Albert Abraham Michelson (surname pronunciation anglicized as Michael-son; December 19, 1852 – May 9, 1931) was an American physicist known for his work on measuring the speed of light and especially for the Michelson–Morley experiment.

In 1879, he was posted to the Nautical Almanac Office, Washington (part of the United States Naval Observatory),[13][14][15] to work with Simon Newcomb.

In 1883 he accepted a position as professor of physics at the Case School of Applied Science in Cleveland, Ohio, and concentrated on developing an improved interferometer.

[20] In 1907, Michelson had the honor of being the first American to receive a Nobel Prize in Physics "for his optical precision instruments and the spectroscopic and metrological investigations carried out with their aid".

[citation needed] He returned to military service in the closing months of World War One as a Lieutenant Commander in the Naval Reserve, serving in the Bureau of Ordnance.

In 1877 Michelson married Margaret Hemingway, daughter of a wealthy New York stockbroker and lawyer and the niece of his commander William T. Sampson.

[33] As early as 1869, while serving as an officer in the United States Navy, Michelson started planning a repeat of the rotating-mirror method of Léon Foucault for measuring the speed of light, using improved optics and a longer baseline.

He conducted some preliminary measurements using largely improvised equipment in 1878, about the same time that his work came to the attention of Simon Newcomb, director of the Nautical Almanac Office who was already advanced in planning his own study.

Though this result has subsequently been shown to be severely biased by the poor electrical standards in use at the time, it seems to have set a fashion for rather lower measured values.

In 1922, the United States Coast and Geodetic Survey began two years of painstaking measurement of the baseline using the recently available invar tapes.

[36] Famous as the measurement is, it was beset by problems, not least of which was the haze created by the smoke from forest fires which blurred the mirror image.

These instruments and related collaborations included the participation of fellow physicists Dayton Miller, Hendrik Lorentz, and Robert Shankland.

The period after 1927 marked the advent of new measurements of the speed of light using novel electro-optic devices, all substantially lower than Michelson's 1926 value.

Michelson sought another measurement, but this time in an evacuated tube to avoid difficulties in interpreting the image owing to atmospheric effects.

In 1929, he began a collaboration with Francis G. Pease and Fred Pearson to perform a measurement in a 1.6 km tube 3 feet in diameter at the Irvine Ranch near Santa Ana, California.

Michelson died with only 36 of the 233 measurement series completed and the experiment was subsequently beset by geological instability and condensation problems before the result of 299774±11 km/s, consistent with the prevailing electro-optic values, was published posthumously in 1935.

Aside from the efforts to reduce as much as possible the systematic errors, repeated measurements were performed at multiple levels to obtain more accurate results.

There has been some historical controversy over whether Albert Einstein was aware of the Michelson–Morley results when he developed his theory of special relativity, which pronounced the aether to be "superfluous".

Michelson had invented astronomical interferometry and built such an instrument at the Mount Wilson Observatory which was used to measure the diameter of the red giant Betelgeuse.

A periscope arrangement was used to direct light from two subpupils, separated by up to 20 feet (6m), into the main pupil of the 100 inch (2.5m) Hooker Telescope, producing interference fringes observed through the eyepiece.

In the 1890s Michelson built a mechanical device called the harmonic analyzer, for computing coefficients of Fourier series and drawing graphs of their partial sums.

[45][46] In Season 3 Episode 26 of the television series Bonanza ("Look to the Stars", broadcast March 18, 1962), Ben Cartwright (Lorne Greene) helps the 16-year-old Michelson (portrayed by 25-year-old Douglas Lambert (1936–1986)) obtain an appointment to the U.S.

His aunt Bertha Meyers owned a house on Main Street toward the east end of town and Michelson probably visited her family there frequently.

O. Alan Weltzien, 2008), it is an appreciation of Michelson from Maclean's vantage point as a graduate student regularly watching him play billiards.