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1 vote
0 answers
69 views

Coordinate transformation and absolute motion in general relativity

In special relativity, all motion is relative. But in the presence of black hole, all motion is with respect to black hole. The curvature of spacetime depends on how far we are away from the black ...
Chandra Prakash's user avatar
-1 votes
3 answers
124 views

Any experiment for relative simultaneity?

Any introduction of relative simultaneity usually is like this : Alice on a train car shines two beams of light towards both ends where two clock are. She sees both clocks see the light at the same ...
Aug's user avatar
  • 291
5 votes
0 answers
173 views

Sum of geodesic deviation around a triangle in curved spacetime?

So I was pondering about geodesic deviations and I'm confused about the following. Let's say I have $3$ geodesics $\gamma_1(t)$ , $\gamma_2(t)$ and $\gamma_3(t)$. I introduce a parameter $s$ such that ...
More Anonymous's user avatar
1 vote
1 answer
140 views

Relative velocity and proper time derivative of geodesic deviation?

From wiki To quantify geodesic deviation, one begins by setting up a family of closely spaced geodesics indexed by a continuous variable s and parametrized by an affine parameter $\tau$. That is, for ...
More Anonymous's user avatar
0 votes
1 answer
67 views

If the escape velocity for a body that is very close to a BH is near $c$ but not $c$ can it move away a little bit before it falls inside the BH?

The escape velocity from a common gravtational attractor means that a body lounched away from the attractor will never turn back. But in the case of a BH at the event horizon this escape velocity is $...
Krešimir Bradvica's user avatar
2 votes
3 answers
553 views

If I accelerate through space, can I say all stars gain kinetic energy?

Suppose I accelerate through empty space. Say all stars are small heavy marbles I can use to do work with by means of their velocity. Say I can let them smash into some generator that turns their ...
MatterGauge's user avatar
0 votes
2 answers
140 views

Is there any physical experiment that could tell us which object is moving to the other?

Imagine in empty space there are two objects in where one of them is moving to the other. How we can know which one is moving to the other? If there is an experiment that could tell us, would this ...
user avatar
16 votes
10 answers
5k views

Why do bodies traveling at constant velocity experience the same physics?

I am new to special relativity. I don't have a background in physics. I was reading Brian Green's The Elegant Universe and got hung up on an example. In fact, Einstein realized that the principle of ...
Dimitar Dimitrov's user avatar
7 votes
1 answer
414 views

How to calculate relative velocity in curved spacetime?

Is there a nice geometric way to calculate relative velocity in curved space time? I'm looking from something similar to how the separation vector $n$ between $2$ neighboring geodesics obey: $$ \...
More Anonymous's user avatar
2 votes
1 answer
66 views

How would we know whether a object is moving in deep space?

In deep space, there isn't anything we can compare our position with (According to my knowledge). In other words, we won't be able to define an origin so how would we know whether we are in motion or ...
Vedant Rana's user avatar
1 vote
1 answer
169 views

Acceleration and geodesics in General Relativity

Consider this situation: A) An aeroplane travels a distance from point A to point B which are located on the opposite sides of the Earth. The aeroplane has taken the shortest possible distance to ...
curiosity's user avatar
  • 159
2 votes
1 answer
253 views

Does General Relativity actually satisfy the General Principle of Relativity?

The “General Principle of Relativity” being “All systems of reference are equivalent with respect to the formulation of the fundamental laws of physics”. To my knowledge, this is related historically ...
Thatpotatoisaspy's user avatar
1 vote
2 answers
122 views

Non-uniform relative motion between inertial reference frames?

I have the following doubt: let person A be in free fall being gravitationally attracted towards a massive body M. Suppose then that person B is completely isolated in space and in particular very far ...
MMM's user avatar
  • 193
7 votes
6 answers
3k views

Does Special Relativity Imply Multiple Realities?

Thank you for reading. Before you answer my question, I feel I need to let you know that I'm still a beginner in special relativity...so the more thorough the answer, the better. Thank you! Alright, ...
joshuaronis's user avatar
  • 3,065
1 vote
2 answers
122 views

Relativity and electromagnetic field

I have a question regarding Misner, Charles W.; Thorne, Kip S.; Wheeler, John Archibald (1973), Gravitation ISBN 978-0-7167-0344-0. It is a book about Einstein's theory of gravitation. At the page 79,...
PackSciences's user avatar

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