Linked Questions

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What does an external observer see if you shine a laser pointer while crossing an event horizon?

If I understand correctly, the event horizon of a black hole is the boundary beyond which we cannot perceive or describe any events, and all objects appear to freeze when falling in until their light ...
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1answer
118 views

Black hole's time effect and matter (or energy) position

Ok, so after I've read a few (around 50 :P ) articles on subject of black holes. There are a few gaps in my understanding of it. Please follow my reasoning, I bet there is a mistake in there, and I ...
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3answers
2k views

So Black Holes Actually Merge! In 1/5th of a Second - How?

I've read a lot of conflicting answers in these forums. However, today saw the awesome announcement of gravitational waves. Two black holes merged: http://www.slate.com/blogs/bad_astronomy/2016/02/11/...
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10answers
9k views

Can black holes form in a finite amount of time?

One thing I know about black holes is that an object gets closer to the event horizon, gravitation time dilation make it move more slower from an outside perspective, so that it looks like it take an ...
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1answer
99 views

Where is the black hole information paradox?

If an object falls into a Schwarzschild black hole and a distant observer watches, they see the object fall slower and slower as it approaches the event horizon, until it is "frozen." (To the observer,...
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0answers
47 views

How long does it take for the image of an object falling into a black hole to disappear?

From what I've read on other questions and answers, an outside observer cannot see an object fall into a black hole, but rather the image of the object will look like it is stuck on the surface of the ...
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3answers
148 views

Why can't gravity force an object past the speed of light? [duplicate]

I hope this question is not a duplicate (it doesn't seem to be) and that it is appropriate for this site. If we had a universe with only two bodies. One is ultra massive, and the other is very small. ...
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0answers
17 views

Do orbiting masses accelerate or decelerate (relative to us) near black holes? [duplicate]

Apologies if this question seems stupid; I was just curious after watching a documentary, and I am not a trained astrophysicist. Simply put, I cannot reconcile the (perhaps misunderstood) facts that ...
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3answers
19k views

What is the relation between orbital velocity and escape velocity in strongly relativistic situations?

For practical purposes, I'm considering a non-rotating black hole or neutron star, because I find Kerr black holes a little confusing. The ratio between orbital velocity and escape velocity in ...
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7answers
4k views

Can matter really fall through an event horizon?

This question is closely related to Event horizons without singularities from about a year ago (May 2012), which John Rennie answered nicely and persuasively. My variant of the question is this: ...
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1answer
54 views

Black Holes and Time [duplicate]

My understanding is that if I am outside a black hole and watch something fall in, the object will appear to slow down and will never actually get sucked in. So how can we ever get a black hole if ...
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1answer
110 views

How do growing event horizons affect observations of objects falling into black holes? [closed]

There are many questions on this forum about objects falling into black holes. Most of them describe that to distant observers, the objects never quite reach the event horizons and appear to be frozen ...
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1answer
182 views

Is the M87 black hole really a black hole? [duplicate]

I apologize if this is a silly question, but... From what I've been told, new black holes cannot form, because time slows to nearly stopped as matter approaches the event horizon. Instead, a new ...
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2answers
3k views

What is the physical size of a black hole?

Something that's always confused me. How large is a black hole's physical size - not mass? From descriptions, it would seem that the 'singularity' is a single point, but is it really? Say for ...
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9answers
8k 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 "...

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