A relatively recent discovery in the realm of physics, quantum entanglement is bizarre, eerie, mysterious, and seemingly magical. Albert Einstein shied away from the theory, calling it "spooky action at a distance." Since then, however, numerous experiments have confirmed this strange phenomenon. Basically, entangled particles can be separated from each other, over incredibly long distances--light years, in fact--and still mysteriously change when its partner is acted upon, almost as if there were an invisible umbilical cord connecting them. This seemingly conscious connection between entangled particles even occurs faster than the speed of light, a fact that made Einstein so leery about this possibility. The frontier of scientific discovery always has been a place of wonder, imagination, curiosity and delight, and never more so than in our time. This topic is very complex; this is only the most basic description of the phenomenon, and I am but an enthralled layman. That aside, it's incredibly fascinating--I suggest you take the time to learn a little about it! The ramifications of this discovery are very interesting--some even speculate that people can be entangled in a way, an incredibly fascinating ramification that only suggests something many of us believe anyway, though for different reasons.
Needless to say, the Universe is a big, strange and wonderful place.