BRIAN GREENE: Star Trek has always made beaming, or teleporting, look pretty convenient. It seems like pure science fiction, but could entanglement make it possible?
Remarkably, tests are already underway, here on the Canary Islands, off the coast of Africa.
ANTON ZEILINGER (University of Vienna): We do the experiments here, on the Canary Islands, because you have two observatories. And, after all, it's a nice environment.
BRIAN GREENE: Anton Zeilinger is a long way from teleporting himself or any other human. But he is trying to use quantum entanglement to teleport tiny individual particles, in this case, photons, particles of light.
He starts by generating a pair of entangled photons in a lab on the island of La Palma. One entangled photon stays on La Palma, while the other is sent by laser-guided telescope to the island of Tenerife, 89 miles away.
Next, Zeilinger brings in a third photon, the one he wants to teleport, and has it interact with the entangled photon on La Palma.
The team studies the interaction, comparing the quantum states of the two particles. And here's the amazing part. Because of spooky action, the team is able to use that comparison to transform the entangled photon on the distant island into an identical copy of that third photon.
It will be as if the third photon has teleported across the sea, without traversing the space between the islands.
ANTON ZEILINGER: We, sort of, extract the information carried by the original and make a new original there.
BRIAN GREENE: Using this technique, Zeilinger has successfully teleported dozens of particles. But could this go even further?
Since we're made of particles, could this process make human teleportation possible one day?
ATTENDANT: Welcome to New York City.
BRIAN GREENE: Let's say I want to get to Paris for a quick lunch. Well, in theory, entanglement might someday make that possible. Here's what I'd need. A chamber or particles here in New York that's entangled with another chamber of particles in Paris.
ATTENDANT: Right this way, Mr. Greene.
BRIAN GREENE: I would step into a pod that acts sort of like a scanner or fax machine. While the device scans the huge number of particles in my body—more particles than there are stars in the observable universe—it's jointly scanning the particles in the other chamber. And it creates a list that compares the quantum state of the two sets of particles. And here's where entanglement comes in. Because of spooky action at a distance, that list also reveals how the original state of my particles is related to the state of the particles in Paris.
Next, the operator sends that list to Paris. There they use the data to reconstruct the exact quantum state of every single one of my particles.
And a new me materializes.
It's not that the particles traveled from New York to Paris. It's that entanglement allows my quantum state to be extracted in New York and reconstituted in Paris, down to the last particle.
ATTENDANT: Bonjour, Monsieur Greene.
BRIAN GREENE: Hi, there.
So, here I am in Paris, an exact replica of myself. And I'd better be, because measuring the quantum states of all my particles in New York has destroyed the original me.
EDWARD FARHI: It is absolutely required in the quantum teleportation protocol that the thing that is teleported is destroyed in the process. And you know, that does make you a little anxious.
I guess you would just end up being a lump of neutrons, protons and electrons. You wouldn't look too good.
BRIAN GREENE: Now, we are a long way from human teleportation today, but the possibility raises a question: is the Brian Greene who arrives in Paris really me?
Well, there should be no difference between the old me in New York and the new me, here in Paris. And the reason is that, according to quantum mechanics, it's not the physical particles that make me me, it's the information those particles contain. And that information has been teleported exactly, for all the trillions of trillions of particles that make up my body.
ANTON ZEILINGER: It is a very deep philosophical question, whether what arrives at the receiving station is the original or not. My position is that, by "original" we mean something which has all the properties of the original. And if this is the case, then it is the original.
JOHN CLAUSER: I wouldn't step into that machine.
BRIAN GREENE: Whether or not human teleportation ever becomes a reality, the fuzzy uncertainty of quantum mechanics has all sorts of other potential applications