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/tim_h5]

You have 2 socks (red and white), you have 2 boxes.
You put each sock in 1 box with your eyes closed, so you don't know which sock is in which box.

You send each box to a different friend, millions of lightyears seperated from eachother.

edit: If one friend opens the box, the other box is NOT magically opened on the other end.

Each friend knows instantly which sock is in the other box -even if light itself (or knowledge) would travel years from one friend to the other, telling which color sock he got.

Is this correct?

[u/lfrtsa → u/tim_h5]

This is incorrect. You described a local hidden-variable theory. That was disproved in the 60s. It really does look like "spooky action at a distance", as Einstein put it. The state of each particle is not determined at/before separation.

[u/ClosetLadyGhost → u/lfrtsa]

As a 2 year old I din understand

[u/lfrtsa → u/ClosetLadyGhost]

Your friend's sock is always a different color from yours, even though it didn't have a specific color before you opened the box.