Friday, August 17, 2012

"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.


steve hsu said...

A biologist writes in to correct Mandelbrot's comments on Delbruck:


"Delbruck, who knew no biology" is absolutely not true.

Delbruck learned plenty of biology (including Drosophila genetics) in Berlin, before he ever got to the USA. He, along with other physicists from Bohr's circle who got interested in biology, learned it mainly from an illustrious guy called Timofeev-Ressovsky ( In fact, they published a very classic paper together in 1935 ( ), in which they, naively aping Rutherford's experiment, estimated a size of the gene ( ). The idea was actually Timofeef's - the initial experiments were done before Delbruck came to town.

Interestingly, Timofeev-Ressovsky was a pupil of Koltsov, the guy who in 1927 wrote that genes are inherited via "two mirror strands that would replicate in a semi-conservative fashion using each strand as a template". Apparently, it was Watson who brought the idea of the template-based gene propagation to Crick. Watson denies ever hearing of Koltsov - almost certainly true. But also almost certainly true is that Watson, being Luria and Delbruck's protege, heard the idea from Delbruck who, in turn, got it from Timofeev-Ressovsky (who was always adamant that Koltsov's insight had to be at least part true).

Also, before Delbruck was hired by Caltech in 1947, he spent 8 years in the USA doing all kind of biological research, some of it with Luria (including the famous 1943 Luria–Delbruck experiment). It is inconceivable that Luria, being a medical doctor by education, had not contributed to Delbruck's understanding of biology.

I guess that it all goes to show that we shouldn't buy too much into the idea that a bright physicist can get in, teach himself biology by teaching some 101 course and make several seminal contributions as a result :-)


Abhinav Singh said...

One can get an overview of Delbruck's biological education from his Royal Society biographical memoirs:
He was far from being a novice at the time of his appointment at Caltech as faculty, infact he was elected to NAS in 1949.

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