The interferometer was proposed by Albert A. Michelson in 1890, following a suggestion by Hippolyte Fizeau.
The first such interferometer built was at the Mount Wilson observatory, making use of its 100-inch (~250 centimeters) mirror.
It was used to make the first-ever measurement of a stellar diameter, by Michelson and Francis G. Pease, when the diameter of Betelgeuse was measured in December 1920.
The diameter was found to be 240 million miles (~380 million kilometers), about the size of the orbit of Mars, or about 300 times larger than the Sun.
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