1639 in science
The year 1639 in science and technology involved some significant events.
Astronomy
- Giovanni Battista Zupi observes that the planet Mercury has orbital phases.
- December 4 – English astronomers Jeremiah Horrocks and William Crabtree are the first and only scientific observers of a transit of Venus, predicted by Horrocks.
Exploration
- The Casiquiare canal, a river forming a natural canal between the Amazon River and Orinoco River basins, is first encountered by Europeans
Mathematics
- Girard Desargues introduces the concept of infinity into geometry.
Births
- April 12 – Martin Lister, English naturalist and physician
- December 18 – Gottfried Kirch, German astronomer
- approx. date – Daniel Greysolon, Sieur du Lhut, French explorer
Deaths
- June 6 – Peter Crüger, German polymath
- August 7 – Martin van den Hove, Dutch astronomer
- Mutio Oddi, Italian mathematician
