What's needed to use quantum entanglement for FTL data transfer?

[Orenshved]

Hey all, I need help with the book I'm currently writing.
What would it take (even theoretically) to use quantum entanglement for FTL data transfer? From what I understand, the state of entangled particles can not be changed without breaking the entanglement.
Do you think this would ever be possible? Or does everything about it break the laws of physics? (which could still be fine in a SciFi book, especially if it breaks Newtonian physics, but not Quantum physics).
Thanks.

 

[Buzz Bloom]

In writing SF you can violate any laws of physics you need to for the benefit of the story. Physics as understood today says FLT of data transfer in impossible. There are some very good stories by Ursula Le Guin with no FTL travel but with FTL messages.

 

[Orenshved]

In writing SF you can violate any laws of physics you need to for the benefit of the story. Physics as understood today says FLT of data transfer in impossible. There are some very good stories by Ursula Le Guin with no FTL travel but with FTL messages.

True, but what I'm going for here (since this technological leap happened during the plot), is a way to say something other, and hopefully more interesting than "they figured out how to transfer FTL data."

 

[Jarvis323]

True, but what I'm going for here (since this technological leap happened during the plot), is a way to say something other, and hopefully more interesting than "they figured out how to transfer FTL data."

The following is the way I imagine it would work if it were possible.

What you would need is a way to bias the outcome of the measurement on one end. That way the measurement will force the other entangled particle into a particular state with a probability greater than if the measurement of the other particle hadn't happend.

Then, you would have to have first sent over a large cache of entangled particles and have designed a protocol so that each side knows when to look/observe.

Since it would be statistical in nature, you'de probably want to make hundreds of measurements to deterime the statistical distribution and determine if that indicated that the paired particles on the other side had been measured or not. Then you have essentially a bit of information you get out of that, and you do it repeatedly, and so long as you have synchronized properly you would get a bit stream.

Note you would have to first have sent over the particle cache so your up front cost is limited by the speed of light.

 

[Vanadium 50]

Or does everything about it break the laws of physics?

Yes.

You might as well talk about FTL radios, or FTL carrier pigeons.

 

[Jarvis323]

Note that laws of physics are not necessarilly right, and we constantly are finding we've been wrong about things. It's perfectly realistic for something to end up being possible even if we had thought previously it was impossible.

In other words you can always invent a physics breakthrough to make something possible in the fictional universe.

 

[GTOM]

Well while right now, the consensus is that we can't do that, but some experiments are pretty interesting.
Like direct counterfactual communication that used Zeno effect together with entanglement.
If there is any way to make a difference between normal state of an entangled set and the state of altered set when the other side gave a special info to it, that is a single bit.

 

[GTOM]

https://www.scientificamerican.com/...ze-quantum-effects-with-entangled-drum-duet1/

 

[PeroK]

Note that laws of physics are not necessarilly right, and we constantly are finding we've been wrong about things. It's perfectly realistic for something to end up being possible even if we had thought previously it was impossible.

What was the last significant impossible thing that became possible?

It was possible to exceed the speed of light until 1905. And the Heisenberg Uncertainty Principle made some things impossible that had previously been possible. So, it cuts both ways.

 

[Nugatory]

What would it take (even theoretically) to use quantum entanglement for FTL data transfer?

Theoretically it’s impossible. If you mean “hypothetically”, it is possible, you just need the hypothesis that the theory of quantum mechanics is wrong in some way; and for fiction the details of the hypothesis aren’t as important as advancing the plot.

Note that any form of FTL data transfer leads to all the problems plot opportunities of FTL travel: reverse causality, time travel paradoxes, tachyonic anti-telephones (Google for that), and the like. FTL data transfer won’t let you go back in time to kill your parents before you’re born, but it will let you hire a hitman who will create that messy paradox for you.

 

[Nugatory]

https://www.scientificamerican.com/...ze-quantum-effects-with-entangled-drum-duet1/

And to quote that article, “We’re not discovering anything new about quantum mechanics here”. These experiments aren’t suggesting new opportunities, they are further reinforcing our already well-supported belief that quantum mechanics is an accurate description of how the universe works.

 

[GTOM]

And to quote that article, “We’re not discovering anything new about quantum mechanics here”. These experiments aren’t suggesting new opportunities, they are further reinforcing our already well-supported belief that quantum mechanics is an accurate description of how the universe works.

https://bigthink.com/surprising-science/breakthrough-quantum-entanglement-heisenberg

" This effect allowed the team to measure both the positions and the momentum of the virtual drumheads at the same time. "One of the drums responds to all the forces of the other drum in the opposing way, kind of with a negative mass," Sillanpää explained.

Theoretically, this should not be possible under the Heisenberg uncertainty principle, one of the most well-known tenets of quantum mechanics. "

Yes i know bigthink isn't the most reliable one, but this experiment still signals that we can entangle more and more particles and make more observations about them.

https://www.sciencealert.com/scientists-have-finally-achieved-direct-counterfactual-quantum-communication#:~:text=Direct counterfactual quantum communication on the other hands,when an unstable quantum system is repeatedly measured.

While this don't talk about ftl but really interesting.

I don't want to predict anything, but at this point i can't say i am total sure theese things can't lead to be able to make a difference between whether the other side altered the state of the observed entangled objects or not.

Sorry i know no personal speculation but i am uncertain, whether something can become observable that we can't observe know, and the point that entanglement arent used for signalling is unable to observe the effect to gather useful information. (Without compare measurements on both sides of course)

 

[Nugatory]

Theoretically, this should not be possible under the Heisenberg uncertainty principle, one of the most well-known tenets of quantum mechanics. "

That part starting with the word “Theoretically” is not quoting the experimenters (who know what they’re talking about) , it’s the author of the article trying to explain and getting it wrong. It’s a safe bet that the author doesn’t know what the uncertainty principle is.

 

[BWV]

Read one book (relative recent but forget the name) where the premise was entanglement allowed instantaneous teleportation from the standpoint of the traveller, but the actual time for an outside observer was at light speed - so traveling 50 LY was instantaneously for you but took 50 years outside your reference frame. As others said, who cares if it’s outside known physics, it made for interesting plots with massive ‘time travel’ into the far future - much like Alaistar Reynolds whose books contain no relativity violations, the only magic being ships that can accelerate at 1G as long as they like.

Sad truth is interstellar travel is likely an impossible endeavor, but still fun to imagine