Ptolemy’s 2nd-century Geocentric Theory

Definition

Ptolemy's Geocentric Theory posits that Earth is at the center of our solar system with all other celestial bodies revolving around it.

Analogy

Imagine you're at a concert standing right in front of your favorite band - they're playing just for you! That's how Earth was seen in Ptolemy’s Geocentric Theory - everything else (the sun, moon, stars) revolved around it like musicians around a soloist.

Related terms

Heliocentric Theory: Proposed by Copernicus, this theory suggests that the sun is at the center of our solar system with Earth and other planets revolving around it.

Astronomy: This is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry to explain their origin and evolution.

Epicycles: In Ptolemaic cosmology, these are small circles whose centers move around larger circles (deferents) along which a planet moves.