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tzimie
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In our IT company sometimes we make presentations, sometimes even just for fun, not related to IT things. I suggested the presentation with the title above and many people are interested. They are quite smart, but there will be no formulas in my presentation.
Please review my list. Any suggestions/notes/advice?
1. Black holes
1.1 Spaghettification - human gets torn apart at event horizon (false, humans are torn apart approx 1s before singularity, for stellar size BH far away from horizon, for supermassive - deep inside)
1.2 Something spectacular happens when one crosses a horizon (apparent horizon retracts and never crosses your body).
1.3 There is a library inside a black hole )
1.4 In order to create a BH, matter must be compressed to immense density (again, true for small BH only).
1.5 When neutron star moves close to c, it becomes BH because a. It becomes "heavier" in GR (mention the obsolete concept of "relativistic mass") - false, b. it contracts (true but doesn't make it BH)
1.6 Time freezes near the horizon (true for hovering observers only, free falling observer can't be replaced with a sequence of hovering observers at same points)
1.7 So free falling observer would see the future of the universe (in fact, he accelerates so quickly that light behind him is redshifted, so he observes the universe slowed down)
1.8 As falling spaceship is "stuck" near the horizon for billion years, theoretically one can fly there and take him back (put Eddington–Finkelstein diagrams in Powerpoint)
1.9 As black holes evaporate, and it takes an infinite time to fall into it, it evaporated before you cross the horizon - (1.6-1.9 the same source of confusion)
1.10 Why spaceship can't avoid singularity - because it is in the future!
2. Rotating Black Holes
2.1 Ergospheres
2.2 Ring singularity (idealistic solution)
2.3 We really don't know what is inside because CTC is incompatible with QM so we need TOE.
3. GR in general
3.1 Again on "relativistic mass", are objects become "heavier" when move near c?
3.2 Are they heavier when heated (and this is true)
3.3 Mass of light. Does light gravitate? (talk about "sources" of gravity in GR)
3.4 Special cases, 2 parallel light beams in the same direction (don't attract) and opposite directions (do attract)
3.5 Energy is conserved (conservation is not well defined in curved spacetime).
3.6 GR is the only theory of gravity (mention Einstein–Cartan theory)
4. Cosmology
4.1 "When Universe was a size of an atom..."
4.2 "Big Bang" - not an explosion, where the name comes from
4.3 Why something infinite can expand.
4.3 "Universe at time t after Big Bang" is not a valid frame of reference and nothing is conversed there
4.4 Difference between Dark Energy and Dark Matter.
Please review my list. Any suggestions/notes/advice?
1. Black holes
1.1 Spaghettification - human gets torn apart at event horizon (false, humans are torn apart approx 1s before singularity, for stellar size BH far away from horizon, for supermassive - deep inside)
1.2 Something spectacular happens when one crosses a horizon (apparent horizon retracts and never crosses your body).
1.3 There is a library inside a black hole )
1.4 In order to create a BH, matter must be compressed to immense density (again, true for small BH only).
1.5 When neutron star moves close to c, it becomes BH because a. It becomes "heavier" in GR (mention the obsolete concept of "relativistic mass") - false, b. it contracts (true but doesn't make it BH)
1.6 Time freezes near the horizon (true for hovering observers only, free falling observer can't be replaced with a sequence of hovering observers at same points)
1.7 So free falling observer would see the future of the universe (in fact, he accelerates so quickly that light behind him is redshifted, so he observes the universe slowed down)
1.8 As falling spaceship is "stuck" near the horizon for billion years, theoretically one can fly there and take him back (put Eddington–Finkelstein diagrams in Powerpoint)
1.9 As black holes evaporate, and it takes an infinite time to fall into it, it evaporated before you cross the horizon - (1.6-1.9 the same source of confusion)
1.10 Why spaceship can't avoid singularity - because it is in the future!
2. Rotating Black Holes
2.1 Ergospheres
2.2 Ring singularity (idealistic solution)
2.3 We really don't know what is inside because CTC is incompatible with QM so we need TOE.
3. GR in general
3.1 Again on "relativistic mass", are objects become "heavier" when move near c?
3.2 Are they heavier when heated (and this is true)
3.3 Mass of light. Does light gravitate? (talk about "sources" of gravity in GR)
3.4 Special cases, 2 parallel light beams in the same direction (don't attract) and opposite directions (do attract)
3.5 Energy is conserved (conservation is not well defined in curved spacetime).
3.6 GR is the only theory of gravity (mention Einstein–Cartan theory)
4. Cosmology
4.1 "When Universe was a size of an atom..."
4.2 "Big Bang" - not an explosion, where the name comes from
4.3 Why something infinite can expand.
4.3 "Universe at time t after Big Bang" is not a valid frame of reference and nothing is conversed there
4.4 Difference between Dark Energy and Dark Matter.