| Date | Text | |
|---|---|---|
20 Apr 1646
Charles Plumier |
birth Charles Plumier Charles Plumier, French botanist (died 1704) |
|
20 Apr 1702
Comet of 1702 |
Comet of 1702 (astronomy) Comet of 1702 (C/1702 H1): The 10th-closest comet approach in history, it missed Earth by a distance of 0.0437 AU (6,537,000 km). |
|
20 Apr 1745
Philippe Pinel |
birth Philippe Pinel Philippe Pinel, French psychiatrist (died 1826) |
|
20 Apr 1814
Filippo de Filippi |
birth Filippo de Filippi Filippo de Filippi, Italian zoologist (died 1867). |
|
20 Apr 1821
Franz Karl Achard |
death Franz Karl Achard Franz Karl Achard (born 1753), chemist. |
|
20 Apr 1887
Margaret Newton |
birth Margaret Newton Margaret Newton (died 1971), Canadian plant pathologist. |
|
20 Apr 1905
Albrecht Unsöld |
birth Albrecht Unsöld Albrecht Unsöld (died 1995), astronomer |
|
20 Apr 1913
Willi Hennig |
birth Willi Hennig Willi Hennig (died 1976), German entomologist and pioneer of cladistics. |
|
20 Apr 1918
Karl Ferdinand Braun |
death Karl Ferdinand Braun Karl Ferdinand Braun (born 1850), physicist. |
|
20 Apr 1928
Charles David Keeling |
birth Charles David Keeling Charles David Keeling (died 2005), American atmospheric chemist, geochemist and oceanograper. |
|
20 Apr 1932
Giuseppe Peano |
death Giuseppe Peano Giuseppe Peano (born 1858), Italian mathematician. |
|
20 Apr 1955
Svante Pääbo |
birth Svante Pääbo Svante Pääbo, Swedish evolutionary geneticist. |
|
20 Apr 1967
Surveyor 3 |
Surveyor 3 (astronomy and space ) Surveyor 3 probe lands on the Moon. |
|
20 Apr 1985
Charles Richter |
death Charles Richter Charles Richter (b. 1900), American geophysicist and inventor. |
|
20 Apr 2004
NASA |
NASA (physics) NASA launches Gravity Probe B in an effort to test Einstein's general theory of relativity. |
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