Richard Threlkeld Cox (August 5, 1898 – May 2, 1991) was a professor of

physics Physics is the natural science that studies matter, its 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 which ...

Johns Hopkins University Johns Hopkins University (Johns Hopkins, Hopkins, or JHU) is a private research university in Baltimore, Maryland. Founded in 1876, Johns Hopkins is the oldest research university in the United States and in the western hemisphere. It consi ...

, known for

Cox's theorem Cox's theorem, named after the physicist Richard Threlkeld Cox, is a derivation of the laws of probability theory from a certain set of postulates. This derivation justifies the so-called "logical" interpretation of probability, as the laws of p ...

relating to the foundations of

probability Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, ...

Biography

He was born in

Portland, Oregon Portland (, ) is a port city in the Pacific Northwest and the largest city in the U.S. state of Oregon. Situated at the confluence of the Willamette and Columbia rivers, Portland is the county seat of Multnomah County, the most populous ...

, the son of attorney Lewis Cox and Elinor Cox. After Lewis Cox died, Elinor Cox married John Latané, who became a professor at Johns Hopkins University in 1913. In 1915 Richard enrolled at Johns Hopkins University to study physics, but his studies were cut short when he was drafted for

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

. He stayed in the US after being drafted and returned to Johns Hopkins University after the war, completing his BA in 1920. He earned his PhD in 1924; his dissertation was ''A Study of Pfund's Pressure Gauge''. He taught at

New York University New York University (NYU) is a private research university in New York City. Chartered in 1831 by the New York State Legislature, NYU was founded by a group of New Yorkers led by then- Secretary of the Treasury Albert Gallatin. In 1832, th ...

(NYU) from 1924 to 1943, before returning to Johns Hopkins to teach. He studied probability theory, the scattering of electrons, and the discharges of

electric eel The electric eels are a genus, ''Electrophorus'', of neotropical freshwater fish from South America in the family Gymnotidae. They are known for their ability to stun their prey by generating electricity, delivering shocks at up to 860 volt ...

s. Richard Cox's most important work was

. His wife, Shelby Shackleford (1899

Halifax, Virginia Halifax is a town in Halifax County, Virginia, United States, along the Banister River. The population was 1,309 at the 2010 census. It is the county seat of Halifax County. History Carlbrook, Halifax County Courthouse, Mountain Road Historic ...

– 1987), whom he married in 1926, was an accomplished artist and illustrated ''Electric Eel Calling'', a book on electric eels. He died on May 2, 1991. His doctoral students include Carl T. Chase and

Clifford Shull Clifford Glenwood Shull (September 23, 1915 in Pittsburgh, Pennsylvania – March 31, 2001) was a Nobel Prize-winning American physicist. Biography Shull attended Schenley High School in Pittsburgh, received his BS from Carnegie Institute of Tec ...

Cox and parity violation

According to T. D. Lee and C. N. Yang,

parity violation In physics, a parity transformation (also called parity inversion) is the flip in the sign of ''one'' spatial coordinate. In three dimensions, it can also refer to the simultaneous flip in the sign of all three spatial coordinates (a point ref ...

implies that electrons produced by β decay should be longitudinally polarized. In 1959, Lee Grodzins indicated how a 1928 experiment by R. T. Cox, C. G. McIlwraith, and B. Kurrelmeyer on double scattering of β rays from radium confirms the polarization effect predicted by Lee and Yang. Carl T. Chase in 1929 and 1930 performed experiments confirming the 1928 experiment by Cox, McIlwraith, and Kurrelmeyer.

Louis Witten interview

Witten Witten () is a city with almost 100,000 inhabitants in the Ennepe-Ruhr-Kreis (district) in North Rhine-Westphalia, Germany. Geography Witten is situated in the Ruhr valley, in the southern Ruhr area. Bordering municipalities * Bochum * Dortmun ...

: ... I wanted to tell you something about Richard Cox. You mentioned Richard Cox. He did a lot of things, but he also did some experiments in

condensed matter physics Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid phases which arise from electromagnetic forces between atoms. More generally, the su ...

. He discovered an anomaly which wasn't consistent with physics. It couldn't be explained. It wasn't at all consistent, and he was told his experiment was wrong, and he knew that his experiment was right. So he published it, and it was an anomaly in the literature. Some years later, it was discovered that parity wasn't conserved, and his anomaly was non-parity. It's well known now by many people that his experiment was the first experiment that would have shown parity wasn't conserved if they had interpreted it correctly.
Rickles: But he didn't give that interpretation; he just thought there was something strange.
Witten: That's right. But he knew that his experiment was right and that people were trying to tell him that his experiment was wrong.

Selected works

* Cox, R. T., "Of Inference and Inquiry - An Essay in Inductive Logic", In The Maximum Entropy Formalism, Ed. Levine and Tribus, M.I.T. Press, 1979. * * ''The Algebra of Probable Inference'', Johns Hopkins University Press, Baltimore, MD, (1961).

References

External links

* {{DEFAULTSORT:Cox, Richard Threlkeld 1898 births 1991 deaths 20th-century American physicists American statisticians Johns Hopkins University faculty Scientists from Portland, Oregon Johns Hopkins University alumni New York University faculty American military personnel of World War I