2. Isaac and the Apple Tree

3. Approximate Force of Gravity

4. Exact Force of Gravity

5. Inverse Square Law

6. Einstein’s Theory of Relativity Explains how gravity works Spacetime

7. Warping of Spacetime

8. Orbits in Spacetime

9. Demonstration Video Gravity in terms of Spacetime. https://www.youtube.com/watch?v=0w7zc6kvf1o What is gravitational lensing? https://www.youtube.com/watch?v=4qoDHdIsIg4

10. Gravitational Lensing Experiment gave evidence of Einstein’s Theory of Relativity

11. Discussion Questions 1. Somewhere between the Earth and the Moon, gravity from these two bodies on an object would be equal. Is this location closer to the Earth or the Moon? Why? 2. The value of “g” at Earth’s surface is about 9.8m/s 2. What is the value of “g” at twice the Earth’s radius? How do you know? 3. You weigh a tiny bit less when you are in the lobby of a massive skyscraper than you do here in school. Why is that?

12. Discussion Questions (cont.) 4. What is Spacetime? 5. Why does the Moon orbit the Earth according to Einstein? 6. If the Sun were to shrink in diameter to the size of a black hole, but maintain its mass, would the orbit of Earth change? Why or Why not?

13. Practice

14. Practice with Scientific Notation

15. Work Cited http://idology.files.wordpress.com/2008/12/isaac_newton_hd.jpg http://www.sciencemuseum.org.uk/onlinestuff/snot/~/media/818B16FC66D44386927D7 89A9280BA5D.ashx?db=master http://llamabutchers.mu.nu/Earth%20from%20Moon.gif http://www.freedigitalphotos.net/images/photos/man-binoculars.jpg http://rosettasister.files.wordpress.com/2009/02/alberteinstein.jpg http://bierbower.net/images/Gravity%20Its%20the%20Law.jpg http://www.math.sunysb.edu/~tony/whatsnew/column/grav-lens- 0299/images/HSTgravlens.jpg http://kwisp.files.wordpress.com/2010/01/e9889d89b84b4324b0d3c35d9d8f6332.jpg