All Questions
32
questions
1
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1
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The apparent dilatation of time in General Relativity
Maybe this a dumb question, but, is the gravitational dilatation of time caused because a particle travelling through a geodesic in a curved space-time must cover a larger distance than the one ...
- 1,525
0
votes
0
answers
53
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Question on gravity and spacetime curvature [duplicate]
In General Theory of Relativity, it is explained that the fabric of reality i.e. spacetime bends around objects with mass, and that curvature causes other objects to come close to/ fall towards the ...
13
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3
answers
2k
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In general relativity, why is Earth able to accelerate?
I was told and convinced that gravity is not a force, and in free fall you're an inertial frame and experience no force, and when on the surface of Earth you would be accelerating upwards.
What I ...
- 320
0
votes
2
answers
158
views
Does a straight line in flat space become a geodesic in curved space when the space becomes curved?
Flexible foam has shortest path from Point-A to Point-B. When the foam is not curved (space-time is not curved), the shortest path is Path-1 (straight line - before curving the foam). But if the foam ...
- 1
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0
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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
1
vote
1
answer
96
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How to explain the trajectory of object going up then come down with curvature of spacetime?
I can understand that the Moon is orbiting the Earth because it is going in a straight path within the distortion of spacetime caused by the Earth's mass, so not outside force is required. However, if ...
- 13k
1
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1
answer
358
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Curvature in the Newtonian Gravity
Let me give a little bit of insight. I was trying to calculate the geodesic of different curves when I realised some relation (if I can call it like that), between General Relativity and Newton's Law ...
- 1,525
3
votes
4
answers
491
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Why is it said that, because gravity can bend light, that this entails a curvature of space-time?
Why can't gravity affect light directly without any reference to space-time?
How does light bending show that space-time is curved?
I would have thought that it shows that massless particles are ...
- 65
1
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1
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117
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Universe flatness
On: https://en.wikipedia.org/wiki/Shape_of_the_universe
It is written:
"The exact shape is still a matter of debate in physical cosmology, but experimental data from various independent sources (...
- 97
1
vote
4
answers
213
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How does the curvature of space-time explain a ball falling in reverse?
If we throw a perfect uniform ball up in the air without any rotation in a vacuum room in a perfect perpendicular direction of earths gravitational pull and mark the part of the ball that is pointing ...
- 121
-8
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4
answers
199
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Curvature vs Gravity [closed]
I understand how and why spacetime curvature is responsible for the formation of geodesics and how objects follow those curved spacetime paths.
"Matter tells spacetime how to bend and spacetime ...
- 335
2
votes
1
answer
55
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Spacetimes where $R_{ij}\neq 0$ but $R_{ij}V^iV^j=0$ on a timelike and/or null geodesic?
Do there exist spacetimes with a timelike and/or null geodesic $\gamma$ with tangent vector $V$ for which $R_{ij}\neq 0$ on the geodesic, but $R_{ij}V^iV^j=0$ on it? If so, are there any general ...
- 1,588
4
votes
4
answers
239
views
If a light beam is sent tangent across earth would it curve at 9.8 $\rm m/s^2$? [closed]
Just to see if my understanding of the curvature of light is correct.
- 361
1
vote
1
answer
304
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Combining the Einstein field equations with the geodesic equation
I've seen this question How does Einstein field equations interact with geodesic equation?, but it doesn't make any sense to me. If spacetime is a Lorentzian manifold, then surely one thing general ...
- 2,475
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0
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32
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Rindler metric and equivalance principle [duplicate]
I'm trying to understand the connection between The Equivalence principle and the Rindler space. According to Einstein the inhabitants of the elevator should feel the acceleration. However, for an ...
- 146