"Atomic theory of the lambda transition in liquid helium" AND WITH "Atomic theory of liquid helium near absolute zero" in Physical Review.

FEYNMAN, R.P. "Atomic theory of the lambda transition in liquid helium", in Physical Review, 1953, vol 91, pp 1291-1301. BOUND WITH: "Atomic theory of liquid helium near absolute zero". Physical Review, vol 91, pp 1301-1308, in the same issue. Both bound in cloth, the July-Sept volume of Physical Review. No wrappers. Very good copy. [++] "The problems that Feynman worked on came from solid-state theory. He became especially interested in liquid helium. At ordinary temperatures and pressures, helium exists as a gas; but at extremely low temperatures (a few degrees above absolute zero), helium becomes a liquid indeed, a liquid with strange properties. Liquid helium displays superfluidity, that is, it flows with no viscosity or friction at all (unlike ordinary liquids). The phenomenon had been discovered experimentally during the 1930s, and the great Russian theorist Lev Landau had provided a successful phenomenological description during the 1940s. Feynman brought his newest tools to bear on the problem path integrals and Feynman diagrams to explain superfluidity on a rigorously quantum-mechanical basis. In addition to the particle-like quantum excitations that had been studied, Feynman realized that a new quantum effect also played a role: the formation of quantum vortices. Once again his intuitive, pictorial approach proved successful." --Kaiser, David. "Feynman, Richard Phillips." Complete Dictionary of Scientific Biography, vol. 21, Charles Scribner's Sons, 2008, pp. 18-26.…