Typed letter signed (‘W. Heisenberg’) to Samuel Goudsmit, in German, saying in part “You can be sure that I will not of my own volition resume the unpleasant discussions of past years, especially not publicly, and I am like you of the view that it is more interesting to discuss physics than the difficulties of times past’, also enquiring about Goudsmit’s opinion on his work at the Brookhaven National Laboratory, and adding Heisenberg is unsure whether he will attend a conference at MIT but he hopes to be able to travel to the US sooner or later, one page, 4to, Max Planck-Institut für Physik, Göttingen, 22 June 1949.
***It seems pausible that Heisenberg’s mentioning of “the unpleasant discussions of past yeas” refers to the role he played in the Nazi atomic bomb programme. Samuel Goudsmit was chief scientific advisor in the US ‘Alsos Mission’, which aimed at uncovering and countering the Nazi programme: Goudsmit interrogated Heisenberg only two days after his capture in May 1945. By 1949 he was senior scientist at the Brookhaven National Laboratory, which inaugurated the first nuclear reactor in the United States in 1950.