All Questions
497
questions
-4
votes
2
answers
64
views
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 ...
-2
votes
3
answers
84
views
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 ...
1
vote
2
answers
91
views
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 ...
- 11
-4
votes
1
answer
99
views
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
...
- 4,783
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
0
votes
1
answer
68
views
If velocity is relative, why does time dilate for some observers and not others? [duplicate]
I'm trying to get my head around relativity and time dilation. What I can't figure out is how time can dilate for fast-moving observers if all velocity is relative. Here's a scenario:
Alice and Bob ...
- 109
5
votes
3
answers
643
views
Special relativity and accelerating twins
Imagine two twins synchronise their clocks and then twin A quickly accelerates to velocity v. After a time T twin B quickly accelerates to 2v and catches up with twin A. Which one will be younger? How ...
- 81
0
votes
1
answer
53
views
Length contraction doesn't affect the perpendicular direction...but it seems as if it can
A is a stationary observer watching B who is moving relative to A. Both of them hold two identical light clocks and each shoots light rays to estimate the lengths of their clocks. A's light ray will ...
2
votes
4
answers
1k
views
Time Dilation when they meet
I am starting over because what I was asking was unclear. I have read many articles, such as How can time dilation be symmetric? and others suggested by people here and understand the overall concepts ...
- 69
1
vote
0
answers
90
views
Special Theory of Relativity Contradiction [duplicate]
I’m struggling with an apparent contradiction of special theory of relativity (STR) that I cannot resolve.
Imagine two twins flying by each other in space along the same straight line but in the ...
- 11
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
3
votes
2
answers
169
views
Schutz description of Galilean invariance of interval
In B. Schutz's textbook "A First Course in General Relativity", there is a sentence on page 172 discussing Galilean relativity and how the distance between events is invariant in coordinate ...
- 137
-4
votes
1
answer
116
views
Absolute rest in special relativity
I am new to special relativity and with still little experience in Physics. I would like to know why a privileged frame of reference that determines absolute rest is not possible. I want you to ...
- 13
1
vote
6
answers
119
views
Question regarding time dilation
if people in semi-light-speed ships age slower, does the world appeared to those people also 'age slower'? Because it is the external world which is moving at semi-light-speed to the people in the ...
- 11
0
votes
1
answer
137
views
Confusion regarding Special Relativity and Relativity of Velocity? [duplicate]
Suppose that there are two points in an empty space A and B and observers at A and B having clocks:
If A were to be traveling near speed of light, when clock at A passes 1 hour, observer at A ...
