Chinese Physicists Teleport Photons Over 100 Kilometers

Popular Science ^ | May 11, 2012 | Dan Nosowitz

[Innovative]

Teleportation, sci-fi-y as it sounds, is actually not fictional or even new; two years ago, Chinese physicists broke the then-current record for quantum teleportation by teleporting photons over 10 miles. But a new effort from that same team demolishes that record, beaming the photons over 97 kilometers.

The physicists, working from the University of Science and Technology of China in Shanghai, have again taken advantage of quantum entanglement for the purposes of moving an object from one place to another without ever moving in the space between. According to Technology Review, "The idea is not that the physical object is teleported but the information that describes it. This can then be applied to a similar object in a new location which effectively takes on the new identity."

The task uses a 1.3-watt laser "and some fancy optics" to beam those photons and retrieve them at the final location. The trick seems to be maintaining the photons' information, since the beam widens over space, but eventually teleportation of this sort could be used to beam information incredibly quickly up to satellites.

[count-your-change]

Now if they can transport a futon that would be news.

[FredZarguna]

In principle, all that is required is that the particles be quantum mechanical particles. Neutrons are not proscribed.

Unfortunately, though they appear similar (despite the fact that no two have a heater that works -- or fails to work -- in quite the same way) Volkswagons are not indistinguihable particles, so a single state vector cannot describe a system composed of two VW's. This makes them ineligible for QT.

[FredZarguna]

I'm just an old ex-cotton chopper/picker with an eitght grade educakion.

A transparent attempt at deception, since true cotton-pickers use the word "edumacashun."

But I have often thought the simplest way (ha, that's an oxymoron) to do such was gather all the information down to the subatomic structure of an object, transmit it and reconstruct a clone of the object elsewhere. IE: a clone

Again, betraying your false pretense at ignorance by correctly describing exactly what is done.

The key thing to understand is that in a very deep sense every quantum particle in the universe is indistinguishable from every other. Quite profoundly, two photons (for example) are identical in a way that two identical ball-bearings, or two identical twins are not. Thus when a photon is cloned on the other side of the universe, it is -- for all material purposes -- exactly the same as moving the original photon there.

Now "just" repeat that process for every electron, neutron, and proton in a person's body, and you have moved him across the universe.

[Museum Twenty]

Hello — OK, so maybe it shouldn’t include the syllable “port”? To me, “porting” means moving something, with or without “tele”.

If you have the same program open twice on a PC, it is considered Multiple Instances. That sounds like what this is.

An instance is an occurrence of an object, regardless of how many times the object occurs, with identicality being implied/assumed thanks to Spooky Action.

The quick verb could be “Spooky”, meaning make another instance of something (wherever).

If I have item X in New York, and want it to also be in London, I could “Spooky” it to London. And, by Spooky Action (no transporting involved), it is there. And, in London, it is equally as X as it is in New York.

I do not pick up from the article that the original in New York would disappear. In fact, it is not relevant unless the Effect of Spooky Action continues past creation, which is not, as I can tell, herein implied.

If the Effect of Spooky Action were continued past creation, the items could be considered “Haunted”.

I believe the items actually are Haunted in Theoretical Quantum Mechanics, but we haven’t done that in the laboratory.

Also, in cases where there is Haunting, which Instance inherits change (via Spooky Action) from which, if they are Identical? Would change occur in either direction? Sounds like conflicts would occur. And what if one Instance is destroyed?

Also #2: There doesn’t seem to be a limit on the number of instances. If New York & London, why not Paris & Munich?

[A.Hun]

Now if they can transport a futon that would be news.

That actually made me laugh out loud!!

[count-your-change]

From an old MAD magazine bit about Captain Kirk and futon torpedoes.

[Mycroft Holmes]

That is a succinct, crisp presentation of the Current Standard Model. Nicely done. Bravo!

I, for one, welcome our new Entangled Overlords /.

[Gadsden1st]

Does this mean we now have two dead cats?

[Mycroft Holmes]

Does this mean we now have two dead cats?

No, one live and one dead cat. They are complementary.

[Cringing Negativism Network]

“Teleporting photons”?...

When I was in boy scouts, i teleported photons all the way to the surface of the moon, with my green BSA flashlight.

This is Chicoms, bragging about being Chicoms.

Commie nonsense.

[Gadsden1st]

Then if we did this to Obama, we could vote for him.

[Mycroft Holmes]

Then if we did this to Obama, we could vote for him. (re: Clone dead/alive cat.)

Isn't that how we got Romney?

[Hot Tabasco]

Teleportation is a cool idea, I mean, what could go wrong?

[Future Snake Eater]

You’re talking about quantum encryption. Yes, we’ve been working on that for many years now.

[trebb]

Maybe the original is destroyed as it is codified and the new code “creates” the “teleported” version. Can’t think of how why ecept for the fact that nothing is truly destroyed/created (other than wht God accomplished), but all springs from other forms and changes to other forms.

[wally_bert]

I will have to look for a copy.

[Black_Shark]

Umm.... I think I understand why I went into Econ and not Physics ;)

That pretty much went right over my head.

“However, since an observer at distance cannot know the state of our “nearby” photon (which is remote from his point of view) without exchanging state descriptions with us, there is actually no information being transmitted until an ordinary radio transmission (or pony express rider, or some other conventional information process) actually verifies the content. Roughly, the particles “know” they have been changed (”spooky action at a distance,” in Einstein’s words) but this knowledge cannot do anyone any good until ordinary messages can be exchanged. “

How do particles “know” if they are not sentient?

[FredZarguna]

But it *is* teleported. A “cloned” quantum particle with the same wavefunction is not different in any material sense; your analysis is mistaken because you are thinking as if these photons are classical particles. They are not. Because they are entangled there is really no way to know which one is “here” and which one is “there.” Both particles are actually in both places and neither particle is in either place. There is only a state vector which describes both of them until we do an experiment that subsequently untangles them.

[FredZarguna]

It’s just an analogy. They are not self-aware. It’s just a shorthand for saying that the the wave function of the entangled system is changed. This has effects within the system which cannot be observed until a subsequent experiment is done.

[FredZarguna]

That you have (or have not) two dead cats was never the point. The point was that you ostensibly have a cat (or two cats, or N-cats) that are in a state of neither "aliveness" or "deadness." Contrary to what is printed in the popular literature, a number of physicists have had a lot of problems with Schroedinger's Cat over the years, including the question of whether the state of being alive or being dead even corresponds to an "Observable," in the quantum mechanical sense. Or if the cat's own self-awareness (cats are not particles, after all) fundamentally changes the experiment and so on.

Einstein had a much better analogy for mixed eignestates, and his version had no cat and did not involve potentially problematic metaphysical questions about whether there is a bounded Hermitean operator corresponding to "Life" or "Death." In his paradox, there is a keg of gunpowder in Schroedinger's Box. The question then becomes, when a quantum of radiation is introduced, is the gunpowder in an (un)exploded state or a mixed state of the two?

He argued that not even the most strident defender of quantum mechanics would remain in the room, secure in the belief that the gunpowder was in a mixed combination of eigenstates until the box was actually open.

Probably true.

That paradox is stripped of the silly aspects of the Schroedinger's Cat paradox, but for the same reason did not catch on in the imaginations of popular science writers who don't really understand science very well.

Assuming something that I don't believe -- that there's a quantum mechanical operator corresponding to "Life" -- for the purposes of advancing a hypothetical, if you could find a complementary physical property for a two-cat state, flipping that state in the near cat could kill the remote cat and bring the local cat back to life. Flipping that eigenstate again would bring the remote dead cat back to life, and kill the local one.

This is instructive in the instant case because no one believes physics can bring a dead entity back to life once truly dead. A perfectly good alternative explanation -- precisely because the two cats are indistinguishable -- is that you have merely teleported the dead cat to the live cat's former location, while teleporting the live cat back at the same time.