美国国家公共电台 NPR Beam Me Up, Scotty ... Sort Of. Chinese Scientists 'Teleport' Photon To Space（在线收听）

DAVID GREENE, HOST:

I mean, let's listen to this.

(SOUNDBITE OF TV SHOW, "STAR TREK: THE ORIGINAL SERIES")

JAMES DOOHAN: (As Captain Montgomery Scott) Ready to transport.

WILLIAM SHATNER: (As Captain James T. Kirk) Energize.

D. GREENE: Yes, the familiar sound of "Star Trek." You know, beam me up, Scotty. Well, I mean, it's total fantasy, right? Or is it? A few days ago, a team of Chinese scientists announced that they pulled off a successful teleportation. It involved a photon going from Earth into space. But quantum physics experts are telling us that we should not be all that excited about this, which is kind of sad because I was getting pretty excited about this.

Brian Greene - no relation I'm aware of at least - is a professor of physics and math of Columbia University. And he is going to explain all of this for us. Professor, thanks for coming on.

BRIAN GREENE: My pleasure.

D. GREENE: So this is not like "Star Trek"?

B. GREENE: Well, it's somewhere in between. In "Star Trek"...

D. GREENE: Oh.

B. GREENE: ...Of course, we're teleporting people. We're teleporting objects of everyday life. Here, we're just teleporting individual, single particles. But honestly, you should be hugely excited about that.

D. GREENE: OK.

B. GREENE: It's crazy, wonderful thing that we can do this.

D. GREENE: Well - so this is a photon that teleported. What exactly is a photon for people who aren't familiar?

B. GREENE: A photon is a little particle of light.

D. GREENE: OK.

B. GREENE: So in some sense, it's the smallest bundle or packet of light that there is.

D. GREENE: And this thing literally traveled in some very short amount of time over many, many miles.

B. GREENE: No, that's not quite right.

D. GREENE: OK.

B. GREENE: This kind of teleportation does not involve the object that you're teleporting literally traveling from the origin to the destination. Instead, what actually travels is the information describing the state of that particle. That's what travels from the start line to the finish line.

D. GREENE: So is this all that different than, say, encrypting information and sending something quietly and secretly across the internet to some other city?

B. GREENE: Well, in a sense, it is because here, there is a channel which is only possible because of the laws of quantum physics. You see, what the Chinese did was, they had two photons, one on the ground and one on the satellite that are so-called entangled. And entangled particles have a weird connection. Einstein called it spooky action.

D. GREENE: (Laughter) OK.

B. GREENE: Whatever you do to the photon, say, on Earth immediately affects the photon up on the satellite. And that's what allows the information of a third photon that you want to teleport to be transmitted from Earth to the satellite effectively instantaneously.

D. GREENE: Let me just make sure I understand this. It is sounding like the implications here are not necessarily that I'm going to be beamed up by Scotty like in the movies, but there could be almost an arms race in terms of being able to send secret information, which could be used for spying, espionage. I mean, has China does something kind of scary here when it comes to intelligence work?

B. GREENE: I should say that others have performed this teleportation before the Chinese. What the Chinese have done - they have executed this teleportation over the longest distance to date. But there is a security issue here because the first country to really build a quantum computer or quantum internet - they will be able to send effectively unhackable messages, and then they can even use the technology to try to hack into more conventional messages.

D. GREENE: And in terms of caring about one day being able to teleport or escape a terrible situation, like a dinner party you don't want to be at - does this take us any closer to being able to do that?

B. GREENE: Yeah, but don't hold your breath. I mean, it's an infinitesimal step.

D. GREENE: Brian Greene is a professor of physics and math at Columbia University and joined us on Skype. Professor, thanks so much.

B. GREENE: My pleasure.

(SOUNDBITE OF ALABAMA SHAKES SONG, "SOUND & COLOR")