All Questions
81
questions
0
votes
3
answers
130
views
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 ...
- 33
1
vote
2
answers
72
views
Train example of special relativity
My friend Eric is at the center of the train. The train is moving forward. The front end and back end of the train flash a light at the same time. From Eric's perspective, both light arrives at him at ...
- 13
2
votes
3
answers
240
views
Relativity, Lorentz Transforms and the time it takes to perceive
I've been working a bit at understanding relativity a bit more, and understanding Lorentz transformations. I want to make sure I understand the meaning of a Lorentz transofmration, and when to use it ...
- 160
9
votes
5
answers
2k
views
A bar that appears straight in one reference frame appears bent in another?
Is there a relativistic effect at play that explains the following thought experiment, that I am unaware of?
The apparatus depicted in the image has two straight bars in the middle emitting light from ...
- 93
0
votes
2
answers
86
views
Time desync with light delay: can we still "look into the future"?
I'm reasonably familiar with special relativity and its effect such as time desynchronization, but I'm having trouble understanding how these effects come into play when we also consider the time for ...
- 728
1
vote
1
answer
145
views
How to calculate positions when switching reference frames in a Minkowski spacetime diagram
The below Minkowski spacetime diagram includes three worldlines, where B is the observer and has a rest frame. A and C both have a velocity of 0.71c.
I then created a second diagram where worldline A ...
- 13
0
votes
2
answers
67
views
Question about length contractions [duplicate]
So I'm kind of confused about length contractions, whenever I think about length contractions I think about the faster an object goes it will be able to impair more photons which would create an ...
0
votes
6
answers
173
views
If time runs slow for moving train, how can it cover same distance in less time than someone on the ground unless the track decreases in its view?
According to special relativity,
Δt=γ*Δt' ... (1)
Where,
Δt is the time the train takes to completely pass by me according to my watch,
Δt' is the time I should see has passed for someone on the train....
-2
votes
4
answers
163
views
Relativity of simultaneity in flat spacetime
In Einstein’s (1917) thought experiment on the relativity of simultaneity…
The lightening flashes at A and B are both equal distance from the center of the train and the center of the platform.
The ...
- 27
-1
votes
2
answers
116
views
Does special relativity imply that there's such a thing as absolute time, or base time?
If time measured by one observer moving at a greater velocity than another observer is observed to be passing more slowly, does this imply that there's such a thing as "absolute time" or &...
3
votes
1
answer
106
views
How does the second postulate of special relativity imply invariance of spacetime interval?
I have trouble understanding why the second postulate of Special Relativity implies the invariance of spacetime interval $\Delta s^2=-c^2\Delta t^2+\Delta x^2+\Delta y^2+\Delta z^2$.
Suppose we have ...
- 209
3
votes
4
answers
731
views
Intuitive Derivation of Length Contraction in Special Relativity via Thought Experiment
I am trying to intuitively derive length contraction in special relativity using a thought experiment, without relying on Lorentz transformations. My aim is to obtain a derivation similar to how time ...
- 33
0
votes
3
answers
176
views
How do I make spacetime diagram consistent with length contraction? [closed]
Say the Earth and a distant galaxy is a distance $l$ away from each other. There is also a spaceship starting its journey at the Earth with a speed $u$ towards the galaxy.
I tried to draw a spacetime ...
- 111
0
votes
0
answers
40
views
Twin paradox symmetry in time dilation during the first leg [duplicate]
I was watching this Ted Ed video on Youtube about the twin paradox and found the explanation with the spacetime graph a bit confusing. At 3:00 in the video, they show a graph and explain how bursts ...
2
votes
1
answer
651
views
Relativity of Simultaneity - Is there ever a Preferential Frame of Reference? [closed]
A regular description of the paradox involves a train travelling through a tunnel which is fitted with doors at either end which can be raised and lowered. In their respective rest frames the length ...
- 133