Copernicus sees a heliocentric Universe with Earth and planets revolving around the Sun. Mercator makes cylindrical map projections. Brahe observes a supernova. New Gregorian Calendar. Kepler's Mysteries of the Cosmos.
Western science challenges Chinese superiority.
Appearance of Halley's Comet. Galileo uses telescope to see craters on the Moon and the moons of Jupiter. Inquisition forces Galileo to recant his belief in Copernican theory. Kepler describes laws of planetary motion. Briggs introduces decimal notation.