All Questions
25
questions
-4
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In SR, why do we claim length contraction rather than faster than $c$ travel in the rocket frame? [closed]
In special relativity, a rocket traveling at .5c will take .86 years (in the astronauts frame) to travel 1 light year (in a stationary observer frame). There are two possible ways to look at this
...
- 4,783
3
votes
3
answers
356
views
One-way Tachyonic anti-telephone
When you have length contraction in special relativity
$$L' = L/\gamma$$ the interpretation is that $L'$ is the length of an object with rest-length $L$ moving with respect to an observer at rest. ...
- 1,200
0
votes
1
answer
79
views
FTL Length contraction? [closed]
I found this interesting question in a textbook about special relativity:
A length-contracted object has length $L=\frac{L_0}{\gamma}$. Joe differentiates this with respect to time and finds
$$\frac{\...
1
vote
1
answer
849
views
Why Going Faster-Than-Light (FTL) Leads to Time Paradoxes? [duplicate]
In this video: https://www.youtube.com/watch?v=an0M-wcHw5A&lc=UgxqC71gefTRIuVubGt4AaABAg.9jI6ltMIeu59jx2P8cpn_z
In the video the following events happen:
A supernova goes off.
Earth sees the ...
- 2,706
-1
votes
1
answer
122
views
Can an object appear to be moving faster than light due to time dilation?
If I were to travel tword earth from a distant star at .9 C, I would see that earth would be experiencing more time than I would, but does this mean that I would see earth approaching at more than the ...
-7
votes
3
answers
244
views
Can one record a speed faster than $c$?
A ship goes to the moon at 0,5 c, the captain will record on his clock about 2 seconds and a half, right?
Now he increases the speed to 0,999 c (or more), thanks to relativity he should record on his ...
- 691
-5
votes
1
answer
112
views
These guys occur but why? [closed]
We all know that if we consider the assumption of Einstein that is no material object can travel faster than light to be true then two effects that are
Length Contraction And Time Dilation
seem to be ...
6
votes
5
answers
3k
views
If a muon travelling fast can “extend” its lifespan due to relativistic effects, would the muon see itself travelling faster than light?
In other words, if I put a bomb set for 2.2 microseconds and send it out at .99c, would it travel further than (.99c x 2.2 microseconds)? And if it does, like muons do, wouldn’t the bomb be able to ...
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4
votes
3
answers
183
views
Can information travel faster than speed of light in this situation?
I know the answer is no but I have a thought experiment that seem to be violating that. Imagine two persons living on two different planets namely A and C which are 10 light years apart. There is a ...
- 49
15
votes
9
answers
5k
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Since the speed of light is constant and also the speed limit; would you, in your reference frame, have no upper bound on your speed? [closed]
Let us imagine you are in a vacuum and after having maintained a speed of 0 km/s (standing still) you accelerate to 297,000 km/s (99%). You know this is now your speed because you have a speedometer ...
- 357
1
vote
2
answers
143
views
Why is my contrived superluminal thought experiment wrong?
An astronaut is on an odd mission. Each day, the spacecraft is accelerated by 10% of the speed of light, and at night the astronaut sleeps and will loose all memories of the previous day. Each day ...
- 137
0
votes
0
answers
29
views
Exceeding the speed of light in view of special theory of relativity [duplicate]
Is there any rigorous way to show that it is impossible to have any inertial reference frame with the speed of light apart from the blow up of the Lorentz factor?
- 199
5
votes
11
answers
3k
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Why can't we surpass the speed of light? [closed]
Can anyone provide me with a complete mathematical proof about why an observer frame cannot surpass the vacuum speed of light?
I have looked for answers in Quora and FB groups but no one is really ...
0
votes
1
answer
574
views
Is the speed of light constant relative to the observer? [duplicate]
Is the speed of light constant relative to the observer?
Hypothetically, I am standing at the front of a train. The train is traveling 100 mph. I shine a flashlight pointing forward in the direction ...
-4
votes
3
answers
138
views
How is the speed of light constant in this situation?
Let's take an example, where A is a photon moving with the speed of light, and B is a car, that moves with half of the speed of light
At t=0, a kid in B(thinking that the car is not moving) observes ...
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