The Full Wiki

Albert Abraham Michelson: Wikis

Advertisements
  
  
  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Did you know ...


More interesting facts on Albert Abraham Michelson

Include this on your site/blog:

Encyclopedia

From Wikipedia, the free encyclopedia

Albert Abraham Michelson

Born December 19, 1852(1852-12-19)
Strzelno, Kingdom of Prussia
Died May 9, 1931 (aged 78)
Pasadena, California
Nationality United States
Fields Physics
Institutions Case Western Reserve University
Clark University
University of Chicago
Alma mater United States Naval Academy
University of Berlin
Doctoral advisor Hermann Helmholtz
Doctoral students Robert Millikan
Known for Speed of light
Michelson-Morley experiment
Notable awards Nobel Prize for Physics (1907)
Signature

Albert Abraham Michelson (December 19, 1852 – May 9, 1931) was an American physicist known for his work on the measurement of the speed of light and especially for the Michelson-Morley experiment. In 1907 he received the Nobel Prize in Physics. He became the first American to receive the Nobel Prize in sciences.

Contents

Biography

Michelson was born in Strzelno, Provinz Posen in the Kingdom of Prussia (now Poland) into a Jewish family.[1] He moved to the United States with his parents in 1855, when he was two years old. He grew up in the rough mining towns of Murphy's Camp, California and Virginia City, Nevada, where his father was a merchant. He spent his high school years in San Francisco in the home of his aunt, Henriette Levy (née Michelson), who was the mother of author Harriet Lane Levy.[2]

President Ulysses S. Grant awarded Michelson a special appointment to the U.S. Naval Academy in 1869. During his four years as a midshipman at the Academy, Michelson excelled in optics, heat and climatology as well as drawing. After his graduation in 1873 and two years at sea, he returned to the Academy in 1875 to become an instructor in physics and chemistry until 1879. In 1879, he was posted to the Nautical Almanac Office, Washington, to work with Simon Newcomb, but in the following year, he obtained leave of absence to continue his studies in Europe. He visited the Universities of Berlin and Heidelberg, and the Collège de France and École Polytechnique in Paris.

Michelson was fascinated with the sciences and the problem of measuring the speed of light in particular. While at Annapolis, he conducted his first experiments of the speed of light, as part of a class demonstration in 1877. After two years of studies in Europe, he resigned from the Navy in 1881. 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. In 1887 he and Edward Morley carried out the famous Michelson-Morley experiment which seemed to rule out the existence of the aether. He later moved on to use astronomical interferometers in the measurement of stellar diameters and in measuring the separations of binary stars.

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 1899, he married Edna Stanton and they raised one son and three daughters.

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 meteorological 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.

Michelson died in Pasadena, California at the age of 78. The University of Chicago Residence Halls remembered Michelson and his achievements by dedicating Michelson House in his honor. Case Western Reserve has also dedicated a Michelson House to him, and an academic building at the United States Naval Academy also bears his name. Michelson Laboratory at Naval Air Weapons Station China Lake in Ridgecrest, California is named after him. There is an interesting 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.

Speed of light

Page one of Michelson's Experimental Determination of the Velocity of Light
Concluding page of Michelson's Experimental Determination of the Velocity of Light
Advertisements

Early measurements

As early as 1877, while still serving as an officer in the United States Navy, Michelson started planning a refinement 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 which time 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 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.

Mount Wilson and Lookout Mountain

In 1906, a novel electrical method was used by E. B. Rosa and N. E. Dorsey of the National Bureau of Standards to obtain a value for the speed of light of 299,781±10 km/s. 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.

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 U.S. 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.[3]

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 Geodetic Survey, with an estimated error of less than one part in 1 million, was compromised by a shift in the baseline arising from the Santa Barbara earthquake of 29 June 1925, which was an estimated magnitude of 6.3 on the Richter scale.

Michelson, Pease & 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 1930, he began a collaboration with Francis G. Pease and Fred Pearson to perform a measurement in a 1.6 km tube at Pasadena, 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 299,774±11 km/s, consistent with the prevailing electro-optic values, was published posthumously in 1935.

Interferometry

In 1887 he collaborated with colleague Edward Williams Morley of Western Reserve College, now part of Case Western Reserve University, in the Michelson-Morley experiment. Their experiment for the expected motion of the Earth relative to the aether, the hypothetical medium in which light was supposed to travel, resulted in a null result. Surprised, Michelson repeated the experiment with greater and greater precision over the next years, but continued to find no ability to measure the aether. The Michelson-Morley results were immensely influential in the physics community, leading Hendrik Lorentz to devise his now-famous Lorentz contraction equations as a means of explaining the null result.

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". Regardless of Einstein's specific knowledge, the experiment is today considered the canonical experiment in regards to showing the lack of a detectable aether.[4][5]

Astronomical interferometry

From 1920 and into 1921 Michelson and Francis G. Pease became the first individuals to measure the diameter of a star other than the Sun. They used an astronomical interferometer at the Mount Wilson Observatory to measure the diameter of the super-giant star Betelgeuse. A periscope arrangement was used to obtain a densified pupil in the interferometer, a method later investigated in detail by Antoine Émile Henry Labeyrie for use in "Hypertelescopes". The measurement of stellar diameters and the separations of binary stars took up an increasing amount of Michelson's life after this.

Michelson in popular culture

In an episode of the television series Bonanza (Look to the Stars, broadcast March 18, 1962), Ben Cartwright (Lorne Greene) helps the 16-year-old Albert Abraham Michelson (portrayed by 25-year-old Douglas Lambert (1936-1986)) obtain an appointment to the U.S. Naval Academy, despite the opposition of the bigoted town schoolteacher (played by William Schallert). Bonanza was set in and around Virginia City, Nevada, 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 is now a tasting room for Twisted Oak Winery.

Michelson House in Shoreland Hall, an undergraduate dorm at The University of Chicago, is named after him.

Michelson House, an undergraduate residence hall at Case Western Reserve University in Cleveland, Ohio, is named after him.

Michelson Hall (housing the departments of Computer Science and Chemistry) at the US Naval Academy is named after him.

Honours and awards

A monument at United States Naval Academy marks the path of Michelson's experiments measuring the speed of light.

Notes

  1. ^ http://www.aip.org/history/gap/Michelson/Michelson.html
  2. ^ Levy, 920 O'Farrell Street, 47.
  3. ^ Garner, C. L., Captain (retired) (April 1949). "A Geodetic Measurement of Unusually High Accuracy". Coast and Geodetic Survey. pp. 68–74. http://www.pvaa.us/nightwatch/GeodeticMeasurementOfUnusuallyHighAccuracy.pdf. Retrieved 2009-08-13. 
  4. ^ Note that while Einstein's 1905 paper On the Electrodynamics of Moving Bodies appears to reference the experiment on first glance—"together with the unsuccessful attempts to discover any motion of the earth relatively to the 'light medium,' suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest"—it has been shown that Einstein was referring to a different category of experiments here.
  5. ^ Holton, Gerald, "Einstein, Michelson, and the 'Crucial' Experiment", Isis, Vol. 60, No. 2 (Summer, 1969), pp. 133-197

References

  • Livingston, D. M. (1973). The Master of Light: A Biography of Albert A. Michelson. ISBN 0226487113. 
  • Levy, Harriet Lane (1996). 920 O'Farrell Street. Berkeley: Heyday Books. ISBN 0930588916. 

External links


Quotes

Up to date as of January 14, 2010

From Wikiquote

The more important fundamental laws and facts of physical science have all been discovered, and these are so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote.

Albert Abraham Michelson (19 December 18529 May 1931) was an American physicist known for his work on the measurement of the speed of light and especially for the Michelson-Morley experiment. In 1907 he received the Nobel Prize in Physics, the first American to receive the Nobel Prize in sciences.

Sourced

  • It appears, from all that precedes, reasonably certain that if there be any relative motion between the earth and the luminiferous ether, it must be small; quite small enough entirely to refute Fresnel's explanation of aberration.
  • Before entering into these details, however, it may be well to reply to the very natural question: What would be the use of such extreme refinement in the science of measurement? Very briefly and in general terms the answer would be that in this direction the greater part of all future discovery must lie. The more important fundamental laws and facts of physical science have all been discovered, and these are so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote. Nevertheless, it has been found that there are apparent exceptions to most of these laws, and this is particularly true when the observations are pushed to a limit, i.e., whenever the circumstances of experiment are such that extreme cases can be examined. Such examination almost surely leads, not to the overthrow of the law, but to the discovery of other facts and laws whose action produces the apparent exceptions.

    As instances of such discoveries, which are in most cases due to the increasing order of accuracy made possible by improvements in measuring instruments, may be mentioned: first, the departure of actual gases from the simple laws of the so-called perfect gas, one of the practical results being the liquefaction of air and all known gases; second, the discovery of the velocity of light by astronomical means, depending on the accuracy of telescopes and of astronomical clocks; third, the determination of distances of stars and the orbits of double stars, which depend on measurements of the order of accuracy of one-tenth of a second—an angle which may be represented as that which a pin's head subtends at a distance of a mile. But perhaps the most striking of such instances are the discovery of a new planet by observations of the small irregularities noticed by Leverier in the motions of the planet Uranus, and the more recent brilliant discovery by Lord Rayleigh of a new element in the atmosphere through the minute but unexplained anomalies found in weighing a given volume of nitrogen. Many instances might be cited, but these will suffice to justify the statement that "our future discoveries must be looked for in the sixth place of decimals." It follows that every means which facilitates accuracy in measurement is a possible factor in a future discovery, and this will, I trust, be a sufficient excuse for bringing to your notice the various methods and results which form the subject matter of these lectures.
    • Light waves and their uses. By Albert Abraham Michelson. Published by The University of Chicago Press, 1903.
    • In the sentence "An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals," he may be quoting Lord Kelvin.

External links

Wikipedia
Wikipedia has an article about:
Wikisource has original works written by or about:

1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

"ALBERT ABRAHAM MICHELSON (1852-), American physicist, was born in Strelno, Germany, Dec. 19 1852. His parents moved to San Francisco, Cal., where he studied in the public schools. He graduated from U.S. Naval Academy in 1873 and was instructor in physics and chemistry there during 18 75-9. He was then for a short time in the Nautical Almanac office. From 1880 to 1882 he studied in Berlin, Heidelberg and Paris. He resigned from the navy in 1881. In 1883 he was appointed professor of physics at the Case School of Applied Science, Cleveland, 0., and six years later accepted a similar position at Clark University. In 1892 he was appointed professor and head of the department of physics at the university of Chicago. He early directed his researches to the velocity of light and while in Cleveland invented his interferometer (see 14.693), which enabled him to measure distances by means of the length of light-waves. In 1892 he was a member of the Bureau Internationale des Poids et Mesures and in 1897 of the International Committee of Weights and Measures. He was made president of the American Physical Society in 1901 and of the American Society for the Advancement of Science in 1910. He received medals and prizes from many learned societies and in 1907 was awarded the Nobel Prize for physics. In 1920 he was able to demonstrate by means of light-interference that the diameter of Alpha Orionis was 260,000,000 miles. This was the first computation ever made of the size of a star. He was the author of numerous papers on light and in 1903 published Light Waves and Their Uses, being Lowell lectures for 1899. In 1921 he was awarded the gold medal of the Society of Arts, London. (For the " Michelson-Morley experiment, " in interference of light, with its bearing on the Einstein theory, see RELATIVITY.)


<< Herbert Stern Michelham

Michigan >>


Advertisements






Got something to say? Make a comment.
Your name
Your email address
Message