In real experiments recently, Dr. Farhi told the movie fans, physicists had managed to "teleport" a single elementary particle, a photon, which transmits light, about one and a half miles, "a little less exotic than what you see in the movie." What is actually teleported in these experiments, he explained, is not the particle itself but all the quantum information about the particle.

To accomplish this is no small matter. Among other things, the teleporters have to create a pair of so-called entangled particles, which maintain a kind of spooky correlation even though they are separated by light years. Both of them exist in a kind of quantum fog of possibility until one or the other is observed. Measuring one particle instantly affects its separated-at-birth twin no matter how far away. If one is found to be spinning clockwise, for example, the other will be found to be spinning counter clockwise.

In order to use this magic to "teleport" a third particle, Dr. Farhi emphasized, you have to send a conventional signal between the entangled twins, and that takes time, according to Einstein. "You cannot get that thing over there faster than the speed of light," Dr. Farhi said, to cheers from the crowd.

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Dr. Tegmark said that even inaccurate science fiction movies could inspire scientists to think. You could see something that you think is impossible, he said, but that might start you thinking. "Why is that impossible? It can trigger a train of thought," he said.