Egyptian Astronomy

While the Chinese, the Babylonians, and the Chaldeans used astronomical observations to help them rule and regulate the living, the ancient Egyptians used the observations and measurements they made to help the dead find their place in the afterlife. Actually, Egyptian astronomers worked for both the living and the dead. They created a calendar to help predict the annual flooding of the Nile—essential information for a people whose entire agriculture was subject to the whims of that river. To create their calendar, Egyptian sky watchers concentrated in particular on the rising of the star Sirius (which they called Sothis). Working from these data (measuring the time from one rising of Sirius to the next), Egyptian astronomers were able to determine that a year was 365.25 days long.