George Gamow and the atomic bomb

by Alex Wellerstein, published January 18th, 2013

George Gamow stands out as a colorful physicist among a generation of colorful physicists. He was a known wit, a friend to many of the “golden generation” of physicists, and — on top of all that — was a Russian émigré who had made a dramatic defection from the Soviet Union during a Solvay Conference. He was also a well-known popularizer of science, authoring well over a dozen works of physics aimed at the general public, often illustrated with his own amusing little drawings. He was quite a card: who else adds a scientist’s name to a massively important paper just to make a silly pun?

George Gamow, laughing and smoking, probably ca. the 1950s. Photo from the AIP Emilio Segrè Visual Archives.

George Gamow, laughing and smoking, probably ca. the 1950s. Photo via the AIP Emilio Segrè Visual Archives.

(Later in life, he became a very difficult person to be around, on account of his alcoholism. It was this fact that made me a little surprised that there was a free wine bar sponsored in the name of George Gamow at a meeting of the History of Science Society a few years back.)

Gamow’s scientific interests were all over the place — he was completely uninterested in disciplinary boundaries — and he was enormously influential on his peers as a “program builder.”1  It’s a little-known fact that Edward Teller came up with the idea of using a solid core of plutonium in the implosion design — an intuition he had because of his work with Gamow on the molten, compressed iron core of the Earth.2 Gamow’s work on nucleosynthesis and the Big Bang was immensely important to the advancement of cosmological thinking. Incidentally, Gamow did not like the term “Big Bang,”  because it sounded too much like nukes. He later even had an excursion into molecular biology.

But during World War II, Gamow didn’t work on the atomic bomb, though he continued to work on nuclear physics. One of the most charming letters I’ve found in the archives was written by Gamow to Vannevar Bush on August 12, 1945. You will note, of course, that this comes just three days after the bombing of Nagasaki, and is the same day the Smyth Report was released. In a clear but stylized handwriting, with a touch of refugee’s English, Gamow wrote the following letter to Bush:3

Click image to view PDF.

Click image to view PDF.

Aug 12th, 1945
19 Thoreau Drive
Bethesda, Md.

Dear Dr. Bush,

I am writing to you because I think you are the best man to advice me what to do. As you know I was in no way connected with the project of “atomic bomb” developement, while on the other hand, working all my life on nuclear physics, I naturally could not help not thinking about it and have rather clear ideas about the possibilities involved etc. As long as the whole thing remained a supersecret I was naturally trying to hold all my thoughts to myself. However now, when the thing exploded and all the newspapers are full of informations, I wonder where the boundary between what can and what cannot be told should be placed. Thus, for example, in my course of nuclear physics which I am giving in G.W.U. this summer I will have to speak next week about nuclear transformations, thermonuclear reaction, and nuclear chain reactions. Should I entirely avoid mentioning explosive reactions or not?

Again, I am now preparing the new edition of my Book on Nuclear Physics for Oxford Univ. Press. How much could be told in it about this part of the problem? Finally I was recently asked to write a small popular book on Atomic Energy. Must I reject such offer or not?

You understand of course that in all these cases the question is not about the technical details which I do not know, but about broad “purely scientific” point of view. As the matter of fact I do not think I know much more on the subject that the scientists in other countries, as for example in Soviet Russia, know at present, so that such utterings on my part will hardly be of any particular use for the “competitors.” Still, I would not like to do anything in this direction, without first receiving your advice.

Hoping to hear from you soon

Your very truly G Gamow.

Gamow’s concern was not unique to him, though he was a little ahead of the curve when it came to expressing it. He, like most other physicists, quickly saw that nuclear physics was going to become a much more troublesome thing in the age of atomic bombs. One of the biggest concerns at the time, by those inside the bomb project and those not, was that if nuclear physics became a top-secret area, it would severely impact the education of new physicists.

His letter did not go unnoticed; Vannevar Bush wrote him back a careful reply two days later, pointing out that the Smyth Report was released at almost the same time that Gamow’s letter was written, and that one of its explicit purposes was to make that firm line of security visible to folks like Gamow. Bush then offered up this bit of speculation:

I have no doubt that later there will be constituted in some way an official body to determine the proper bounds of scientific discussion, and undoubtedly competent scientists will be present on any such body. How this may possibly be done it is too early to know. However, in the interim there is a guide in the form of a report [the Smyth Report] and after the body is established there will be a place to turn which anyone can use who may be in doubt. 

The reality was somewhat more complicated than this, in the end. Policing “the proper bounds of scientific discussion” was ostensibly the role of the Atomic Energy Commission, but they found it quite hard to do such a thing in practice.

Gamow was, in the end, somewhat sucked into the weapons complex. He was a lecturer to US Naval Officers on fission physics just before Operation Crossroads, and later he was involved in the work on the hydrogen bomb, at Los Alamos. While there he drew this rather unusual little drawing celebrating the discovery/invention of the Teller-Ulam design in 1951:4

Gamow's drawing of Ulam and Teller, March 1951

What does it mean? Stanislaw Ulam as a very Bugs-Bunnyish hare, Edward Teller as a tortoise? The most banal and boring interpretation would be that Teller had been working at the H-bomb problem for a long time, and it was Ulam — the relative new-comer — had scooped him.

But I can’t help but wonder if there is more to its imagery than that — Gamow’s pen was famously more quick-witted than that. Perhaps there is meant to be a secret clue as to the differences in their approaches?

One stab at it: Teller’s Classical Super involved a propagating thermonuclear reaction in a large mass of fusion fuel — you light one end of a deuterium candle, and the thermonuclear “fire” travels along it. Ulam’s compression scheme (which would be translated into radiation implosion in collaboration with Teller) involved trying to ignite the entire fusion fuel mass all at once, more or less. Teller’s approach is a much slower reaction than Ulam’s; this is part of the reason that Teller’s Classical Super wouldn’t work (the fuel cools too quickly and can’t sustain the temperatures needed for fusion). So Ulam is the fast rabbit, Teller is the slow turtle, and in this instance (unlike Aesop), the rabbit wins the race.

Or perhaps it has something to do with the different geometries? Why does the Teller turtle have three rocks? Is the carrot a reference to the relatively long geometry of the Ulam approach, versus the spherical symmetry of the Alarm Clock design? Is the “P” on Ulam’s hat for his native Poland, or something else?

Are there secrets hidden in Gamow’s humor? Might Gamow be having the last laugh?

  1. Nasser Zakariya, “Making Knowledge Whole: Genres of Synthesis and Grammars of Ignorance,” Historical Studies in the Natural Sciences 42, No. 5 (November 2012), 432-475. []
  2. Robert Christy usually gets the credit for the solid core. It was Teller’s initial idea, but it was Christy who proved it would work. []
  3. George Gamow to Vannevar Bush (12 August 1945), General Records of the Office of Scientific Research and Development, National Archives and Records Administration, RG 227, Box 110, “Security – S-1.” []
  4. This scan comes from the copy reproduced in Peter Galison’s Image and Logic. []

7 Responses to “George Gamow and the atomic bomb”

  1. Charles Day says:

    Gamov’s letter reminds me of the reactions of some of the captive German nuclear physicists who were told of the Hiroshima bomb while being secretly recorded. As soon as they knew the bomb was possible, they could speculate more effectively about how it was made.

  2. Allen Thomson says:

    It’s likely a coincidence, but googling “hydrogen bomb” and “carrot-shaped” does produce a result.

  3. Blake says:

    Additionally, in a Super, is not the secondary known to be tapered toward the distal end of the assembly, so as to presumably compensate for the reduced intensity of thermal x-rays at the far end, thus producing a more simultaneously axisymmetric convergent shock on the Pu spark-plug?

    • So it is supposed to be. (Again, what I meant by the geometries.) But I’m 1. not sure if that tapering had been considered by then (assuming it is true), or 2. whether that is really very different from the Classical Super (which was also more or less a tube).

  4. jck says:

    There is the letter “gamma” on the hat if you look closely… The P and the sun for radiation pressure ?