All Questions
39
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669
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When do we talk about spaghettification or pancakification in black holes?
So I've been doing some research for a while now, and yesterday came across the video of PBS space time talking about what happens to quantum information in a black hole. In the thought experiment ...
0
votes
2
answers
105
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Realistic black holes
If I understand the answers provided in this Link Why singularity in a black hole, and not just "very dense"?
Then the singularity at $r=0$ may just be a mathematical artifact, and may not ...
1
vote
2
answers
103
views
Are black holes XXXL stars?
Am I right to think that black holes are stars that are so dense and heavy that radiation and matter cannot leave from it's surface?
1
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1
answer
175
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Would a black hole instantly form when a neutron star slips below the phantom event horizon?
So lets say we have a neutron star that is just few inches away from the phantom horizon and only needs 500 kg before collapsing. So lets say hypothetically that a ship that is designed to survive the ...
- 1,534
1
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0
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42
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Influence of external gravitational fields on the volume of a part of the black hole event horizon
FIRST QUESTION: In the event that a smaller black hole orbiting a larger black hole in an elongated elliptical orbit reaches the so-called perihelion of its trajectory, can it temporarily change the ...
- 2,255
2
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3
answers
196
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Astrophysical vs. Schwarzschild Black Holes
I have heard the idea that real astronomical black holes cannot be called Schwarzschild BHs, not because of rotation but because Schwarzschild contains no mass and is eternal, due to being a ...
- 9,500
-1
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3
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286
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Is a black hole a single particle or a bunch of particles that binds together?
We know that in a neutron star all electrons and protons combine together and make neutrons because of the gravitational pulls. We also know that a black hole is much denser than a neutron star, we ...
1
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3
answers
633
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Inside the Photon sphere of a black hole
A photon sphere is defined as the innermost orbit in which the gravitational force of the compact object causes light to orbit it. The event horizon is the boundary at which the escape velocity is the ...
- 11
2
votes
0
answers
136
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What happens when a neutron star becomes a black hole?
Suppose you have a neutron star that's as close as can be imagined to the required mass to become a black hole, perhaps just one proton mass away from this limit, when it collides with a dust grain ...
- 121
1
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1
answer
81
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Rotating black hole
I know that everything that is shaped from gravity force is rotating, and gravity is a central force. but I want to know how can we detect that a black hole has an angular momentum? By which ...
- 39
1
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2
answers
148
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If black holes never form (like M87) then does this mean that theoretically we could decode light and information that is still coming out of them?
I have read this question:
This isn't some accounting trick, it means we will never see an event horizon form. At this point someone will usually pop up and say that means black holes don't really ...
- 29k
1
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0
answers
52
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If event horizons (black holes) never form in a finite time, then how can they merge to create a common event horizon in a finite time? [duplicate]
There is another question about this topic, but that is asking about gravitational waves, and I am not. I am specifically asking about the timescale of the merger being finite (actually quick), ...
- 29k
1
vote
0
answers
81
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What would happen if an asteroid-sized primordial black hole encountered a very large star?
What would happen if an asteroid-sized primordial black hole encountered a very large star? I thought about this and Googled for answers but got no results. Maybe I'm asking the wrong question. I know ...
- 753
1
vote
0
answers
117
views
Is it correct that a sphere of water the size of Venus's orbit would instantly be a black hole? [duplicate]
Let's say I have a genie and wish for a sphere of water at earth density the size of Venus' orbit - would it be instantly indistinguishable from a supermassive black hole due to the schwarzchild ...
- 11
1
vote
1
answer
93
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Is it justified to call the Event Horizon Telescope image of a black hole a photograph? [closed]
As this image is the result of processing data from an array of radio telescopes sensitive to wavelengths far away from the visible spectrum, to what extent can it be called a "photograph", ...
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