I trust Yudkowsky on many things, but not on that explanation. It's still quite complicated, and a couple of times I miserably failed to reconstruct it over a beer or two. A red flag.

Plus, I'd rather expect at least one professional (QED) physicist exists able to explain it and he isn't one. Mermin is, but the explanation is decidedly less clear.

BTW I came here to say Bell's inequality as well. For me it's as baffling as science could ever be.