The problem addressed by the present work refers to a sequence of ideas, which have been worked out recently by Lenard, namely, whether it might be possible to demonstrate an absolute reference system, the primordial ether, using Michelson's interference experiment (M.I.). The negative outcome of Michelson's experiment in the usual setting, namely, with terrestrial light, has shown, according to Lenard's interpretation, that the ether carrying terrestrial light waves should be considered as taking part in the movement of the earth. This, however, needs not be the case with extraterrestrial light as Lenard has shown. It could be that light quanta from extraterrestrial sources running with the primordial ether were still linked on the earth to the primordial ether, which should lead to an at least partially positive outcome of the M.I. with extraterrestrial light. A negative outcome should permit elucidating the behaviour of light quanta entering the ether of different property. In the following I will report on experiments conducted with extraterrestrial light.
Originally published as "?ber das Verhalten des Lichtes auberirdischer Lichtquellen," Annalen der Physik, V73, pp. 105-126 (1924).
