Relativity

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Relativity

• Jennifer Keehn

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• 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

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What Was Known

• Newtons three laws
• Maxwells Laws of Electromagnetism

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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

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But This is Inconsistent with Classical Mechanics!

• In classical mechanics, vuV
• Einsteins postulate says that the speed of light
  is independent of the motion of all observers and
  sources.

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Consequences of Einsteins Postulates

• Time Dilation
• Length Contraction
• Momentum
• Total Energy

• TTo(1-(v/c)2)-1/2
• LLo(1-(v/c)2)1/2
• Pmv(1-(v/c)2)-1/2
• Emc2(1-(v/c)2)-1/2

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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

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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.

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General Relativity

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

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Curvature of Space

• Curvature of Space8?G/c4(mass-energy density)

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Testing the General Theory of Relativity

• Deflection of Starlight
• First tested during total solar eclipse in 1919

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Slowing Down of Clocks by Gravity

• Clock closer to the mass measures a shorter
  elapsed proper time than a clock that is further
  out.
• Rc2MG/c2, where Rc is the Schwarzschild radius.