What are the 4 models of the universe?

Related questions

1. What is Ptolemy best known for?
2. How is Ptolemy?
3. Was Cleopatra's body ever found?
4. How old was Cleopatra when she gave birth?
5. What does Ptolemy mean?
6. Who proved Ptolemy wrong?
7. What is Ptolemy known for?
8. Was Ptolemy a pharaoh?
9. What were Ptolemy accomplishments?
10. What did Ptolemy accomplish?

Tags

1. #aristarchus
2. #models
3. #earth
4. #planets
5. #copernicus
6. #concentric
7. #while
8. #universe
9. #model
10. #aristotle
11. #ptolemy
12. #common
13. #stars
14. #eudoxus
15. #center
16. #whose
17. #spheres