In the northern hemisphere, December 21 marks the winter solstice; the shortest, darkest day of the year. From here the days become progressively longer as the sun inches northward, rising a little higher each day.
None of this would have been news to the ancient Egyptian architects of course. They designed Karnak Temple so that the rising solstice sun would pour directly through the main axis of the temple.
Pragmatically, the day also heralded the start of the plantation season. The solstice coincided with the waters of the Nile receding after the annual flooding.
It is thought that distinctive pylons (or ceremonial gateways) that front Egyptian temples formed a giant hieroglyph—the "akhet" symbol that represented the horizon. The akhet sign comprises of two mountain peaks with a sun-disc resting between them, and was a potent symbol of rebirth.
These photos come from the current issue of Nile Magazine. The solstice sunrise at Karnak Temple was taken by Marie E. Bryan, and the sun bursting forth above the eastern horizon is courtesy of Kelly A. Cummings.
Enjoy the full article in the current issue of Nile Magazine.