All Questions
12
questions
1
vote
0
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51
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Newtonian approximation for the tidal forces at the event horizon of a black hole
I'm currently working on a problem where I have to calculate the tidal forces a person experiences if their feet touches the Schwartzschild radius and their head is $1.8m$ elevated above the ...
0
votes
1
answer
118
views
Is there an equation that is quick to use that calculates gravity around black holes?
Is there an equation the can calculate gravity around black holes but is less time consuming than EFE? I want to find an equation that is simpler/faster than Einstein's Field Equations but can still ...
-2
votes
1
answer
328
views
Do black holes exert infinite forces?
Black holes have infinite mass so according to Newton's law of universal gravitation should exert and infinite amount of gravity force.
- 90
3
votes
4
answers
817
views
Do black holes attract more in GR than Newtonian gravity beyond their event horizon? [duplicate]
I was once shown that if a black hole with the mass of our Sun replaced our Sun in the solar system (I believe it was in a simulation program), the attraction it has on the planets will be the same ...
- 2,650
1
vote
1
answer
58
views
Does the Higgs VEV depend on the gravitational potential?
If I take the non-relativistic limit of the Klein-Gordon equation in a curved space-time I will get a contribution from the Newtonian gravitational potential. Shouldn't this gravitational contribution ...
- 2,645
0
votes
1
answer
209
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Could a causal mass decrease cause antigravity, i.e. repulsive gravity?
Suppose some mass $M$ is located at rest in some point of space. It creates gravitational potential well, which attracts test bodies towards $M$:
Now suppose that the mass of a body drastically ...
- 1,732
3
votes
4
answers
378
views
Is there a peak gravitational force between bodies?
Suppose Object A is exerting gravitational force on Object B. Object A increases in mass, and so increases in volume, increasing the gravitational force on Object B. But, since mass occupies space the ...
- 133
0
votes
3
answers
131
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Black Hole gravity pull [duplicate]
Please I want to Know that if the radius of the black hole = 0 then how it have its surface and how it absorbs things?
$$\begin{align}
g &= \frac{Gm}{0^2} \\
&= \infty
\end{align}$$
then ...
- 27
2
votes
0
answers
1k
views
Force of gravity in the event horizon [closed]
I recently posted a question about black holes and gravity (this) and I discovered the Schwarzschild radius: $r_s=\frac{2GM}{c^2}$.
I thought with a friend of mine about the actual force (in Newtons) ...
- 989
11
votes
3
answers
7k
views
Does the mass of a star change as it collapses into a black hole?
I know (I think!) that when a really big star collapses on itself it creates a black hole.
My question: When a star collapses, is the mass equal to the mass of the star when it's not a black hole? Or ...
- 989
1
vote
2
answers
143
views
Would a black hole created on the surface burrow through the crust?
If scientists created a microscopic black hole with an initial mass of one ton on the surface of the earth, would the gravitational attraction to the center be enough for it to "burrow" until it eats ...
- 11
13
votes
4
answers
7k
views
Can a black hole be explained by Newtonian gravity?
In the simple explanation that a black hole appears when a big star
collapses under missing internal pressure and huge gravity, I can't see
any need to invoke relativity. Is this correct?
- 1,436