ASTR 3740 Spring 2020 Homepage

ASTR 3740 Relativity & Cosmology Spring 2020 Midterm 2 (General Relativity and Black Holes): Most interesting/baffling things (votes)

1. (20) White holes, wormholdes, and parallel universes. Kerr geometry with ring singularity, sisytube, and antiverse. The mathematical solutions are complicated but unreal.
2. (10) Spacetime diagrams, Penrose diagrams. Sequence of spacetime diagrams Schwarzschild → Finkelstein → Kruskal. Spacelike, timelike intervals.
3. (9) The inner horizon inside a black hole is the most violent place in the Universe. The concentration of energy at the inner horizon.
4. (5) River/waterfall model. Space falls, but absolute spacetime does not exist.
5. (5) The singularity is a surface, not a point.
6. (4) Inside a BH, versus what movies say.
7. (3) Negative mass falls.
8. (3) Gravity equals curvature.
9. (3) Black holes don't suck.
10. (3) Objects that fall through the horizon of a black hole appear to freeze there.
11. (2) Supermassive black holes have a weaker tidal force at the horizon, so you could fall inside their horizons without being torn apart.
12. (2) Einstein's Principle of Equivalence.
13. (2) Working with Einstein's equations.
14. (2) Superluminal jets.
15. (1) Precision of LIGO
16. (1) Einstein won Nobel Prize for photo-electric not relativity.
17. (1) Gravity pulls on space, not you.
18. (1) Hawking radiation/evaporation.
19. (1) Gravitational waves, and their quantization.
20. (1) How space/time switch roles inside horizon.
21. (1) The singularity.
22. (1) My faith in Newtonian gravity, instantaneously transmitted, is undermined.

Updated 2020 Apr 27