2 7 6 D O C . 1 5 6 B A S I C C O N C E P T S O F P H Y S I C S Bündel fliegender elektrischer Teilchen von dem Molekülgitter eines Kristalles in ganz analoger Weise abgebeugt wird wie ein Röntgenstrahlbündel oder wie ein Bündel von Lichtstrahlen durch ein optisches Beugungsgitter. Wir stehen hier vor einer neuen Eigenschaft der Materie, von welcher die bishe- rigen streng kausalen Theorien der Bewegung keine Rechenschaft zu geben ver- mögen.[11] Noch besteht eine gewisse Hoffnung, dass die Feldtheorie mit ihrem streng kausalen Aufbau sich den neu erkannten Thatsachen werde anpassen lassen. Aber es soll nicht verschwiegen werden, dass die erfolgreichsten Theoretiker der jungen Generation an eine solche Möglichkeit nicht glauben. Jedenfalls kann unserer Generation der Vorwurf nicht gemacht werden, dass sie ihre Denkkraft in epigonenhafter Kleinarbeit zersplittere. Verfeinerung des Thatsa- chen-Wissens, Verfeinerung der theoretischen Deduktion und Ringen mit den tief- sten prinzipiellen Problemen in engem Anschluss an die Thatsachen charakterisiert die gegenwärtige stürmische Entwicklung der Physik. TDC. [2 106]. The document consists of nine pages. Page numbers presented here in the margin in square brackets depart from those in the original, where they appear in the top right corner of the page. [1] Draft of a lecture to be delivered at Davoser Hochschulkurse. Published in English as Einstein 1928t (Doc. 329). [2] From the date of the opening of the Davoser Hochschulkurse (Grandjean, 2011, p. 4). See also annotation to Einstein 1929d (Doc. 157), delivered at the same event. [3] Einstein refers to the statistical interpretation of the new theory of quantum mechanics, espe- cially as articulated by Max Born (see Born 1926) and by Niels Bohr during debates with Einstein himself (see Bohr 1949 and Bacciagaluppi and Valentini 2009), who was skeptical of the new theory. For a broader historical discussion of the questioning of classical notions of causality by physicists at the time in Germany, see Forman 1971 as well as Meyenn 1994 and Carson et al 2011 for later debates of that work. [4] Perhaps an echo of Heinrich Hertz’s image theory of scientific reasoning, as expressed in the introduction to his mechanics (Hertz 1894, pp.1ff), a portion that Einstein had studied as a student (see Einstein 1902b [Vol. 2, Doc. 3], note 42). [5] For a more detailed discussion of Einstein’s view of the role of the molecular theory of heat for the foundation of atomic theory, see, e.g., Einstein 1915a (Vol. 3, Doc. 20). [6] Early programmatic expositions of such an electromagnetic worldview include Wien 1900 and Abraham 1905, esp. §16, pp.136–147, for further historical discussion, see Jungnickel and McCormmach 1986, 236–245. For a discussion of how this worldview played out in the debates on quantum theory, see Seth 2004 and Katzir 2005 and further references therein. For a discussion of Einstein’s interest in efforts to remove from physics the dualism of particles and fields, e.g. by reduc- ing particles to epiphenomena of the field itself (see Holton 1972 and Stachel 1992). [7] A reference to the photoelectric effect, whose non-classical explanation in terms of the light quantum hypothesis was given in Einstein 1905i (Vol. 2, Doc. 14) [8] A reference to Bohr’s model of the atom, as proposed first in Bohr 1913. [9] The word “genaueren” is transcribed in an unknown hand. [10] A reference to De Broglie, whose work Broglie 1925 was prefigured by Einstein’s concept of the ghost field (Stachel 2002, pp. 367–402). [11] From this point on, the document is in Einstein’s hand. This part is not included in the published English translation, Einstein 1928t (Doc. 329). [p. 9]