Summary
Principle of Equivalence
- “No experiment performed in one place can distinguish a gravitational field from an accelerated reference frame”
- Einstein’s theory tested by experiments
- Clocks run slow in presence of gravity (acceleration)
- Extends Special theory of relativity to any reference frames
General relativity
- Took Einstein 16 years to extend special theory of relativity to any accelerating reference frame
Gravitational mass is unified with inertial mass
- Not a mysterious accident! A direct consequence of the theory!
Replaces Newton’s theory
- No need for forces!
- Replaced by curved space-time coupled to matter! More next time.
Newton’s laws still work for “everyday problems”