1. Relativity Jennifer Keehn

2. “I want to know how God created this world. I am not interested in this or that phenomena, in the spectrum of this or that element. I want to know His thoughts; the rest are details.” -Albert Einstein

3. What Was Known Newton’s three laws Maxwell’s Laws of Electromagnetism

4. Special Relativity: Two Postulates The laws of physics are the same for all non-accelerating observers The speed of light in a vacuum is constant for all observers, regardless of motion

5. But This is Inconsistent with Classical Mechanics! In classical mechanics, v+u=V Einstein’s postulate says that the speed of light is independent of the motion of all observers and sources.

6. Consequences of Einstein’s Postulates Time Dilation Length Contraction Momentum Total Energy T=T o (1-(v/c) 2 ) -1/2 L=L o (1-(v/c) 2 ) 1/2 P=mv(1-(v/c) 2 ) -1/2 E=mc 2 (1-(v/c) 2 ) -1/2

7. General Relativity: Principle of Equivalence “I was sitting in a chair in the patent office at Bern when all of a sudden a thought occurred to me: if a person falls freely he will not feel his own weight. This simple thought made a deep impression on me. It impelled me toward a theory of gravitation.” -Albert Einstein

8. Principle of Equivalence There is no local experiment that can be done to distinguish between the effects of a uniform gravitational field in a non- accelerating inertial frame and the effects of a uniformly accelerating reference frame.

9. General Relativity The presence of matter causes spacetime to warp or curve. The theory gives us a procedure for calculating the curvature of spacetime.

10. Curvature of Space Curvature of Space=8  G/c 4(mass-energy density)

11. Testing the General Theory of Relativity Deflection of Starlight First tested during total solar eclipse in 1919

12. Slowing Down of Clocks by Gravity Clock closer to the mass measures a shorter elapsed proper time than a clock that is further out. R c =2MG/c 2, where R c is the Schwarzschild radius.