The geocentric theory stated that the earth was the center of the universe and was the most accepted viewpoint for a long, long time. The heliocentric theory, on the other hand, states that the earth revolves around the Sun. The first advocate of a heliocentric model was Aristarchus of Samos in ancient Greece.

1. Early model of the universe
By: Aristachus

2. Aristarchus

3. Aristarchus
Aristarchus of Samos was an ancient Greek
astronomer and mathematician who presented the
first known heliocentric model that placed the Sun at
the center of the known universe with the Earth
revolving around it.

4. Aristarchus, the famous ancient astronomer and
mathematician born in Samos: Aristarchus (310 BC-230 BC)
was a famous Greek mathematician and astronomer, popular
for his theories regarding the heliocentrism of our solar
system. He was the first to say that the Sun, and not the
Earth, was the center of our universe

5. The heliocentric theory argues that the sun is the
central body of the solar system and perhaps of the
universe. Everything else (planets and their satellites,
asteroids, comets, etc.) revolves around it.
The Heliocentric Theory

6. His theory took more than a century to become widely accepted. [Adapted from
Nicolaus Copernicus, 1543, De revolutionibus orbium coelestium (“On the Revolutions of
the Heavenly Spheres.”)] But the evidence for a heliocentric solar system gradually
mounted.
His theory took more than a century to become widely accepted. [Adapted from
Nicolaus Copernicus, 1543, De revolutionibus orbium coelestium (“On the
Revolutions of the Heavenly Spheres.”)] But the evidence for a heliocentric solar
system gradually mounted.

7. Heliocentric Model

8. The geocentric theory stated that the earth was the center of the universe
and was the most accepted viewpoint for a long, long time. The heliocentric
theory, on the other hand, states that the earth revolves around the Sun.
The first advocate of a heliocentric model was Aristarchus of Samos in
ancient Greece.

9. The geocentric theory stated that the earth was the center of the universe
and was the most accepted viewpoint for a long, long time. The heliocentric
theory, on the other hand, states that the earth revolves around the Sun.
The first advocate of a heliocentric model was Aristarchus of Samos in
ancient Greece.

10. Who proved the heliocentric theory?
Nicolaus Copernicus
It was not until the 16th century that a mathematical model of a
heliocentric system was presented, by the Renaissance mathematician,
astronomer, and Catholic cleric Nicolaus Copernicus, leading to the
Copernican Revolution.