4 8 D O C U M E N T 3 J U N E 1 9 2 7 Prinzipien, in der er die Wellenseite der Qu. M. näher analysiert und bei der er auch noch ein paar wesentliche Fehler in meiner Arbeit gefunden hat. Doch nun noch- mal vielen herzlichen Dank! Ihr dankbar ergebener Werner Heisenberg. ALS. [12 174].  Heisenberg (1901–1976) was Lecturer in Physics at the University of Copenhagen and Assistent to Niels Bohr.  Presumably, Einstein had sent Heisenberg his comments on Heisenberg 1927, the proofs of which had been sent to him by Niels Bohr (see Niels Bohr to Einstein, 13 April 1927 [Vol. 15, Doc. 513]).  Erwin Schrödinger (1876–1961) was Professor of Theoretical Physics at the University of Zurich.  Niels Bohr (1885–1962) was Professor of Theoretical Physics at the University of Copenhagen.  Bohr’s considerations were presented at a meeting in Como commemorating the centenary of the death of Alessandro Volta. The lecture was published as Bohr 1928a see also the German trans- lation Bohr 1928b and 1928c, a reworked version published in Nature. One of the mistakes in Heisenberg 1927 corrected by Bohr was the assertion that classically a -ray microscope would allow one to measure the position of a particle with arbitrary precision. In a note added in proof Heisenberg admits his mistake, acknowledging Bohr’s criticism that the finite aperture of the microscope limits the instrument’s precision. In his note, Heisenberg briefly indicates two more points on which he had erred. 3. From Max von Laue Zehlendorf, 11. 6. 27. Lieber Einstein! Du wirst wohl auch schon wissen, daß Sommerfeld die Berufung nach Berlin abgelehnt hat. Unter diesen Umständen würde ich gern Planck’s Nachfolger. Der Fakultätsbericht gibt dem Ministerium freie Hand. Könntest Du nicht Deinen Ein- fluß dahin geltend machen, daß es mich dazu nimmt? Es müßte aber bald gesche- hen, bevor das Ministerium etwa einen anderen Entschluß faßt. Mit herzlichem Gruß Dein M. Laue. TLS. [16 034].  Laue (1879–1960) was Professor of Theoretical Physics at the University of Berlin.  Arnold Sommerfeld (1868–1951) was Professor of Theoretical Physics at the University of Munich.  Max Planck had retired from his position as Professor of Physics at the University of Berlin on 2 November 1926. Sommerfeld was invited to be his successor on 24 March 1927 but declined the offer on 11 June (see Wolfgang Windelband to Sommerfeld, 24 March 1927 and Sommerfeld to Min- istry, 11 June 1927 [Sommerfeld 2000, vol. 2, docs. 108, 113]).