This Tool Was Built to Hold the Sky
An astrolabe turns the sky into a flat, handheld model. Its rotating framework, called the rete, acts like a moving star map over a plate made for a specific latitude.Astrolabe: How a Flat Disc Modeled the Sky
As the Rete Turns, Time Moves
When the rete rotates, the stars and the ecliptic move across the plate beneath it. One full turn matches the passage of a day, so the instrument becomes a model of the visible sky.Astrolabe: How a Flat Disc Modeled the Sky
