astronomers

Eratosthenes

240 BCE

Calculated the tilt of Earth's axis relative to the plane of its equator with good accuracy. This is important because this shed some light that Earth did not spin straight up.

Claudius Ptolemy

4 BCE

He believed that the Earth was the center of the universe, the geocentric theory. This is important because this led to other astronomers to dig deeper to discover the truth of what was the center of the universe.

Nicolaus Copernicus

1532

Formulated a model of the universe that placed the sun rather than the earth at the center of the universe. This is important because later he was proven to be right.

Tycho Brahe

1564

Made some of the most accurate observations of planetary positions. This is important because this would eventually prove useful to his predecessors.

Johannes Kepler

1609

Improved the heliocentric theory of Nicolaus Copernicus, explaining how the planets' speeds varied, and using elliptical orbits rather than circular orbits with epicycles. This is important because we were now understanding and improving the heliocentric theory since Nicolaus Copernicus

Sir Isaac Newton

1700

Newton developed the three laws of motion which form the basic principles of modern physics. This is important because his discovery of calculus led the way to way more methods of solving math problems

Albert Einstein

1905

Discovered the theory of relativity and his equation E=MC2, which developed atomic power and the atomic bomb. His discoveries are important because scientists still use his equations to find new discoveries.