All Questions
41
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
65
views
If an observer was trapped in a closed box with no way to interact with the external surroundings how will he know if he is moving or at rest [duplicate]
I am a high-school student. Recently we learned the concepts of relative motion and velocity. The idea that anything in motion can subsequently be at rest depending on the frame of reference ...
- 21
0
votes
1
answer
53
views
Special-Relativity and how things not accelerating appear to be the same in all frames of reference [duplicate]
As someone who knows very little special-relativity (and none of the math) I understood that if you take a car moving down the road (at constant velocity) and approaching an observer, there is no ...
- 1
0
votes
3
answers
117
views
Details on analyzing relative motion
I have been viewing some videos and reading some articles about Relativity and relative motion. My search abilities seem to be rather lacking. I am looking for articles, questions, and/or forums ...
0
votes
3
answers
127
views
Relativity of bodies in motion in space
I have learnt that if we are travelling in space we have no way to tell if we are moving towards something or if it is the something that is moving towards us; to either object they judge that they ...
- 1
0
votes
0
answers
72
views
What is the ceiling on the perceived relative speeds of two bodies, from the point of view of a third observer? [duplicate]
What is the ceiling on the perceived relative speeds of two bodies, from the point of view of a third observer's reference frame?
We all know the ceiling on perceived speed relative to oneself is $c$. ...
1
vote
1
answer
98
views
Where does the relative velocity composition law equation come from?
I'm trying to understand this paper (equation $2.8$ specifically):
Bini, D., Carini, P., & Jantzen, R. T. ($1995$). Relative observer kinematics in general relativity. Classical and Quantum ...
- 1,389
0
votes
3
answers
97
views
Why is the speed of near speed of light moving particles not over the speed of light?
I've been looking for an answer to this question for a while now and I've seen the mathematical explanation
$$Vr=[V1+V2]/[1+V1*V2/c²]$$
I understand that the result cannot be greater than $c$ because ...
-3
votes
3
answers
100
views
If I'm moving with almost speed of light but without any acceleration will I see any relativistic effects?
As the moving is relative there is no matter on which speed you are moving if there is no acceleration. We will fill it exactly the same as no moving (if other objects moves with the same speed).
So, ...
- 768
0
votes
1
answer
434
views
What is the velocity of a photon with respect to another one? [duplicate]
When light comes from a source, there are numerous photons associated with the energy packets.
Now, what is the velocity of a single photon with respect to another photon coming form the same source i....
-2
votes
2
answers
445
views
What would an outside observer see if I throw a ball in the opposite direction of the train's movement towards a catcher? [duplicate]
Without taking air resistance into consideration, what would a stationary observer see if I am inside a moving train traveling at 60mph and throw a ball at 60mph opposite the direction of the train? ...
-1
votes
1
answer
101
views
Measuring the speed of an object
If I understand correctly someone said (Einstein?) that all motion is relative. However, if it were possible; given that light always travels in a vacuum at a fixed speed, could all other motion be ...
- 719
1
vote
4
answers
83
views
How can we tell if a charge is moving in a Magnetic Field?
In the equation $\vec F=q\vec v×\vec B$ ($\vec B$ is the magnetic field), what is $\vec v$ with respect to?
If we were to imagine $\vec B$ to be infinitely large. How could we tell if the charge is ...
- 11
1
vote
2
answers
184
views
Very basic special relativity (relative velocities)
My question involves broadly why calculating different (Einstein) relative velocities give different answers:
Say we have car 1 traveling in front of car 2. Car 1 goes at velocity $3c/4$, while car 2 ...
- 111
0
votes
0
answers
45
views
Speed of one frame with respect to another in special relativity [duplicate]
To derive the Lorentz transformation we begin with the general relationship between two frames as below:
$x' = Ax + Bt$
$y' = y$
$z' = z$
$t' = Cx + Dt$
If frame $S'$ is moving at speed $v$ with ...
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