-Astronomical+discoveries


 * 2400 BC. - Astronomical Calendar
 * 238 BC. - Ptolemy III suggested adding one day every four years to calendar - implemented two centuries later under Julius Caesar and known as the Julian calendar.
 * Alexandria University - Ptolemaic Period scientists reached solid conclusions on the earth's rotation around the sun and the approximate geosphere of the planet
 * Positioning the pyramids - aligned accurately with the star B Scorpii's rising direction.
 * Astronomers were simply priests - their main duty was to calculate the time of the Nile flood, which occurred at the summer solstice when the bright star Sirius rose before the sun.