Chapter 1 The Copernican Revolution

1. Chapter 1The Copernican Revolution

2. The planets’ motions • Wanderers among the stars • Retrograde motion

3. Figure 1.1Planetary Motions

4. Geocentric models of the Universe • Earth at center of solar system • Aristotle (384 - 322 B.C.) • Ptolemy (87 - 150 A.D. approximately)

5. Figure 1.2 - Geocentric Model

6. Figure 1.3 - Ptolemy’s Model

7. History of modern astronomy and heliocentric models • Sun at center of solar system • Copernicus (1473 - 1543) • Brahe (1546 - 1601) • Galileo (1564 - 1642) • Kepler (1571 - 1630)

8. Figure 1.4 - Nicholas Copernicus 1473 - 1543

9. Figure 1.5 - Retrograde Motion

10. Figure 1.6 - Galileo Galilei 1564 - 1642

11. Figure 1.7Galilean Moons

12. Figure 1.8a - Venus PhasesSun-centered model

13. Figure 1.8b - Venus PhasesPtolemy’s model

14. Figure 1.9 - Johannes Kepler 1571 - 1630

15. Figure 1.10Tycho Brahe1546 - 1601

16. Kepler’s laws ofplanetary motion • 1st law - elliptical orbits • 2nd law - equal areas in equal times • 3rd law - P2 proportional to a3

17. Figure 1.11 - Ellipse

18. Figure 1.12Orbital Properties

19. Figure 1.13 - Kepler’s Second Law

20. Figure 1.14 - Astronomical Unit

21. Figure 1.15 - Isaac Newton 1642 - 1727

22. Newton’s Three Laws of Motion 1. Motion remains constant unless force acts 2. Force = mass X acceleration 3. Forces occur in pairs on two bodies

23. Figure 1.16Newton’s First Law

24. Newton’s Law of GravityThe force of gravity is • Stronger with larger masses • Stronger with smaller distances

25. Figure 1.17 - Gravity

26. Figure 1.18 Gravitational Force

27. Figure 1.19 Sun’s Gravity

28. Figure 1.20 - Center of Mass

29. Figure 1.21 Orbits