P2 Katie B's Timeline

By katieb
  • 200

    Ptolemy

    Ptolemy
    87-150 AD
    Ptolemy thought that the sun and planets orbited the Earth (geocentric theory). In order of Mercury, Venus, Sun, Mars, Jupiter, and Saturn.
  • Jan 1, 1473

    Nicholas Copernicus

    Nicholas Copernicus
    1473-1543
    Copernicus thought that the planets revolved around the sun (heliocentric theory). Because of the rising and setting of the sun, moon and stars.
  • Jan 1, 1564

    Galileo Galilei

    Galileo Galilei
    1564-1642
    Galileo explained how to improve the telescope. He built the first highpowered astronomical telescope. So people could see Jupiter's moons and the surface of our moon.
  • Jan 1, 1571

    Johannes Kepler

    Johannes Kepler
    1571-1630
    Kepler discovered that the orbits of the planets were not flat circles but instead they were ellipses.

  • Sir Isaac Newton

    Sir Isaac Newton
    1642-1727
    Newton explained that a body will preserve it's velocity and direction so long as no force in it's motion's direction acts on it, that is the law of inertia. Every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of the masses of the products and inversely proportional to the square of the distance between them. That is the law of gravity.