The gap I still have in my understanding:
One hypothesis is that there is no spooky action. One particle was 'always' going to resolve one way, likewise with the other. Like inspecting 'heads' on one side of a coin 'forces' 'tails' onto the other side.
I accept that this coin-hypothesis has been disproved by people who actually know what they're talking about.
But to me, this implies that you should build your spooky FTL message by transmitting "Measured" rather than heads/tails:
Have an array of 8 particles at both locations. They represent measured/unmeasured rather than heads/tails. You got yourself a one-way single-use FTL byte.
For this to not work (which I'm sure it doesn't) you'd need to be unable to distinguish between a measured/unmeasured particle. To me this is equivalent of being unable to prove that there is anything spooky going on.
So how can you have it both ways? How can you theoretically know that something was sent when measurement itself would destroy any evidence of something being sent?
Is entanglement real or is it just that two things happen to be aligned the same way and measuring them reveals how they always were?
Like if I gave two people red balls without telling them what the colour is. One takes it out and sees it is red, the other now instantly has a red ball. But they were always red. So there is no actual interaction between the balls, they were just set up in a pre-defined matching state.
To our observations the balls are in a quantum state (the balls are wrapped in paper you can’t see through) but they always had a specific state. We just weren’t capable of determining that state because the interior is invisible to us. The interaction would always have produced that outcome, so it appears like they are communicating when in reality it would happen regardless.
Most people don't understand enough about the fundamental properties of modern Physics.
What we usually call the speed of light is in fact the maximum speed of information propagation.
It is not about light, and you should think about quantum entanglement as a hidden variable, there is no magic there.
I read a book about particle physics and understood a very small amount of it. My understanding is that you cannot have faster than light anything because nothing can travel faster than light. For instance, the gravitational field of this coffee cup in my hand spans the entire universe. The cup is gravitationally attracting me, the Earth, the Sun, and every other atom in the universe (albeit at a remarkably low level of power). Even this gravitational field is not FTL though, because some particle exists that does the work of attracting. My cup is emitting gravitons or something like that, and those gravitons travel at the speed of light. A graviton leaves my cup, travels at the speed of light to Mars, and when it hits Mars, it attracts it.
What I am saying is that, in my understanding, there is no action that can occur without a particle that acts, and since no particle can travel FTL, nothing can happen FTL.
In the case of Quantum entanglement, mustn't some particle travel from the first quantum thing to the entangled quantum thing in order to have an effect?
I believe that my understanding is flawed! I don't know how to get a clearer view though. Any advice?
It makes me a little sad, because we're in this frustrating position of knowing how "effectively unlimited" the universe is, but also knowing how impossible it is to realistically explore it, at least not without a fundamental change to our understanding of physics.
I think it'd be cool to set up colonies on other planets, or hell, other solar systems, but the inability to communicate seems like a pretty hard blocker. I mean, even sticking to the solar system, will start taking six hours for the light to even reach earth from Pluto, assuming it can even have a direct path.
I don't know anything about physics, so I was hoping that the entanglement hypothesis might allow us to fix that, but clearly that wasn't the case. This makes me sad.
This is my two cents:
Maybe entanglement is a much more 'immediately physical' phenomenon than 'spooky action at a distance'. Just guessing as a layman here: maybe entangled particles are just physically connected {along some higher dimension / some unknown process}.
Spinning together (effectively switching spaces constantly) such that they are always the same state. So the undetermined measurement stems from being unable to tell which particle specifically you have at the time of measurement.
The idea of a particle's spin being 1/2 feels tied to this idea - (that a 720 rotation happens: if a particle P1 spins 360 in space A, spins 360 in space B before returning to space A, maybe entanglement is P1 and P2 filling space A and B to 'full'?)
In other words - detector A may receive particle B or A depending on the particle's current orientation at measurement.
Weird thoughts. Take with a lot of salt.
Can we simply tell that the entanglement was collapsed on the other end? That would be sufficient to transmit information. If planet x is habitable when I get there, I measure/collapse this specific particle, whose counterpart is back on earth in a detector named "habitable". When the detector fires on earth because this particle was measured/collapsed on planet x, people on earth know planet x is habitable. There's no need to know the outcome of the measurement, just the fact that it was measured/collapsed is information enough.
Another good article on this subject: https://bigthink.com/starts-with-a-bang/quantum-entanglement...
Transmission speed limit of quantum entanglement:
But what if we figure out a way to make a particle generator that is entangled to another particle generator?
Then we could generate particles from each that can be potentially entangled to the original system as well. Can it work that way?
If we keep looking at one bit there's probably not much we can do. But when we start looking at entanglement of systems then maybe some we learn about some phenomenon that makes this possible.
Excuse my ignorance, I'm not even a physics major so I probably spewed meaninglessness but I'd love to learn more from replies!
It's still not a very satisfactory explanation IMHO.
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"3 Body Problem" has so many problems!
Wake me up when the next "Expanse"-level sci-fi lands.
The problem with entanglement is obviously that it does not scale many-to-many, just like Erlang. You need Java to do many-to-many or C with a GC VM.
I’ve been working on quantum computing and quantum communication for 15 years now and what I really want people to know is that entanglement is “beyond classical correlation.”
Correlation which is not beyond classical is shaking up a shoebox with a pair of gloves in it, and having two people take the gloves far away from each other to then observe what hand they got. They then understand the hand the other has. There’s one bit of information here corresponding to which hand went to person A.
Entanglement is just this but “more.” You can’t communicate with a pair of gloves. Person A does not know when person B has realized person A knows what glove they have. Just the same, it does not matter who matters which of the two particles in a Bell pair first! Many quantum information theorists don’t even believe the wave function is “real” but just a mathematical tool for making predictions about measurement outcomes.
You should come at entanglement from this angle, because the main difference between the bell test and the pair of gloves is the state of the particles is undetermined before measurement, and the chosen measurements will result in different correlations between the measurement outcomes.