Seth Carlo Chandler
Seth Carlo Chandler , Jr. (born September 16, 1846 in Boston , Massachusetts , † December 31, 1913 in Wellesley Hills , Massachusetts) was an American astronomer .
In his senior year of high school , he did math for Benjamin Peirce of the Harvard College Observatory .
After graduating, Chandler became Benjamin Apthorp Gould's assistant . Gould was the director of the Longitude Department of the US Coast Survey program, which focused on geodetic surveillance. When Gould went to Argentina , Chandler also left the observatory and became an insurance specialist. However, he continued to work as an amateur astronomer at the Harvard College Observatory.
Chandler's greatest scientific achievement is the discovery of the periodic circular motion of the earth's axis of rotation, named after him, in relation to an earth-fixed coordinate system . The amplitude of this movement (so-called "Chandler wobble") is about 0.17 arc seconds , which corresponds to 5 m on the earth's surface. The mean period of oscillation is 435 days. This oscillation, also known as the “free pole movement ” of the earth, is due to the fact that the main polar axis of inertia (figure axis) does not coincide with the earth's axis of rotation. This causes the flattened top to wobble. Why the axis of rotation has not shifted to the main axis of inertia in the course of the earth's history is a current subject of research. The latest research suggests that mass shifts in the atmosphere and oceans are responsible for maintaining the oscillation.
Chandler also worked in other areas of astronomy such as variable stars . He was an independent co-discoverer of the Nova T Coronae Borealis , improved the determination of the constant of aberration and calculated orbital elements of asteroids and comets .
In 1883 Chandler was elected to the American Academy of Arts and Sciences , in 1888 to the National Academy of Sciences .
Chandler received the Royal Astronomical Society gold medal in 1896 and the James Craig Watson Medal in 1894. A lunar crater was named after him.
Web links
- Publications by SC Chandler in the Astrophysics Data System
- Obituaries for SC Chandler in the Astrophysics Data System
Individual evidence
- ^ Members of the American Academy. Listed by election year, 1850–1899 ( PDF ). Retrieved September 24, 2015
| personal data | |
|---|---|
| SURNAME | Chandler, Seth Carlo |
| BRIEF DESCRIPTION | American astronomer |
| DATE OF BIRTH | September 16, 1846 |
| PLACE OF BIRTH | Boston , Massachusetts |
| DATE OF DEATH | December 31, 1913 |
| Place of death | Wellesley Hills , Massachusetts |