Linked Questions

8
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2answers
3k views

Time dilation at a black hole [duplicate]

According to the Wikipedia article on black holes: Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer sees the infalling ...
0
votes
3answers
783 views

Formation of the event horizon seems impossible with singularity inside seems impossible [duplicate]

According to what I was reading, the formation of an event horizon appears if the mass becomes compact enough. Unfortunately, due to time dilation the time for mass to fall into the event horizon ...
0
votes
1answer
565 views

Does infalling matter ever cross the event horizon? [duplicate]

Assume you are immortal, then say if you fell towards a blackhole, to an observer far away you will appear to slow down as you approach event horizon and gradually come to stand still. However for ...
8
votes
1answer
268 views

Is it possible for a black hole to form for an observer at spatial infinity? [duplicate]

To my knowledge if you calculate the coordinate time (time experienced by an observer at spatial infinity) it takes an infinite amount of time for an object to fall past the horizon of a Schwarzschild ...
1
vote
1answer
136 views

Can we observe a star collapse into a black hole? [duplicate]

Let's say that I happen by a star that has just burned out and is collasping into a black hole. I seat at infinity to watch it as a Schwarzschild observer. Will I ever see the black hole collapse into ...
5
votes
1answer
167 views

How stellar black holes are formed? [duplicate]

This is a kind of follow-up of my previous Phys.SE question Can something (again) ever fall through the event horizon? that seems to have established that, for an outside observer, things never fall ...
4
votes
0answers
123 views

Why can't we accept that there's no black hole? [duplicate]

According to a distant observer, any mass never falls into the event horizon, they just appear to be moving slower towards it. So, why can't we tell people this : there are black holes, but it's just ...
0
votes
1answer
144 views

For a distant observer can a black hole form and grow in finite time? [duplicate]

Consider an observer at a significant distance away from a collapsing star. As such when a singularity is born at the core of the star the observer would never see it grow anymore than the ...
1
vote
1answer
72 views

Collapse of Black Hole [duplicate]

If a body begins to collapse, it will form a black hole when its radius is less than the gravitational radius ($r_g$). However, for an observer (stationary in the Schwarschild metric), he/she will ...
0
votes
1answer
55 views

Are black holes totally black and formed? [duplicate]

Good morning, I know some similar questions have been asked but I don't find a convincing answer in these. Excuse me if I have missed the answer. My question is: I have learned that some black holes ...
0
votes
0answers
52 views

Due to TIME stopping, are contemporary Black Holes really just Large SHELLS of Matter and not Singularities? [duplicate]

If TIME slows down as you approach a Black Hole, has there been sufficient time in our Universe (13.8 Billion Years since the Big Bang occurred) for ANY matter inside the Event Horizon of ANY Black ...
2
votes
0answers
50 views

How are the predictions of the Schwarzschild solution consistent with our observations of black holes? [duplicate]

I am fully aware that there may be many misunderstandings in the following. However, in recent lectures we covered the Schwarzschild solution, and after some interesting mathematics we reached ...
0
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0answers
45 views

How can our universe have black holes? [duplicate]

Assuming that we were never inside a blackhole at any point in the history of the universe, how can blackholes exist against Gravitational time dilation? For any point in space time in the known ...
2
votes
0answers
45 views

How can non-infinitesimal Black holes form in finite time for a distant observer? [duplicate]

Say you are on earth observing a staring hypernova at safe distance from earth. Now as soon as the core collapses to its Schwarzschild radius the singularity would come into existence and so would ...
1
vote
0answers
44 views

Thoughts on Black Holes [duplicate]

Given that time slows to a stand-still at the event horizon of a Black Hole, how long would it take a black hole to form, from the perspective of an outside observer? It would seem, as a massive star ...

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