F > L > P > S

Andrei Sakharov with daughter, 1948.

Excerpts below from The World of Andrei Sakharov (link goes to full text) by Gennady Gorelik. See Out on the tail for a discussion of Landau's logarithmic ranking of physicists.

(p.159) Discussing Tamm’s desire that Landau be his official dissertation opponent in his Memoirs, he remarked that the latter “fortunately, refused; I would have felt very awkward because I realized the dissertation’s inadequacies.” Sakharov also talked about his failure in pure physics in the summer of 1947, and how Pomeranchuk (his dissertation opponent) did “a hatchet job” on the same problem, while Landau dealt with it “in an elegant and productive way.” This gave Sakharov the basis to humbly “formulate a system of inequalities: L > P > S” (L for Landau, P for Pomeranchuk, S for Sakharov).

... Sakharov for some reason came to the Institute of Physical Problems, where Landau headed up the Theoretical Department and a separate group doing research and calculations for “the Problem.”

After we finished discussing our work, Landau and I walked out into the Institute garden. This was the only time we talked without witnesses, heart-to-heart. He said: “I really don’t like all this.” (The context was nuclear weapons in general and his participation in this work in particular.)
“Why?” I asked somewhat naively.
“Too much fuss.”
Landau usually smiled a lot and easily, baring his large teeth, but this time he was sad, even mournful.

Landau on the Soviet nuclear weapons effort:

(p.190, quote from 1952-3) "One must use all one’s strength not to get involved in the thick of atomic work. But one has to be very careful refusing it . . . If it weren’t for Box Five [Jewish ethnicity], I would not be doing special [nuclear-weaponry] work, but pure science, in which I now lag behind. The special work gives me a certain amount of personal security. But it’s far from my serving 'for the good of the Homeland' ... I have been reduced to the level of a “scientist slave” and this defines it all."

... Zeldovich was close enough to Landau to know how he felt about this work. Zeldovich considered Landau his teacher, and it was on Landau’s recommendation that Zeldovich was elected Corresponding Member of the Academy of Sciences. However, in the early 1950s, Landau berated Zeldovich with the foulest possible language when the latter attempted to drag him more deeply into secret work in spite of his unwillingness.

On Sakharov and Zeldovich.  Gorelik interprets events surrounding the development of the Soviet H-bomb as I did in the earlier post: Sakharov's Third Idea.

(p.188) From an eyewitness: These two prominent theorists had very different “styles of thinking.” Sakharov was characterized by inventiveness and great profundity while Zeldovich by very quick thinking and high erudition. These scientists created an extraordinarily creative climate; the Institute [Installation] became orphaned after their departure at the end of the 1960s.

Another eyewitness recalls how interesting it was to follow the discussion of these outwardly opposite individuals: One was short in stature, bespectacled, rapid in his movements, and spoke clearly; the other was tall, languid, and spoke with a slight burr. But they were linked by sharp minds and enormous physical intuition. Mutual problems stimulated their thinking and they quickly grasped the crux of processes; hardly anyone managed to follow the course of their reasoning.

... Sakharov himself did not underestimate the heroism of what he had done. Twenty years later, when he received an invitation to come to the United States and lecture, his wife asked him what would interest him the most in America. By that time his imagination was already involved in cosmology and the physics of elementary particles, and he had an altogether different view of the government for which he had created thermonuclear weapons. However, he told his wife that he wanted very much to sit side by side with Ulam to compare the paths by which they had arrived at the same solution (it was in the 1970s, when the roles played by Ulam and Teller in creating the H-bomb were not clear).

Zeldovich admired Sakharov’s talent, treated him “extraordinarily carefully,” “timidly,” and said: “What am I? Now, Andrei, he’s something else!” According to another witness, Zeldovich said: “I can understand and take the measure of other physicists, but Andrei — he’s something else, something special."