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Instant Quantum Communication Is Near
fljmayer writes "In this experiment, researchers in Australia and Japan were able to transfer quantum information from one place to another without having to physically move it. It was destroyed in one place and instantly resurrected in another, 'alive' again and unchanged. This is a major advance, as previous teleportation experiments were either very slow or caused some information to be lost."
Sorry I'm posting from a quantum computer... And also not posting....
Hint: the title is unrelated to both the summary and the article.
How we know is more important than what we know.
Don't worry, no USEFUL information was transferred.
Neither Australia nor Japan is close to me, so unfortunately Instant Quantum Communication Is Not Near.
Better known as 318230.
Yes. Yes, of course there is. Unfortunately, there is no law of physics limiting the scope of journalistic hyperbole.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
Not really.
Your post shows you have read neither the summary or the article.
And your cat is dead.
Sig Battery depleted. Reverting to safe mode.
I read the article 3 days ago when it was news.
How we know is more important than what we know.
Yes, it's in the details,I haven't read this article, but I assume it's similar to other methods than seem to invoke FTL.
You can't be sure what state you have before you transfer it, and if you do measure it, it changes the state. Therefore, when you teleport the current state, the receiver can see what state it's in, let's say 0 or 1. But since the sender didn't know if it was a 0 or a 1, the information is useless.
Personally I think spooky action at a distance isn't spooky at all. Consider the time-honored classic of two electrons in a correlated state being shot out of some device. Assume they are entangled in such a way that when you measure one to be up, you instantly know the other is down. Physicists will say, how could the other electron possibly know this, instantly. But a very simple explanation is that the device always shoots 1 up, 1 down. Sure you don't know if it's up or down until you measure it, but that doesn't make it spooky at all.
The actual spookiness is in the details, like what if I now measure it's spin with respect to a different axis, the classical and quantum results differ then, but I cannot think of any practical application this provides us.
It's the same old teleportation thing, except now faster and with higher fidelity.
The article is extremely light on information and (as usual) rife with such misleading phrases as "SchrÃdinger's Cat" and "spooky action at a distance".
Fun with Anagarams! LADS HOST, SHALT DOS. HAS DOLTS. AD SLOTHS, HATS SOLD. ASS HO, LTD.
Isn't there some law of physics that says information can not be transmitted faster than the speed of light?
Yes. The headline is incorrect. The experiment 'teleported' the quantum state of photons (but not the photons themselves, that is almost certainly impossible, or at least, grossly impractical) in a way that was much faster than previous experiments. But still slower than the speed of light.
To be fair to the headline, the text of the article mentions that the state was transmitted instantly, which implies speeds faster than light.
Hurray, networks and computers full of no USEFUL information!
No. This has been possible to do for millennia. We've finally got around to actually attempting it.
Sleep your way to a whiter smile...date a dentist!
Basically, the rate of correlation when measuring entangled things is a function of the orientations of the detectors. The only way to explain that is: 1> Assume that the universe is deterministic, so the entire future state of the system is known at the time of the event that creates the entanglement; 2> Assume that a change made to one member of an entangled pair have an instant effect across any distance on the other member of that pair.
Since entanglement and randomness are inextricably linked here, there's no way to use the effect to either foresee the future or communicate faster than light (and by extension, change the past). So you're right that there's no practical application for it.
It just raises some extremely thought-provoking questions about the nature of our reality.
Fun with Anagarams! LADS HOST, SHALT DOS. HAS DOLTS. AD SLOTHS, HATS SOLD. ASS HO, LTD.
The original article will post six hours from now... but what is 'now'?
Colonel Sandurz: Try here. Stop.
Dark Helmet: What the hell am I looking at? When does this happen in the movie?
Colonel Sandurz: Now. You're looking at now, sir. Everything that happens now, is happening now.
Dark Helmet: What happened to then?
Colonel Sandurz: We passed then.
Dark Helmet: When?
Colonel Sandurz: Just now. We're at now now.
Dark Helmet: Go back to then.
Colonel Sandurz: When?
Dark Helmet: Now.
Colonel Sandurz: Now?
Dark Helmet: Now.
Colonel Sandurz: I can't.
Dark Helmet: Why?
Colonel Sandurz: We missed it.
Dark Helmet: When?
Colonel Sandurz: Just now.
Dark Helmet: When will then be now?
Colonel Sandurz: Soon.
Dark Helmet: How soon?
What about porn? Can we use this to transmit porn at lighting fast speeds over an extended period of time and for massive profit?
Transferring information faster than the speed of light through the use of quantum entanglement is impossible. Only through the use of a second, traditionally light-speed-bound communication channel one make any use of the oddness that is quantum entanglement.
That said, it might still have practical uses, but instantaneous communication to the other side of the galaxy is not one of them.
As odd as it sounds, there's not actually any difference between teleporting "only" the quantum state of the photons and teleporting the photons themselves -- provide the state you're teleporting is the entire state of the photon. Quantum mechanical particles are entirely defined by their state; beyond that state, they're all the same. (Of course, this is counterintuitive.)
Still, while the state change technically is propagated instantaneously (a pair of entangled photons are sharing a single state, so changes in the state are "instant"), it's impossible to make any use of this (to transmit information, for example) without transmitting information via conventional means, which can be no faster than light.
There is no law, there is just an equation. It must always be balanced.
The Equation must be balanced
Physicists will say, how could the other electron possibly know this, instantly
Why would they assume that the electrons are separated? Because we perceive them that way?
Isn't it easier to assume that they're not separate entities and that we just don't know how the universe is put together than to assume that we understand the universe and there's a 'magical' force communicating across infinite distance?
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
This article is awful. Terribly written, incoherent and obviously inaccurate.
This sounds like an extension of previous quantum state "teleportation" via entanglement. These are interesting phenomena, but cannot be used to transmit information faster than the speed of light.
It's not really quite clear what the breakthrough is here. But I'm fairly certain it doesn't involve a group velocity (i.e. information transmission) greater than c.
Sorry, you have reached your Quantum limit here at Comcast, you are now at 56kbps speeds.
If he read neither the post nor the summary, then why would you assume he bothered checking the status of the cat?
What you are suggesting sounds like an ansible. This is a science fiction FTL communication device invented by Orson Scott Card. It's based on the idea of a trapped subatomic particle that has been split in two, while the resulting pair of particles remain permanently linked such that any change made to one is reflected instantly in the other no matter how much spacial distance separates them.
Quantum entanglement can be thought of as working like that, except that as soon as one of the split particles interacts with anything else at all in any way and the resulting change is "transferred" to the paired particle, that entanglement is broken.
Fun with Anagarams! LADS HOST, SHALT DOS. HAS DOLTS. AD SLOTHS, HATS SOLD. ASS HO, LTD.
Hurray, networks and computers full of no USEFUL information!
Could be useful for Facebook and Twitter.
Faster! Faster! Faster would be better!
I wasn't posting from a quantum computer until you looked at this.
That's why I invested in a box of kittens. You feed them into the Quantum computer to avoid problems like that.
This is the kind of comment that gets you slapped with a trout.
It wasn't my cat, but Schrödinger might be a bit miffed since he preferred it both alive and dead at the same time.
That's just something he came up with so he wouldn't have to explain death to his kids.
"Daddy, what's wrong with Mr. Whiskers?" ..."
"Well, see, if we put him in this box
Through the magic of Slashdot, I will now attempt to transmit information forward through time! (Gentlemen, I bid you adieu!)
CAC 40 3908.58 +0.7% ; NIKKEI 225,9441.03 -1.21% ; FTSE100,5896.87
This email is to inform you that your cat is either alive or dead.
Wow, your comment is either truly profound or you have no clue how to spell. Quick, someone check in on his cat...
Two of my imaginary friends reproduced once
Hopefully now we'll soon be able to instantly transmit a stream of random bits wherever we choose!!
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
Intentional misspelling is intentional. My comment is about as profound as the previous, that governments would just disappear quantum physicists for effectively doing "science". I'm not entirely sure I'd see the point. It would just produce a technological dark-age (relatively to the potential of having mainstream quantum machines/computers eventually). The two posts, you see, are entangled. One is spun into silliness in the form of conspiracy, the other is spun in the opposite direction as a Yo Dawg meme.
3 kittens were harmed in making this post?
Accept Eris as your Fnord and personally sate her
Yeah fox news is coming in from the future. Problem is that it is the future of a completely different universe.
As a non-physicist, I have yet to hear a good explanation for any useful means of turning faster-than-light travel into time travel, and every explanation I have heard sounds pretty absurd.
If an a cause triggers an effect somewhere else in a faster-than-light fashion, sure, an outside observer in some frame of reference might be able to observe it occurring before the cause. This happens any time that the outside observer is closer to the effect than to the cause. However, at no point does that observer observe the effect before the cause occurs. If that observer is, for example, five light years away from the effect and ten light years away from the cause, then the observer still observes the effect five years after the cause occurred.
Similarly, when we have observer A seeing a body B moving slower than the speed of light and a body C moving faster than the speed of light towards it (but slower than the speed of light relative to A), observer A will observe both body B and body C observing each other's past events in reverse chronological order from the order that body A observes them. However, they have still already happened from the perspective of each of B and C by the time either of the other bodies observes the event, so no causality is violated. And even if information could travel at an effectively infinite speed between B and C, this would still hold true because the near infinitely small time it takes information to travel from B to C would ensure that any information passed back to B would arrive later. If B is closer to A, it would appear to have been received by B after it was sent by B, but before it was sent by C. From another frame of reference the reverse might be true. The key to preserving causality is that there must not be a frame of reference in which both are true.
Could somebody please explain to me what I'm missing?
Check out my sci-fi/humor trilogy at PatriotsBooks.
It's not really quite clear what the breakthrough is here. But I'm fairly certain it doesn't involve a group velocity (i.e. information transmission) greater than c.
You're right, it isn't. This article makes me sick. If people take shit like this seriously they can't be blamed for not being able to differentiate real science from quantum woo.
It's better to just ignore than try to correct it.
Teleportation is a real phenomenon, albeit a bit old. This is not their breakthrough. The breakthrough is doing it with a cat state (the name is a reference to Schrödinger's cat; this kind of state was inspired in it). These states are usually very fragile, and strongly entangled, hence the interest.
Also other breakthrough is doing it with the measurement of the number of photons and position. This is a promising technique, that I am personally working with at the moment to test Bell inequalities, because of its high resistance to noise. But I don't think it is very exciting to the general public...
entropy happens
Isn't it easier to assume that they're not separate entities and that we just don't know how the universe is put together [...]
Sure, you can do that. But if you stop there, you'll know nothing; so we have to go on and keep trying to understand.
[...] than to assume that we understand the universe and there's a 'magical' force communicating across infinite distance?
The thing is, that's not what physicists are saying -- that's just a bastardized explanation used when you can't make someone take a few classes that require quite a bit of math to understand[1]. In fact, most physicists, if pressed, will admit no one knows what is really going on. For example, there's a famous quote by Richard Feynman: "I think I can safely say that nobody understands quantum mechanics".
What physicists do know is a theory that allows us to very successfully predict the outcome of many experiments and understand many phenomena better than any classical (completely understood) theory; and certainly better than if we just give up and assume that "we just don't know how the universe is put together", as you suggest. The amazing thing is that this theory can explain every phenomena we have ever seen (except gravity) and predict the outcome of any experiment we can perform.
The problem is, this theory (quantum mechanics) just doesn't make clear what's really going on. There are many tentative interpretations that are consistent with the theory and the experimental results, each of them having at least one very strange feature (instant collapse of the wavefunction -- which I guess would be the "magical force" you mentioned --, or parallel universes, etc.) that fails to convince most people, including physicists.
Most (all?) physicists working with quantum physics know this very well. But since "what's really going on" is not very important to do research, they don't think about it that much. What they really want is to predict more stuff and come up with new ways to use the strange behavior we see for our advantage.
[1] By the way: there's an excellent very basic course on YouTube about quantum entanglement: http://www.youtube.com/view_play_list?p=A27CEA1B8B27EB67. It only requires high-school algebra (including complex numbers, I don't know it everyone takes that in high school), and patience to follow it through. I guarantee you that you'll end up having a good idea of how this quantum stuff works (at a very basic level) without any mention of magical forces communicating across infinite distances.