1621 in science
The year 1621 in science and technology involved some significant events.Astronomy
- Johann Schreck, also known as Johannes Schreck, Terrenz or Terrentius, introduces the telescope to China.
Botany
- The University of Oxford Botanic Garden, the oldest botanical garden in Great Britain, is founded as a physic garden by Henry Danvers, 1st Earl of Danby.
Medicine
- Robert Burton publishes his treatise The Anatomy of Melancholy.
Physics
- Willebrord Snellius formulates Snell's law on refraction.
Technology
- A simple microscope is developed.
- Cornelius Vermuyden begins reclamation of Canvey Island in England.
Births
- January 27 – Thomas Willis, English physician who contributes to knowledge of the nervous and cardiovascular systems
Deaths
- July 2 – Thomas Harriot, English ethnographer, astronomer and mathematician
- September 1 – Bahāʾ al-dīn al-ʿĀmilī, Arab philosopher and astronomer
- Jan Jesenius, Slovak physician
