Questions tagged [length-contraction]
38 questions
65
votes
14 answers
Why isn't length contraction permanent even though time dilation is?
It's my understanding that when something is going near the speed of light in reference to an observer, time dilation occurs and time goes slower for that fast-moving object. However, when that object goes back to "rest", it has genuinely aged…
theboombody
- 937
9
votes
8 answers
Help understanding Bell's spaceship paradox
The problem statement of Bell's Spaceship paradox is this:
Two spaceships float in space and are at rest relative to each other. They are
connected by a string. The string is strong, but it cannot withstand an arbitrary
amount of stretching.…
QCD_IS_GOOD
- 7,145
8
votes
9 answers
Confusion about Length Contraction (ex in Muon decay)
I am a bit confused about the implications of length contractions;
For example, in the muon decay problem, we assume that the distance between the muon and the earth is contracted only in the frame of reference of the muon (I've heard justification…
Peter G. Chang
- 183
5
votes
2 answers
Lorentz transformation paradox
I got to solve a simple exercise about special relativity when I kinda came to the conclusion it doesn't stroke with my intuition.
The homework-problem
The problem was about two people Sam and Leyla in a reference frame $S'$ that moves to the…
5
votes
2 answers
Does space between objects contract?
I had a question, let us assume a coordinate system where there is 2 objects moving at relativistic speeds (at same velocity) for the observer therefore the observer will observe the length contraction being by Lorentz factor $L' =…
user43495
5
votes
2 answers
length contraction in a gravitational field
As space-time is distorted in a gravitational field,
relativistic effects such as time dilation and length contraction take effect.
Time dilation is explained simply enough: closer to the source of gravity, slower the time passage.
However, space…
5
votes
3 answers
Gravitational Length Contraction
General Relativity predicts that a clock at rest in a gravitational field will run slower than a clock in free fall. Similarly, will a vertical ruler on the earth's surface be shorter than a ruler in free fall? Why or why not and by how much?
nahano
- 569
5
votes
2 answers
How can Lorentz contraction be "directly" measured?
If one is watching a relativistic object of e.g. spherical shape, which emits enough light to be detectable, it will, despite being Lorentz contracted, appear of its natural shape, although rotated. This phenomenon is called Terrel…
Ruslan
- 30,001
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5
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6 answers
Does Light Experience Length Contraction?
Lorentz length contractions states that the length of any moving object gets divided by the Lorentz factor equal to the Lorentz factor for that object (always $\geq 1$), equal to
$$
\gamma=\frac{1}{\sqrt { 1-\frac { { v }^{ 2 } }{ { c }^{ 2 } } }…
Arc676
- 293
4
votes
3 answers
Why are the proper time and the proper length not defined in the same frame of reference?
I've just read this interesting Wikipedia article about time dilation and length contraction in special relativity.
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Derivation of time dilation
Applying the above postulates, consider the inside of any vehicle (usually exemplified by a train)…
Quantum Force
- 1,653
4
votes
2 answers
Does this proof for time dilation ignore length contraction?
A simple proof for time dilation can be found here
http://en.wikipedia.org/wiki/Time_dilation#Simple_inference_of_time_dilation_due_to_relative_velocity
What I am confused about is that when the proof calculates the longer distance light has to…
QCD_IS_GOOD
- 7,145
4
votes
1 answer
Length Contraction in a Particle Accelerator
Consider $N$ particles equally spaced on a circle which are uniformly accelerated to $99\%$ the speed of light.
In Newtonian mechanics, the distance between the particles would be $2\pi r/N$ (for large $N$). If we add up all the distances between…
nahano
- 569
3
votes
1 answer
Length contraction alongside acceleration
Let's have a ship, a target and a ship traveler which we use as point of view. Assuming no other object are observed and we are so far from any other object that gravity distortion are negligible, I'm confused of the effect of length contraction…
3
votes
1 answer
Length contraction, front middle or back
I still don't have a solid understanding of Length contraction. Imagine we have a ruler of length $L$ that starts at rest upon a ground with markings on it, then accelerates until nearly the speed of light.
For a stationary observer, the ruler…
QCD_IS_GOOD
- 7,145
3
votes
6 answers
Time dilation derivation of special relativity
In almost all of the derivations using the postulates of special relativity (SR), we use experiments involving light signals. For example, we make a clock using a light signal or measure lengths using light signals, etc. The reason for doing this is…
Isomorphic
- 1,616