All Questions
Tagged with spacetime inertial-frames
43
questions
22
votes
2
answers
8k
views
How do I derive the Lorentz contraction from the invariant interval?
While reviewing some basic special relativity, I stumbled upon this problem:
From the definition of the proper time:
$$c^2d\tau^2=c^2dt^2-dx^2$$
I was able to derive the time dilation formula by using ...
- 16.4k
25
votes
8
answers
5k
views
In the theory of special relativity speed is relative so who decides which observer’s time moves slower? [duplicate]
If for example we have 2 people one moving in speed v relative to the other, according to special relativity the time passing for the moving person is slower than for the stationary person. However ...
- 375
5
votes
1
answer
9k
views
General matrix Lorentz transformation
I just finished an introduction course into theory of relativity and am trying to find the general matrix Lorentz transformation. I have already looked into this question, but I could not make much ...
- 192
9
votes
5
answers
8k
views
Why is causality preserved in special relativity?
PART 1:
I was reading the article Relativity of simultaneity Wikipedia. I couldn't understand this line:
"if the two events are causally connected ("event A causes event B"), the causal order is ...
- 1,601
5
votes
3
answers
2k
views
Isn't the aether existent?
Before you say I'm wrong consider this, Einstein is supposedly the first person to get completely get rid of the various aether models that were proposed. But didn't Einstein actually prove them right ...
- 63
53
votes
3
answers
68k
views
What is a Lorentz boost and how to calculate it?
I know very little about special relativity. I never learnt it properly, but every time I read someone saying
If you boost in the $x$-direction, you get such and such
my mind goes blank! I tried ...
- 837
14
votes
18
answers
4k
views
What is an event in Special Relativity?
Lorentz transformations help us transform coordinates of one frame to that of another.
For example, let the coordinates of an event in an inertial frame $S$ be $(x, t)$, then the coordinates in frame ...
- 2,918
6
votes
5
answers
865
views
The effects of Lorentz transformation on shape
Imagine a solid 3D cube. Now imagine that this cube is traveling close to the speed of light. To what degree will the spatial geometric properties of this object (or in general of any 3D object) ...
- 431
6
votes
2
answers
431
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Confusion regarding bundle structure of Galilean spacetime in Penrose's The Road to Reality
I am reading Roger Penrose's The Road to Reality. In section 17.3, I encounter the following passage. To give a context, Penrose was explaining that even though an Aristotelian spacetime can be ...
- 682
2
votes
1
answer
2k
views
Appearance of an angle of inclination on a horizontal rod moving upwards after a Lorentz Transformation [closed]
If i have in one inertial reference frame called $S':(x',y',z',t')$ a rod with lenght $l$ in the plane $z'=0$ and parallel with the $x'$ axis, moving with a velocity $u$ in the direction of the $y'$ ...
- 276
8
votes
4
answers
5k
views
Why is time-order invariant in timelike interval?
Why do two observers measure the same order of events if we are inside the light cone?
(e.g. if $ds^2 > 0$ time-order is preserved according to the classical mechanics book I am reading, but it ...
- 253
6
votes
3
answers
1k
views
What's incorrect with using the two formulas for Lorentz contraction and time dilation at the same time?
Lorentz contraction: $L = L_0 / \gamma$
Time dilation: $t = \tau \gamma$
Using the above two formulas at the same time leads to contradiction to the principle of the constancy of light velocity.
What’...
- 69
1
vote
1
answer
2k
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Space time diagrams: Length contraction
I am trying to get a better understanding for length contraction in a geometric sense and came across this diagram:
but what I am having trouble with is why in the ref frame of the blue vector are ...
- 579
0
votes
3
answers
1k
views
Why are the coordinate axes of a moving frame $K'$ tilted in spacetime diagrams?
I am currently trying to self-teach special relativity (if relevant, I am still in school). I think that I already have a good intuitive understanding of, for example, time dilation and length ...
- 3,778
11
votes
8
answers
3k
views
Are Lorentz aether theory and special relativity fully equivalent?
Following up on this question on whether it's possible to construct a physical theory with invariant space-time and variable speed of light.
I am looking for a authoritative and more definitive ...
- 335