Davis, Raymond, Jr.

Davis, Raymond, Jr.
▪ 2007

      American physicist (b. Oct. 14, 1914, Washington, D.C.—d. May 31, 2006, Blue Point, N.Y.), won the Nobel Prize for Physics in 2002 (with Masatoshi Koshiba) for having detected neutrinos. Riccardo Giacconi also won a share of the award for his work on X-rays. Davis received a Ph.D. from Yale University in 1942. He joined (1948) Brookhaven National Laboratory in Upton, N.Y., where he remained until his retirement in 1984. In 1985 Davis took a post as a research professor with the University of Pennsylvania. Davis's prizewinning work focused on neutrinos, subatomic particles that had long baffled scientists. Since the 1920s it had been suspected that the Sun shines because of nuclear fusion reactions that transform hydrogen into helium and release energy. Later, theoretical calculations indicated that countless neutrinos must be released in those reactions and, consequently, that Earth must be exposed to a constant flood of solar neutrinos. Because neutrinos interact weakly with matter, however, only one in every trillion is stopped on its way to Earth. Neutrinos thus developed a reputation for being undetectable. In the 1960s, in a gold mine in South Dakota, Davis built an underground neutrino detector, a huge tank filled with more than 600 tons of the cleaning fluid tetrachloroethylene. He calculated that high-energy neutrinos passing through the tank should form 20 argon atoms a month on average, and he developed a way to count those exceedingly rare atoms. Monitoring the tank for more than 25 years, he was able to confirm that the Sun produces neutrinos, but he consistently found fewer neutrinos than predicted.

* * *

▪ American scientist
born Oct. 14, 1914, Washington, D.C., U.S.
died May 31, 2006, Blue Point, N.Y.

      American physicist who, with Koshiba Masatoshi, won the Nobel Prize for Physics in 2002 for detecting neutrinos. Riccardo Giacconi (Giacconi, Riccardo) also won a share of the award for his work on X-rays.

      Davis received a Ph.D. from Yale University in 1942. After military service during World War II, he joined Brookhaven National Laboratory in Upton, N.Y., in 1948. He remained there until his retirement in 1984. In 1985 Davis took a post as a research professor with the University of Pennsylvania.

      Davis's prizewinning work focused on neutrinos (neutrino), subatomic particles that had long baffled scientists. Since the 1920s it had been suspected that the Sun shines because of nuclear fusion reactions that transform hydrogen into helium and release energy. Later, theoretical calculations indicated that countless neutrinos must be released in those reactions and, consequently, that Earth must be exposed to a constant flood of solar neutrinos. Because neutrinos interact weakly with matter, however, only one in every trillion is stopped on its way to Earth. Neutrinos thus developed a reputation for being undetectable.

      Some of Davis's contemporaries had speculated that one type of nuclear reaction might produce neutrinos with enough energy to make them detectable. If such a neutrino collided with a chlorine atom, it should form a radioactive argon nucleus. In the 1960s, in a gold mine in South Dakota, Davis built an underground neutrino detector, a huge tank filled with more than 600 tons of the cleaning fluid tetrachloroethylene. He calculated that high-energy neutrinos passing through the tank should form 20 argon atoms a month on average, and he developed a way to count those exceedingly rare atoms. Monitoring the tank for more than 25 years, he was able to confirm that the Sun produces neutrinos, but he consistently found fewer neutrinos than predicted. This deficit became known as the solar neutrino problem. Davis's results were later confirmed by Koshiba, who also found evidence that neutrinos change from one type to another in flight. Because Davis's detector was sensitive to only one type, those that had switched identity eluded detection.

* * *


Universalium. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Davis , Raymond — (1914–) American chemist Born in Washington DC, Davis was educated at the universities of Maryland and Yale where he obtained his PhD in 1942. After serving four years in the USAAF, Davis took the post of senior chemist at the Brookhaven National …   Scientists

  • Raymond Davis Jr. — Raymond Davis Jr. (* 14. Oktober 1914 in Washington (D.C.); † 31. Mai 2006 in Blue Point, New York) war ein US amerikanischer Chemiker, der 2002 mit dem Nobelpreis für Physik „für bahnbrechende Arbeiten in der Astrophysik, insbesondere für den… …   Deutsch Wikipedia

  • Raymond Davis, Jr. — Infobox Scientist name = Raymond Davis, Jr. birth date = birth date|1914|10|14|df=yes birth place = Washington, D.C., USA death date = death date and age|2006|05|31|1914|10|14|df=yescite news |author=Kenneth Chang |title=Raymond Davis Jr.,… …   Wikipedia

  • Raymond Davis Jr. — Pour les articles homonymes, voir Davis. Raymond Davis Jr. (14 octobre 1914 à Washington, D.C. – 31 mai 2006) est un chimiste et un physicien américain. Il est colauréat avec Masatoshi Koshiba d une moitié du prix Nobel de physique de 2002[1 …   Wikipédia en Français

  • Raymond Davis junior — Raymond Davis junior, 1978 Raymond Davis Jr. (* 14. Oktober 1914 in Washington D.C.; † 31. Mai 2006 in Blue Point, New York) war ein US amerikanischer Chemiker, der 2002 mit dem Nobelpreis für Physik „für bahnbrechende Arbeiten in der A …   Deutsch Wikipedia

  • Davis Love III — Personal information Full name Davis Milton Love III Born …   Wikipedia

  • Raymond Allen Davis — (* 2. Oktober 1973 in Wise, Virginia) ist ein US amerikanischer Staatsangehöriger, ehemaliger Soldat der US Army, Beschäftigter beim amerikanischen Konsulat in Lahore (Pakistan) und Mitarbeiter der CIA. Davis geriet in den Fokus der… …   Deutsch Wikipedia

  • Raymond Davis — may refer to: Raymond Davis Jr. (1914–2006), American physicist and chemist Ray Davis (musician) (1940–2005), member of The Parliaments, Parliament, Funkadelic, and The Temptations Ray Davis (banker), chief executive officer of the US bank Umpqua …   Wikipedia

  • Raymond Barbuti — Raymond J. Ray Barbuti (* 12. Juni 1905 im Nassau County, New York; † 8. Juli 1988 in Canaan, N.Y.) war ein American Football Spieler, Leichtathlet und Olympiasieger. Er studierte an der Syracuse University als er bei den IC4A Meisterschaften den …   Deutsch Wikipedia

  • Davis — ist ein häufiger Familienname. Er steht zum König David im Alten Testament, im allgemeinen mit einer patronymischen s Bildung zu dem häufigen Vornamen David, als Verkürzung aus Davids. Davis ist auch der Name einer Universitätsstadt in… …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”