All Questions
Tagged with black-holes event-horizon
1,182
questions
38
votes
9
answers
8k
views
Why singularity in a black hole, and not just "very dense"?
Why does there have to be a singularity in a black hole, and not just a very dense lump of matter of finite size? If there's any such thing as granularity of space, couldn't the "singularity" be just ...
- 530
31
votes
6
answers
7k
views
Why can't you escape a black hole?
I understand that the event horizon of a black hole forms at the radius from the singularity where the escape velocity is $c$. But it's also true that you don't have to go escape velocity to escape an ...
- 5,061
11
votes
3
answers
4k
views
Information encoded on the surface of a black hole
If an object that enters a black hole has its information content frozen at the event horizon, in what sense is it frozen? The usual analogy is of a hologram encoded in 2d which can be decoded into a ...
- 517
24
votes
4
answers
6k
views
Could a ship equipped with Alcubierre drive theoretically escape from a black hole?
Could a ship equipped with Alcubierre drive theoretically escape from a black hole?
Also, could it reach parts of the universe that are receding faster than the speed of light from us?
- 589
11
votes
4
answers
780
views
Solid objects inside the event horizon - can they remain "solid"?
So, once something is inside a black hole's event horizon, it can only move towards the center. This is fine for a point-object. But 3D solid objects rely on molecular forces to stay in one piece. ...
- 5,238
16
votes
5
answers
3k
views
Is the observable region of the universe within the event horizon of a super-massive black hole?
Observations:
I have read that for a free-falling observer within the event
horizon of a black hole that all lines of sight will end at the
singularity which is black.
I also look up and see that the ...
Nicholas Lee
18
votes
3
answers
7k
views
What will the universe look like for anyone falling into a black hole?
I've heard that, from the perspective of an external observer, something falling into a black hole will eventually look "frozen": light waves will move to the infrared and further into lower ...
Oleg Stroganov
66
votes
10
answers
10k
views
Do all black holes have a singularity?
If a large star goes supernova, but not enough mass collapses to form a black hole, it often forms a neutron star. My understanding is that this is the densest object that can exist because of the ...
- 5,061
23
votes
7
answers
20k
views
How can super massive black holes have a lower density than water?
I heard on a podcast recently that the supermassive black holes at the centre of some galaxies could have densities less than water, so in theory, they could float on the substance they were gobbling ...
- 353
41
votes
10
answers
12k
views
Does any particle ever reach any singularity inside the black hole?
I am not a professional physicist, so I may say something rubbish in here, but this question has always popped in my mind every time I read or hear anyone speak of particles hitting singularities and "...
user1549
9
votes
5
answers
1k
views
Event Horizon violability?
Is the "event horizon" of a black hole potentially violable? Black holes are commonly described as being unidirectional (matter / energy goes in, but doesn't come out), but is the event horizon of a ...
- 341
41
votes
6
answers
4k
views
If I fall into an evaporating black hole, where do I end up?
This question has been bothering me for a while. I have a crude hypothesis...
As I understand it, an observer falling into a black hole will cross the event horizon at some specific future (proper) ...
- 527