Tagged Questions

0
votes
1answer
57 views

Dense Spherical Black Hole Shell with a Region Inside

I'm going to propose a thought experiment, based on two ideas. One: A uniform spherical shell, by the Shell Theorem, does not exert any gravitational force on objects existing in the interior of the ...
2
votes
1answer
431 views

Is anti-gravity possible in theoretical physics?

Is anti-gravity possible in string theory? I have read some articles about scientists making assumptions about the existence of anti-gravity, but is it possible in string theory?
3
votes
2answers
200 views

Has anyone else thought about gravity in this way?

Picture yourself standing on a ball that is expanding at such a rate that it makes you stick to the ball. Everything in the universe is expanding at this same rate. To escape the earths gravitational ...
4
votes
4answers
404 views

what is the difference between a blackhole and a point particle

Theoretically, What is the difference between a black hole and a point particle of certain nonzero mass. Of-course the former exists while its not clear whether the later exists or not, but both have ...
10
votes
5answers
6k views

How exactly does time slow down near a black hole?

How exactly does time slow down near a black hole? I have heard this as a possible way of time traveling, and I do understand that it is due in some way to the massive gravity around a black hole, but ...
0
votes
0answers
136 views

Spinning X-Rays [closed]

X-Ray jets emit from galaxies as a result of spinning mass. I'm thinking about the ties between electricity and magnetism here, and how Gauss law ties all this stuff together. OK, so is there a way ...
3
votes
5answers
781 views

How does the curvature of spacetime induce gravitational attraction?

I don't know how to ask this more clearly than in the title.
10
votes
7answers
3k views

Tesla's theory of gravity

I was reading up on Tesla's Wikipedia page last night, and I came across this: When he was 81, Tesla stated he had completed a "dynamic theory of gravity". He stated that it was "worked out ...