2. Where it all Began Scientists believe that the universe started from a PRIMEVAL ATOM The Primeval atom was a very hot and very dense mass of energy

3. Evidence for the Big Bang The galaxies are really far apart The distance between galaxies is still expanding So this bang is probably still happening and creating new galaxies and other things in our universe

4. The Geocentric Theory Geo = Earth Centric=Centered Geocentric = “Earth Centered” It means that the Earth is in the center of the universe

5. The Geocentric Model of the Solar System

6. Heliocentric Helio = sun Helio=Sun Heliocentric = “sun centered” It means that the sun is in the center of the Universe

7. The Heliocentric Model of the Solar System

9. PRACTICE 1) Scientists believe that the universe is a. Shrinking b. Constant c. Expanding d. None of the above 2) The theory that the universe began with a tremendous explosion is called ____________________. 3) The universe is believed to have started with the ____________. 4) What was the Primeval atom made up of? 5) Given the conditions of the primeval atom, is it possible for anything to live in the atom? Explain your answer 6) How are the geocentric and heliocentric views different?

10. FAMOUS PEOPLE YOU SHOULD KNOW

11. Ptolemy Believed that the earth was at the center of the universe

12. Copernicus Believed the sun was at the center of the universe

13. Kepler Believed that the planets did revolve around the sun in an elliptical pattern. The sun was not at the exact center

14. Galileo First person to use a telescope to look at the stars, planets, universe and so on. This gave him proof that the sun was in the center of our solar system

15. Newton Believed sun was in the center of the universe but gravity is what holds everything together in place

16. Practice Classify the following famous as either Heliocentric believers or geocentric believers 1. Copernicus 2. Ptolemy 3. Galileo 4. Newton 5. Kepler