Questions tagged [faster-than-light]
"Faster-than-light", also known as superluminal velocities, refers to any sort of travel at a speed greater than the speed of light. Prohibited in mainstream physics due to the Special theory of relativity.
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How can quantum entanglement not be non-local?
I know this kind of question has been brought up many times.I have read many posts here regarding this but I still have a problem with a certain aspect of it so please bear with me.
Lets consider the ...
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Would Doubly Special Relativity or Mach's Principle allow faster-than-light travel to occur without violating causality?
Doubly Special Relativity posits that the Planck length is the same in all reference frames. Mach's Principle posits inertia is produced by the combined mass of the universe.
From my limited ...
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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 ...
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Why is FTL travel impossible if the universe expands FTL?
If the universe is expanding spacetime faster than light (FTL), is FTL travel no longer completely impossible?
Do not care about energy requirements or needing new tech, just if it is NOT physically ...
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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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Please help me with this paradox [closed]
Physicists believe that some galaxies are moving away from us at faster than the speed of light. A galaxy that is moving away from us at faster than the speed of light would be moving backwards in ...
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How would wormhole-based FTL violate causality?
We already have an answer why physically traveling faster than light would violate causality (the clock on board our hypothetical FTL spaceship would tick backwards to some outside observers).
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Could a delayed choice Aharonov-Bohm experiment be used for FTL information transfer?
Tim Maudlin about a delayed choice Aharonov-Bohm experiment, the section between 1:35:00 and 1:38:30
In the interview above Tim Maudlin mentions some sort of delayed choice Aharonov-Bohm experiment. ...
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Whats wrong with concept of "faster than light" information transfer device? (not about technical implementation, just about theory) [closed]
Yesterday, while lying in bed, an idea came to me, and I don’t understand why it won’t work?
Setup:
1.1) Two infinite stores of entangled pairs of photons, each connected to a double-slit device.
1.2)...
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If the speed of causality changes, could you go FTL?
In the middle of some research, I reached a sort of confusion that I’d like to sort out. In flat space FTL is impossible, because in a Minkowski metric,
$$\mathrm{d}s^2=c^2 \mathrm{d}t^2-\mathrm{d}x^2-...
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Can quantum entanglement travel faster than the speed of light? [duplicate]
Recently I was watching a video on quantum computing where the narrators describe that quantum entanglement information travels faster than light!
Is it really possible for anything to move faster ...
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The choice of measurement basis on one half of an entangled state affects the other half. Can this be used to communicate faster than light?
It is often stated, particularly in popular physics articles and videos about quantum entanglement, that if one measures a particle A that is entangled with some other particle B, then this ...
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Transmitting Data faster than the speed of light using entangled particles [duplicate]
If we have a pair of super-asymmetrical entangled particles, and move them a light year away so that they retain their quantum entanglement, and we set a clockwise spin (or vertical polarization) as 0 ...
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Does the fact that we are able to see CMBR implies that universe expanded faster than light?
Supposedly, the universe underwent rapid expansion immediately after the big bang, surpassing the speed of light. If we can detect remnants from that era, does this suggest they moved faster than ...
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Causality and processes in QFT
We have virtual particles in quantum field theory (QFT). In general, they don't have the need to obey causality.
My question is:
Do the processes in QFT (electron self-energy, photon self-energy, ...
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