Ordinary entanglement is having a strange pair of coins. Toss them both and they will never come up both heads or both tails. Give one to a friend, walk to the

Ordinary entanglement is having a strange pair of coins. Toss them both and they will never come up both heads or both tails. Give one to a friend, walk to the ends of the earth, toss the coin, then call your friend: comparing notes, they've come up different again... spooky! Maybe the coins colluded when they were made, and there's no spooky action at a distance, just some hidden information inside the coins. This is what the Bell tests disprove. You can make a series of measurements that result in data that could not have been agreed upon by the coins ahead of time. (In quantum mechanics, the entangled particles are never perfectly correlated or anticorrelated like this, but they coincide or not at a rate much different than ordinary particles)