All Questions
Tagged with spacetime reference-frames
197
questions
7
votes
4
answers
962
views
Do you always experience the gravitational influence of other mass as you see them in your frame?
You see a galaxy far away. That galaxy is attracting you with a certain amount of gravity. I'm wondering if the gravity influence of the galaxy on you, as measured by you, always ends up being what ...
- 161
2
votes
1
answer
157
views
When you are in a gravitational field, do object far away get physically closer to you as you get closer to the mass?
An observer A is close to a black hole and an observer B one light year away. They are both remaining at constant radial distance from the black hole. A is at 2 Rs away from the center of the black ...
- 161
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
191
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
0
answers
26
views
Question on Example 5.9 of Prof. Hartle Gravity textbook
I'm reading the Gravity Hartle book (ed.2003) and I'm having trouble with the question in the last part of Example 5.9 - Frequency Measured by an Accelerating Observer. More specifically the problem ...
- 1
0
votes
1
answer
172
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 ...
1
vote
1
answer
86
views
What does hypersurface of simultaneity exactly mean?
HSS - "Hyper Surface of Simultaneity"
Listening to different sources online I understood that HSS for a observer represents the points that are at same moment of time.
Consider a 1d world. ...
4
votes
1
answer
112
views
How to relate Riemannian and Lorentzian tetrad fields on the same manifold/spacetime?
Consider Gibbons and Hawkings paper wherein a Riemannian metric $\overset{\mathcal{R}}{g}_{\mu\nu}$ and everywhere well defined normalized line field $l_{\mu}$ on spacetime $M$ may be used to ...
- 2,847
0
votes
0
answers
50
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
0
votes
2
answers
114
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Do all observers see the same curved spacetime -- or would that be a (prohibited) preferred inertial frame? [duplicate]
My question -- pardon if not asked in the most incisive scientific prose
Do all observers see the same curved-space time?
Let me clarify:
Given that objects traveling at different relative speeds will ...
0
votes
2
answers
103
views
Justification of string breakage in Bell's Spaceship paradox from observer's frame
In Bell's Spaceship Paradox, are there any direct observations that the stationary observer can make that would justify the breaking of the string without taking into consideration as to what's taking ...
- 166
41
votes
4
answers
5k
views
Rotate an object about the time axis
Is there a notion of rotating an object about its time axis? I'm not sure if this question totally makes sense, but it seems intuitive to me that an object with dimensions in the three spatial ...
- 521
2
votes
3
answers
130
views
How to prove: Are perpendicular coordinates (wrt to relative velocity) unchanged (or only scaled) while deriving the Lorentz Transformations?
Thank you for helping with this question and I'm sorry if it's kind of stupid.
TLDR: In many textbooks and other derivations deriving the Lorentz Transformations, they omit coordinate axes orthogonal ...
- 31
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 ...
-1
votes
3
answers
174
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Trajectory of light send from a moving box [closed]
In a closed box in inertial motion a ball bounces up and down vertically. Apart from this movement, the ball is motionless relative to the box. The trajectory of the ball seen by a stationary observer ...
- 97