Publisher Information: Charlottenberg: 1926.
Bothe, Walther (1891-1957). Typed letter signed with manuscript corrections, in German, to Walther Gerlach (1889-1979). 1 page on one sheet; letterhead of the Physikalisch-Technische Reichsanstalt. Charlottenburg, 20 July 1926. 277 x 217 mm. Creased where previously folded, but fine otherwise.
Letter with excellent scientific content from Walther Bothe, winner of the 1954 Nobel Prize in physics for his “coincidence method,” to Walther Gerlach, co-discoverer of spin quantization in a magnetic field (the “Stern-Gerlach” effect). Bothe discusses an experiment he is planning for the purpose of investigating a certain property of light quanta (photons), part of the extensive researches on the corpuscular theory of light that occupied him in the mid-1920s. The letter can be translated as follows:
"Thank you very much for your kind letter and the reprint. Your attempt seems very interesting and I am very excited about the outcome. It has hardly any points of contact with mine. My goal is to decide whether the impulse h[nu]/c is also coupled to the energy h in the interference field (as is well known, this is not classically the case). For this purpose I examine an all-round radiation field. If this results in a simple superimposition of the normal effects, there is another flagrant deviation from the classical theory, and one must then conclude that there is no longer any continuity of the energy flow in the general radiation field, since, for example, certainly no energy flows through the nodal planes of a standing wave; the concept of light quanta would then completely lose the graphic meaning which it has for the plane wave. It is of course still doubtful whether the experiment can be carried out. The Greek letter “[nu]” in the equation stands for photon frequency, the “h” is Planck’s constant and “c” represents the speed of light."
“From 1923 until 1926 Bothe concentrated, especially on experimental and theoretical work on the corpuscular theory of light. He had, some months before the discovery of the Compton effect, observed, in a Wilson chamber filled with hydrogen, the short track of the recoil electrons of X-rays and he did further work on the direction of the emission of photo electrons. Together he and [Hans] Geiger related the Compton effect to the theory of Bohr, Kramers, and Slater, and the results of their work provided strong support for the corpuscular theory of light” (Walther Bothe – Biographical. NobelPrize.org. Nobel Media AB 2021. Sun. 13 Jun 2021).Book Id: 46299