Orientation in time and space is a basic need of every society, and in ancient Egypt the sky provided abundant material for this purpose. The most obvious rhythm and the first basic spatial distinction were provided by the sun which every day rises in the east and sets in the west. For more sophisticated goals, such as keeping a calendar and establishing with precision the four cardinal points, the ancient Egyptians appear to have turned to the night sky and to the more complex movements of various celestial bodies.
From the point of view of an observer, the stars slowly and constantly rotate around the north celestial pole. This point corresponds to the direction of the axis of the planet Earth and is currently marked by Polaris, the North Star. Four millennia ago, however, the axis of our planet pointed in a slightly different direction, and the north celestial pole was not marked by any star. The entire sky rotated around a dark spot: whilst the further stars periodically disappeared under the horizon, those lying closer to the center of rotation never set. In ancient Egypt, because of their constant presence, the circumpolar stars earned the appellative of‘‘the Imperishable Ones’’.
Stars were grouped in constellations, divided into southern and northern groups (Neugebauer and Parker 1969: 183-202); New Kingdom sources mention about a dozen in each group but only a few can be identified (Wilkinson 2003: 91). Five ‘‘stars that know no rest’’ (five planets) moved independently against this ‘‘fixed’’ background (Neugebauer and Parker 1969: 175-82), and so did the moon. Among the stars that set and rose, the most important was the bright Sirius, called Sopdet by the Egyptians and Sothis by the Greeks. The moon and Sirius played a fundamental role in the organization of the ancient Egyptian society: the phases of the former and the annual cycle of the latter lay at the basis of ancient Egyptian time-keeping system.
World History
