Is a pair of magic coins a good analogy for quantum entanglement?

[Runner 1]

[Sorry for asking so many questions by the way, but I enjoy learning ;) ]

I've always been kind of confused with quantum entanglement, and what it means experimentally, but I just read something that someone posted on another website:

You know, it's like if I had a pair of dice in two soundproof containers, one I would send to you, the other one I would keep. These dice are quantum entangled, so whenever I shake mine yours is shaken too, and the sum of both values is always 7, until one of us opens the box, then no shaking is possible anymore.

So I can shake to my heart's desire, the only thing you can find out by opening the box is that you have 2 and I have 5, or you have 4 and I have 3, but that does not really help either of us, because all you know is what random number I am going to see when I open the box. You can use this to say "when mine says 3 and yours 4 we'll meet and have a beer" but that information must be transferred beforehand, so no actual information transfer takes place. You just know what my dice says, but in reality you actually know what 7 minus your dice says.

Is this an accurate analogy to the situation with quantum entanglement? If so, this is probably the clearest explanation of it I've seen yet.

 

[Ken G]

Is this an accurate analogy to the situation with quantum entanglement? If so, this is probably the clearest explanation of it I've seen yet.

It's not a bad analogy, but it isn't the same thing as quantum entanglement. For one thing, any time you look at your die, the entanglement with the other die is broken for any future "shakes" or your die. But that can sort of be fixed by just shaking it once, without first looking at it-- as long as you don't take the analogy too seriously (shaking a real die would decohere any of its entanglements). It's just pretty hard to get a perfect analogy without it being the genuine article, so as analogies go, that one seems not too bad.