DeWitt Bristol Brace (January 5, 1859 – October 2, 1905) was an American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

who was known for his optical experiments, especially as regards the relative motion of Earth and the

luminiferous aether Luminiferous aether or ether (''luminiferous'' meaning 'light-bearing') was the postulated Transmission medium, medium for the propagation of light. It was invoked to explain the ability of the apparently wave-based light to propagate through empt ...

Life and work

Brace was born in

Wilson, New York Wilson is a town in Niagara County, New York, United States. The population was 5,993 at the 2010 census. The town was named after an early settler, Reuben Wilson, who built and dwelt in a log cabin on the shore of Lake Ontario at the site of ...

, prepared for his studies in Lockport and graduated in 1881 at the

Boston University Boston University (BU) is a Private university, private research university in Boston, Massachusetts, United States. BU was founded in 1839 by a group of Boston Methodism, Methodists with its original campus in Newbury (town), Vermont, Newbur ...

. Afterwards he spent two years at the

Johns Hopkins University The Johns Hopkins University (often abbreviated as Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland, United States. Founded in 1876 based on the European research institution model, J ...

with

Henry Augustus Rowland Henry Augustus Rowland (November 27, 1848 – April 16, 1901) was an American physicist and Johns Hopkins educator. Between 1899 and 1901 he served as the first president of the American Physical Society. He is remembered for the high qualit ...

, and two years at the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

under

Hermann von Helmholtz Hermann Ludwig Ferdinand von Helmholtz (; ; 31 August 1821 – 8 September 1894; "von" since 1883) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The ...

and

Gustav Kirchhoff Gustav Robert Kirchhoff (; 12 March 1824 – 17 October 1887) was a German chemist, mathematician, physicist, and spectroscopist who contributed to the fundamental understanding of electrical circuits, spectroscopy and the emission of black-body ...

, where he graduated in 1885. From 1887 to 1888 he was

assistant professor Assistant professor is an academic rank just below the rank of an associate professor used in universities or colleges, mainly in the United States, Canada, Japan, and South Korea. Overview This position is generally taken after earning a doct ...

at the

University of Michigan The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...

and from 1888 to 1905 Professor of

Physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

at the

University of Nebraska–Lincoln The University of Nebraska–Lincoln (Nebraska, NU, or UNL) is a Public university, public Land-grant university, land-grant research university in Lincoln, Nebraska, United States. Chartered in 1869 by the Nebraska Legislature as part of the M ...

. There, Brace founded the Physics Laboratory, but he fell ill in 1905 and died at the time of opening of the new laboratory that still bears his name. Brace was mainly concerned with researches on

optics Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of optical instruments, instruments that use or Photodetector, detect it. Optics usually describes t ...

. For example, he invented new types of

polarizing filter A polarizer or polariser is an optical filter that lets light waves of a specific polarization pass through while blocking light waves of other polarizations. It can filter a beam of light of undefined or mixed polarization into a beam of well ...

s. He carried out a series of experiments which should determine the state of motion of the earth in the ether ("ether drift"), but the results were all negative. Particularly important was the improved version of an experiment by

Lord Rayleigh John William Strutt, 3rd Baron Rayleigh ( ; 12 November 1842 – 30 June 1919), was an English physicist who received the Nobel Prize in Physics in 1904 "for his investigations of the densities of the most important gases and for his discovery ...

, where he demonstrated with great accuracy that the

Lorentz contraction Lorentz is a name derived from the Roman surname, Laurentius, which means "from Laurentum". It is the German form of Laurence. Notable people with the name include: Given name * Lorentz Aspen (born 1978), Norwegian heavy metal pianist and keyboa ...

does not lead to

birefringence Birefringence, also called double refraction, is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. These optically anisotropic materials are described as birefrin ...

. He also attempted to measure the

speed of light The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time i ...

with great precision, but he died in the midst of his work. Brace was a fellow and vice president of the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is a United States–based international nonprofit with the stated mission of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsib ...

, and member of the Council of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of ...

Publications

* On Double Refraction in Matter moving through the Aether (Philosophical Magazine, S. 6., Vol. 7, No. 40., April 1904, pp. 317–329) * The Ether and moving Matter (Congress of arts and science, universal exposition, St. Louis 1904, (1906), vol. 4, pp. 105–117) * The Negative Results of Second and Third Order Tests of the "Aether Drift," and Possible First Order Methods (Philosophical Magazine (1905), vol. 10, pp. 71–80) * The Aether "Drift" and Rotary Polarization. (Phil. Mag., London, (Ser. 6), 10, 1905, pp. 383–396) * A Repetition of Fizeau's Experiment on the Change produced by the Earth's Motion on the Rotation of a Refracted Ray (Phil. Mag., London, (Ser. 6), 10, 1905, pp. 591–599)

References

External links

Brace at the University of Nebraska
{{DEFAULTSORT:Brace, Dewitt Bristol 1859 births 1905 deaths 20th-century American physicists University of Nebraska–Lincoln faculty Fellows of the American Association for the Advancement of Science University of Michigan faculty Boston University alumni Johns Hopkins University alumni

Life and work

See also

Publications

References

External links