Velocity of Light is Not Uniform (Nov, 1934)

The idea of a variable speed of light has been around for a while and is still an active area of research. However, I’ve always heard about it in regards to time frames measured in billions of years. I’m thinking that if the speed of light changed appreciably between 1911 and 1931 we might have noticed.

Velocity of Light is Not Uniform

MANY experiments to determine the speed of light have been made from time to time, but the results are not uniform. Yet scientists have said that this is the one uniform thing in the universe. Dr. M. E. J. G. de Bray has concluded that the variations are real, and that the speed of light does vary over a long period; having been at a minimum in 1911, and a maximum in 1931. This may reassure those who were alarmed by Soddy’s suggestion that light might cease to travel at all.