The Heliocentric Theory

The heliocentric theory was a view of the universe that said that Earth, the stars, and the other planets revolve around the unmoving sun. This theory was discovered by a Polish astronomer named Nicolaus Copernicus in the early 1500's during the scientific revolution and changed people's view of the universe.

Before the Heliocentric Theory
Before Copernicus created his heliocentric theory, the people believed in the geocentric theory created by Ptolemy. His theory put Earth at the center of the universe and said that the moon and the stars revolved around it. Scientists and the people believed this to be true until Copernicus challenged Ptolemy's thoery with his heliocentric theory.

Proof of the Heliocentric Theory
Another scientist around 100 years later named Johannes Kepler built on and proved Copernicus's theory. Kepler, a German atronomer, used mathematical laws to show that the planets do revolve around the sun. He also stated that one mathematical law showed the planets don't move in circular orbits like Copernicus thought, but in elliptical orbits that are oval shaped. Next, Galileo's observations with his telescope also supported the heliocentric theory.