Albert A. Michelson

Albert A. Michelson
University of Berlin
Known for	Speed of light Hyperfine structure Fine structure Michelson–Morley experiment Michelson–Gale–Pearson experiment Michelson interferometer Michelson stellar interferometer
Spouses	Margaret Hemingway ​ ​ (m. 1877; div. 1898)​ ; 3 children Edna Stanton ​ (m. 1899)​ ; 3 children
Military career
Allegiance	United States
Branch	United States Navy United States Navy Reserve [2]
Service years	1873–1881; 1918–1921[2]
Rank	Commander
Unit	United States Naval Academy
Awards	Robert Millikan William Smythe
Signature

Albert Abraham Michelson

In 1889 Michelson became a professor at Clark University at Worcester, Massachusetts, and in 1892 was appointed professor and the first head of the department of physics at the newly organized University of Chicago. In 1902, he was elected as a member of the American Philosophical Society.^[21]

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". He also won the Copley Medal in 1907, the Henry Draper Medal in 1916 and the Gold Medal of the Royal Astronomical Society in 1923. A crater on the Moon is named after him.^{[citation needed]}

He returned to military service in the closing months of

Michelson died in Pasadena, California, at the age of 78.^[22] The University of Chicago Residence Halls remembered Michelson and his achievements by dedicating 'Michelson House' in his honor. Case Western Reserve has dedicated a Michelson House to him, and Michelson Hall (an academic building of science classrooms, laboratories and offices) at the United States Naval Academy also bears his name. Michelson Laboratory at Naval Air Weapons Station China Lake in Ridgecrest, California, is named for him. There is a display in the publicly accessible area of the Lab which includes facsimiles of Michelson's Nobel Prize medal, the prize document, and examples of his diffraction gratings. In 2017, a newly renovated physics research center at the University of Chicago was renamed in honor of Michelson as well.^[23]

Numerous awards, lectures, and honors have been created in Albert A. Michelson's name.^[24] Some of the current awards and lectures named for Michelson include the following: the Bomem-Michelson Award and Lecture annually presented until 2017 by the Coblentz Society;^[25] the Michelson–Morley Award and Lecture, along with the Michelson Lecture Series,^[26] and the Michelson Postdoctoral Prize Lectureship,^[27] all of which are given annually by Case Western Reserve University; the A.A. Michelson Award presented every year by the Computer Measurement Group;^[28] the Albert A. Michelson Award given by the Navy League of the United States;^[29] and the Michelson Memorial Lecture Series^[30] presented annually by the Division of Mathematics and Science at the U.S. Naval Academy.

Family

In 1877 Michelson married Margaret Hemingway, daughter of a wealthy New York stockbroker and lawyer and the niece of his commander William T. Sampson. They had two sons and a daughter.^[31][32]

In 1899, he married Edna Stanton. They raised three daughters.^[32]

He is a great uncle of physicist Peter Michelson.^[33]

Speed of light

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Early measurements

Michelson was fascinated by light all his life. Once asked why he studied light, he reputedly said, "because it's so much fun".^[34]

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.

Michelson's formal experiments took place in June and July 1879. He constructed a frame building along the north sea wall of the Naval Academy to house the machinery.^[35] Michelson published his result of 299,910 ± 50 km/s in 1879 before joining Newcomb in Washington DC to assist with his measurements there. Thus began a long professional collaboration and friendship between the two.

Simon Newcomb, with his more adequately funded project, obtained a value of 299,860 ± 30 km/s, just at the extreme edge of consistency with Michelson's. Michelson continued to "refine" his method and in 1883 published a measurement of 299,853 ± 60 km/s, rather closer to that of his mentor.

From 1920, Michelson started planning a definitive measurement from the Mount Wilson Observatory, using a baseline to Lookout Mountain, a prominent bump on the south ridge of Mount San Antonio ("Old Baldy"), some 22 miles distant.

In 1922, the United States Coast and Geodetic Survey began two years of painstaking measurement of the baseline using the recently available invar tapes. With the baseline length established in 1924, measurements were carried out over the next two years to obtain the published value of 299,796 ± 4 km/s.^[37]

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. It is also probable that the intensively detailed work of the

The now-famous Michelson–Morley experiment also influenced the affirmation attempts of peer Albert Einstein's theory of general relativity and special relativity, using similar optical instrumentation. These instruments and related collaborations included the participation of fellow physicists Dayton Miller, Hendrik Lorentz, and Robert Shankland.

Michelson, Pease, and Pearson

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.^[38][39] In multiple reflections the light path was increased to 5 miles. For the first time in history the speed of light was measured in an almost perfect vacuum of 0.5 mm of mercury. 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.^[39]

Application of basic statistical principles in Michelson's study of speed of light

During June and early July 1879, Michelson refined experimental arrangements from those developed by Hippolyte Fizeau and Léon Foucault. The experimental setup was as follows: Light generated from a source is directed towards a rotating mirror through a slit on a fixed plate; the rotating mirror reflects the incoming light and at a certain angle, towards the direction where another fixed flat mirror is placed whose surface is perpendicular to the incoming ray of light; the rotating mirror should have rotated by an angle α by the time the ray of light travels back and is reflected again towards the fixed plate (the distance between the fixed mirror and the rotating one is recorded as D); a displacement from the slit is detected on the plate which measures d; the distance from the rotating mirror to the fixed plate is designated as the radius r while the number of revolutions per second of the mirror is recorded as ω. In this way, tan(2α) = d/r; Δt = (α/2π)/ω; speed of light can be derived as c = 2D/Δt.

While at plain sight, four measured quantities are involved: distance D, radius r, displacement d and rotating mirror revolution per second ω, which seems simple; yet based on the limitation of the measurement technology at that time, great efforts were made by Michelson to reduce systematic errors and apply subsequent corrections. For instance, he adopted a steel measuring tape with a said length of 100 feet and he intended to measure tens of times across the distance; still, he measured its length against a copy of the official standard yard to find out it as 100.006 feet, thus eliminating a systematic error, albeit small.

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. As R.J. MacKay and R.W. Oldford remarked in their article,

A statistical model for repeated measurements with the assumption of independence or identical distributions is unrealistic. In the case of light speed study, each measurement is approached as the sum of quantity of interest and measurement error. In the absence of systematic error, the measurement error of speed of light can be modeled by a random sample from a distribution with unknown expectation and finite variance; thus, the speed of light is represented by the expectation of the model distribution and the ultimate goal is to estimate the expectation of the model distribution on the acquired dataset. The law of large numbers suggests to estimate the expectation by the sample mean.^[41]

Michelson–Morley interferometry experiment

In 1887 he collaborated with colleague

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". In a later interview, Einstein said of the Michelson–Morley experiment, "I was not conscious it had influenced me directly ... I guess I just took it for granted that it was true."^[42] Regardless of Einstein's specific knowledge, the experiment is today considered the canonical experiment in regards to showing the lack of a detectable aether.^[43][44]

The precision of their equipment allowed Michelson and Morley to be the first to get precise values for the fine structure in the atomic spectral lines^[45] for which in 1916 Arnold Sommerfeld gave a theoretical explanation, introducing the fine-structure constant.

Astronomical interferometry

Optical

In 1920 Michelson and

Beginning in the 1970s, astronomical interferometry was revived, with the configurations using two (or more) separate apertures (with diameters small compared to their separation) being often referred to as "Michelson Stellar Interferometry". This was to distinguish it from

Gravitational wave

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. He and S. W. Stratton published a paper about this machine in the American Journal of Science in 1898.^[46][47]

Michelson in popular culture

In Season 3 Episode 26 of the television series

, where Michelson lived with his parents prior to leaving for the Naval Academy. In a voice-over at the end of the episode, Greene mentions Michelson's 1907 Nobel Prize.

The home in which Michelson lived as a child in Murphys Camp, California was in the store of his father, first on Main Street, Murphys, CA across from the Sperry & Perry Hotel and after the 1859 fire, in a store next to the hotel. His aunt Bertha Meyers owned a house on Main Street toward the east end of town and Michelson probably visited her family there frequently.

New Beast Theater Works in collaboration with High Concept Laboratories produced a 'semi-opera' about Michelson, his obsessive working style and its effect on his family life. The production ran from February 11 to February 26, 2011, in Chicago at The Building Stage. Michelson was portrayed by Jon Stutzman. The play was directed by David Maral with music composed by Joshua Dumas.^{[citation needed]}

Norman Fitzroy Maclean wrote an essay "Billiards is a Good Game"; published in The Norman Maclean Reader (ed. O. Alan Weltzien, 2008), it is an appreciation of Michelson from Maclean's vantage point as a graduate student regularly watching him play billiards.^[48]

Honors and awards

• 1888 – Rumford Prize
• 1903 – Matteucci Medal
• 1907 – Copley Medal
• 1907 – Nobel Prize in Physics^[36]
• 1912 – Elliott Cresson Medal
• 1916 –
  National Academy of Sciences^[49]
• 1922 – Prix Jules Janssen, the highest award of the Société astronomique de France, the French astronomical society.
• 1923 – Gold Medal of the Royal Astronomical Society
• 1923 –
  Franklin Medal

Michelson was a member of the Royal Society, the National Academy of Sciences, the American Physical Society and the American Association for the Advancement of Science.

The Computer Measurement Group gives an annual A. A. Michelson Award.

See also

• List of Jewish Nobel laureates
• List of Naval Academy Nobel Laureates
• List of Poles

Biography

• Jaffe, Bernard (1960) Michelson and the Speed of Light, Doubleday. New York

Notes

References

• Livingston, D. M. (1973). The Master of Light: A Biography of Albert A. Michelson. University of Chicago Press.
  ISBN 978-0-226-48711-3
  .
• ISBN 978-0-930588-91-5
  .

Works

• Light waves and their uses. Chicago: University Press. 1907.
• Détermination expérimentale de la valeur du mètre en longueurs d'ondes lumineuses. Paris : Gauthier-Villars et fils, 1894. (French translation of Experimental Determination of the Velocity of Light)

• 
  Light waves and their uses (1907)
• 
  French translation of Experimental Determination of the Velocity of Light (1894)

External links

Wikisource has original works by or about:
Albert A. Michelson

Wikiquote has quotations related to Albert A. Michelson.

Wikimedia Commons has media related to Albert A. Michelson.

• Three Glimpses of Albert Abraham Michelson at the Peak of His Career This video includes audio of Michelson speaking.
• National Academy of Sciences Biographical Memoir
• Michelson's Life and Works from the American Institute of Physics Archived July 16, 2012, at the Wayback Machine
• U.S. Naval Academy and The Navy
• From USNA to Nobel: Albert A. Michelson's Life and Contributions^{[permanent dead link]}
• Michelson House at the University of Chicago
• Albert A. Michelson on Nobelprize.org including the Nobel Lecture, December 12, 1907 Recent Advances in Spectroscopy
• Works by Albert A. Michelson at Project Gutenberg
• Works by or about Albert A. Michelson at Internet Archive
• IMDB: Bonanza episode Look to the Stars
• Norman Maclean: "Billiards Is a Good Game": Gamesmanship and America's First Nobel Prize Scientist; reprinted in Lapham's Quarterly
• The U.S. Naval Academy Observatory Programs and Times Gone By: A Tale of Two Domes
• "NAWS China Lake". Archived from the original on September 22, 2008. Retrieved September 3, 2010.
• Nineteenth Century Astronomy at the U.S. Naval Academy

Archival collections

• Guide to the Albert A. Michelson Papers 1891–1969 Archived September 7, 2019, at the Wayback Machine at the University of Chicago Special Collections Research Center
• USNA Guide to the Albert A. Michelson Collection, 1803–1989
• William Polk Jesse student notebooks, 1919–1921, Niels Bohr Library & Archives (contains notes on the lectures of Albert A. Michelson, including courses taught by Michelson: Mechanics and Wave Motion, Electricity and Magnetism, and Physical Optics)