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 r ...
at
Johns Hopkins University
Johns Hopkins University (Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland. Founded in 1876, Johns Hopkins is the oldest research university in the United States and in the western hem ...
, 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 pro ...
relating to the foundations of
probability
Probability is the branch of mathematics concerning numerical descriptions of how likely an Event (probability theory), 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 ...
.
[.]
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 co ...
, 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 one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
. 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, the ...
(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 volts ...
s.
Richard Cox's most important work was
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 pro ...
.
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 Di ...
– 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
Yang Chen-Ning or Chen-Ning Yang (; born 1 October 1922), also known as C. N. Yang or by the English name Frank Yang, is a Chinese Theoretical physics, theoretical physicist who made significant contributions to statistical mechanics, integrab ...
,
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 refle ...
implies that electrons produced by
β decay should be longitudinally polarized.
In 1959,
Lee Grodzins
Lee may refer to:
Name
Given name
* Lee (given name), a given name in English
Surname
* Chinese surnames romanized as Li or Lee:
** Li (surname 李) or Lee (Hanzi ), a common Chinese surname
** Li (surname 利) or Lee (Hanzi ), a Chinese s ...
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
* Dortmu ...
:
... 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 sub ...
. 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 Rickles is a surname. Notable people with the surname include:
* Dean Rickles (born 1977), English academic
* Don Rickles (1926–2017), American stand-up comedian and actor
* Donald Rickles (1927–1985), American radio and television announcer, ...
:
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