Koshiba Masatoshi

Koshiba Masatoshi

▪ Japanese physicist
born September 19, 1926, Toyohashi, Japan

      Japanese physicist who, with Raymond Davis, Jr. (Davis, Raymond, Jr.), won the Nobel Prize for Physics in 2002 for their detection of neutrinos. Riccardo Giacconi (Giacconi, Riccardo) also won a share of the award for his work on the cosmic sources of X rays.

      Koshiba earned a Ph.D. from the University of Rochester in New York in 1955. He then joined the University of Tokyo, where he became professor in 1960 and emeritus professor in 1987. From 1987 to 1997 Koshiba taught at Tokai University.

      Koshiba's award-winning work centred on neutrinos (neutrino), subatomic particles that had long perplexed 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 these 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 a trillion is stopped on its way to Earth. Neutrinos thus developed a reputation as being undetectable.

      In the 1980s Koshiba, drawing on the work done by Davis, constructed an underground neutrino detector in a zinc mine in Japan. Called Kamiokande II, it was an enormous water tank surrounded by electronic detectors to sense flashes of light produced when neutrinos interacted with atomic nuclei in water molecules. Koshiba was able to confirm Davis's results—that the Sun produces neutrinos and that fewer neutrinos were found than had been expected (a deficit that became known as the solar neutrino problem). In 1987 Kamiokande also detected neutrinos from a supernova explosion outside the Milky Way. After building a larger, more sensitive detector named Super-Kamiokande, which became operational in 1996, Koshiba found strong evidence for what scientists had already suspected—that neutrinos, of which three types are known, change from one type into another in flight.

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Masatoshi Koshiba — Born September 19, 1926 (1926 09 19) (age 85) Toyohashi, Aichi, Japan Nationality Japan …   Wikipedia

  • Koshiba — Masatoshi Koshiba (jap. 小柴 昌俊, Koshiba Masatoshi; * 19. September 1926 in Toyohashi, Aichi, Japan) ist ein japanischer Physiker, der 2002 mit dem Nobelpreis für Physik „für bahnbrechende Arbeiten in der Astrophysik, insbesondere für den Nachweis… …   Deutsch Wikipedia

  • Masatoshi Koshiba — (jap. 小柴 昌俊, Koshiba Masatoshi; * 19. September 1926 in Toyohashi, Aichi, Japan) ist ein japanischer Physiker, der 2002 mit dem Nobelpreis für Physik „für bahnbrechende Arbeiten in der Astrophysik, insbesondere für den Nachweis kosmischer… …   Deutsch Wikipedia

  • Masatoshi Koshiba — Nacimiento 19 de septiembre de 1926 (85 años) Toyohashi, Prefectura de Aichi, Japón Nacionalidad Japón …   Wikipedia Español

  • Masatoshi Koshiba — (19 septembre 1926 à Toyohashi, préfecture d Aichi, Japon) est un physicien japonais. Il est colauréat avec Raymond Davis Jr. d une moitié du prix Nobel de physique de 2002[1]. Sommaire 1 Biographie …   Wikipédia en Français

  • Koshiba — biographical name Masatoshi 1926 Japanese astrophysicist …   New Collegiate Dictionary

  • Raymond Davis Jr. — Raymond Davis Jr. Saltar a navegación, búsqueda Raymond Davis Jr. (14 de octubre, de 1914 31 de mayo de 2006) es un físico estadounidense, nacido en Washington DC, es un ganador del Premio Nobel de Física en 2002. Compartió en Premio Nobel con el …   Wikipedia Español

  • 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… …   Universalium

  • Bahcall — John Norris Bahcall (* 30. Dezember 1934 in Shreveport, Louisiana; † 17. August 2005 in New York City, N.Y.) war ein führender amerikanischer Astrophysiker. Er fand neue Wege zur Erforschung der Sonne und war der Initiator des Hubble… …   Deutsch Wikipedia

  • Das Land der aufgehenden Sonne — 日本国 Nihon koku/Nippon koku Japan …   Deutsch Wikipedia

Share the article and excerpts

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