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Willem de Sitter | |
|---|---|
 De Sitter,c. 1930s | |
| Born | (1872-05-06)6 May 1872 |
| Died | 20 November 1934(1934-11-20) (aged 62) Leiden,South Holland, Netherlands |
| Nationality | Dutch |
| Alma mater | Groningen University |
| Known for | De Sitter Universe |
| Scientific career | |
| Fields | Physics |
| Doctoral advisor | Jacobus Kapteyn[1] |
| Doctoral students | |
| Signature | |
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| Part of a series on |
| Physical cosmology |
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Early universe |
Components · Structure |
Willem de Sitter (6 May 1872 – 20 November 1934) was a Dutch mathematician, physicist, and astronomer. He is known for thede Sitter universe, which is acosmological model that was named after him.
Born inSneek, Netherlands, de Sitter studiedmathematics at theUniversity of Groningen and then joined theGroningenastronomical laboratory. He worked at theCape Observatory inSouth Africa (1897–1899). Then, in 1908, De Sitter was appointed to the chair of astronomy atLeiden University. He was director of theLeiden Observatory from 1919 until his death.
De Sitter made major contributions to the field ofphysical cosmology. In 1916-17, he published a series of papers describing the consequences ofAlbert Einstein'stheory of relativity to the understanding of astronomy, which were directly affectedArthur Eddington's 1919 findings in the famous experiment of thesolar eclipse.[2] He co-authored a paper with Einstein in 1932 in which they discussed the implications of cosmological data for the curvature of the universe. He also came up with the concept of theDe Sitter space andDe Sitter universe, a solution for Einstein'sgeneral relativity in which there is no matter and a positivecosmological constant. This results in an exponentially expanding, empty universe. De Sitter was also well-known for his research on the motions of the moons ofJupiter, and was invited to give theGeorge Darwin Lecture at theRoyal Astronomical Society in 1931.[3]
Willem de Sitter died after a brief illness in November 1934.[4][5][6]
In 1912, he became a member of theRoyal Netherlands Academy of Arts and Sciences.[7]
One of his sons,Ulbo de Sitter (1902 – 1980), was a Dutch geologist, and one of Ulbo's sons was a Dutch sociologistUlbo de Sitter (1930 – 2010).
Another son of Willem, Aernout de Sitter (1905 – 15 September 1944[8]), was the director of theBosscha Observatory inLembang,Indonesia (then the Dutch East Indies), where he studied theMessier 4globular cluster.
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