All Questions
11
questions
0
votes
1
answer
591
views
What is the definition of the "characteristic radius"?
Upon solving exercises regarding relativity, I have run into the problem below.
The inverse square radius of curvature of spacetime is of orer the tidal field, $R^{-2} \approx \nabla^2 \phi$ where $\...
- 1,669
3
votes
1
answer
342
views
Is this geometric argument enough to show that special relativity assumes flat spacetime?
I am preparing myself to teach a class about special relativity a few weeks from now. To make sure they'll understand that spacetime must be flat for special relativity to work, I came up with the ...
- 1,263
-1
votes
1
answer
73
views
Does the space and time wraping depends on the relative velocity of frame of reference? [closed]
why i am asking this question is that,
i thought that photon takes no time to reach the earth or any other place in the universe due to length contraction. the reason for this is space wraps completly ...
- 23
0
votes
2
answers
319
views
Doubt-Schild's argument about spacetime curvature
Reading MTW Gravitation book, to me is unclear the point related to the Schild's argument about spacetime curvature. It is basically the following:
Consider two observers at rest in the gravitational ...
- 1
2
votes
1
answer
1k
views
How does density relate to the curvature of space time in this scenario?
Assume there is a spaceship floating between two much larger and more massive spherical bodies m1 and m2. The two bodies m1 and m2 have equivalent mass, while the body m1 is much more dense than m2. ...
- 23
1
vote
2
answers
106
views
Can we tell that we're in a flat space time? Or just in reference to other objects?
If you are sitting in space, far from any planet or large gravitational object, can you be sure that you're in a flat spacetime? Is it possible that some very distant object is heavily warping ...
- 121
1
vote
1
answer
488
views
Which curvilinear coordinate systems can I use to describe flat space-time?
Can I use a coordinate system that has an intrinsic curvature to describe a flat space (such as Minkowski space)?
Say, for example, I wanted to provide coordinates for an infinite flat plane (${E}^{2}...
0
votes
0
answers
173
views
Confusion in Special Relativity: Rotating frame of reference
Suppose we are observing a rotating frame from an inertial frame, free from gravity, and try to measure the circumference of a circle drawn in the rotating frame. Since our measuring rod would be ...
- 112
0
votes
1
answer
90
views
Can everything be described without anything needing to actually "bend"? [closed]
Is space bending because gravity actually causes small particles to move differently? If large source of gravity is somewhere are particles extending towards it, creating a "bend" in space? So "bend" ...
5
votes
1
answer
396
views
How does Spacetime Curvature increase the velocity of particles falling towards the earth?
Two particles fall side by side, towards the earth. The horizontal distance between them is 10m. As they advance nearer and nearer to the earth's surface, the horizontal distance decreases, from 10m ...
- 1,283
-12
votes
1
answer
931
views
Why are we talking about space curvature as if we know what space is? [closed]
1) Why are we talking about space curvature as if we know what space is?
Every question about gravity seems to evoke an answer involving "space curvature" which seems like an undefined placeholder ...
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