Nova Geminorum 1912 and the Origin of the Idea of Gravitational Lensing

Einstein's early calculations of gravitational lensing, contained in a scratch notebook and dated to the spring of 1912, are reexamined. A hitherto unknown letter by Einstein suggests that he entertained the idea of explaining the phenomenon of new stars by gravitational lensing in the fall of 1915 much more seriously than was previously assumed. A reexamination of the relevant calculations by Einstein shows that, indeed, at least some of them most likely date from early October 1915. But in support of earlier historical interpretation of Einstein's notes, it is argued that the appearance of Nova Geminorum 1912 (DN Gem) in March 1912 may, in fact, provide a relevant context and motivation for Einstein's lensing calculations on the occasion of his first meeting with Erwin Freundlich during a visit in Berlin in April 1912. We also comment on the significance of Einstein's consideration of gravitational lensing in the fall of 1915 for the reconstruction of Einstein's final steps in his path towards general relativity.Comment: 31 p

Lehrbuch der Physik,

First pub. 1902-24: 2. verb. und verm. Aufl. hrsg. von Gerhard Schmidt.Supplemented by the author's "Die physik 1914-1926 (Braunschweig, Vieweg, 1927)"Vols. 1-2 translated by H. Pflaum; v. 3, by E. Berg; v. 4, first half, by H. Pflaum; v. 4, second half, translated by A. Foehringer and G. Kluge, edited by G.C. Schmidt.Plates of v. 2 in pocket.Bibliographies at end of chapters.1. bd. Einleitung. Mechanik. Einige Messinstrumente und Messmethoden. Die Lehre von den gasen, flüssigkeiten und Festen Körpern. 1918--2. bd. Lehre vom Schall (Akustik) Lehre von der Strahlenden Energie. 1922--3. bd. Die Lehre von der Wärme. 1922--4. bd. Die Lehre von der Elektrizität. 1. Hälfte, 1925. 2. Hälfte, 1913-24.Mode of access: Internet