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The Fizeau experiment was carried out by Hippolyte Fizeau in the 1851 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, because the refractive index, n, would be dependent on the density of the luminiferous aether, so the Fresnel drag coefficient is

${\displaystyle (1-{\frac {1}{n^{2}}})}$.

The velocity of light in a moving medium is therefore:

${\displaystyle V={\frac {c}{n}}+v(1-{\frac {1}{n^{2}}})}$

This was confirmed by Fizeau's experiment in 1851. Based on the work of Hendrik Lorentz (1895) and Albert Einstein (1905) it was shown by Jakob Laub and Max von Laue (1907) that the Fresnel drag coefficient and Fizeau's experiment is 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 (1886), and by Pieter Zeeman (1914).

See also

• History of special relativity

References

• Fizeau, H. (1851). "Sur les hypothèses relatives à l'éther lumineux". Comptes Rendus. 33: 349–355.

• Fizeau, H. (1859). "Sur les hypothèses relatives à l'éther lumineux". Ann. de Chim. et de Phys. 57: 385–404.

• Michelson, A. A. and Morley, E.W. (1886). "Influence of motion of the medium on the motion of light". Am. J. Science. 31: 377–386.{{cite journal}}: CS1 maint: multiple names: authors list (link)

• Laue, M. (1907). "Die Mitführung des Lichtes durch bewegte Körper nach dem Relativitätsprinzip". Annalen der Physik. 23: 989–990.

• Zeeman, Pieter (1914). "Fresnel's coefficient for light of different colours. (First part)". Proc. Kon. Acad. van Weten. 17: 445–451.

• Zeeman, Pieter (1915). "Fresnel's coefficient for light of different colours. (Second part)". Proc. Kon. Acad. van Weten. 18: 398–408.

• Miller, A.I. (1981). Albert Einstein’s special theory of relativity. Emergence (1905) and early interpretation (1905–1911). Reading: Addison–Wesley. ISBN 0-201-04679-2.

See also

• aether drag hypothesis
• velocity-addition formula
• Michelson-Morley experiment

• Physics experiments