Entanglement does not allow for information to be sent. It is used that way in Science Fiction, but in reality information cannot travel faster than the speed of light. There are some phenomena that do travel faster than the speed of light, but they are not useful for sending information.
Again, information is the key bit.
This is rather important since if information can travel faster than the speed of light, causality falls the hell apart and the universe basically wouldn't function in anything like a reasonable manner[1].
A greatly simplified explanation for why entanglement doesn't send information -
Let's say you have two electrons, A and B, and they are entangled. Quantum particles like electrons have certain measurable properties that are random, the most commonly used example is spin. Once a particle's spin has been measured, it will be the same on every subsequent measurement. Spin is either Up or Down.
So, to summarize, an electron has a property called spin. We do not know what an electron's spin is until we measure it, and once we measure it, the spin will not change. Basically it is a coin flip, and we cannot influence what the result is.
Two entangled electrons, this means if we measure electron A's spin, and it turns out to be Up, then if we measure electron B's spin it will also be Up. That is entanglement. (Note that you have to measure both, measuring A has no noticeable effect on B)
(The reverse of this is also true, if you measure B's spin, then A's spin will always be the same when measured)
Notice that we cannot control B's behavior, we cannot make it flash on and off or anything like that. All we can do is ensure that A and B both share the same random result. Again, the result is random! Random results are not information. We cannot use random results to communicate anything! Quantum Entanglement says basically "we know that if we measure particle A, that particle B's measurement will be the same". It is a bit more complicated than that, but from an information theory point of view, that is all that is important - Quantum Entanglement cannot be used to send information.
[1] If information can travel faster than the speed of light then thanks relativistic time dialation to you can just throw someone onto a fast moving aircraft and start sending information to the past. Honestly, and in all seriousness, if this was possible I'd expect high frequency traders to already be trying it.
> You are incorrect, no matter what pop science tells itself, these matters are not settled.
Causality is one way, or the universe makes no sense.
FTL information communication makes sending messages to the past trivial to implement. Outside of a Marvel movie, that literally breaks all of reality. Since reality isn't broken to pieces, and because we have a crap ton of evidence in favor of information being limited to the speed of light, we can safely assume that instantaneous information transfer isn't possible.
This is not one of those still under debate things, this is one of those things that people spent a century debating, and every "what-if" was tested and eliminated one by one until we were left with "information cannot travel faster than the speed of light"[1].
Some things CAN travel faster than the speed of light, but they do not contain useful information. This is a bit confusing, because outside of mathematics, and software engineers who actually paid attention in their theoretical computer science classes, we aren't used to thinking about information as a fundamental aspect of reality.
> Besides the qubit is a dead end, the future of quantum computing is quantum holography.
Quantum Computers will get us over the scaling problem we've ran into as a species with classical computing, but we are still algorithmically limited in what we know when it comes to solving certain problems. If a 64qubit computer existed tomorrow, we still wouldn't have AGI, although we'd have much better physics/chemistry/biology simulations which would help with a ton of fields.
[1] Even if, for example, a black hole instantly spits you out in some other part of the galaxy, it will do so by destroying you and emitting you as random radiation someplace else. Because that information is emitted randomly, there is no chance of reconstructing you.
How do you keep saying this regarding communication through time? You're going on about science fiction. Time dilation and "trivial communications backwards in time" are a stretch, though I am not placing limits in reality, only pointing out that it's nature is not fully worked out.
> How do you keep saying this regarding communication through time? You're going on about science fiction.
That is my point, if we assume instant communication of information is possible, then communication through time is possible. Since that is rather ridiculous, we can assume that instant communication is not possible.
Due to time dilation, people traveling on the international space station are actually traveling slower than we are. This isn't just a theoretical problem, GPS satellites have to account for time dilation.
This means people on the ISS are literally living a little bit "in the past".
Using this fun bit of physics, it becomes a pretty easy thought experiment to figure out a way to get people on rocket ship significantly out of sync with Earth time (just make the rocket ship go really fast for awhile) such that any information sent to the rocket ship, if it was sent using instantaneous communication, would create all sorts of horrible time paradoxes.
Again, this isn't some science fiction thing, this is a practical problem with faster than light communication, and it is a really strong commons sense argument for why information cannot travel faster than the speed of light.
Your account of the implications of time dilation is completely incorrect. It would be impossible for me to persuade you without a wall of text.
They are not "living in the past". Imagine two gears, one smaller and one larger. The smaller makes more iterations. The gears in the larger aren't rotating in the past, they are merely turning more slowly.
Your understanding of these matters is not accurate. You mistake your conventional learnings with truth.
(Everything you've regurgitated has been popularly conjectured for decades, I could have gotten your reply from Universe in a Nutshell or some similar pop sci anology.)
> They are not "living in the past". Imagine two gears, one smaller and one larger. The smaller makes more iterations. The gears in the larger aren't rotating in the past, they are merely turning more slowly.
I understand how reference frames work, and my point is your explanation falls apart if instantaneous communication is possible, because instantaneous communication breaks the entire idea of reference frames.
It doesn't make any sense to instantly send information from one reference frame to another. The entire concept just... like it isn't even a thing that can happen because it literally makes no sense.
Shove a ship into space with a magic instantaneous entangled data transmitter that is paired to one on Earth. Have the ship go really fast then land back a few hundred years in the earth's future compared to when it took off. If that ship uses its transmitter, information would be sent "back in time" on Earth, and that makes no bloody sense.
And I say magic entangled transmitter because it breaks all the laws of physics and common sense!
Information cannot travel instantly, reality falls to pieces if it does. There are circumstances we can come up with where random noise can travel faster than light, but that is the extent of it.
> It would be impossible for me to persuade you without a wall of text.
> (Everything you've regurgitated has been popularly conjectured for decades, I could have gotten your reply from Universe in a Nutshell or some similar pop sci anology.)
The strange part here is you are seemingly well read on the topic but you believe entangled particles can communications faster than light!
You are wrong. Instantaneous communications is possible, and the information would merely be sluggish (like a signal with a much longer sync rate) not go "back in time."
Besides, one cannot travel at the speed of light, that is science fiction. An ~80% clip is probably as fast, or comfortably fast as we will ever likely get (in a thousand years at our rate of development.)
And you're right, I am well read, and have fifteen years of experience communicating with disembodied jackasses through entanglement (and I've been on the other side of the world, these signals are not propagated classically.)
Good luck with your studies, don't let your certainties impair your learning.
Entanglement does not allow for information to be sent. It is used that way in Science Fiction, but in reality information cannot travel faster than the speed of light. There are some phenomena that do travel faster than the speed of light, but they are not useful for sending information.
Again, information is the key bit.
This is rather important since if information can travel faster than the speed of light, causality falls the hell apart and the universe basically wouldn't function in anything like a reasonable manner[1].
A greatly simplified explanation for why entanglement doesn't send information -
Let's say you have two electrons, A and B, and they are entangled. Quantum particles like electrons have certain measurable properties that are random, the most commonly used example is spin. Once a particle's spin has been measured, it will be the same on every subsequent measurement. Spin is either Up or Down.
So, to summarize, an electron has a property called spin. We do not know what an electron's spin is until we measure it, and once we measure it, the spin will not change. Basically it is a coin flip, and we cannot influence what the result is.
Two entangled electrons, this means if we measure electron A's spin, and it turns out to be Up, then if we measure electron B's spin it will also be Up. That is entanglement. (Note that you have to measure both, measuring A has no noticeable effect on B)
(The reverse of this is also true, if you measure B's spin, then A's spin will always be the same when measured)
Notice that we cannot control B's behavior, we cannot make it flash on and off or anything like that. All we can do is ensure that A and B both share the same random result. Again, the result is random! Random results are not information. We cannot use random results to communicate anything! Quantum Entanglement says basically "we know that if we measure particle A, that particle B's measurement will be the same". It is a bit more complicated than that, but from an information theory point of view, that is all that is important - Quantum Entanglement cannot be used to send information.
[1] If information can travel faster than the speed of light then thanks relativistic time dialation to you can just throw someone onto a fast moving aircraft and start sending information to the past. Honestly, and in all seriousness, if this was possible I'd expect high frequency traders to already be trying it.