Questions tagged [event-horizon]

An event horizon is the notion of a distance away from the gravitational center of mass of a black hole. Observers outside of the event horizon can escape however any object including light which approaches a black hole and crosses the event horizon cannot escape the gravitational pull and are consumed.

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How does time work beyond the cosmic event horizon?

The faster you move through space, the slower you move through time - the calculations show that as you approach lightspeed, time comes to a standstill. How does time work beyond the cosmic event ...
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If two black hole event horizons overlap (touch) can they ever separate again?

Hypothetical question based on my understanding that two event horizons that overlap (touch) can't ever separate again: Imagine a 1 billion solar mass black hole (so the event horizon is massive and ...
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Does time dilation at the event horizon prevent us from seeing any changes?

If gravity is so strong at event horizon as we assume, and thus time dilation makes time infinitely slow for us, the distant observers, how could we ever observe any events ocurring over time? Wouldn'...
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If a photon were 1 Planck length away from the event horizon of a blackhole, would it be able to escape the blackhole's gravitational pull?

I understand that one could theoretically replace the sun with a blackhole without affecting the orbits of the planets. This leads me to believe that a blackhole isn't a "cosmic vacuum cleaner" so ...
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What resolution would earth-moon telescope achieve?

Event horizon achieved earth-size telescope by using seperate telescopes around the world to interpolate an image of a black hole at resolution of 60 arcmicroseconds. What resolution could we get if ...
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Why did the Event Horizon Telescope take so long to take a photo of a black hole?

The Event Horizon Telescope is in the news now because they are about to release the first ever picture of a black hole. They have been working on this since 2006. Why did it take 13 years to produce ...
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Shouldn't we not be able to see some black holes?

Whenever there is a picture of a black hole, (even though they are artist depictions, this is how they are described) most are shown kind of in a flat disk like this. My question is, why do we see ...
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Need help with a simple Blackhole question

Suppose the amount of mass in a black hole doubles. Does the event horizon change? If so, how much does it change?
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Why is cosmological event horizon closer to us than the particle horizon?

From what I learned, cosmological event horizon is the horizon that moves away from us at/more than the speed of light. And particle horizon is the horizon that particles inside the horizon can have a ...
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Black Hole growth [duplicate]

The latest info on black holes with regard to their formation is that since space and time go to infinity at the event horizon, from an outside perspective nothing ever enters a black hole, and it ...
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Information Paradox with Hawking's Radiation

A theory about Blackholes storing the information from the universe. Being said that Blackholes are condensed mass sufficient enough to break every particle into different elementary particles, ...
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Would a future hole in the Cosmic Microwave Background show us the edge of the universe?

If my understanding is correct, the Cosmic Microwave Background always come from our event horizon. By event horizon I mean the edge of the observable universe. If the universe is finite does it mean ...
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Reshaping black holes to “push” the event horizon

I watched this simulation made by LIGO (Laser Interferometer Gravitational-Wave Observatory) where 2 black holes merge into one. https://www.youtube.com/watch?v=I_88S8DWbcU I was therefore thinking ...
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Is it possible to throw a camera attached to a rope within the event-horizon of a black hole and then pull it back in?

I have heard that when something passes the event-horizon of a black hole nothing can stop it from getting pulled in. Is that true for objects partially past the event-horizon? Would it be possible to ...
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How do we know that Singularity is not an object with reasonable radius?

So for example: a Neutron star has a radius of 10km and 2 solar masses. A singularity can have a radius of 1m and 10 solar masses, with a 1km event horizon radius. Basically it will just be a more ...
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Theoretical measure of distance to black hole?

Would it be possible to measure the distance to a black hole of known mass by measuring the radius of the most redshifted radiation that is detectable? The idea is that since the point where that ...
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Whats the deal with black holes and “no information from inside the event horizon can leave”?

I don't know if this would fall under the other questions but I have always been confused by this... Information has left the black hole; its mass, rotation, location, and a few other properties. My ...
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Why do “they” portray colliding black holes like that?

When I see an animation of two colliding black holes anywhere, it looks like two merging beads of water. But why would the event horizon form a bridge during collision? There is no material flowing in-...