Where was Parallax invented?

Answer 1

Specifically, who knows. You might as well try and discern where the idea of eating came from. However the first recorded ancient astronomers, who most likely used parallax, were the Sumerians who tracked stars in the night sky for agriculture and navigational reasons.

Answer 2

Parallax was first observed by the ancient Greeks in the 3rd century BC as they noticed that stars appeared to shift position relative to each other as the Earth orbited the Sun. This phenomenon allowed astronomers to measure the distance to nearby stars and is a fundamental concept in astronomy.