All Questions
Tagged with faster-than-light special-relativity
387
questions
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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
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- 4,783
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0
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58
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Faster than the Speed of Light with No Cerenkov Radiation
A charged particle in vacuum and stable motion would induce a time-variant but non-radiating electromagnetic field, whose pattern moves at exactly the particle's speed, but in a medium with lower ...
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2
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129
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Can a non-local theory be consistent with special relativity?
If there was a non-local theory that explained quantum entanglement correlations, does it follow that it would violate special relativity?
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1
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1
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130
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Does the no signalling theorem in quantum mechanics beg the question?
I had always thought similarly and then came across a paper here that argues this.
The abstract is as follows:
Many authors state that quantum nonlocality could not involve any controllable ...
0
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1
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52
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Do superluminal shadows drop the local temperature on distant objects?
There are lots of examples online of the scenario of someone with sufficient machinery casting a shadow of their thumb on the moon. It's argued the shadow travels faster than light, instantaneously ...
- 31
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3
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150
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Two-way tachyonic anti-telephone
Consider the two-way tachyonic antitelephone where the speed at which message is transmitted is $a$. A person $A$ sends a message to $B$ which is moving away with a speed of $v$ with respect to $A$. ...
- 1,200
3
votes
3
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356
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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
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3
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134
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Faster than light is possible? [duplicate]
I know that some particles can go near or more than half the speed of light. So, say we shoot two particles in opposite directions at more than half the speed of light. Say one is moving at 50% the ...
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1
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Lorentz transform causes Faster than light motion for Spacelike-separated object?
Consider a 5-meter rod which exists on the x-axis of a frame of reference:
Now consider an observer moving at a velocity $0.1c$ relative to this reference frame, from right to left. Their frame of ...
-4
votes
1
answer
86
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FTL Communication using Quantum Entanglement (A new Approach) [closed]
Ok i have a proposition:
Imagine there are two people 1 on earth and other in space.
They syncronised their clocks before they left earth and agreed that they will factor in time dilation and ...
1
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1
answer
149
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How does a refractive index of less than one not violate relativity?
If I am not mistaken, this video says that X-rays travel faster in glass than in a vacuum. Special Relativity says that information can not travel faster than the speed of light in a vacuum, so what ...
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2
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Are there cases in quantum field theory's formalism were virtual particles are allowed to exceed the $c$ speed limit?
Virtual particles even today contrary to the overwhelming evidence in my opinion that they have a real effect on normal particles (i.e. Casimir effect, $g-2$ muon Fermilab experiment) are considered ...
- 4,170
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79
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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{\...
5
votes
1
answer
361
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Stuck on thought experiment about light [duplicate]
Say we have a very long fluid pipe with the width of a few astronomical units, and that this pipe is perfectly resistant to sustain the stress of a perfectly incompressible fluid going through it ...
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0
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19
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If a photon travelled in the opposite direction of another photon [duplicate]
If a photon travels in the opposite direction as another photon, then what is the speed of the second photon relative to the first. Is it 2 times the speed of light? Also what if two photons travelled ...
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