Cornell University physicist N. David Mermin once described quantum entanglement as “the closest thing we have to magic,” since it means that disturbances in one part of the universe can instantly affect distant other parts of the universe, somehow bypassing the cosmic speed-of-light limit. Albert Einstein memorably dubbed it “spooky action at a distance.” Today, The Royal Swedish Academy of Sciences honored three physicists with the 2022 Nobel Prize in Physics for their work on entanglement. Alain Aspect, John F. Clauser, and Anton Zeilinger were recognized “for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.”
When subatomic particles interact, they can become invisibly connected even though they may be physically separated. So knowledge about one partner can instantly reveal knowledge about its twin. If you measure the state of one, you will know the state of the other without having to make a second measurement because the first measurement determines the properties of the other particle as well.
From ARS Technica, by Jennifer Ouellette – 10/4/2022