Beschreibung:

PAULI, Wolfgang. Autograph postcard signed ("W. Pauli") to Samuel A. Goudsmit. Hamburg, 13 March 1926. -- Autograph postcard signed ("W. Pauli") to Samuel A. Goudsmit. Zurich, 17 April, 1931. Written on both sides, 8 o, in German, margin of first card punched with holes, affecting a few letters. This is the historic postcard in which the 26 year old Pauli finally acknowledges that Goudsmit and Uhlenbeck were correct in their discovery of electron spin based on the resolution of the problem of factor two by H. L. Thomas. In the description of the 3 autograph letters from Heisenberg to Goudsmit over this issue [see lot 126] we discussed the problems posed by factor two that were expressed by Heisenberg, and which continued to vex both Heisenberg and Pauli who were in regular correspondence over this and other newly developing issues in quantum physics. Mehra and Rechenberg III, V.5 discuss the intellectual interaction between Bohr, Heisenberg, and Pauli on the issue of factor two in minute detail under the heading, "The Electron Spin, Fine Structure and Anomalous Zeeman Effects." In general, it is fair to summarize from their exposition that what Heisenberg was writing to Goudsmit he was also writing to Pauli. For example, they cite a letter from Heisenberg to Pauli on November 21, 1925 covering some of the same material as the letter from Heisenberg to Goudsmit written on the same day. As the letters from Heisenberg to Goudsmit show, Heisenberg was very sympathetic to Goudsmit while Pauli was openly hostile, and Heisenberg found himself having to defend electron spin to Pauli on several occasions. Pauli's highly critical reaction to electron spin was a typical expression of his character and scientific approach. He has been called, "the conscience of nuclear physics." While Pauli was arguing with Heisenberg over the advantages of Goudsmit's hypothesis he was also discussing the problem with Bohr in both letters and conversations. Pauli continued to raise objection after objection. Beyond the technical formulaic expressions found also in Heisenberg's letters to Goudsmit, Pauli wrote apparently to both Bohr and Heisenberg, in expression of his trouble in reconciling the Factor 2, a paraphrase of Shakespeare's King Richard's desperate appeal, translated as " A half, a half, a kingdom for the factor 1/2" (Mehra & Rechenberg III, 269). Even after Llewellyn Hilleth Thomas solved the matter successfully [See lot 264], and Bohr communicated Thomas' work to Pauli in a letter of 20 February 1926, Pauli was not satisfied. On February 26 he wrote, "In any case, I regard the publication of the present note by Thomas in Nature as a mistake, and would be glad if you [i.e. Bohr] would prevent it or achieve a substantial change in the text of the note" (quoted by Mehra & Rechenberg III, 271). Nevertheless, Bohr continued to attempt to convince Pauli of the correctness of Thomas' solution in a letter of March 3. On March 8, Goudsmit himself paid a visit to Pauli in Hamburg, carrying further details of Thomas' calculations. Even this failed, as Pauli wrote a critical letter to Bohr's assistant, Kramers, explaining his continuing objections on the same day. The following day Bohr sent still another letter which must have been convincing, as on March 12 Pauli wrote to Bohr stating, "Many thanks for your letter of 9 [March] and the enclosed remarks of Thomas. Now all that remains for me is to capitulate completely ! . . ." (Mehra & Rechenberg III, 272). On the same day Pauli wrote a letter to Kramers, and one day later he wrote our postcard to Goudsmit withdrawing his objections to electron spin: "First of all I am writing to you today to inform you that because of recent communications from Copenhagen [i.e. the letters from Bohr] I have realized that I have been wrong in my objections against Thomas and that his deliberations about relativity can be put into an entirely correct and faultless form. Therefore the questions referring to fine stru