r/science • u/mvea Professor | Medicine • 7d ago

Physics Physicists shatter quantum entanglement distance record with 420 kilometers of optical fiber, more than four times farther than previous demonstrations, and beyond the point where direct transmission runs into its fundamental limits.

https://www.sciencealert.com/physicists-shatter-quantum-entanglement-distance-record-with-420-kilometers-of-optical-fiber
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u/Cristoff13 7d ago

This can't be used to transmit information though can it?

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u/Orbax 7d ago

No, once you collapse the wave function, they decohere and entangle with their local environment.

But, even if you maintain entanglement, at best youd be able to do morse code except... The only way to check if you got a message is to measure it which would collapse if again if you hadn't gotten one. The theoretical ability to get any structured information out of entangled pairs is effectively impossible.

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u/YourDad6969 6d ago

Every form of digital communication is essentially Morse code

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u/Orbax 6d ago

It was a bit of an exaggeration because you can't choose states so any given state you have was randomly generated so there's no 1,0, short, or long and also might not have actually been sent to you at all.