may 12, 498 - Aryabhata I (476-ca 550), Indian astronomer and mathematician, using Hindu (aka Arabic) numerals accurately calculates pi () to 3.1416, and the solar year to 365.3586805 days. A thousand years before Copernicus, Aryabhata propounds a heliocentric universe with elliptically orbiting planets and a spherical Earth spinning on its axis, explaining the apparent rotation of the heavens. Writes Aryabhatiya, history's first exposition on plane and spherical trigonometry, algebra and arithmetic.
