December 16, 2017
Sarah Cochrane, Assistant Archivist
Ninety-two years ago, on 16 December 1925, Werner Heisenberg wrote a letter to Samuel Goudsmit regarding electron spin, about which an article had been published in September of that same year by Goudsmit and George Eugene Uhlenbeck – both graduate students working under Paul Ehrenfest at the University of Leiden at the time. This is the missing link in a string of correspondence between the two young physicists from fall/winter 1925-1926.
In March 2017, Esther Goudsmit, daughter of Samuel Goudsmit, sent the letter (in German) and its translation to NBL&A. She had found it in a drawer of miscellanea and decided it was important that it be united with the rest of her father’s papers. Confirming that it was missing from the collection, we interfiled it with the 1925 Chronological correspondence (box 2, folder 5). You can read the December 16 letter here.