All Questions
23
questions
0
votes
1
answer
75
views
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
views
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
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....
-1
votes
3
answers
104
views
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
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
-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 ...
- 335
-3
votes
2
answers
132
views
Time dilation and contradiction
Suppose we have a reference $R$ and a reference $R'$ with velocity $v \ne 0$ respect to $R$ then we know that:
$$\Delta t = \gamma \Delta t'$$
but respect to $R'$ the reference $R$ has also velocity $...
- 385
1
vote
3
answers
129
views
Exact meaning of Lorentz transformations [closed]
This is my first year in Physics and we have been shown about S.R very superficially, just having a bunch of equations to apply. However, I feel rather confused about results such as time dilation, ...
0
votes
0
answers
32
views
How do we know that gravity emission is not time dilated like luminosity? $g'=γg$
It seems like gravity emission would be expected to decrease with time dilation. I've thought this from my first reading of Special and General Relativity, and I never heard a satisfying explanation ...
- 275
1
vote
1
answer
48
views
Why is the book using the equation of $\Delta t$? [closed]
I have a question on a worked out example from a text book. The example is as follows.
A proposed plane would carry intercontinental travelers at speeds many times those of today’s fastest airliners. ...
- 73
1
vote
2
answers
120
views
Time transformation term in Lorentz transformation
In the lorentz tranformation, I have got the following equation for time:
$$t' = \dfrac{t - \dfrac{ux}{c^2}}{\sqrt{1-\dfrac{u^2}{c}}}$$
The $S'$ system is moving relative to $S$ system with speed $u$, ...
- 11
17
votes
4
answers
13k
views
Why does everyone say that the faster you move through space, the slower you move through time, when that's not the case?
Suppose, I'm on earth and my brother is moving away from earth at a constant speed, $v=0.8c$. Now, if 5 seconds $(t_0)$ pass for me, the amount of time that will pass for my brother according to me ...
- 1,018
1
vote
4
answers
81
views
A star is just born and starts travelling towards us at 99 percent speed of light. So how would an immortal observer observe the light from it?
An immortal observer is observing a new born star from billions of lightyears away travelling towards it at near the speed of light (99%).
The star is a short living one and dies soon before reaching ...
8
votes
3
answers
697
views
Can the Lorentz transformations be derived this way?
This approach is seeming intuitive to me as I can visualize what's going on at each step and there's not much complex math. But I'm not sure if I'm on the right track or if I'm making some mistakes. ...
- 6,355
0
votes
2
answers
175
views
Is time dilation derivable from (non-)simultaneity?
My friend, Nima Fathali, used to claim that the fact time dilation can be deduced from the (non-)simultaneity though I used to claim otherwise saying that these two qualities are independent of each ...
- 2,503