All Questions
Tagged with special-relativity observers
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Wikipedia states that the relativistic Doppler effect is the same whether it is the source or the receiver that is stationary. Can this be true?
According to Wikipedia, the relativistic Doppler effect is simply the classical Doppler effect for a stationary source, $1-v/c$, times the relativistic time dilation, $1/\sqrt{1-v^2/c^2}$ (where v is ...
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Relativity problem about light signals and rockets equipped with mirrors [closed]
I find in a relativity book a problem that states:
"A rocket with its own length $L$ moves away from Earth at a constant velocity $v$. A radar signal emitted from a ground station is reflected ...
- 207k
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Co-ordinates and change of frame in relativity [closed]
Given an inertial co-ordinate system, and observer at the origin. I'll make it concrete, for simplicity. He sees an object at the point $x = +10$, moving at velocity $v = +1$. He's subjected to a ...
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Since the speed of light is constant and also the speed limit; would you, in your reference frame, have no upper bound on your speed? [closed]
Let us imagine you are in a vacuum and after having maintained a speed of 0 km/s (standing still) you accelerate to 297,000 km/s (99%). You know this is now your speed because you have a speedometer ...
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Comparing potential energy in non-relativistic classical physics and in special relativity
Preface
In classic physics the potential energy of a compressed (or stretched) spring is
$E_{\rm sp} = (\frac{1}{2})k_{\rm sp}(\Delta l)^2$
where $\Delta l$ is the length that the spring is compressed ...
CommunityBot
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2
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What effect would relativity have for an objective with absolutely no momentum? [closed]
I know as you near the speed of light time slows down and mass increases to near infinite. What I'm curious about is what would happen if an object lost all momentum. No movement at all not even the ...
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3
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Clocks are not synchronized in moving system (book of David J. Griffiths) [closed]
In the electrodynamics book of David J. Griffiths, in section 12.1.2, there is a paragraph about the synchronization of the clocks on a moving train. I don't understand why " Clocks that are ...
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Who will die first between two people on different spaceships, where both are in inertial frames? [duplicate]
Here's something that's really been confusing me.
If two people on separate spaceships pass each other by, where both are in inertial frames, person A (on spaceship 1) could say that he is at rest and ...
- 15.9k
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1
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Velocity of light in different directions [duplicate]
From what I understand, we have not been able to measure unidirectional speed of light. It is said that theoretically it is possible for light to travel at $c/2$ in one direction and infinity speed in ...
- 207k
2
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5
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Derivation of the length-contraction formula
i saw the derivation of the length contraction and it goes like this:
what i dont understand is why does interval between the photon striking and coming back have to be compared? why can't I simply ...
CommunityBot
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In SR, why do we claim length contraction rather than faster than $c$ travel in the rocket frame? [closed]
In special relativity, a rocket traveling at .5c will take .86 years (in the astronauts frame) to travel 1 light year (in a stationary observer frame). There are two possible ways to look at this
...
- 358k
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0
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Does two clocks moving toward each other at the same speed, then decelerating at the same rate coming to a stop create a paradox? [duplicate]
Note I have asked this question previously but upon reflection I realized I was not specific enough, leading to confusion in the answers. I have decided to ask the question again instead of editing my ...
- 207k
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If you have two clocks moving toward each other and they both stop when they meet does it point to a paradox?
Say they both decelerate at the same rate also. If clock A sees clock B as slower than itself and clock B see clock A as slower than itself due to relativity isn't this a paradox because when they ...
- 207k
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2
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Thought experiment circumventing finite speed of light via relativity of simultaneity - what's wrong?
I just watched this video regarding block universe: https://www.youtube.com/watch?v=wwSzpaTHyS8&t=676s and it provoked the following thought experiment:
Let's assume two observers, O1 and O2, at ...
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Can you tell who is moving through time? [closed]
In relativity, there is no way to tell if you are moving through space. So, if you were inside of a box, there would be no way for you to tell if you were moving or not. However, can you know who is ...
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