All Questions
20
questions
1
vote
3
answers
175
views
Seemingly equivalent linear form of the Sagnac effect
This is a derivative of the question regarding the Sagnac effect. Judging from the metric $ds^2=-dt^2+(rd\phi)^2$ for a constant $r$ for this question, it should be no different from that on a line ...
- 1,030
2
votes
3
answers
193
views
Sagnac effect viewed in the rotating frame
Consider the Sagnac effect. It is quite simple viewed from the rest inertial frame what the time difference should be. However, if viewed from the frame fixed to and rotating together with the emitter/...
- 1,030
0
votes
1
answer
175
views
How is special relativity explained by general relativity?
To be more specific about this, I am under the below assumptions and then will explain my question further. Please let me know if any of the assumptions are incorrect.
(1) Special relativity describes ...
0
votes
0
answers
51
views
Geometric definition absolute velocity in affine spaces
currently I am reading the following paper by Halvorson and Clifton (https://arxiv.org/abs/quant-ph/0103041) where they try to argue that localizable particles are inconsistent with relativistic ...
- 21
1
vote
1
answer
52
views
Is distance irrelevant to time if two events are in the same inertial reference frame? [closed]
Assuming that there is some observer "O" at location 0, and there are two events A and B, with B occurring 1m farther from A. Both A and B are equipped with two synchronized clocks reading ...
6
votes
2
answers
750
views
Can a Kerr black hole be viewed as a Schwarzschild black hole by changing the frame of reference?
In a local universe empty of any matter except a Kerr black hole and an observer, that observer is spinning at the same rate as the black hole and observes it from a great distance directly above its ...
- 643
0
votes
1
answer
304
views
What will be the Lorentz transformation formula for 2 frames where they do not cross each other at $t=t'=0$?
For the standard Lorentz transformation,
we assume that F' crosses F at $t=t'=0$
and is moving to the right i.e. velocity $= +v$.
In that case, we use
\begin{gathered}x'=\gamma(x-vt),
\\t'=\gamma\left(...
- 4,476
0
votes
2
answers
231
views
Is there an eloquent way of qualitatively explaining why the time coordinate of an event is shifted proportionally to its spatial coordinates?
We know that time must shift alongside space because $\frac{dx}{dt} = \frac{dx'}{dt'}$ when $\frac{dx}{dt} = c$. This just means that the speed of light is invariant in all reference frames (light ...
- 365
0
votes
3
answers
231
views
Defining Simultaneity
I've been learning about relativity, and I'm just starting to wrap my head around what it means for events to be simultaneous in one reference frame, but not simultaneous in another.
Taking as the ...
- 3,075
2
votes
3
answers
727
views
What makes the Earth accelerate in a free-falling object's frame of reference?
If I'm an object in free fall near earth, then I'm an inertial frame of reference and I see the earth accelerating towards me with no force acting upon it. What causes that acceleration? The spacetime ...
4
votes
1
answer
268
views
Space-time diagram from the point of view of someone who accelerates in a $\delta(t)$ way
Suppose the situation shown in the following space-time diagram:
This diagram was drawn by the inertial observer standing in "the blue system", called A from azul in Spanish. In it we see the ...
- 1,872
0
votes
1
answer
48
views
Relativity equations
In the equations for time dilation and length contraction, what is a good way of choosing who is the relative time and length and who is the proper time and length so we can get good measurements of ...
2
votes
0
answers
62
views
About General Relativity and Reference Frames
So, I came up with this question which is intriguing me since a bit. Maybe it's stupid, but it's always better to ask.
The question is about inertial reference frames (I'll name them IRF)
We know ...
- 3,705
2
votes
2
answers
196
views
Is speed essentially infinite for a massless object moving at $c$?
My current understanding of the topic does not allow me to answer this question.
Also, by 'object' I mean a theoretical massless macroscopic object (if we assume such an object is possible, and if ...
- 209
3
votes
1
answer
527
views
Is any reference frame truly inertial?
I'm aware of the potential duplicate question here. However, that question centres on the Newtonian argument of there being a force, and hence acceleration. However, my issue is with the expansion of ...
- 1,788