Special Relativity: The Postulates
A problem for classical physics: Michelson-Morley Experiment
- Found Speed of light to be the same in all directions even though the earth is moving around the sun
Einstein’s Postulates
- Principle of Relativity:
- The laws of physics are the same in all frames of reference which are moving at constant velocity
- Speed of Light:
- Light is always propagated in empty space with the same velocity c independent of the state of motion of the source or the observer
Relative character of “simultaneity”
- Adopting an operational definition of measurement of time at different places, we find that the meaning of “simultaneous” depends upon the relative motion of the observer.
- Time is not absolute!