By R27
  • 100

    "Few centuries B.C." Aristotle

    Aristotle saw objects wandering around in the sky in a predictable type of motion, so he put those objects, planets, into orbit with the Earth as its center.
  • 120

    2nd century A.D. Ptolemy

    Ptolemy viewed the Earth as the center of the universe. He used a system with numberous circles and epicycles that could explain all movement.
  • Newton

    Newton went to a small farm in the country to escape the plague and saw an apple fall, which led to the founding of his universal laws of gravitation. Using Kepler's laws of planeary motion, he thought about how high gravity reached and explained it; coming up with the Law of universal Gravitation.
  • Cavendish

    Cavendish came up with the first reliable measurement of G, the eniveral gravitational constant. He preformed experiments to find the density of the Eatch, which eventually bebame known as the Cavendish experiment.
  • Einstein

    1905- Extended Newton's equations; determined that the speed of light is constant if the object is mving at a constant velocity.
    1916- Supported Newton's equations; determined that a person cannot distinguish from gravitation and constant acceleration. This determined that mass and energy effect the gravitational field.