ES2

Eratosthenes

240 BCE

Eratosthenes is known for making the first good measurement of the size of Earth. This is an important discovery because it gave other astronomers a foundation to work with.

Ptolemy

150 BCE

Ptolemy came up with the geocentric model, and even though everything he thought was wrong, it was still an important discovery because it gave other scientist a theory to compete with.

Copernicus

1543

Nicholas Copernicus came up with the model of the universe which placed the sun in the center. This was an important discovery because many other astronomers used his model to develop further information on our universe.

Tycho

1572

After noticing a star in the sky that was brighter than Venus, Tycho built a new sextant and then published a detailed account of his findings about the new star.
This discovery was important because Kepler would go on to use Tycho's findings to devise the laws of planetary motion.

Kepler

1600

Kepler used the findings of Tycho to discover that the planets move in an elliptical motion rather than perfect circles. This discovery was important because it changed the way scientists thought about our solar system.

Newton

1687

Newton came up with the three laws of motion, this discovery was important because it is still relevant today and helps explain gravity.

Einstein

1905

Einstein proposed the idea that light should be thought of as a stream of particles instead of just a single wave. This idea led to the photoelectric effect. This discovery was important because it contradicted the current 19th century belief