Carl David Anderson
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Carl David Anderson (September 3, 1905 – January 11, 1991) was an American experimental physicist who shared the 1936 Nobel Prize in Physics with Victor Hess for his discovery of the positron, which confirmed the theory of antimatter.
Early life
Carl David Anderson was born on September 3, 1905, in New York City, to Swedish immigrants, Carl David Anderson Sr. and Emma Adolfina Ajaxson.
Anderson studied physics and engineering at Caltech, receiving a B.S. in 1927 and a Ph.D. in 1930.
Research
Discovery of the positron
Under the supervision of Robert Millikan, Anderson began investigations into cosmic rays during the course of which he encountered unexpected particle tracks in his (modern versions now commonly referred to as an Anderson) cloud chamber photographs that he correctly interpreted as having been created by a particle with the same mass as the electron, but with opposite electric charge.
This discovery, announced in 1932 and later confirmed by others, validated Paul Dirac's theoretical prediction of the existence of the positron. Anderson first detected the particles in cosmic rays. He then produced more conclusive proof by shooting gamma rays produced by the natural radioactive nuclide ThC'' (208Tl)<ref>ThC" is a historical designation of 208Tl, see Decay chains</ref> into other materials, resulting in the creation of positron-electron pairs.
For this work, Anderson shared the 1936 Nobel Prize in Physics with Victor Hess.<ref>The Nobel Prize in Physics 1936. nobelprize.org</ref> Fifty years later, Anderson acknowledged that his discovery was inspired by the work of his Caltech classmate, Chung-Yao Chao, whose research formed the foundation from which much of Anderson's work developed but was not credited at the time.<ref name="Chinese">Template:Cite journal</ref>
Discovery of the muon
In 1936, Anderson and his first graduate student, Seth Neddermeyer, discovered the muon<ref>Template:Cite journal</ref> (or 'mu-meson', as it was known for many years), a subatomic particle 207 times more massive than the electron, but with the same negative electric charge and spin 1/2 as the electron, again in cosmic rays.
Anderson and Neddermeyer at first believed that they had seen a pion, a particle which Hideki Yukawa had postulated in his theory of the strong interaction. When it became clear that what Anderson had seen was not the pion, the physicist I. I. Rabi, puzzled as to how the unexpected discovery could fit into any logical scheme of particle physics, quizzically asked "Who ordered that?" (sometimes the story goes that he was dining with colleagues at a Chinese restaurant at the time).
The muon was the first of a long list of subatomic particles whose discovery initially baffled theoreticians who could not make the confusing "zoo" fit into some tidy conceptual scheme. Willis Lamb, in his 1955 Nobel Prize Lecture, joked that he had heard it said that "the finder of a new elementary particle used to be rewarded by a Nobel Prize, but such a discovery now ought to be punished by a 10,000 dollar fine."<ref>Willis E. Lamb, Jr. (December 12, 1955) Fine structure of the hydrogen atom. Nobel Lecture</ref>
Personal life and death
In 1946, Anderson married Lorraine Bergman, with whom he had two sons.<ref>Template:Cite web</ref>
Anderson died on January 11, 1991, in San Marino, California, at the age of 85. His remains were interred at the Forest Lawn Memorial Park in Los Angeles, California. He was a Christian. <ref>Template:Cite book</ref>
Awards
Anderson was elected to the National Academy of Sciences and the American Philosophical Society in 1938.<ref>Template:Cite web</ref><ref>Template:Cite web</ref> He was elected a Fellow of the American Academy of Arts and Sciences in 1950.<ref name=AAAS>Template:Cite web</ref> He received the Elliott Cresson Medal of the Franklin Institute in 1937 and the Golden Plate Award of the American Academy of Achievement in 1975.<ref>Template:Cite web</ref>
Select publications
References
Further reading
External links
- 1983 Audio Interview with Carl Anderson by Martin Sherwin Voices of the Manhattan Project
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- American National Biography, vol. 1, pp. 445–446.
- Annotated bibliography for Carl David Anderson from the Alsos Digital Library for Nuclear Issues
- Carl Anderson and the Discovery of the Positron
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- National Academy of Sciences Biographical Memoir
- Oral History interview transcript with Carl D. Anderson on 30 June 1966, American Institute of Physics, Niels Bohr Library and Archives
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Template:Nobel Prize in Physics Laureates 1926-1950 Template:1936 Nobel Prize winners
- 1905 births
- 1991 deaths
- 20th-century American physicists
- American Nobel laureates
- American people of Swedish descent
- Burials at Forest Lawn Memorial Park (Hollywood Hills)
- California Institute of Technology alumni
- California Institute of Technology faculty
- American experimental physicists
- Fellows of the American Academy of Arts and Sciences
- Fellows of the American Physical Society
- John H. Francis Polytechnic High School alumni
- Nobel laureates in Physics
- American particle physicists
- Scientists from California
- Scientists from New York City
- Members of the United States National Academy of Sciences
- Members of the American Philosophical Society