Forces in molecules. Offprint from: Physical Review, Second Series, Vol. 56, No. 4, August 15, 1939

PRESENTATION OFFPRINT INSCRIBED BY FEYNMAN. First edition, extremely rare offprint, inscribed by Feynman, of Feynman's senior undergraduate thesis at MIT, a fundamental discovery "that has played an important role in theoretical chemistry and condensed matter physics" (Selected Papers, p. 1), published when he was just twenty-one. This is a remarkable paper, documenting the first steps in original research of one of the most brilliant minds of the twentieth century. "Feynman was one of the most creative and influential physicists of the twentieth century. A veteran of the Manhattan Project of World War II and a 1965 Nobel laureate in physics, he made lasting contributions across many domains, from electrodynamics and quantum theory to nuclear and particle physics, solid-state physics, and gravitation" (DSB). Feynman showed that "the force on an atom's nucleus is no more or less than the electrical force from the surrounding field of charged electrons - the electrostatic force. Once the distribution of charge has been calculated quantum mechanically, then from that point forward quantum mechanics disappears from the picture. The problem becomes classical; the nuclei can be treated as static points of mass and charge. Feynman's approach applies to all chemical bonds. If two nuclei act as though strongly attracted to each other, as the hydrogen nuclei do when they bond to form a water molecule, it is because the nuclei are each drawn toward the electrical charge concentrated quantum mechanically between them" (Gleick, Genius: The Life and Science of Richard Feynman). His discovery, now known as Feynman's theorem or the Feynman-Hellmann theorem, has endured as an efficient approach to the calculation of forces in molecules. "The importance of the forces on the atomic nuclei for molecular geometry, the theory of chemical binding, and for crystal structure is evident" (Selected Papers, p. 1). ABPC/RBH lists no copy of any offprint of any of Feynman's papers in Physical Review (where he published almost all of his most important work). Not on OCLC. Provenance: Signed 'R. P. Feynman' in pencil in top margin of first page. This offprint was signed by Feynman and given by him to Robert Kinsel Smith (1920-99), a classmate and personal friend of Feynman's at Princeton University, where both Feynman and Kinsel Smith studied for their PhDs (a letter from Kinsel Smith's son testifying to this provenance accompanies the offprint). Born in Far Rockaway in the Queens section of New York City, Feynman (1918-88) entered the Massachusetts Institute of Technology (MIT) in 1935 to begin his undergraduate studies. Although he originally majored in mathematics, he later switched to electrical engineering, as he considered mathematics to be too abstract. Noticing that he 'had gone too far,' he then switched to physics, which he claimed was 'somewhere in between.' To complete their bachelor's degree, all physics majors at MIT were then (as now) required to write a 'senior thesis'. "Thirteen physics majors completed senior theses in 1939. The world of accumulated knowledge was still small enough that MIT could expect a thesis to represent original and possibly publishable work. The thesis should begin the scientist's normal career and meanwhile supply missing blocks in the wall of organized knowledge, by analyzing such minutiae as the spectra of singly ionized gadolinium or hydrated manganese chloride crystals . Seniors could devise new laboratory instruments or investigate crystals that produced electrical currents when squeezed. Feynman's thesis began as a circumscribed problem like these. It ended as a fundamental discovery about the forces acting within the molecules of any substance" (Gleick). Feynman recounted his work on the thesis in an interview with Charles Weiner in March, 1966. "I went to Slater [the renowned solid-state theorist John Clarke Slater (1900-76)], and he gave me a problem, which was . why does quartz have such a small coefficient.…