relativity principle, to the abandonment of the aether.
2. Now, Sagnac[1] has recently provided a new optical effect for deciding the aether question.
Remarkably, this effect is of first order; nevertheless all measurements take place in one and the same point of the system.
The Effect can very well be observed also at small translatory velocities by means of interference phenomena, which was actually done by Sagnac.
The effect was demonstrated indeed. Order of magnitude and sense of displacement were in agreement, and additionally, the observed fringe displacements were even in terms of numbers in noticeable good agreement with the calculated ones.
Sagnac thus concludes from theory and experiment:[2] The fringe displacement measures the relative velocity of the system with respect to the aether (or the relative aether wind, vent relatif de l’éther), thus is proves the existence of the aether.
- ↑ G. Sagnac, L’éther lumineux démontré par l’effet du vent relatif d’éther, C. R. 157, 708, 27. October 1913; Sur la preuve de la réalité de l’éther lumineux, same place p. 1410, 22. December 1913.
- ↑ A. a. 0., S. 710 u. 1413.
