Relativity Principle #2 Time Dilation

• A moving clock runs slower than a stationary one.

  • Moving relative to what? Relative to the observer!
  • If you are on earth and you look at a space ship traveling at near the speed of light, you will see clocks on the space ship running slower
  • If you are on a space ship traveling at near the speed of light, you will see clocks on the earth are running slower.
  • Which clock is right?

Notes: