All Questions
Tagged with special-relativityobservers
856 questions
-4votes
1answer
102views
Twins Paradox Resolution [closed]
In what sense is the following explanation of the Twins Paradox faulty in logic: Each twin views the other as length contracted, but the twin on earth only sees the rocket in motion and thus shortened ...
- 61
-11votes
0answers
104views
Why is the measured speed of light assumed to be the same for all observers? [closed]
Is the speed of light always measured using a two way mirror device? I have not found any reports where the one way light speed has been measured directly. But for some reason this important ...
5votes
1answer
105views
Speed Time Dilation and travelling 90% of $c$
If a spaceship travelled away from Earth at 90% of the Speed of Light over a distance of 10 light years, then I read that an atomic clock would record a "time taken" of less than 5 years (...
4votes
4answers
830views
Contrasting results about time intervals measured by stationary and moving observers: why?
While studying relativity, a problem arose about time intervals measured by stationary and moving observers. In particular, one of the first steps after clarifying the two postulates is to prove that $...
- 1,999
6votes
3answers
1kviews
How can two events which are not causally related be perceived to be simultaneous by an moving observer?
It is said that if two events are causally related, then there exists a moving observer which perceives both of them happening at the same place, which I sort of understand but how can two events ...
0votes
1answer
126views
Change of observer in Special Relativity
A uniformly accelerated observer leaves some photons behind, meaning photons emitted behind Rindler horizon never reach the observer. Some incoming photons appear 'out of nothing', Unruh effect. Is a ...
- 15
0votes
1answer
53views
SR Question about sync [closed]
let us say we have a cat which is accelerating and a stationary observer and we compare time dialation and length contraction for both of them their velocities are assumed one way velocity but for ...
0votes
5answers
299views
How is time dilation symmetry broken?
In special-relativity, if observer A sees observer B moving with constant velocity $v$ then B is subject to time dilation gamma < 1. Symmetrically, B observes A to move with velocity $-v$ and ...
1vote
1answer
84views
Principle of relativity on example with two inertial frames
Let we have two inertial frames $OXY$ and $O'XY'$: Accordingly to principle of relativity there are two cases: First inertial frame is stationary. Second inertial frame is moving with velocity V (...
- 453
2votes
0answers
84views
3-momentum of particle for observer
The question presents a particle with four-momentum $p^\mu \equiv mcv^\mu = (p^0, \vec{p})$, where $v^\mu$ is the particle's four-velocity and $\vec{p}$ is its three-momentum. There's an observer with ...
- 21
0votes
2answers
155views
Frame of Reference: How much physics sits in it?
A naive question about nuances on meaning of the concept frame of reference and how much "intrinsically physical" information it carries about considered physical system. To my knowledge (...
- 1,701
0votes
1answer
53views
Distance and Length contraction and its reciprocity
Considering the situation:---- There are 3 observers: A (On earth), B (on spaceship), C (On Sun). The spaceship, initially at rest on earth, starts moving towards Sun at velocity 'v'. Now firstly, as ...
- 85
-3votes
2answers
121views
Moving information faster than light ("the observer causality dilemma") [closed]
I'm not entirely sure what I'm missing here, but let's take a simple scenario. Observer A is riding a train car at half the speed of light. He brings with him a mirror and a laser pointer. He hangs ...
- 326
-4votes
3answers
196views
Why can't we measure our own speed using the speed of light?
If a emitter/reflector/sensor array is travelling in a certain direction, the distance the light travels changes based on the angle between the direction of travel and the direction of the light beam. ...
- 326
4votes
3answers
350views
How to define a common time between two clocks? - clock synchronization in special relativity
I have a basic understanding of SR, its postulates and SR math. I was going through Einstein's 1905 paper on SR, the part about synchronizing the clock goes as follows - If at the point A of space ...
- 359
