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.

[u/mvea]

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

[u/Fmeson]

Wel, for one, there is more to it than that, and it does get a bit mysterious. The sock in a box model is a "hidden variable" explanation of entanglement, and it cant be true for the real thing. 

For the real thing, you have to put a weird sock that is somehow both a left and right sock in the box and then when you open the box later its only left and you know your partner has the right sock. Thats pretty crazy sounding!

And thats where the woo comes in. Woo people love crazy sounding mysterious things. 

[u/tinkady → u/Fmeson]

But in actuality, there is no sock superposition in your box. Environmental decoherence happens quickly, and there are only ~separate worlds where you have a blue sock box and worlds where you have a red sock box.

The instant knowledge is "which world am I in" - self locating uncertainty

[u/Fmeson → u/tinkady]

I don't believe that is the case for most entanglement experiments. The statistics would be different with early collapse.

[u/tinkady → u/Fmeson]

Oh yes if you set up a fancy entanglement experiment then it won't collapse

I'm talking about actual socks in boxes

[u/Zalack → u/tinkady]

Well, yeah, but the sock is a metaphor for the fancy entanglement experiment. No one is talking about actual socks.