1. General Theory of Relativity
(a gravity theory):
Ingredients:
The Principle of Equivalence: acceleration ~ gravity
Riemann's Curved Geometry: acceleration ~ curved space-time
( ' ~ ' means 'is equivalent to'.)
This implies: gravity ~ curved space-time (Einstein's Field Eqns.)
This is important when objects are massive, like sun or black hole.
Supercedes Newton's Law in these cases.
Three experimental-observational proofs of General Relativity:
1. Perihelion precession of Mercury's orbit. (Slow rotation of
ellipse.
2. Light bends near the sun.
Time slows in a strong gravity field.
(Ex. Gravitational redshift, and clocks flown in planes vs those on ground.)

3. The General Theory of Relativity (GTR)
is based on:
The Principle of Equivalence: acceleration ~ gravity
Conceived by
Ernst Mach

5. George Riemann
Riemann's Curved Geometry was another ingredient:
acceleration ~ curved space-time

6. The essential idea of Einstein’s GTR gravity ~ curved space-time
(Einstein's Field Eqns. )
This is important when objects are massive, like sun or black hole.
Supercedes Newton's Law in these cases.

7. Black hole—HELP! We need Einstein!

8. Three experimental-observational proofs of General Relativity:
Perihelion precession of Mercury's orbit
(slow rotation of ellipse
16 degrees/10,000 yrs).

9. Three experimental-observational proofs of General Relativity:
2. Light bends near the sun.

10. Arthur Eddington went to South Africa
during a total eclipse of the sun
To test the bending of light
by the sun’s gravity.

11. Three experimental-observational proofs of General Relativity:
3. Time slows in gravity