All Questions
Tagged with information faster-than-light
35 questions
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Have we observed any real-like phenomena faster than the speed of light in vacuum? [duplicate]
A common thought experiment about shadows ask, what would happen if a bat flew across a very, very distant star? The farther the star, the faster its shadow would move, and there's no reason it couldn'...
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1
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90
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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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1
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56
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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 ...
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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 ...
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8
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1
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Could information be transferred through a wormhole?
There was a paper published recently about the possibility of sending messages through a wormhole,see reference here. It has also been speculated that any entangled pair of particles—even particles ...
- 1,019
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Communication via entanglement [duplicate]
For years now i have in my haed a thought experiment for information exchange via quantum entanglement. And i am aware that something must be wrong with it but i can't figure out what it is.
The ...
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1
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Faster than light communication by entangled photons [duplicate]
Faster than light communication is not possible. If I measure the polarization of an entangled photon and it turns out to be right circularly polarized. In that instant, dont I know that someone ...
3
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1
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108
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Nonlocality of a bug on movie screen
I am currently learning quantum mechanics using Griffiths. In the appendix, he goes to talk about EPR and Bell's inequality, and that experimental verification of Bell's inequality rejects the "...
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4
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Faster than light information
I've seen there are a few answers on here previously about faster than light information travel, and my understanding is that it is impossible.
However, I've just read an article https://www....
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1
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1
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Example of information travelling faster than the speed of light?
In the following situation, information seems to travel faster than the speed of light. Is there a mistake in my reasoning?
Suppose we have an electric circuit. For times $t<0$, there is no current ...
- 1,502
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4
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Could the speed of causality be (significantly) faster than $c$?
The other day my son (13) asked me whether it was possible that light went very slightly slower than our best measured $c$, and at the same time had a very tiny mass, but we aren't able to measure ...
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Does "Superluminal travel of non-information" means we already "achieved" superluminal speeds?
From what I understood of Vsauce video talking about "Superluminal travel of non-information," the absence of information seems to travel faster than the speed of light, since we perceive ...
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4
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Contradictions caused by moving faster than light
There was a Joe Rogan episode with Brian Greene where Joe thinks aliens are watching us because the universe is infinite and there are an infinite number of them. So some of them must be watching.
...
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3
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2
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381
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Proof for impossibility of FTL Signals
Is there is formal proof for the fact that signals must always travel at a speed less than the speed of light in a vacuum?
I understand that special relativity dictates that for massive particles to ...
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2
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Moving a 2x2 the length of the solar system [duplicate]
If we were able to push a 2x2 piece of wood that is the length of our solar system, how would it behave? My colleague says since its all part of the same molecular structure, the whole piece of wood ...
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47
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Speed of light vs Tug of war [duplicate]
Suppose there's a "theoretical rope" that's 299 792 459 meters long in empty space.
The speed of light is 299 792 458 m/s.
Is it possible that if the rope is "tugged" on one end, ...
- 173
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2
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99
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Why can't light travel three days into the future then transmit that information back to us prior to us arriving at that position? [closed]
Example: If a football game between the Pittsburgh Steelers @ Tennessee Titans will happen in 3 days Sunday 10/25/2020 at 1pm, why can't light leave today 10/22/2020 and go to where the Earth will be ...
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2
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Exceeding the speed of light by means of a shadow, will we ever be able to transmit information faster than light? [closed]
I bumped into this:
Can a shadow move faster than the speed of light?
while trying to see if I could find out anything about what I'd been thinking for 2 years now.
Bear with me here, cause I'm only ...
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3
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87
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Speed Of light spot [duplicate]
Let us suppose I have an laser.I'm swinging my hand so that the spot of light moves in screen. Screen is at arbitrary distance so when I swing my hands the spot go up and down on screen, Now It is ...
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Why do physicists say information can't travel faster than light speed?
I often hear in physics videos light speed is the ultimate speedlimit two parts of the universe can communicate at, or even that speed of light is actual speed of causality.
Where does that notion ...
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4
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No FTL information implies no FTL travel?
The general consensus in the scientific community is that it is impossible to transmit information faster than light.
There is also speculation that it might be possible to open wormholes or travel ...
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How come no information can travel faster than light when we can measure a black hole's mass? [duplicate]
So I learned about the Schwartzchild radius, which is the radius of an object's event horizon. But how we define an event horizon is that it's a region of space where the gravitational acceleration ...
3
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1
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Can scatter interference patterns from entangled pairs carry information?
I am having problems wrap around why you can't send information faster than light with a similar setup to the quantum eraser experiment. ( https://arxiv.org/abs/quant-ph/9903047v1 )
What I mean is, ...
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Super Fast Message [duplicate]
It is known that a shadow can travel faster than the speed of light and break no known laws of physics, because it is not an actual thing. A shadow is just the blockage of light. However in the ...
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Superluminal clarification and FTL information transmission
Sixty Symbols recently released a video about superluminal motions (https://youtu.be/IsEDigUHsOQ).
This sparked a question I hadn’t considered before – although, I’m fairly sure it must be rather ...
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3
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Why cant information and forces travel faster than the speed of light when they aren't mass?
I understand why the speed of light is a constant in all reference frames, and the reason behind why the mass of an object increases as it approaches the speed of light.( Since the added energy has to ...
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Speed of Dark experiment, does it *really* travel faster than light? [duplicate]
I have seen many folks doing this Moon shadow experiment concluding that shadow from point A on the Moon can travel to point B on the Moon faster than light.
What I fail to understand here (and I am ...
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Sending information faster than light
If I could ever send my friend any information faster than light it would violate causality. If he just guesses the information and acts on it before he could ever receive it, everything is fine. What ...
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Why does the speed of light totally prevent instantaneous information exchange?
Based on the classical light-cone approach it's easy to see you can't transmit information faster than $c$ but why does the speed of light (as far as I know) treat information transmission in this way ...
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What do physicists mean by "information"?
On the question why certain velocities (i.e. phase velocity) can be greater than the speed of light, people will say something like:
since no matter or "information" is transferred, therefore the ...
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155
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Information faster than light? [duplicate]
Imagine that you have two typewriters on the other side of the galaxy. Their typebars are connected by ropes (stretched to the maximum), so anything you type will instantly appear at the second ...
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3
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800
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Quantum entanglement: does it necessarily imply superluminal information transfer? [duplicate]
From what I understand, information is communicated instantly between two quantum-entangled particles regardless of the spatial distance between them. However, does this necessarily imply superluminal ...
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Are Electromagnetic Waves The Only Means of Transmitting Information?
We've been using EMF to transmit energy (information) for over a century.
I was wondering is there any other way to send a message on long distances, even faster than EMF waves can travel? For example ...
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3
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330
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If a star were to suddenly dissapear, would it still have gravity? [closed]
I am wondering whether or not literally anything can travel faster than the speed of light. For example, if gravity from a star immediately ceases to have an effect if it suddenly and magically ...
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2
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155
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sending information over a wire--mechanically [duplicate]
Possible Duplicate:
Is it possible for information to be transmitted faster than light?
I've thought about this since I was a little kid. I know it isn't exactly feasible, but it still bothers me....
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