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276 BCE
Eratosthenes (276–195 B.C)
used the sun to measure the size of the earth, his measurement was 24,660 miles only 211 miles off the true measurement, This is important as it was the first time we had an idea of how big the earth was. -
90
Claudius Ptolemy (A.D. 90–168)
set up a model of the solar system in which the sun, stars, and other planets revolved around Earth. Known as the Ptolemaic system, it was a model that was later proven to be completely wrong. -
1473
Nicolaus Copernicus (1473–1543)
proposed a model of the solar system that involved the Earth revolving around the sun. it is important because it shows that the sun is in the center of the universe. -
Period: 1571 to
Johannes Kepler and Tycho Brahe
determined that planets traveled around the sun not in circles but in ellipses. it made a new calculation that astronomers still use today. -
Period: to
Sir Isaac Newton
most famous for his work on forces, specifically gravity. its important because gravity is the thing that keeps us on earth and lets earth orbit the sun. -
Period: to
Albert Einstein
suggested that the laws of physics are the same throughout the universe, that the speed of light in a vacuum is constant, and that space and time are linked in an entity known as space-time, which is distorted by gravity.