Review Questions for Exam 1:

1. Explain how Roemer used the eclipses of Jupiter to measure the speed of light.

2.

3. State what the equivalence principle is and some of its implications.

4. What are Newton's three laws of motion?

5. Imagine an asteroid in our Solar System that felt a gravitational pull from the Sun that is 4x less than what the Earth feels. What is its period (use Newton's force law and Kepler's third law)?

6. Why do neutron stars that are in a tight binary system get closer together over time?

7. Does Newton's idea of gravity break down? If so, how?

8. Does Einstein's idea of gravity break down? If so, how?

9. Define entropy.

10. Explain how gravity may just be a consequence of the second law of thermodynamics.

11. Name the two assumptions for special relativity.

12. Explain how time dilation leads to mass increase (i.e., that moving objects increase their mass).

13. How does one define a straight path through spacetime?

14.

15. Who is ageing faster, you sitting there taking thinking about this question or that astronaut in the space shuttle flying overhead?

16. Using the idea of gravity as an emergent property, explain why two galaxies would come together.