The office of north
A traveler wants a still point. So does a builder. For a long age Thuban, a modest lamp in Draco, magnitude about 3.67, stood near the north celestial pole, close enough to count as north. Around 2700 BCE it was at its nearest. People who needed a direction used the sky they had.
We do not have their log. We have the geometry, and later argument about whether particular shafts and temples were aimed at that lamp. The argument is not the night. The night is a slow circle the axis draws among the stars, too slow for one life to watch.
ASTRONOMY
What moved
Earth’s axis precesses with a period of about 26,000 years. The pole describes a circle among the stars. A North Star is a temporary neighbor of that circle, not a law of the sky. Distance to Thuban is on the order of 300 light-years. The closeness was geometric. The star did not fail. Polaris holds the office now. It will not keep it.
THE FENCE
Do not say the Egyptians were wrong because they used Thuban. They used the sky they had. We use the sky we have. Both are orientation. Neither is destiny.
Question
If north can move, what else that feels like a fixture is only a long appointment?
