Fizeau experiment
The Fizeau experiment was carried out by Hippolyte Fizeau in the 1850s to measure the relative speeds of light in moving water.
Fizeau's test was designed to evaluate the prediction by Augustin Fresnel that a moving dispersive medium should create a partial offset in the speed of any light moving through it. Fizeau's result (that lightspeeds were partially dragged) is now generally considered as supporting evidence for the "velocity addition" characteristics of special relativity.
The experiment sent two beams of light through a pair of tubes filled with flowing water, so that one beam was always travelling in the same direction as the flowing water, and the other was travelling against the flow. The timelag between the two beams was then measured with an interferometer.
Although it is referred to as the Fizeau experiment, Fizeau was an active experimenter who carried out a wide variety of different experiments involving measuring the speed of light in different situations.
Fizeau's result was replicated by Albert Michelson and Edward Morley, and by Pieter Zeeman.
References
- H. Fizeau, "Sur les hypothèses relatives à l'éther lumineux et sur une expérience qui parait démontrer que le mouvement des corps change la vitesse avec laquelle la lumière se propage dans leur intérieur" Ann. de Chim. et de Phys. 57 385-404 (1859)
- A. A. Michelson and E.W. Morley, "Influence of motion of the medium on the motion of light" Am. J. Science 31 377-386 (1886)
- Pieter Zeeman, "Fresnel's coefficient for light of different colours. (First part)" Proc. Kon. Acad. van Weten. 17 445-451 (1914)
- Pieter Zeeman, "Fresnel's coefficient for light of different colours. (Second part)" Proc. Kon. Acad. van Weten. 18 398-408 (1915)