All Questions
14
questions
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1
answer
106
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Another dimensions [closed]
Just a science ponderer, and pretty much interested in physics. Please guide me if I am wrong.
There have been many statements made by the physicists about the existence of other dimensions (...
- 19
9
votes
3
answers
6k
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Why is Spacetime described as flat even though we live in 3 dimensions of space?
I’ve always heard and seen diagrams that show spacetime as being “flat” or in 2 dimensions with curvature. How does this correspond to the 3 spacial dimensions that we perceive to exist in?
- 135
0
votes
1
answer
106
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How do you use the Riemann tensor to show curvature in time?
I know that the Riemann tensor shows curvature in space. However, in the case of general relativity, where space AND time is curved, how would one use the Riemann tensor to show curvature in a ...
- 33
0
votes
1
answer
76
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Does intrinsic curvature in a higher dimension mean that the lower dimensions also exhibit curvature?
If our universe has intrinsic curvature in a higher dimension, would that mean the 3 dimensions that we live in would be curved? and if so would the lower dimensions exhibit intrinsic or extrinsic ...
- 23
25
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10
answers
7k
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Why do physicists say that spacetime is not bending "into" or "out" of a fourth dimension?
I understand that there is no need for a fourth-dimensional space to bend into, but why do physicists seem to be against the idea? Is this simply because there is no proof of a fourth dimension, or is ...
- 510
0
votes
3
answers
956
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Gravity bends space, so how can space have only 3 dimensions? [duplicate]
Due to the laws of gravity and electromagnetic attraction (decreases with $\frac{1}{r^2}$) we know that space should be limited to 3 dimensions.
At the same time we know that gravity bends space. All ...
- 117
4
votes
3
answers
691
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Why does GTR not need a higher dimension to describe the bending of spacetime?
I am a bit confused on how GTR uses intrinsic curvature instead of extrinsic curvature. Maybe it is just a misunderstanding, but I will do my best to describe my question:
If we take an object of $n$ ...
- 3,778
0
votes
1
answer
95
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Gravity creating other dimensions [duplicate]
It is a well known fact that gravity can bend space, kind of like a rock placed on a sheet of paper, bending the paper. But, doing this will make another third dimension, that the marble actually ...
2
votes
1
answer
92
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For the case where universe is not flat, has it got an extrinsic curvature towards (an)other spatial dimension(s)? [duplicate]
I got the idea that expansion of the universe is not to somewhere, it is just getting stretched of spacetime since a point of singularity. And I know that universe was calculated as flat (which means ...
- 41
1
vote
0
answers
77
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Can a 2D universe be closed?
Consider a universe as a curved 1D line looped onto itself. The second dimension is time. On one hand, this line is easy to visualize as a circle embedded in a flat 2D plane. However, there is only ...
- 12.7k
-5
votes
4
answers
350
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In Einstein's General Relativity, do the space-time dimensions curve?
In Einstein's General Relativity, do the space-time dimensions curve according to the positions of stars, planets, and masses?
- 107
0
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3
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83
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Query regarding bent space-time in General Relativity [duplicate]
I am just a beginner in this topic and I accept I haven't gone through whole of the content of GR. However after going through some of the basic ideas, I encountered a problem.
If I did my homework ...
user143929
1
vote
1
answer
375
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Space curvature based on net energy = 0
In Neil DeGrass Tyson's epic video, at 2:26:50
https://www.youtube.com/watch?v=AdHlVY8pEk0&list=PL1L9zQimONkUOxXJyM0xcJja9ItQu1P8l&src_vid=AdHlVY8pEk0&feature=iv&annotation_id=...
- 463
16
votes
5
answers
5k
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Does space curvature automatically imply extra dimensions?
Total newbie with basically no physics knowledge here :) I would welcome any correction to the steps of my reasoning that lead to my question, which could easily turn out to be invalid :)
My current ...
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