1611 in science

Astronomy

• February 27 – Sunspots are observed by telescope by Frisian astronomers Johannes Fabricius and David Fabricius and Johannes publishes the results of these observations in De Maculis in Sole observatis in Wittenberg later this year. Such early discoveries are overlooked however, and the first sighting is claimed a few months later by Galileo Galilei and Christoph Scheiner.

  Mathematics

• Johannes Kepler produces Kepler's conjecture on sphere packing.

  Technology

• Completion of Cordouan lighthouse on the Gironde estuary, the first wave-swept light.

  Births

• January 28 – Johannes Hevelius, German astronomer
• March 1 – John Pell, English mathematician
• Willem Piso, Dutch physician and naturalist
• Georg Marcgrave, German naturalist, explorer of Brazil

  Deaths

• August 9 – John Blagrave, English mathematician
• Henry Hudson, English explorer