On Time-Lags in Fluorescence and in the Kerr and Faraday Effects

Abstract

A critical study of the experimental literature is made in regard to the existence of time-lags or "dark-times" in fluorescence and it is found that not a single experiment shows the existence of such things. Moreover experiments seem to show that in all the cases when the emitting state is the state reached directly as a result of the excitation process, the emission begins immediately upon excitation and decreases exponentially. Experiments interpreted as showing the existence of time-lags in the Kerr and Faraday effects are also considered and it is found that they do not prove the reality of such time-lags. An analysis is made of the way in which the "optical shutter" of Beams' works, with the result that it is found to behave quite differently from what it was supposed to do. Wave trains of light that were supposed to be cut off by it in parts of 3 cm length are certainly not reduced to less than 300 cm, or 100 times more than assumed.