Equant

/ˈiːkwənt/ noun

Definition

In astronomy, a point used in models of planetary motion where an orbiting body appears to move at a constant angular velocity.

Etymology

From Medieval Latin 'aequans' (making equal), from 'aequare' (to make equal). Ptolemy used this geometric trick to make irregular planetary paths appear uniform.

Kelly Says

The 'equant point' was Ptolemy's creative cheat code—by placing the observer at an imaginary spot instead of Earth's center, orbits looked perfectly regular, hiding the real physics for 1,400 years.

Related Words

Explore More Words

Get the Word Orb API

Complete word intelligence in one call. Free tier — 50 lookups/day.