from Washington reporting Bohr's announcement that German chemists had split the uranium atom by bombarding it with neutrons. I stopped the barber in mid-snip and ran all the way to the Rad Lab to spread the word. The first person I saw was my graduate student Phil Abelson. I knew the news would shock him. "I have something terribly important to tell you," I said. "I think you should lie down on the table." Phil sensed my seriousness and complied. I told him what I had read. He was stunned; he realized immediately, as I had before, that he was within days of making the same discovery himself. 

... I tracked down Oppenheimer working with his entourage in his bullpen in LeConte Hall. He instantly pronounced the reaction impossible and proceeded to prove mathematically to everyone in the room that someone must have made a mistake. The next day Ken Green and I demonstrated the reaction. I invited Robert over to see [it] ... In less than 15 minutes he not only agreed that the reaction was authentic but also speculated that in the process extra neutrons would boil off that could be used to split more uranium atoms and thereby generate power or make bombs. It was amazing to see how rapidly his mind worked, and he came to the right conclusions. His response demonstrated the scientific ethic at its best. When we proved that his previous position was untenable, he accepted the evidence with good grace, and without looking back he immediately turned to examining where the new knowledge might lead.

This short passage illustrates many aspects of science: the role of luck, the convergence of different avenues of investigation, the overconfidence of theorists and the supremacy of experiments in discerning reality, the startling reach of a powerful mind.

On living like kings

A colleague saw my recent post Living like kings and sent the following message.

Hi Steve,

I found your blog post about physics & scenery, with the nice picture of San Francisco Bay, funny and oddly appropriate to my day. A few hours ago I was sitting in a rocking chair in front of a giant window at Seattle airport watching a beautiful sunset and reading a popular science book on Quantum Mechanics, and thinking that it's a great way to be spending an evening working. Livin' like a king!

(To answer the obvious questions: no, I don't know why Seattle airport has rocking chairs. The book is for a course I'm developing for our new HHMI funded science literacy program, for which I am one of the guinea pigs. I was at the airport on my way to Walla Walla, where I'm giving a talk tomorrow at the NW section of the APS meeting, which I agreed to before realizing how hard it is to get to Walla Walla. It occurred to me, incidentally, that the seat was ideal, since it captures a chair's hard, particle-like nature together with the gentle oscillations of a wave.)

best wishes,

R

Robert Oppenheimer once wrote to his younger brother Frank about ...physics and the obvious excellences of the life it brings :-) Of course, things aren't quite what they were in the good old days.

Ah, the good old days...

"Physics and the excellences of the life it brings" -- those words appear in a letter from Robert Oppenheimer to his younger brother Frank, who was then embarking on his own career in physics. Frank Oppenheimer worked on the Manhattan project and became a high energy experimentalist at Minnesota, but was dismissed over communist party ties. He later helped found the Exploratorium, a science museum in San Francisco.

Here's a nice overview of R. Oppenheimer's life, in the form of a table of contents:

Robert Oppenheimer - Letters and Recollections
by A.K. Smith and C. Weiner

I "Work frantic, bad and graded A"
HARVARD, 1992-1925
II "Making myself for a career"
EUROPE AND AMERICA, 1925-1929
III "Physics and the excellences of the life it brings"
BERKELEY AND PASADENA, 1929-1941
IV "These terrible years of war"
LOS ALAMOS, 1942-1945
V "High promise ... yet only a stone's throw from despair"
LOS ALAMOS, AUGUST TO NOVEMBER 1945

How excellent are things today for young scientists? Here's what Nature had to say:

Is the US producing enough scientists?

Why do young people go into science? Many can't imagine doing anything else—the excitement of discovering new things is irresistible. Robert Oppenheimer once referred to "physics and the obvious excellences of life it brings". Stephen Jay Gould wrote movingly of being a street kid from New York City who hoped one day "to become a scientist and to make, by my own effort, even the tiniest addition to human knowledge..." For talented people, at least in countries where a wide range of opportunities are available, these decisions are often based on the feeling that there is simply no other kind of life that would be as personally rewarding. For others, however, different kinds of rewards no doubt loom large, with employment and salary prospects being the most obvious. As a result, anyone interested in understanding the flow of people into science must come to grips with the larger economic forces that might be shaping it. ...

...Producing more science graduates is undoubtedly a good thing for American science; whether it's a good thing for young American scientists, however, is much less clear, and the current generation of students will be right to be skeptical. The reasons for this were outlined in an excellent 1999 article in the New Republic by Scott Stossel ("Uncontrolled Experiment"). Fundamentally, Stossel argued, American science is a victim of its own success. The impressive increases in funding from the National Institutes of Health have led to an army of graduate students and postdoctoral fellows to carry out the promises of all the funded grant applications. But even this generous level of support isn't adequate to satisfy the demand for independent jobs when these postdocs want to become principal investigators themselves. At the same time, foreign-born students see these low-paying fellowships at well-regarded American graduate programs as relatively attractive. Given that this puts further downward pressure on salaries, the effect is to discourage many American students from embarking on the long training period that is necessary to secure an academic position. To be sure, many students see science as a calling and are perfectly willing to take their chances; others, however, are less likely to ignore the laws of supply and demand when their livelihoods are on the line.

The tone of this editorial is funny -- it's obviously written for the typically monkish and narrowly obsessive researcher, who can't imagine that economic or career considerations might deter someone from pursuing a life in science. (Homo economicus and homo scientus stare at each other in mutual incomprehension :-) Nowadays, success in science seems to be as much a selection for these character or personality traits as it is a selection for talent.

Oppenheimer on Einstein

A great find -- via Brad DeLong -- from 1966. Trying to teach non-science majors about relativity this quarter has only enhanced my regard for Einstein's genius.

More on Oppenheimer and Einstein from this blog.

Note Added: another great Internet find -- a chess game (Princeton, 1933) in which Einstein defeats Oppenheimer (the latter, playing black, appears to lose his queen on a blunder :-)

New York Review of Books:

... Einstein was a physicist, a natural philosopher, the greatest of our time.

What we have heard, what you all know, what is the true part of the myth is his extraordinary originality. The discovery of quanta would surely have come one way or another, but he discovered them. Deep understanding of what it means that no signal could travel faster than light would surely have come; the formal equations were already known; but this simple, brilliant understanding of the physics could well have been slow in coming, and blurred, had he not done it for us. The general theory of relativity which, even today, is not well proved experimentally, no one but he would have done for a long, long time. It is in fact only in the last decade, the last years, that one has seen how a pedestrian and hard-working physicist, or many of them, might reach that theory and understand this singular union of geometry and gravitation; and we can do even that today only because some of the a priori open possibilities are limited by the confirmation of Einstein's discovery that light would be deflected by gravity.


Yet there is another side besides the originality. Einstein brought to the work of originality deep elements of tradition. It is only possible to discover in part how he came by it, by following his reading, his friendships, the meager record that we have. But of these deep-seated elements of tradition—I will not try to enumerate them all; I do not know them all—at least three were indispensable and stayed with him.

THE FIRST IS from the rather beautiful but recondite part of physics that is the explanation of the laws of thermodynamics in terms of the mechanics of large numbers of particles, statistical mechanics. This was with Einstein all the time. It was what enabled him from Planck's discovery of the law of black body radiation to conclude that light was not only waves but particles, particles with an energy proportional to their frequency and momentum determined by their wave-number, the famous relations that de Broglie was to extend to all matter, to electrons first and then clearly to all matter.

It was this statistical tradition that led Einstein to the laws governing the emission and absorption of light by atomic systems. It was this that enabled him to see the connection between de Broglie's waves and the statistics of light-quanta proposed by Bose. It was this that kept him an active proponent and discoverer of the new phenomena of quantum physics up to 1925.

The second and equally deep strand—and here I think we do know where it came from—was his total love of the idea of a field: the following of physical phenomena in minute and infinitely subdividable detail in space and in time. This gave him his first great drama of trying to see how Maxwell's equations could be true. They were the first field equations of physics; they are still true today with only very minor and well-understood modifications. It is this tradition which made him know that there had to be a field theory of gravitation, long before the clues to that theory were securely in his hand.

The third tradition was less one of physics than of philosophy. It is a form of the principle of sufficient reason. It was Einstein who asked what do we mean, what can we measure, what elements in physics are conventional? He insisted that those elements that were conventional could have no part in the real predictions of physics. This also had roots: for one the mathematical invention of Riemann, who saw how very limited the geometry of the Greeks had been, how unreasonably limited. But in a more important sense, it followed from the long tradition of European philosophy, you may say starting with Descartes—if you wish you can start it in the Thirteenth Century, because in fact it did start then—and leading through the British empiricists, and very clearly formulated, though probably without influence in Europe, by Charles Pierce: One had to ask how do we do it, what do we mean, is this just something that we can use to help ourselves in calculating, or is it something that we can actually study in nature by physical means? For the point here is that the laws of nature not only describe the results of observations, but the laws of nature delimit the scope of observations. That was the point of Einstein's understanding of the limiting character of the velocity of light; it also was the nature of the resolution in quantum theory, where the quantum of action, Planck's constant, was recognized as limiting the fineness of the transaction between the system studied and the machinery used to study it, limiting this fineness in a form of atomicity quite different from and quite more radical than any that the Greeks had imagined or than was familiar from the atomic theory of chemistry. ...

Oppenheimer centenary

2004 was the 100th anniversary of J. Robert Oppenheimer's birth. See here for a partial list of recent biographies, and here for a Times review of two of them.

I can think of few figures as complex as Oppenheimer. "American Prometheus" (the title of one of the biographies) is a suitable characterization. From the Times review: "American Prometheus" is a work of voluminous scholarship and lucid insight, unifying its multifaceted portrait with a keen grasp of Oppenheimer's essential nature. What did he do upon finding himself in a Capitol Hill elevator with Senator Joseph McCarthy, the embodiment of Oppenheimer's comeuppance? "We looked at each other," the physicist told a friend, "and I winked."

"American Prometheus" sees the full implications of such a gesture: charm and bravado on the surface, Dostoyevskian darkness underneath. It traces Oppenheimer's arrogance to the kind of upbringing that would give him his own sloop at age 16 (he named it for a chemical compound) and lead one of the oral examiners of his doctoral thesis to say: "I got out of there just in time. He was beginning to ask me questions."

Many of the stories from his time at Berkeley, Caltech, Los Alamos and the IAS concern his role in the Manhattan project, or his communist sympathies and fall from grace during the McCarthy era. His contributions as the founder of what was at the time the leading school of American theoretical physics are often overlooked.

Perhaps most important was his work in the 1930's on the endpoint of stellar evolution, with his students Volkoff and Snyder at Berkeley. They explored many of the properties of black holes long before the term "black hole" was coined by Wheeler. Oppenheimer and company were interested in neutron star stability, and gave the first general-relativistic treatment of this complicated problem. In so doing, they deduced the inevitability of black hole formation for sufficiently massive progenitors. They also were the first to note that an infalling object hits the horizon after a finite proper time (in its own frame), whereas an observer orbiting the hole never actually sees the object hit the horizon. The work received amazingly little attention during Oppenheimer's life. But, had Oppenheimer lived another few decades, it might have won him a Nobel prize.