Charles Greeley Abbot
Encyclopedia
Charles Greeley Abbot (May 31, 1872 – December 17, 1973) was an American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
astrophysicist, astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
and Secretary of the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
. He was born in Wilton, New Hampshire
Wilton, New Hampshire
- Demographics :As of the census of 2000, there were 3,743 people, 1,410 households, and 1,023 families living in the town. The population density was 145.3 people per square mile . There were 1,451 housing units at an average density of 56.3 per square mile...
.
Life
Abbot graduated from Phillips AcademyPhillips Academy
Phillips Academy is a selective, co-educational independent boarding high school for boarding and day students in grades 9–12, along with a post-graduate year...
in 1891 and MIT in 1894, with a degree in chemical physics
Chemical physics
Chemical physics is a subdiscipline of chemistry and physics that investigates physicochemical phenomena using techniques from atomic and molecular physics and condensed matter physics; it is the branch of physics that studies chemical processes from the point of view of physics...
. Samuel Pierpont Langley
Samuel Pierpont Langley
Samuel Pierpont Langley was an American astronomer, physicist, inventor of the bolometer and pioneer of aviation...
was looking for an assistant at the Smithsonian Astrophysical Observatory
Smithsonian Astrophysical Observatory
The Smithsonian Astrophysical Observatory is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory to form the Harvard-Smithsonian Center for Astrophysics .-History:The SAO was founded in 1890 by...
(SAO), and hired Abbot in 1895 because of his skill at laboratory work, despite his lack of experience in astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
.
Langley focused on aeronautics
Aeronautics
Aeronautics is the science involved with the study, design, and manufacturing of airflight-capable machines, or the techniques of operating aircraft and rocketry within the atmosphere...
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
Solar constant
The solar constant, a measure of flux density, is the amount of incoming solar electromagnetic radiation per unit area that would be incident on a plane perpendicular to the rays, at a distance of one astronomical unit...
was badly approximated, proposed a more accurate value of 1.93 cal/cm²/min for the solar constant
Solar constant
The solar constant, a measure of flux density, is the amount of incoming solar electromagnetic radiation per unit area that would be incident on a plane perpendicular to the rays, at a distance of one astronomical unit...
(the modern value is measured in watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s per square meter).
Abbot was secretary of the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
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
Bolometer
A bolometer is a device for measuring the power of incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley...
which measured the Sun's inner corona
Corona
A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph...
at the 1900 solar eclipse
Solar eclipse of May 28, 1900
A total solar eclipse occurred on May 28, 1900. - Viewing :In 1900 the Smithsonian Astrophysical Observatory, then based in Washington, D.C., loaded several railroad cars with scientific equipment and headed to Wadesboro, North Carolina...
in Wadesboro, North Carolina
Wadesboro, North Carolina
Wadesboro is a town in Anson County, North Carolina, United States. The population was 5,780 at the 2010 census. It is the county seat of Anson County.-Geography:Wadesboro is located at ....
.
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
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
and World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
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
Loyal Blaine Aldrich
Loyal Blaine Aldrich was an American astrophysicist and astronomer of the Smithsonian Institution. Upon graduation from the University of Wisconsin in 1907, Aldrich became a Smithsonian Astrophysical Observatory assistant to Charles Greeley Abbot...
became SAO director. He delegated the National Museum largely to his Assistant Secretary, Alexander Wetmore
Alexander Wetmore
Frank Alexander Wetmore was an American ornithologist and avian paleontologist.-Life:Wetmore studied at the University of Kansas...
, who succeeded him as Secretary in 1944.
Awards and honors
Abbot won the Henry Draper MedalHenry Draper Medal
The Henry Draper Medal is awarded by the United States National Academy of Sciences "for investigations in astronomical physics". Named after Henry Draper, the medal is awarded with a gift of USD $15,000...
of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
in 1910 and the Rumford Prize
Rumford Prize
Founded in 1796, the Rumford Prize, awarded by the American Academy of Arts and Sciences, is one of the oldest scientific prizes in the United States. The prize recognizes contributions by scientists to the fields of heat and light...
of the American Academy of Arts and Sciences
American Academy of Arts and Sciences
The American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...
in 1915. He was elected Fellow of the American Academy of Arts and Sciences in 1921.
Studies
Abbot pushed to provide funding to rocketRocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...
pioneer Robert Goddard during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, but to his disappointment this was canceled after the end of the war.
Abbot, like Langley, pursued the idea that the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
'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
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
solar spectrum
Spectrum
A spectrum is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by...
and carried out systematic studies of variation in solar radiation, its relation to the sunspot
Sunspot
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....
cycle, and its effect on weather
Weather
Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...
variation. He also studied the nature of atmospheric
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
transmission and absorption. Abbot perfected various standardised instruments now widely used for measuring the sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
'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
Abbot (crater)
Abbot is a small lunar impact crater that lies on the rugged ground between the Mare Fecunditatis in the south and west, and the Mare Crisium to the north. It is a circular crater with a cup-shaped interior. The inner walls slope downward to the mid-point, and no impacts of significant mark the...
on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
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..
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).