Masatoshi Koshiba
Encyclopedia
is a Japanese physicist
. He jointly won the Nobel Prize in Physics
in 2002.
He graduated from the University of Tokyo
in 1951 and received a Ph.D.
in physics at the University of Rochester
, New York, in 1955. From July 1955 to February 1958 he was Research Associate, Department of Physics, University of Chicago; from
March 1958 to October 1963, he was Associate Professor, Institute of Nuclear Study, University of Tokyo, although from November 1959 to August 1962 he was on leave from the above as Senior Research Associate with the honorary rank of Associate Professor and as the Acting Director, Laboratory of High Energy Physics and Cosmic Radiation, Department of Physics, University of Chicago. At the University of Tokyo he became Associate Professor in March 1963 and then Professor in March 1970 in the Department of Physics, Faculty of Science, and Emeritus Professor there in 1987. From 1987 to 1997, Koshiba taught at Tokai University
. In 2002, he jointly won the Nobel Prize in Physics "for pioneering contributions to astrophysics
, in particular for the detection of cosmic neutrino
s". (The other shares of that year's Prize were awarded to Raymond Davis Jr.
& Riccardo Giacconi
of the U.S.A.)
He is now Senior Counselor of ICEPP
and Emeritus Professor
of University of Tokyo
.
Koshiba's award-winning work centred on neutrinos, 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 Raymond Davis Jr
, 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; this resolves the solar neutrino problem, since early experiments could only detect one type, not all three.
In 2003, he was awarded the Benjamin Franklin Medal in Physics.
Prof. Koshiba is a member of the Board of Sponsors of The Bulletin of the Atomic Scientists
.
He is a foreign fellow of Bangladesh Academy of Sciences
-winning by Masatoshi Koshiba, ex-Professor of department of science, Koshiba hall was established in the University of Tokyo
.
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
. He jointly won the Nobel Prize in Physics
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...
in 2002.
He graduated from the University of Tokyo
University of Tokyo
, abbreviated as , is a major research university located in Tokyo, Japan. The University has 10 faculties with a total of around 30,000 students, 2,100 of whom are foreign. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most prestigious university...
in 1951 and received a Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
in physics at the University of Rochester
University of Rochester
The University of Rochester is a private, nonsectarian, research university in Rochester, New York, United States. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The university has six schools and various interdisciplinary programs.The...
, New York, in 1955. From July 1955 to February 1958 he was Research Associate, Department of Physics, University of Chicago; from
March 1958 to October 1963, he was Associate Professor, Institute of Nuclear Study, University of Tokyo, although from November 1959 to August 1962 he was on leave from the above as Senior Research Associate with the honorary rank of Associate Professor and as the Acting Director, Laboratory of High Energy Physics and Cosmic Radiation, Department of Physics, University of Chicago. At the University of Tokyo he became Associate Professor in March 1963 and then Professor in March 1970 in the Department of Physics, Faculty of Science, and Emeritus Professor there in 1987. From 1987 to 1997, Koshiba taught at Tokai University
Tokai University
is a private university in Tokyo, Japan. It was established in 1943 by Shigeyoshi Matsumae, who had formerly been the engineering president of the Ministry of Communications...
. In 2002, he jointly won the Nobel Prize in Physics "for pioneering contributions to astrophysics
Astrophysics
Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...
, in particular for the detection of cosmic neutrino
Neutrino
A neutrino is an electrically neutral, weakly interacting elementary subatomic particle with a half-integer spin, chirality and a disputed but small non-zero mass. It is able to pass through ordinary matter almost unaffected...
s". (The other shares of that year's Prize were awarded to Raymond Davis Jr.
Raymond Davis Jr.
Raymond Davis, Jr. was an American chemist, physicist, and Nobel Prize in Physics laureate.-Early life and education:...
& Riccardo Giacconi
Riccardo Giacconi
Riccardo Giacconi is an Italian/American Nobel Prize-winning astrophysicist who laid the foundations of X-ray astronomy. He is currently a professor at the Johns Hopkins University.- Biography :...
of the U.S.A.)
He is now Senior Counselor of ICEPP
International Center for Elementary Particle Physics
The is a division of the University of Tokyo, Japan dedicated to the study of particle physics....
and Emeritus Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
of University of Tokyo
University of Tokyo
, abbreviated as , is a major research university located in Tokyo, Japan. The University has 10 faculties with a total of around 30,000 students, 2,100 of whom are foreign. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most prestigious university...
.
Koshiba's award-winning work centred on neutrinos, 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 Raymond Davis Jr
Raymond Davis Jr.
Raymond Davis, Jr. was an American chemist, physicist, and Nobel Prize in Physics laureate.-Early life and education:...
, 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
Solar neutrino problem
The solar neutrino problem was a major discrepancy between measurements of the numbers of neutrinos flowing through the Earth and theoretical models of the solar interior, lasting from the mid-1960s to about 2002...
). In 1987 Kamiokande also detected neutrinos from a supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
explosion outside the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
. After building a larger, more sensitive detector named Super-Kamiokande
Super-Kamiokande
Super-Kamiokande is a neutrino observatory which is under Mount Kamioka near the city of Hida, Gifu Prefecture, Japan...
, 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; this resolves the solar neutrino problem, since early experiments could only detect one type, not all three.
In 2003, he was awarded the Benjamin Franklin Medal in Physics.
Prof. Koshiba is a member of the Board of Sponsors of The Bulletin of the Atomic Scientists
Bulletin of the Atomic Scientists
The Bulletin of the Atomic Scientists is a nontechnical online magazine that covers global security and public policy issues, especially related to the dangers posed by nuclear and other weapons of mass destruction...
.
He is a foreign fellow of Bangladesh Academy of Sciences
Trivia
In commemoration of Nobel PrizeNobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
-winning by Masatoshi Koshiba, ex-Professor of department of science, Koshiba hall was established in the University of Tokyo
University of Tokyo
, abbreviated as , is a major research university located in Tokyo, Japan. The University has 10 faculties with a total of around 30,000 students, 2,100 of whom are foreign. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most prestigious university...
.
See also
- Kamioka ObservatoryKamioka ObservatoryThe is a neutrino physics laboratory located underground in the Mozumi Mine of the Kamioka Mining and Smelting Co. near the Kamioka section of the city of Hida in Gifu Prefecture, Japan. A set of groundbreaking neutrino experiments have taken place at the observatory over the past two decades...
- Super-Kamiokande Neutrino DetectorSuper-KamiokandeSuper-Kamiokande is a neutrino observatory which is under Mount Kamioka near the city of Hida, Gifu Prefecture, Japan...
- Institute for Cosmic Ray ResearchInstitute for Cosmic Ray ResearchThe Institute for Cosmic Ray Research of the University of Tokyo was established in 1976 for the study of cosmic rays....
- International Center for Elementary Particle PhysicsInternational Center for Elementary Particle PhysicsThe is a division of the University of Tokyo, Japan dedicated to the study of particle physics....