2. Einstein’s relativity http://www.youtube.com/watch?v=tpbGuuGosA Y&feature=relatedhttp://www.youtube.com/watch?v=tpbGuuGosA Y&feature=related Did Newton's knew how gravity works / produced? What is the speed limit of the universe? Does gravity exceed that limit? IF the sun is to disappear right now, when will we see it? When will the earth’s orbit be altered by that event? What will we experience?

4. The Speed of Light Is Constant As seen from the ground As seen from the car The faster an object moves, the shorter it becomes in its direction of motion as observed by someone not moving with the object.

5. Time dilation: The time you experience will be different from earthly observer. Post your answer on group discussion and verify your answer with your group members. If you are traveling at 0.5c, then time will elapse at 15% slower (for 1 year of travel, 1.15 year elapse on Earth). If you are traveling at 0.87c, then time will elapse at ½ rate. If you are traveling at 0.995c, then time will elapse at 1/10 rate. Lets say your twin has traveled away. He said he will e-mail you every day at noon ( 24 hours in his time reference) to let you know how he is doing. His ship will be traveling at 0.87c. How often will you receive his e-mail? Lets say in his reference frame, he has been traveling for 2 years ( 1 year each way). How much time have elapsed for you?

6. Watch the black holes video: http://www.youtube.com/watch?v=f0VOn9r4dq8 &feature=relatedhttp://www.youtube.com/watch?v=f0VOn9r4dq8 &feature=related Explain fabric of space time. Does the sun cause curve in space time? Earth? The moon? you? Do you understand the kayak analogy of black hole? Explain. If you get too close, what happens to you? Can you still escape?

7. Curved Spacetime In the absence of any matter in the spacetime, straight lines are straight. In the presence of matter, spacetime curves. This pulls the two masses toward each other.

8. Schwarzschild (Nonrotating) BlackHole Kerr (Rotating) Black Hole R sch (km) = 3M(in M sun )

10. Accretion Disk Around a Supermassive Black Hole 300-million solar mass black hole in the center of galaxy NGC 7052

12. Evaporation of a Black Hole Because the gravitational energy used to create the particles came from the black hole, the hole loses mass and shrinks, eventually evaporating completely.