Encyclopedia Britannica
In 1878 Michelson began work on what was to be the passion of his life, the accurate measurement of the speed of light.
One of Michelson’s last measuring devices is depicted by Barry Setterfield here:
Wherever one may stand on the cdk (slowing of light speed) issue, I thought Barry had a wonderful article on the history of speed of light measurements here: Rotating Mirror Experiments. Michelson’s measurements may have detected a slowing in the speed of light.
The persistent downward trend in the measured value of c was noted by de Bray after Michelson’s 1924 series results became available. As a result, he wrote to the Editor of Nature on the 20th December, 1924, and to l’Astronomie in France on January 23rd, 1925, calling attention to the trend.56 In the latter case, he predicted a lower value for Michelson’s next determination, which was in the process of being prepared. In the event his prediction was justified. As a result of that circumstance, the Editor of Nature, having ignored his earlier calls, decided to publish de Bray’s next offering, which opened up the discussion in the scientific literature throughout the late twenties, the thirties and into the early forties.
Michelson’s measurements:
year speed of light
1878.0: 300,140 ± 480
1879.5: 299,910 ± 50
1882.8: 299,853 ± 60
1924.6: 299,802 ± 30
1926.5: 299,798 ± 15
Would it be possible to do the same experiment with the same kind of apparatus today? What would the predicted value be?
An even more modest experiment would be duplicating the Bradley abberations of 1740. If we have access to the original equipment, all the better.
One of the goals of the YoungCosmos is to inspire interest and coordinated effort to attempt vital empirical experiments in these major questions. I do know one of our readers has access to the people in charge of Michelson’s equipment (hint, hint). Perhaps after he retires and is immune from persecution, he might be willing to help me look into the matter.
One attempt has already be done to repeat Bradley’s experiment. I do not know the outcome. It might be a worthy physics or historical research project. God bless any science historian willing to look into the matter objectively.
Please Note:
ATTENTION! YOUNG COSMOS HAS MOVED!
Salvador