History of Western Cosmology By kdabroski 350 BCE Aristotle Develops Model of the Universe 270 BCE Aristarchus Proposes Heliocentrism 240 BCE Eratosthenes Measures Earth's Circumference 46 BCE Julian Calendar Adopted 140 Ptolemy Publishes the Almagest 499 Aryabhata Proposes Elliptical Orbits 773 Sanskrit Works Translated into Arabic 780 Astrolabe Invented 1126 Islamic and Indian Texts Translated into Latin 1261 al-Tusi Criticizes Ptolemy 1543 Copernicus Publishes Heliocentric Model 1572 Tycho's Supernova 1576 Tycho Builds Uraniborg 1582 Gregorian Calendar Adopted 1600 Kepler Works with Tycho 1609 Kepler Publishes 3 Laws 1610 Galileo Publishes Observations with Telescope
