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.
947
questions
0
votes
1
answer
52
views
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
0
votes
3
answers
192
views
How do non-local correlations occur in QM without a cause? [closed]
The Copenhagen interpretation of QM ultimately amounts to asserting that non-local correlations occur without a cause since that cause would involve propagation of information faster than the speed ...
user398827
0
votes
1
answer
40
views
What are the implications of the EPR bridge information metric being invariant under all conditions, including distance in this universe?
What if the reason why instantaneous state information is able be transmitted between entangled particles through an EPR bridge is that the metric that this is conveyed in is invariant under all ...
- 207
5
votes
1
answer
90
views
Would the effective speed of an Alcubierre drive be limited by the propagation speed of gravity?
The idea of a warp drive is to "expand space behind the ship and contract it in front"- in this way reaching a target destination faster than one could conventionally. However, the actual ...
- 87
0
votes
3
answers
150
views
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
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
-4
votes
2
answers
102
views
Can we use the fabric of spacetime to go faster than the speed of light?
If the fabric of spacetime isn't bound by the limit of the speed of light (the universe is expanding faster than the speed of light), could humans somehow wrap a spaceship in a bubble of the fabric of ...
-1
votes
1
answer
114
views
How can resolution of particle entanglement be detected, and why can't it be faster than light communication?
Sorry for the length, but this is driving me crazy. And yes, there are other questions on this issue and I have reviewed them, but I cannot see the answer stated simply. What is different about my ...
- 11
0
votes
1
answer
51
views
Speed in a medium
Let's say, that there is medium, where the speed of light is $10^8 \, \rm m/s$. So in that medium if there exists a particle that is moving through without any hindrance what would be the speed limit ...
- 151
0
votes
3
answers
134
views
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 ...
- 11
3
votes
2
answers
252
views
How does the "York time" measure the expansion of space; why is it equal to the divergence of the comoving observer's four velocity for warp drive?
The mysterious York time, θ is important in warp drive topic. It is plotted on the famous diagrams and is considered the measure of the mechanism that "drives" the warp drive bubble at ...
-1
votes
4
answers
122
views
Quantum entanglement and speed of transmitting information [closed]
Imagine Alice and Bob have two pairs of entangled particles, pair A, and pair B. Imagine they have agreed beforehand that pair A measurement preceding pair B measurement constitutes a bit with value 1 ...
0
votes
0
answers
68
views
About information transmission speed [duplicate]
Einstein says information cannot be transmitted faster than light.
Say I set an alarm that ring at 9:00 am. I go to school, and wait until 9:00 am. Then I tell my friends that my alarm rang. If the ...
- 49
0
votes
2
answers
108
views
Can entanglement witnesses on GHZ states with $n > 2$ violate the non-communication theorem?
In experiments involving entangled photons, measuring entanglement in systems with more than two particles ($n > 2$) often employs one photon as a herald to distinguish signal photons from noise. ...
3
votes
1
answer
109
views
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 ...
- 131