Copernicus’s Model Many scientists believed our Earth was the center of the solar system, this theory is called geocentric Copernicus first proposed our solar system was heliocentric – suncentered
Geocentric vs. Heliocentric Geocentric Heliocentric
Kepler’s Laws 1 st law- Law of Ellipses 2 nd law- Law of Equal Areas 3 rd law- Law of Periods
Law of Ellipses- The orbit of every planet is an ellipse (oval shape) with the Sun at one of the two foci.orbit planetellipsefoci
Law of Equal Areas- A line joining a planet and the Sun sweeps out equal areas during equal intervals of time.line
Law of Periods- The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. (measures how long on avg. it takes for the planet to make it around the sun).square orbital period proportional cubesemi-major axis
Newton’s Applications of Kepler’s Laws Newton explained why the planets move. He created his own laws which explained why the planets keep moving around the sun. He theorized that “gravity” and “inertia” caused the planets to keep moving