Paul Irving Richards (1923–1978) was a physicist and applied mathematician. Richard's is best known to electrical engineers for the eponymous
Richards' transformation. However, much of his career was concerned with
radiation transport and
fluid flow. Notably, he produced one of the earliest models of
traffic waves on busy highways.
Early life and education
Richards was born in
Orono, Maine in 1923.[1] In 1943 he dropped out of his undergraduate course at Harvard after the first year to work at the
Radio Research Laboratory (RRL) set up on the campus at Harvard during
World War II to research
electronic countermeasures.[2] At the end of the war, Richards was accepted back into Harvard as a Ph.D student without first completing his bachelor's degree. He received his Ph.D in physics in 1947 with a dissertation on
commensurate line theory that marked the beginning of this field.[3]
Career
At RRL Richards worked on
microwave filters, an important component of
radar and countermeasures against it. This work formed the background for his
commensurate line theory, although that theory was apparently not well developed enough at the time to be put to use in wartime work. The culmination of this theory was in his 1948 paper "Resistor-transmission-line circuits", after which Richards left the field of microwave engineering. The theory formed the basis of most
transmission-line type microwave filters for at least the next thirty-five years and the design technique is still in use today.[3]Richards' transformation, introduced in this work, is still found in modern textbooks on
radio frequency filter design.[4] During this period Richards also discovered a theorem in
complex analysis now known as
Richards' theorem which has applications in
network synthesis.[5]
Between 1947 and 1952 he was a physicist at the
Brookhaven National Laboratory helping to develop the magnetic
time-of-flight mass spectrometer with Earl E. Hays and
Samuel Goudsmit. From 1952 to 1954 he was director of research at
Transistor Products Inc. From 1954 to 1968 he was senior physicist with Technical Operations Inc.[1] In 1956, while at Technical Operations, Richards produced a paper "Shock waves on the highway", one of the earliest theoretical models of
traffic waves (there was another paper on this the previous year by Lighthill and Whitham in the UK, but Richards was apparently not aware of it and his work is independent). The traffic flow model described in this paper is now known as the Lighthill-Whitham-Richards model.[6]
From 1968 until his death on 19 November 1978 he was a senior scientist with Arcon Corporation. At Arcon he was primarily concerned with
radiation transport, particularly
neutrons.[1]
Editorships
Richards was on the publications committee of the
Society for Industrial and Applied Mathematics and was an editor of SIAM Review. Richards was interested in promoting clarity in scientific writing. He wrote a book and several articles on the subject.[1]
Selected works
Books
Manual of Mathematical Physics, Pergamon Press, 1959
OCLC932132.
(with Irving T. Richards) Proper Words in Proper Places, Christopher Publishing House, 1964
OCLC1368687—A guide to technical writing.