l:href='#n_43' type='note'>[43] Detonations I: Hydrodynamic Lenses and Radiation Mirrors.” It described staging and emphasized compression:
In this discussion the following general scheme is considered. By an explosion of [deleted; probably “one or more”] auxiliary fission bombs, one hopes to establish conditions for the explosion of a ‘principal’ bomb. [Deleted]. We proposed to discuss certain general features of such an arrangement. The main purpose of the “auxiliary” system is to induce very high compressions in the principal assembly.
[Five pages deleted.]
The scheme then depends on concentrating, as much as possible, the energy released by the explosion of a fission bomb in the mass of the principal assembly and
How original were Ulam's and Teller's ideas? Who should receive more credit for the breakthrough? Opinion among knowledgeable participants and observers ranges far and wide. Bethe assessed the Teller-Ulam invention of staging and compression most generously in a nearly contemporary review:
It is difficult to describe to a non-scientist the novelty of the new concept. It was entirely unexpected from the previous development. It was also not anticipated by Teller, as witness his despair immediately preceding the new concept. I believe that this very despair stimulated him to an invention that even he might not have made under calmer conditions. The new concept was to me, who had been rather closely associated with the program, about as surprising as the discovery of fission had been to physicists in 1939…. [It] created an entirely new technical situation. Such miracles incidentally do happen occasionally in scientific history but it would be folly to count on their occurrence.
Herbert York weighs the difference between concept and design:
What Ulam did was not a thermonuclear device. It was a general idea. What Teller did was convert that into something which was a sketch of a Super that would work. Teller sketched out a super bomb. Ulam simply presented a fairly general idea in dealing with that topic. I think Teller has slighted Ulam, but I think also Teller does deserve fifty-one percent of the credit.
Ulam discounted the originality of the invention late in life, but by then Teller had worked for years to deny his colleague's contribution. “It was a different arrangement,” Ulam said. “It was not new physics. It's not to my mind any such very great intellectual feat. It was partly chance. It could have come a year earlier or two years earlier. It might have… shortened the time between the [H-bomb] decision and the actual production of a physical object.”
Norris Bradbury in retirement discounted not the originality of the invention but its serendipity:
Don't ask me who's the father of the H-bomb, because nobody is… The whole thing was a matter of people putting ideas into a pot around a coffee table… Somebody had an idea and that doesn't work, but they give me an idea, but that doesn't work, but you can give me an idea. Because they were beating one idea against another around a table, in front of a blackboard and so on. It wasn't anybody's real invention; it was just a lot of people working on it…
Eventually an idea appeared, which looked as if it might work, and for which the technology for the [primary] was reasonably available. Not completely, but could be gotten together pretty fast if you put some more work on that… It's a very complicated technical question.
Marshall Rosenbluth sets the Teller-Ulam invention in the context of the work Teller in particular had done on the Cylinder:
It's sort of obvious, once you start doing detailed calculations on radiation flowing out from a bomb to this little test experiment, then you think, why not use a radiation implosion for the secondary? And similarly on the Booster, doing the calculations of how it was going to get imploded and how it would interact with the fissionable material around it — that would be very much related to what you would want to see in the secondary of a thermonuclear explosion. So at least my feeling was that this is kind of a paradigm of the way physics is done. You reach a certain point in your theoretical thinking and then you get stuck for one reason or another, can't go any further, but you try to think what experiments you might do that would shed some light on the situation, even if it's not very obvious — how you go from here to there to actually where you're trying to go, which in this case was the H-bomb. I can see a very clear path. The planning of the
Carson Mark also connects the invention to
It's true that the Teller-Ulam scheme involved radiation. It's true that Ulam thought that you could use… hydrodynamic shock. That's certainly there too. It doesn't move as rapidly as radiation does. It's harder to control and direct. So if you were trying to exercise Ulam's idea of using hydrodynamic shock you'd find, by God, radiation gets there first. Teller then is supposed to have proposed that it would be better to use radiation than to rely on [material shock]. Well, he was right, it was simpler, but you couldn't have avoided it. Had you sat down to design the thing, asking, now, what's the material shock doing, where is it, how fast does it move? You'd say, dear God, the radiation is going faster, it's there, so let's concentrate on that. So it was hardly an important circumstance that Teller thought of radiation whereas Ulam thought of… material [shock]. The fact that Edward thought of radiation was natural because he had been involved in much more detailed work on the George shot than had Ulam.
Niels Bohr, disappointed that a sense of common danger had not prevented such a threatening development, assessed the Teller-Ulam invention most critically in a conversation a decade later with his friend J. Rud Nielson:
[Bohr] told me what Teller's contribution to the design of the hydrogen bomb was. When I asked him how great a contribution this was, he answered: “Old physicists who have turned administrators might not think of this solution. However, if you had asked a good class of physics students, two or three of them would have suggested this solution.”
Which was perhaps unfairly sharp; neither the Soviets, the British nor the French found the Teller-Ulam configuration the first time around.
But whatever the technical originality of the ideas Ulam and Teller developed together in February 1951, John Manley concluded, the political effect was electrifying. “Teller and Ulam really won [the argument about building the thermonuclear] by figuring out how to do it… You don't really want to work on something that you don't know how to do.” Los Alamos radiochem-ist George Cowan enlarges shrewdly on Manley's point:
Knowing that it was going to work sure encouraged those people to go ahead and do it. Particularly because now, whether you believed that it was a good idea or not, the fact that that power was available — anyone who has a realistic view of the way power gets used by governments would know that you had to do it. There was no longer an option. Despite all the debates, no responsible government would ever voluntarily forgo developing a very powerful new weapon if it knew how to do it. That is something that you can talk about if you're not in the government, but if you are in the government it is not an option.
Ulam understood the historic fatality of his breakthrough very well, however much he discounted its originality, and laid claim to its power. There is an old Jewish legend of a Frankenstein's monster, the Golem, created out of clay and animated with holy words to defend the Jews from anti-Semitic assaults. The creator of the
