View source for Chung-Yao Chao

{{Short description|Chinese physicist (1902–1998)}}
{{Use dmy dates|date=February 2021}}
{{family name hatnote|[[Zhao (surname)|Chao (Zhao)]]|lang=Chinese}}
{{Infobox scientist
| name = Chung-Yao Chao
| image = 趙忠堯.jpg
| image_size =
| alt = 
| caption = 
| birth_date = {{birth date|1902|6|27|df=y}}
| birth_place = [[Zhuji]], China
| death_date = {{death date and age|1998|5|28|1902|6|27|df=y}}
| death_place = [[Beijing]], China
| fields = [[Physics]] 
| workplaces = {{Unbulleted list |Southeast University |National Central University |Nanjing University  |[[National Southwestern Associated University]] |[[University of Science and Technology of China]]}}
| alma_mater = {{Unbulleted list |[[Southeast University]] |[[National Central University]] [[Nanjing University]]|[[California Institute of Technology]]}}
| doctoral_advisor = 
| doctoral_students = 
| known_for = {{longitem|Seminal contributions to the discovery of [[antimatter]]}}
| awards = 
}}
'''Chung-Yao Chao''' ({{zh|s=赵忠尧|p='''Zhào Zhōngyáo'''}}; 27 June 1902 – 28 May 1998) was a Chinese theoretical physicist. He studied the scattering of [[gamma ray]]s 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 [[Bachelor of Science|BS]] in [[physics]] in 1925. Then he earned a [[PhD]] degree in physics under supervision of [[Nobel Prize laureate]] [[Robert Andrews Millikan]] at [[California Institute of Technology]] in 1930. Later he went back to China and joined the physics faculty of [[Tsinghua University]] in [[Beijing]].

==Nobel Prize controversy==
The 1936 [[Nobel Prize for Physics]] went to [[Carl D. Anderson]] for the discovery of the positron. While a graduate student at Caltech in 1930, Chao was the first to experimentally identify [[positron]]s through [[electron–positron annihilation]], but did not realize what they were. Anderson, Chao's classmate at Caltech, used the same [[radioactive]] source, [[Thallium-208|{{chem|208|Tl}}]], as Chao. (Historically, {{chem|208|Tl}} was known as "thorium C double prime" or "ThC", see [[decay chain]]s.) Fifty years later, Anderson admitted that Chao had inspired his discovery: Chao's research formed the foundation from which much of Anderson's own work developed. Chao died in 1998, without sharing in a Nobel Prize acknowledgment.<ref>{{Cite journal|last=Cao|first=Cong|date=2004|title=Chinese Science and the 'Nobel Prize Complex'|url=http://china-us.uoregon.edu/pdf/Minerva-2004.pdf|journal=Minerva|language=en|volume=42|issue=2|pages=151–172|doi=10.1023/b:mine.0000030020.28625.7e|s2cid=144522961|issn=0026-4695}}</ref>

==References==
{{reflist}}

==Further reading==
* {{DSB |first=Zuoyue |last= Wang |title=Zhao Zhongyao |volume=25 |pages=397-402 }}

{{Founding members of the Chinese Academy of Sciences}}
{{Authority control}}

{{DEFAULTSORT:Chao, Chung-Yao}}
[[Category:1902 births]]
[[Category:1998 deaths]]
[[Category:Boxer Indemnity Scholarship recipients]]
[[Category:California Institute of Technology alumni]]
[[Category:Educators from Shaoxing]]
[[Category:Members of the Chinese Academy of Sciences]]
[[Category:Academic staff of the National Central University]]
[[Category:Physicists from Zhejiang]]
[[Category:Nanjing University alumni]]
[[Category:Academic staff of the National Southwestern Associated University]]
[[Category:Scientists from Shaoxing]]
[[Category:Academic staff of Tsinghua University]]
[[Category:Academic staff of the University of Science and Technology of China]]
[[Category:Academic staff of Yunnan University]]
[[Category:Chinese nuclear physicists]]