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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Why the spin 3/2 particle equation would violate causality?
I've recently come around the study of the so called Rarita-Schwinger equation for elementary particles of spin $3/2$.
The point it the article is really short, and no book treats the topic in a very ...
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Why can't quantum tunnelling carry energy or information faster than light?
A few experimenters have at one time or another claimed that quantum tunnelling allows the transfer of information or energy at superluminal speeds.
One was the idea that music was carried across a ...
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Spacetime that allows matter to rotate faster-than-light
Is there a solution to Einstein's equations which allows:
the object to be rotating at sub-light speed when viewed from within itself.
for a distant observer the object to rotate at superluminal ...
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Is the phase velocity of plane wave solutions of the Klein-Gordon equation larger than $c$?
The phase velocity is given by
$$ v= \frac{\omega}{k} \, .$$
Using the usual dispersion relation
$$ E^2 = p^2c^2+ m^2c^4 \leftrightarrow \omega^2 \hbar^2= k^2\hbar^2 c^2 + m^2c^4$$
yields
$$ v= \frac{\...
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Faster than light speed transfer of certain event
I am CS/Math person I am not quite sure what it means in physics
information cannot be transferred faster than light (FTL). I tried to understand the proof of no transfer theorem but I lacked the ...
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Observable Universe from two different perspectives
My layman understanding is that the universe is much bigger than that we can observe however due to the cosmological constant the observable universe is the matter etc. that is not moving away from us ...
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What're some criticisms of the paper "Six observations consistent with the electron neutrino being a tachyon with mass: mνe² = −0.11±0.016 eV²"?
Today I read about this paper making the case that neutrinos have imaginary mass and travel faster than light. I want to get excited, but I have no way to know how likely it is that this paper will be ...
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Relative speed when getting close to the speed of light
I was thinking about the relative speed of an observation reference frame and an object which has been accelerated to a speed close to the speed of light. I'm by no mean an expert and the last physics ...
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Can quantum field excitations propagate faster than light?
(Let's assume we are in the Klein-Gordon free field theory)
If we had e.g. a localised field configuration (i.e. field state which is a field configuration eigenstate) at $t=0$. (By localised field ...
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Do holonomic physical systems really exist?
According to Wikipedia on ‘Holonomic Constraints’:
“In classical mechanics a system may be defined as holonomic if all constraints of the system are holonomic. (...) a holonomic constraint depends ...
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What would a Natario Warp Drive look like, outside & inside the warp bubble?
Within a Natario Warp Metric, all mass in front of the ship is pushed outwards by it's negative energy density, this means no light would interact with the front of the ship at all. And since the ...
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Approach for calculating Alcubierre energy function?
NOTE: I know that the Alcubierre drive is on shaky ground and I'm not asking about its practicality or physical feasibility. I'm also not looking for answers like, "It's sci-fi so you can just make it ...
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Closed Timelike Curves and relatively stationary wormholes
Apologies in advance if this question is off topic, I wasn't sure if this was the most appropriate SE forum or not.
Wormholes are one of the most often cited examples of a possibility for faster than ...
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How do we know that light cannot travel faster than it does?
We assume the speed of light in vacuum is its maximum speed but can we not assume that it could be faster, or slower?
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Dark energy and gravitation force
This might be a silly question to ask but still I had to ask. we know that gravitational force between two galaxies are quite less as compared to the dark energy. so two galaxy are separated at speed ...
