4 ms·
The way Brian Cox puts it, a singularity is a point in time: the end of time. I have trouble really conceptualizing black hole physics, I just think of it as a
by SoftTalker 2mo ago
The way Brian Cox puts it, a singularity is a point in time: the end of time.
I have trouble really conceptualizing black hole physics, I just think of it as a mass so great that nothing, including light, can escape its gravity. Works for me.
- XorNot 2mo agoThe more interesting component is that black hole physics is almost an anti-free will zone. Everywhere else in the universe with mass and energy you can do what you want (sort of). An event horizon throws a hard shroud over that and drastically reduces opportunities: your free will to use mass and energy is significantly curtailed (you must head towards the singularity).
- teamonkey 2mo agoI’m not sure free will has anything to do with it. If you don’t have enough upward velocity to escape earths gravity, hitting the ground is also inevitable.
- Sharlin 2mo agoYour free will outside a black hole is curtailed in exactly the same manner: you cannot do anything to avoid, or even delay, tomorrow.
- XorNot 2mo agoWhich is exactly my point. Under normal circumstances you inexorably move towards the future. But we generally believe we have freedom of action about the spatial coordinates. A black hole is interesting because you inexorably move towards the singularity - which is a defined location in spacetime, and also has a boundary - the event horizon. So now your freedom of action is reduced: you must move towards the singularity, but you also can't actually move outside of the event horizon either.
- PaulHoule 2mo agoThe singularity in a non-rotating, non-charged black hole is as you say. It’s like in a finite amount of time you “run out of time”, like there isn’t any more time on that trajectory. The singularity in a rotating black hole is entirely different but the interior of classical Kerr (rotating) black holes is one of the most controversial if inconsequential topics in theoretical physics because there are reasons to believe (without real proof mind you) the Kerr solution is unstable inside the inner event horizon so that whatever happens in there is not what that theory says. And of course black holes are quantum objects which might actually have an “interior” entirely different from the classical picture.
- SoftTalker 2mo agoTo be honest I really can't get past what "the end of time" even means.
- werdnapk 2mo agoIf it signifies the end of time, then all the stuff in the black hole would need to no longer exist no? If anything is happening in the black hole, then time is still progressing, so nothing must be all that exists?
- shrx 2mo agoTime is necessary for change, not existence.
- mr_toad 2mo agoTime is change that happens in a continuous manner. It’s still possible to conceive of change happening in an unordered unpredictable way that is not like the smooth ordered time that we experience. In a gravitational singularity spacetime breaks down. You could argue that time stops, but it’s also valid to argue that causality breaks down and we can no longer make any predictions about the future. Just because we don’t have a theory describing what could happen, doesn’t rule out that something could happen.