All Questions
137
questions
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2
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81
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is $LT$ a Lorentz invariant?
We know the relations of time dilation and length contraction
$$L=\frac{L_0}\gamma\\
T=\gamma T_0$$
If we multiply them together, we get
$$LT=L_0T_0.$$
This holds for all $L$ and $T.$
So, is $LT=L'T'$ ...
- 219
0
votes
1
answer
47
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Time dilation cancelling out with movement in two directions
I'll preface by saying I'm fairly new to physics - was an English major back in college :-)
I'm learning time dilation. As I understand it, if a rocket is travelling away and then to from Earth at ...
1
vote
1
answer
117
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How would a spacecraft travelling near light speed say 0.9c compensate for time dilation in radio communication from spacecraft to earth?
For a spacecraft travelling at 0.9 c for 5 seconds, only 5 seconds would have passed for an observer on Aircraft, while 26.31 second would pass for a stationary observer watching from Earth.
In a ...
0
votes
1
answer
75
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Doubt about the derivation for the formula of time dilation
If I imagine a photon being released from the plate below as soon as the plates start moving, shouldn't the photon hit the opposite plate a bit behind the point where it would have hit if the plates ...
- 5
0
votes
1
answer
66
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Is the invariance of the 4-dim scalar product the fundamental law behind time dilatation and length contraction?
The Lorentz Group is defined as the group of all transformations that leaves the 4-dim. scalar product invariant. An implication of this definition is that the absolute value of the first matrix ...
- 189
1
vote
4
answers
165
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Is constant acceleration the same relative to other objects at all velocities?
If you are accelerating at a constant rate of 10 $m/s^2$, will you see things around you move at 10 $m/s$ faster every second, even when approaching the speed of light?
a) If not: How do you calculate ...
- 171
0
votes
6
answers
173
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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....
-1
votes
3
answers
104
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Why doesn't Galilean relativity lead to a contradiction in SR?
Two identical spaceships commanded by Alice and Bob are at rest next to each other in outer space. The clocks of the spaceships are synchronised; and when they are close by Alice can see Bob's clock ...
- 99
-2
votes
2
answers
60
views
Time dilation query [closed]
In the light clocks, time ticks via the motion of light and since speed of light is constant therefore when the clock is in motion ,the photon has to cover a greater distance by the perspective of an ...
0
votes
1
answer
57
views
What is the reason of different clock's measurements in different frames? [closed]
I tried to understand what is the reason of different clock's measurements in different frames.
For this I looked at easy example with distance S traveled by man with moving clock (velocity V1=2m/s) ...
- 149
0
votes
0
answers
59
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Relativistic electric field [duplicate]
Assuming a charged particle moves at speeds near the speed of the light. Will the electric field generated by that particle get affected by length contraction and time dilation?
In other words, will ...
- 291
5
votes
3
answers
2k
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Why can clocks not be compared unless they are meeting?
In the answer here to a special relativity question about clock synchronization: https://physics.stackexchange.com/a/485517/141472 it says (bolding mine):
As long as the two space ships are not ...
- 531
0
votes
2
answers
81
views
Time of collision of two relativistic speed particles
Suppose I have two particles, one moving at $0.9c$ to the right, starting at $(-0.9c,0,0)$ in the lab frame at $t=0$ and the second one moving at $0.9c$ to the left, starting at $(0.9c,0,0)$. In the ...
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-2
votes
1
answer
175
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The Achilles Twins Paradox: Proof of a Preferred Frame? [closed]
The Achilles Twins Paradox: Proof of a Preferred Frame?
Abstract: Both Achilles and Bob spend the exact same amount of time accelerating and decelerating at the same rates. Both Achilles and Bob spend ...
-3
votes
3
answers
213
views
Does proper time have two different values or meanings? [closed]
I'm trying to intuitively understand proper time which is defined as the time that is always measured in a moving observer’s or particle's rest frame and is given by the equation
$\Delta\tau = \sqrt{1 ...
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