Harold Irving Ewen

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Harold Irving Ewen (born March 5, 1922 in Chicopee , Massachusetts - † October 8, 2015 ) was an American astrophysicist . Together with Edward Mills Purcell (1912–1997) he worked on the detection of the 21 cm spectral line of hydrogen .

He graduated from Amherst College in 1943 and then went to Harvard University . He did his master's here in 1948 and wanted to do his doctorate in 1951. It was during this time that he met Purcell, who had received $ 500 from the Rumford Foundation to build an antenna to receive the hydrogen line, the Ewen-Purcell horn. Little did they know at the time that Dutch physicists had been trying to detect the radiation for some time. After about a year in April, they were sure they had found the frequency. At the same time there was Hendrik Christoffel van de Hulstat Harvard. Since he had theoretically predicted the 21 cm line, Ewen and Purcell contacted him. He passed it on to his colleague Jan Hendrik Oort , who was also looking for the radiation. After Ewen Oort had explained the frequency switching method , the group around Oort was also able to prove the line on May 11th.

The results were in the same issue of Nature published: Ewen and Purcell, Nature v.168, p.356, 1951 ; and Muller and Oort, Nature v.168, p.357, 1951 . At around 20 pages, his doctoral thesis is one of the shortest ever at Harvard. His doctoral supervisor Purcell received the Nobel Prize for these and other discoveries.

Even and a college friend, Geoff Knigh , founded the Ewen Knight Corporation in 1952 to build radio telescopes for training at Harvard. In 1957 Ewen was elected to the American Academy of Arts and Sciences . In 1958 he founded the Ewen Dae Corporation , which builds the necessary electronic equipment. In 1982 he left Harvard to devote himself to his companies.

From 1989 to 1992 he was Vice President of Millitech Corporation and from 1993 to 2000 he was responsible for special projects . Also from 1992 he was President of EK Associates and since 2004 also Technical Operations Director of Special Projects LLC .

Awards

Harold Ewen received the Beatrice-M.-Tinsley Prize of the American Astronomical Society in 1988 . This honors particularly innovative projects.

Web links

Individual evidence

  1. ↑ Doc Harold Irving Ewen (1921 - 2015)
personal data
SURNAME Ewen, Harold Irving
BRIEF DESCRIPTION American astrophysicist, proof of the 21 cm spectral line of hydrogen
DATE OF BIRTH March 5, 1922
PLACE OF BIRTH Chicopee (Massachusetts)
DATE OF DEATH October 8, 2015