1673 in science

Mathematics

• John Kersey begins publication of The Elements of that Mathematical Art Commonly Called Algebra.
• Samuel Morland publishes A Perpetual Almanack and Several Useful Tables.

  Microbiology

• Antonie van Leeuwenhoek's observations with the microscope are first published in Philosophical Transactions of the Royal Society.

  Physics

• Christiaan Huygens publishes his mathematical analysis of the pendulum, Horologium Oscillatorium sive de motu pendulorum.

  Births

• August 10 – Johann Conrad Dippel, German theologian, alchemist and physician

  Deaths

• May 6 – Werner Rolfinck, German scientist
• August 17 – Regnier de Graaf, Dutch physician and anatomist who discovered the ovarian follicles
• December 15 – Margaret Cavendish, Duchess of Newcastle-upon-Tyne, English natural philosopher