Chung-Yao Chao
Encyclopedia
Chung-Yao Chao was a Chinese
physicist. Chung-Yao Chao studied the scattering of gamma rays
in lead by pair production
in 1930, without knowing that positron
s were involved in the anomalously high scattering cross-section. When the positron was discovered by Carl David Anderson
in 1932, confirming the existence of Paul Dirac's
"antimatter
", it became clear that positrons could explain Chung-Yao Chao's earlier experiments, with the gamma rays being emitted from electron-positron annihilation
.
He entered Nanjing Higher Normal School (later renamed National Southeastern University, National Central University
and Nanjing University
), in 1920 and earned a B.S. in physics
in 1925. Then he earned a Ph.D.
degree in physics under supervision of Nobel Prize laureate Robert Andrews Millikan at the California Institute of Technology
in 1930. Later he went back to China and joined the physics faculty of Tsinghua University
in Beijing
.
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
physicist. Chung-Yao Chao studied the scattering of gamma rays
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
in lead by pair production
Pair production
Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon . For example an electron and its antiparticle, the positron, may be created...
in 1930, without knowing that positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
s were involved in the anomalously high scattering cross-section. When the positron was discovered by Carl David Anderson
Carl David Anderson
Carl David Anderson was an American physicist. He is best known for his discovery of the positron in 1932, an achievement for which he received the 1936 Nobel Prize in Physics, and of the muon in 1936.-Biography:...
in 1932, confirming the existence of Paul Dirac's
Paul Dirac
Paul Adrien Maurice Dirac, OM, FRS was an English theoretical physicist who made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics...
"antimatter
Antimatter
In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles...
", it became clear that positrons could explain Chung-Yao Chao's earlier experiments, with the gamma rays being emitted from electron-positron annihilation
Electron-positron annihilation
Electron–positron annihilation occurs when an electron and a positron collide. The result of the collision is the annihilation of the electron and positron, and the creation of gamma ray photons or, at higher energies, other particles:...
.
He entered Nanjing Higher Normal School (later renamed National Southeastern University, National Central University
National Central University
National Central University is a national comprehensive university in Taiwan .National Central University was founded in 1915 and originated in 258 CE at Nanjing, China. After NCU in Nanjing was renamed Nanjing University in 1949, NCU was re-established in Taiwan in 1962...
and Nanjing University
Nanjing University
Nanjing University , or Nanking University, is one of the oldest and most prestigious institutions of higher learning in China...
), in 1920 and earned a B.S. in physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
in 1925. Then he earned 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...
degree in physics under supervision of Nobel Prize laureate Robert Andrews Millikan at the California Institute of Technology
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...
in 1930. Later he went back to China and joined the physics faculty of Tsinghua University
Tsinghua University
Tsinghua University , colloquially known in Chinese as Qinghua, is a university in Beijing, China. The school is one of the nine universities of the C9 League. It was established in 1911 under the name "Tsinghua Xuetang" or "Tsinghua College" and was renamed the "Tsinghua School" one year later...
in Beijing
Beijing
Beijing , also known as Peking , is the capital of the People's Republic of China and one of the most populous cities in the world, with a population of 19,612,368 as of 2010. The city is the country's political, cultural, and educational center, and home to the headquarters for most of China's...
.