Charles Greeley Abbot

For other people named Charles Abbot, see Charles Abbot (disambiguation).

Charles Greeley Abbot
Portrait of Charles Greeley Abbot
Born	May 31, 1872(1872-05-31) Wilton, New Hampshire, United States
Died	December 17, 1973(1973-12-17) (aged 101) Washington D.C., United States
Nationality	American
Fields	astrophysics
Notable awards	Henry Draper Medal (1910) Rumford Prize (1915)

Charles Greeley Abbot (May 31, 1872 – December 17, 1973)^[1] was an American astrophysicist, astronomer and Secretary of the Smithsonian Institution. He was born in Wilton, New Hampshire.^[2]

Life

Abbot graduated from Phillips Academy in 1891 and MIT in 1894, with a degree in chemical physics. Samuel Pierpont Langley was looking for an assistant at the Smithsonian Astrophysical Observatory (SAO), and hired Abbot in 1895 because of his skill at laboratory work, despite his lack of experience in astronomy.

Langley focused on aeronautics experiments, while Abbot became acting director of the SAO in 1896. When Langley died in 1906, Abbot succeed him as director (in 1907), and Charles Walcott became Smithsonian Secretary. Abbot, recognizing that the solar constant was badly approximated, proposed a more accurate value of 1.93 cal/cm²/min for the solar constant (the modern value is measured in watts per square meter).

Abbot was secretary of the Smithsonian Institution from 1928 to 1944. Responsible for the observatory's solar observations, he designed and built devices for measuring solar radiation, including a greatly improved bolometer which measured the Sun's inner corona at the 1900 solar eclipse in Wadesboro, North Carolina.

In 1918 Abbot became Assistant Secretary of the Smithsonian. He succeeded Walcott as Secretary in 1928, and guided the Institution through the turbulent years of the Great Depression and World War II.

From 1941 he was an original standing committee member of the Foundation for the Study of Cycles.

Abbot retired as both SAO director and Smithsonian Secretary in 1944, being the first Smithsonian Secretary not to die in office. His long-time astrophysical research assistant Loyal Blaine Aldrich became SAO director.^[3] He delegated the National Museum largely to his Assistant Secretary, Alexander Wetmore, who succeeded him as Secretary in 1944.

Awards and honors

Abbot won the Henry Draper Medal of the National Academy of Sciences in 1910^[4] and the Rumford Prize of the American Academy of Arts and Sciences in 1915. He was elected Fellow of the American Academy of Arts and Sciences in 1921.^[5]

Studies

Abbot pushed to provide funding to rocket pioneer Robert Goddard during World War I, but to his disappointment this was canceled after the end of the war.

Abbot, like Langley, pursued the idea that the Sun's radiation was variable and that this variability could influence weather. He persistently searched for variations in the solar constant, hoping that these could be used for weather forecasting, and believed that he had detected such variations, on the order of 3% to 10%. However, modern measurements of greater accuracy indicate that such variability does not occur, apart from tiny variations due to sunspots and faculae.

He completed the mapping of the infrared solar spectrum and carried out systematic studies of variation in solar radiation, its relation to the sunspot cycle, and its effect on weather variation. He also studied the nature of atmospheric transmission and absorption. Abbot perfected various standardised instruments now widely used for measuring the sun's heat, and he invented devices utilizing solar energy.

In 1938, Abbot made an anonymous contribution to the Journal of Parapsychology detailing his studies into clairvoyance. In 1949, he published a replication of his findings in the same journal under his own name.

The crater Abbot on the Moon is named after him; an exception was made and it was named for him while he was still alive. He died in Washington D.C..

References

1. ^ "Charles Greeley Abbot - BIOGRAPHICAL MEMOIRS". National Academy of Sciences. http://www.nap.edu/readingroom.php?book=biomems&page=cabbot.html. Retrieved 2008-05-09. 
2. ^ Chambers Biographical Dictionary, ISBN 0-550-18022-2, page 2
3. ^ "Directors of the SAO, HCO, and CfA". Harvard-Smithsonian Center for Astrophysics. http://www.cfa.harvard.edu/lib/information/directors.html. Retrieved 2011-06-16. 
4. ^ "Henry Draper Medal". National Academy of Sciences. http://www.nasonline.org/site/PageServer?pagename=AWARDS_draper. Retrieved 19 February 2011. 
5. ^ "Book of Members, 1780-2010: Chapter A". American Academy of Arts and Sciences. http://www.amacad.org/publications/BookofMembers/ChapterA.pdf. Retrieved 18 March 2011. 

External links

• National Academy of Sciences biography
• QJRAS 18 (1977) 136
• The University of Wisconsin Digital Collections Center presents The Smithsonian Scientific Series and the following digitized articles originally published by C.G. Abbot: Abbot, Charles Greeley The sun and the welfare of man (1938), Abbot, C. G. (Charles Greeley), 1872 Great inventions (1932), Bishop, Carl Whiting, 1881–1942; Abbot, Charles Greeley; Hrdlicka, Aleš Man from the farthest past (1930).

Persondata
Name	Abbot, Charles Greeley
Alternative names
Short description
Date of birth	May 31, 1872
Place of birth	Wilton, New Hampshire, United States
Date of death	December 17, 1973
Place of death	Washington D.C., United States