All Questions
480
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When gravity is not a force but an effect of mass bending the curvature of space, why? [duplicate]
When gravity is not a force but an effect of mass bending the curvature of space, why do masses bend the curvature of the space in the first place?
The reasoning as it is demonstrated now seems ...
0
votes
1
answer
92
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Are photons affected by "temporal gravity?"
Since objects follow geodesics in spacetime, that is the locally shortest path, it would seem to me that unless objects move, they do not trace any path at all. In other words, if I'm stationary on ...
- 47
-2
votes
3
answers
301
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Why doesn't the curvature of spacetime around Earth cancel the Sun's curvature?
If the Sun and Earth both act on the same medium, which is spacetime, then why the Earth curvature of spacetime around itself does not isolate it from the Sun's curvature? If it does not, and the Sun ...
user348262
17
votes
2
answers
5k
views
Space falling faster than light after it falls inside the event horizon of a black hole?
Typing my question directly so people know what I am asking, afterwards providing background and context.
Q: What does it mean when space is falling, faster than light?
(I am specifically wondering ...
- 398
1
vote
0
answers
146
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Equivalence Principle: Uniform to Non-uniform gravitational fields
2Einstein in his 1916 GR paper describes the equivalence principle and makes a case for general relativity i.e a person in a non-inertial frame is equivalent to a person in a uniform gravitational ...
- 141
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0
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32
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How do we know that gravity emission is not time dilated like luminosity? $g'=γg$
It seems like gravity emission would be expected to decrease with time dilation. I've thought this from my first reading of Special and General Relativity, and I never heard a satisfying explanation ...
- 275
2
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0
answers
47
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Mass curves spacetime. Is there any theorized "anti-mass" that counteracts this effect? [duplicate]
Things like faster-than-light travel have very good reasons for being believed theoretically impossible (e.g. they allow traveling backwards in time). Things like magnetic monopoles are seemingly ...
- 1,090
7
votes
3
answers
1k
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How massive objects affect distance measurements, or "But how far away is a black hole singularity, really?"
My question basically boils down to: Is the singularity of a black hole infinitely far away?
I think questions like mine have been asked before, but they encounter responses like "no meaningful ...
- 215
0
votes
1
answer
35
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Will the trajectory of a body moving straight towards a rotating BH differ if space just rotates around or if space spiralls into the BH?
Will the trajectory of a body moving straight towards a rotating BH differ if space just rotates around or if space spiralls into the BH? Can this difference be clearly measured? Also as a very dense ...
- 2,255
-2
votes
1
answer
78
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How does gravity affect "Timeless" particles like photons?
Just finished a class a while ago and in it was discussed the nature of gravity being due to mass' effect on time etc. etc.
My question is: how then does gravity effect something like a photon, which ...
1
vote
1
answer
150
views
Doubt about General relativity
Matter and [non-gravitational] energy via the stress tensor can cause spacetime curvature because the stress tensor is algebraically related to the Ricci curvature tensor, according to Einstein's ...
user229112
0
votes
3
answers
491
views
Can gravity exist without time?
I have read this question:
I think it's the opposite - when there is no gravity, the difference in time observers measure only depends on their relative velocity. It's when gravity gets very strong ...
- 29k
0
votes
1
answer
98
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How exactly did Einstein check if his equation on general relativity was correct? [duplicate]
I saw the equation on general relativity and then I wondered: how did Einstein check if his equation was right or wrong?
- 625
0
votes
0
answers
25
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Would gravity pulling person toward Earth change if velocity of Earth changes? [duplicate]
So I was reading the Albert Einstein's theory of how gravity works. From my understanding, the more mass an object has, the more space-time around it it bends. All objects travels in completely ...
- 7
0
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1
answer
95
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Do Two IDENTICAL Bodies Cancel-out Each-other's Gravity?
If we were to imagine two objects suspended in space* that were identical, with the exact same number of atoms, would the gravitational forces produced by each cancel each-other out? (maintain their ...
