Timeline for Black hole density
Current License: CC BY-SA 4.0
26 events
| when toggle format | what | by | license | comment | |
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| May 15, 2019 at 2:34 | vote | accept | penguin99 | ||
| Apr 20, 2019 at 13:30 | comment | added | PM 2Ring | Ben Crowell discusses GR singularities in this Physics SE answer. It's a pretty technical answer, but you might be able to get some useful info from it. In particular, "A singularity in GR is like a piece that has been cut out of the manifold. It's not a point or point-set at all". | |
| Apr 20, 2019 at 13:25 | comment | added | PM 2Ring | Well, it's similar to a hole on Earth in the sense that stuff falls down a hole because of gravity. And in the rubber sheet analogy, yes, a BH creates a very steep depression that's impossible to climb back out of, as I mentioned in my comment on Florin's answer. We don't know exactly what the core of a BH is like, we need a quantum gravity theory for that. But it's definitely not a solid object of regular matter. In standard GR, using the rubber sheet analogy, there's nothing there, not even any rubber. | |
| Apr 20, 2019 at 12:48 | comment | added | penguin99 | @PM 2Ring, is the black hole just like a regular hole that things fall into or is it a solid body that just happens to bend space time so much that it creates a really deep impression on the space time fabric? (I'm using the rubber sheet analogy) | |
| Apr 20, 2019 at 3:25 | answer | added | Keith McClary | timeline score: 0 | |
| Apr 17, 2019 at 12:00 | history | tweeted | twitter.com/StackAstronomy/status/1118484395743170560 | ||
| Apr 17, 2019 at 9:50 | answer | added | Mohan Mone | timeline score: 0 | |
| Apr 17, 2019 at 4:19 | answer | added | Florin Andrei | timeline score: 5 | |
| Apr 16, 2019 at 17:43 | comment | added | PM 2Ring | @David Oops. Phone fumble finger again. | |
| Apr 16, 2019 at 17:20 | comment | added | David Richerby | @PM2Ring "There's no limit to how much a BF can consume" Did he eat everything in the fridge again? | |
| Apr 16, 2019 at 17:16 | comment | added | David Richerby | I'm not sure what you mean by "how does this increase its density?" Density is, by definition, the amount of stuff crammed into a unit of space; if you cram more stuff in, it's denser. It seems to be like asking, "How does adding more links to a chain make it longer?" | |
| Apr 16, 2019 at 15:29 | comment | added | Carl Witthoft | This isn't limited to black holes or other high-density special things in the universe. Gravity depends on total mass, and total mass in a given radius sphere depends on material density. | |
| Apr 16, 2019 at 15:28 | history | became hot network question | |||
| Apr 16, 2019 at 15:10 | comment | added | rob | Similar question by the same user on Physics. | |
| Apr 16, 2019 at 14:27 | answer | added | James K | timeline score: 5 | |
| Apr 16, 2019 at 14:00 | comment | added | James K | I've cut it down to one question, this isn't too broad. | |
| Apr 16, 2019 at 14:00 | history | edited | James K | CC BY-SA 4.0 |
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| Apr 16, 2019 at 13:36 | comment | added | penguin99 | @PM 2Ring, ah alright. Thank you. Will wait for more time to get other answers | |
| Apr 16, 2019 at 13:33 | comment | added | PM 2Ring | When stuff falls into a BH, it gets heavier, so its gravity gets stronger. There's no limit to how much a BF can consume, but if too much stuff tries to fall in at once you get a kind of traffic jam just outside the BH, and since that stuff collides at speeds approaching lightspeed, the collisions are extremely spectacular, emitting huge amounts of radiation across the spectrum, and spewing out collision debris, sometimes more than 1000 lightyears for a big active BH like M87*. | |
| Apr 16, 2019 at 13:27 | comment | added | PM 2Ring | From a distance, a BH of 20 solar masses has the same gravity as a normal star that size, from the same distance. It has no extra sucking power, although tidal effects get extreme when you get close, simply due to your distance from the centre. Any light or matter that falls into a BH quickly falls to the centre. Pure general relativity says it gets crushed out of existence, but we expect quantum effects to modify that, but the core of a BH will still be tiny, probably smaller than an atom under quantum gravity. | |
| Apr 16, 2019 at 13:16 | comment | added | PM 2Ring | Also see astronomy.stackexchange.com/q/20236/16685 & astronomy.stackexchange.com/q/24196/16685 | |
| Apr 16, 2019 at 13:14 | comment | added | penguin99 | @PM 2Ring, Thank you. Do I post the same question on the Physics.SE site? | |
| Apr 16, 2019 at 13:10 | comment | added | PM 2Ring | I'll try to find some that will help you. Here's a good one to get you started. astronomy.stackexchange.com/q/2240/16685 | |
| Apr 16, 2019 at 13:07 | comment | added | penguin99 | @PM 2Ring, could you please link the questions? There are just too many on the Physics.SE site | |
| Apr 16, 2019 at 12:15 | review | First posts | |||
| Apr 16, 2019 at 12:42 | |||||
| Apr 16, 2019 at 12:13 | history | asked | penguin99 | CC BY-SA 4.0 |