Scientists Teleport Information Between Ions a Meter Apart 220
erickhill writes with word that scientists from the University of Maryland have successfully transferred information from one charged atom to another without having it cross the intervening space of about one meter. The academic paper is available in the journal Science, though it requires a subscription to see more than the abstract.
Scientists have previously teleported unmolested qubits between photons of light, and between photons and clouds of atoms. But researchers have long sought to teleport qubits between distant atoms. Light's high speed of travel makes photons good transporters of information, but for storing quantum information, atoms are a much better choice because they're easier to hold on to. 'This is a big deal,' comments Myungshik Kim, a quantum physicist at Queen's University Belfast in the United Kingdom. 'To store information as it is in quantum form, you have to have a teleportation scheme available between two stationary qubits. Then you can store them and manipulate them later on.'"
Scientists Teleport Information Between Ions (Score:5, Funny)
Are they positive?
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MPF. that's the most entertaining one-liner I've read in days...
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Don't feel bad (Score:2)
The mods didn't get the joke, but I did. [wikipedia.org]
Unmolested? (Score:5, Funny)
Qubit molester insists entanglement was consensual, stay tuned for details at 11.
Re:Unmolested? (Score:5, Funny)
In breaking news, the molester has been ordered to both sign and not sign the Atomic Sexual Deviancy Register at the same time.
Re:Unmolested? (Score:5, Funny)
Re:Unmolested? (Score:5, Funny)
Sounds neat, but I'm confused... (Score:5, Interesting)
All sources regarding quantum entanglement/teleportation are quite adamant that you can't use it to actually send information instantaneously. Despite there being "spooky action at a distance", any discernible information had to be transfered when you separated the photons themselves at sub-light speeds. In this case it would be atoms, but I assume it still applies? The article lists applications as super-fast quantum computers (I guess any functional quantum computer could be considered fast at what it does) and quantum encryption (a real application I've heard applied to quantum teleportation, though the encrypted data itself still has to travel at c or less).
So, am I right, and this is basically the same ol' non-instant-communication but still quite cool kinda teleportation, only using atoms instead of photons? I'm just checking.
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More importantly, does this kind of teleportation make the same cool sound as the teleportation the original "Star Trek"?
Re:Sounds neat, but I'm confused... (Score:5, Insightful)
The way I understand it:
* you generate two entangled quantum things
* you move them apart
* you look at one of them and figure out its state, by that you knock it out of the superposition
* magic happens and the (inverse of that) state is transported to the other thing
* you look at the other thing an confirm that the state is as expected
Since the stuff is in superposition you shouldn't be able to tell its state beforehand, but due to looking at the other thing an teleportation you can. The other thing has the inverse state thing since they must obey conservation of angular momentum (i.e. one spins up, then the other spins down).
Now what I don't get is why this involves any 'teleportation' or quantum weirdness at all. Analog experiment:
* you have two boxes
* you put into one of those boxes a ball at random
* you move them apart
* you look into your box and can now tell if a ball is in the other box or not
* no magic necessary, no teleportation happens, since the state of both boxes is fixed from the start
I don't get why this teleportation thing is anything special, since as far as I understand it, its completly normal and matches exactly what you would expect.
Good as far as it goes (Score:5, Informative)
Here's an illustration of the non-tranmission of information via entanglement.
Suppose we have a pair of 'magic coins'. Either coin can be flipped and come up either heads or tails, and the other coin will always come up the opposite.
Now, suppose 2 people meet in New York and agree that they will meet again in Oslo if Amy's coin comes up heads and Bill's coin comes up tails, or they will meet in Sidney if Bill's coin comes up heads and Amy's coin comes up tails. Then Amy goes to Peking and flips her coin. It comes up heads, so she meets Bill in Oslo.
The information, which city they will meet in, was AGREED ON BEFORE HAND, it wasn't 'transmitted' by the flip of the coins. The information was in Amy's head when she went to Peking, it traveled by a classical channel governed by relativistic limitations.
This can be seen explicitly if you assume that Amy and Bill DIDN'T agree on which face of the coins meant Oslo or Sidney. In that case when Bill and Amy flip their coins they DO know that their opposite number's coin came up the other way, but neither of them knows which city to go to! In other words, no information was conveyed between them BY the flip of the coins.
But they DON'T know (Score:3, Informative)
At no point can either Amy or Bill determine whether or not the other coin has been flipped. All they can say for sure is that WHEN IT IS, it will come up a certain way. Maybe it already has been flipped, maybe it hasn't. The only way to find out would be using a classical communications channel.
There is a CORRELATION between the two 'coins' with entanglement, but there is NO causality. Flipping one coin does NOT cause the other one to flip, this has actually been verified by various iterations of experimen
Re:Sounds neat, but I'm confused... (Score:4, Informative)
http://en.wikipedia.org/wiki/Bell's_theorem [wikipedia.org]
Yeah, Bells's theorem... (Score:4, Interesting)
Back to the topic at hand, no one can explain what is different about a particle whose wave function has "collapsed" and one that hasn't. If you can tell the difference, then you can use entangled pairs to communicate instantly at a distance. One person makes a measurement or not, and the other guy checks for the collapsed-ness of his particle - instant transmission. But since no one knows what the collapse means we just chalk it all up as magic - or unknowable, or parallel universes, etc... By the way, the collapsedness of the particles wave function is therefore a hidden variable that we don't have access to. This proves the existence of hidden variables in contradiction to Bell's theorem, and offers the distinct possibility that the spin is also there all along as a "hidden variable".
I thus predict that an overturn of at least one assumption in Bell's theorem will be one of the biggest headlines in physics some time this century.
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Re:Sounds neat, but I'm confused... (Score:4, Informative)
Say particles A and B are entangled, and you are in a position to observe B, but not A. You have no way to know whether A has already been observed, because B will look the same to you either way, unless you already know the state of A.
Re:Sounds neat, but I'm confused... (Score:5, Informative)
You can't determine if a particle is in a super-position or not, because any measurement of it will instantly collapse the waveform on both particles, and if you collapse yours first you will be unable to receive the information being transmitted by the other. You will need to know that the other entangled particle has already been collapsed, before you read yours, and that information still has to get to you by a conventional method.
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The 2-slit experiment observed quantum super-position, not entanglement. The quantum state was measured when the photons hit the opposite wall, and that measurement only measured the collapsed state, not the super-position. The super-position was only observed in the pattern of interference in the collapsed states.
The super-position being measured was caused by the photon passing through the two-slits, so even if you took an entangled photon, collapsed it's partner, and sent it through the double-slit, it
Mod patent up. (Score:3, Informative)
Yeah. I will try to give a simplified explanation to non-experts (I'm just a curious guy myself):
First you entangle two particles. Then you let one travel somewhere. (If at bumps into another particle on that way, the particle loses the entanglement.)
Now if you "measure" the first particle, the "wavefunction" (the entanglement) of both particles collapses in a specific way.
By measuring that traveled particle, you can get the information on how the other particle got manipulated when it lost the entanglement
Re:Mod patent up. (Score:5, Informative)
Re:Mod patent up. (Score:4, Informative)
Unfortunately, you can't do either of the things you want to do. Relativity says you can't have synchronized clocks and quantum mechanics doesn't give you any way to know when/if the wave was collapsed.
Re:Mod patent up. (Score:4, Insightful)
If you check to see if a block you have is collapsed, then suddenly it becomes collapsed, even if it wasn't before. That means you can't tell what it was supposed to look like before.
The other option is to only look at the entangled matter after you are sure it has collapsed, and see how the collapsing happened. However, this is also impossible. The way the qbits collapse is completely random, so you can't get any useful information out of reading them.
The best way to think about it is you have two coins taped to each other head to tail or something.
Then the coins are flipped, and separated without looking at them. Then take these coins to opposite ends of the universe.
Now, as soon as one coin is observed, the value of the other coin is known as well. However, looking at either coin does not help to relay information. The only way to do that would be to know how the coin was going to land before looking at it. Or to be able to somehow observe the coin and know if the other has been observed.
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If they can't tell that the other end has already collapsed when they check one end, then how do they know this whole entangling thing works and both ends collapse in tandem?
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Because the other end is at the opposite side of the lab. Light detect by their eyes tells them whether their assistant collapsed one end and the comparison of measurement tells them whether they read the same information their assistant did.
But all of this verification requires information to be passed by ordinary non-quantum means and if you are going to do that you might as well just send a radio signal.
No, it wouldn't (Score:2)
Because you would have to AGREE BEFOREHAND on what each collapse MEANT. Each series of measurements on each end is RANDOM. Thus all each end of the channel knows is a random number. They each know the SAME random number (or its inverse which is the same thing). It is just a random number, it contains no information.
In order for information to be passed, the two sides would have to agree (by communicating using a classical channel) as to what they would interpret their random numbers to mean. The information
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I think the way to think of it is this: there's another (or maybe many other) dimensions in the universe that our feeble minds can't perceive. They still exist, though, and things that may appear to be far apart in space (or even time-space) may be r
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IANAPhysicist, but my understanding is that while light speed is still an issue in physical space, the information sharing is truly instantaneous in this sort of quantum entanglement. It's not a short delay as light travels that distance, but instantaneous.
Well the waveform collapse is instantaneous, yes, but as the WP [wikipedia.org] says, you can't actually use it to communicate information from one end to the other.
I really don't understand the physics of why you're not really sharing information when the waveform coll
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You would not violate causality. If you transmit the information about some bet from yesterday from A to B, and it reaches B yesterday, and B would instantly send it back, then it would reach A instantly after A transmitted the information.
But I also wrote above [slashdot.org], how you could actually transmit information with it. I remember this from a "Spektrum der Wissenschaft" (German version of the "Scientific American") special issue.
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Relativity implies that if information goes from A to B instantaneously for some observers, it also goes from A to B in finite time for some other observers. For all the other observers it goes from A to B in negative finite time, from B to A, in other words. For causality, for A to cause B, then information must always travel from A to B.
Any instantaneous wavefunction collapse cannot transmit information from distant locations, it must create new information for those locations, i.e. a random value.
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I just don't get it.
You "entangle" two atoms creating the qubit. You separate the atoms, then read the qubit?
Isn't the information already present in the entanglement, prior to the separation? Isn't it like spray-painting two objects red, sending them to opposite parts of the world and then proclaiming you've got a way to teleport information across the world, but can only send one message, "red" ?
I'm sure with all the hype I must just misunderstand the whole thing.
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Well, I think that's roughly the essence of why you can't send information instantly. All information about the qubits is actually sent with the qubit itself as you separate them to whatever arbitrary distance you're going to do your 'teleportation' trick. It's a little less obvious to me exactly why that is... my understanding is that it's kinda like you have both a black and red marble and you send one around the world, well when one guy checks and sees that his marble is red, the other guy instantly k
Re:Sounds neat, but I'm confused... (Score:5, Informative)
you have both a black and red marble and you send one around the world, well when one guy checks and sees that his marble is red, the other guy instantly knows that his marble is black.
More to the point, the other guy can find out his marble is black, but only if you communicate to him that your marble was red. Thus information was transferred, but you have to communicate by other means to make it meaningful, which defeats the purpose. It's like sending someone an encrypted message over an insecure channel. Great until you realize you now have to send him the key over the same channel. Sure it's encrypted, but the means of making it useful renders it ineffective.
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It's like sending someone an encrypted message over an insecure channel. Great until you realize you now have to send him the key over the same channel. Sure it's encrypted, but the means of making it useful renders it ineffective.
Sure you can, you just need to use public key encryption. So I guess you're saying we need public key quantum entanglement?
Just kidding, thanks for the clarification. :)
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So I guess you're saying we need public key quantum entanglement?
Wouldn't it be hilarious if that turned out to be the case? If you just knew enough about the other member of your pair, that you could actually transmit information? It would make your comment one hell of a Doug Adams-type footnote.
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Which goes to prove that teleporting physicists have lost their marbles.
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Wrong. In Vienna they are transmitting entangled particles trough the air of half the city (between two towers) right now, and then when they reached the target, they can change the local entangled particle. Thereby instantly changing the remote particle.
So please stop trolling and inform yourself
Here's how it works, in simple words [slashdot.org].
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Quantum teleportation is the faithful transfer of quantum states between systems, relying on the prior establishment of entanglement and using only classical communication during the transmission. We report teleportation of quantum information between atomic quantum memories separated by about 1 meter. A quantum bit stored in a single trapped ytterbium ion (Yb+) is teleported to a second Yb+ atom with an average fidelity of 90% over a replete set of states. The teleportation protocol is based on the heralded entanglement of the atoms through interference and detection of photons emitted from each atom and guided through optical fibers. This scheme may be used for scalable quantum computation and quantum communication.
So yes, this is not true "teleportation". It relies on light actually moving from one atom to another through optical fibers.
Re:Sounds neat, but I'm confused... (Score:4, Informative)
"teleportation" always seems to lead people to the wrong conclusions. This is about transferring the informational content of a qubit. Which you can't perfectly represent with a classical system. I can see how this as the one commenting physicist claims is a "big deal" when it comes to building quantum computers. But it's not about instantaneous matter transport or superluminal communication.
I'm not sure what the article meant by ultra secure "quantum communication". Quantum teleportation *is* a quantum communication *channel* but it's unclear what kind of security they are talking about. Perhaps "Quantum Encryption" but that's another term that often sends people down the wrong track.
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It's the same situation as in 'quantum cryptography'. That is, you can't eavesdrop on it, and while there is information being transferred 'classically' in the open, it gives no help in identifying what's being transferred. I agree it's a bit of a stretch though, because this is a fairly impractical scheme
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You could send something as simple as a yes/no - yes, I've read your message , or no, I haven't.
Add a few more entanglements to it, and you could send more. One time pad X wrt x. If this particular part gets read, yes; if that other part doesn't get read, no.
On/off? requiring a shared sequence.
Someone who understands it better, correct me and be more clear, please.
SB
Re:Sounds neat, but I'm confused... (Score:5, Funny)
Analogy:
I have two basket balls, one has a cat inside - I don't know which one.
I send one basket ball to you.
I open my basket ball (observation).
I find it empty so I can deduce the cat is in yours (no information is transfered to you).
I cannot tell if you have opened yours and observed the cat as dead or alive.
You open yours and find a dead cat (observation).
Information is transfered in the normal manner when you call me up and ask why I sent you a dead cat in a basketball.
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I have two basket balls, one has a cat inside - I don't know which one.
The heavier one. Duh. :-)
No (Score:2)
Because the measurements you each make at each end are RANDOM. You each know that the measurements made by the other end are the same as yours, but that doesn't amount to 'information'. You would have to agree beforehand what EVERY possible sequence of random values would be when it was actually measured, which means all the information you could possibly transmit would have to be carried with each party (subject to classical relativistic mechanics).
Thus you each DO 'know' something when you do your measure
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http://tech.slashdot.org/article.pl?sid=08/08/06 [slashdot.org]
So does this mean it is possible to send inf
Here's the whole link (Score:2)
http://tech.slashdot.org/tech/08/08/06/0043220.shtml [slashdot.org]
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Previously entangled qbits decay to the same state, even though their decay is separated by space and time.
Therefore, it's not necessary for light in its travels to cover all the granular space bits between point A and point B. The line has gaps and lands, and touching the lands between A and B is optional.
Did I miss something? You physicists and math weenies weigh in here.
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I thought it was as simple as just modifying the spin of one entangled particle half to make the other half change, and this could be used as a form of one-way data communication. I didn't think you'd have to store the information beforehand when splitting entangled particles.
I've also heard that the 'spooky effect' may actually be faster than light. Not good for teleportation but great for data transmission. If we could just build a device, put it on the moon, and have it's entangled twin on earth, and we
Think of it like this (Score:2)
2 entangled quantum states are like 2 magic coins. When you flip one coin and it comes up heads, the other coin comes up tails.
Now, suppose I flip my coin, and your 100 light years away. You don't know if I have flipped my coin or not, nor if it came up heads or tails. You flip yours, it comes up tails, you now know mine must have come up heads. What information has passed between us? ALL we each know is how the other's coin came up. There is no way to use that fact to communicate anything else.
Now, you CAN
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Yes. Setting up the entangled state here requires both atoms to emit photons, so that occurs at light speed.
It follows the same old rules. Although the state of one atom, once measured, will affect the other atom instantaneously, there's no possibility for FTL communication.
Okay, can you clarify for me why exactly you can't? Is it because you can't actually control what state the measured atom, and thus the distant atom, will take?
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Yes, you definitely can NOT control the state. All you can do is measure the unknown state, find out what it is; and the other end will see the same state when it measures. Which of course tells you nothing of use (no information).
Re:Sounds neat, but I'm confused... (Score:5, Informative)
Sure, I'll try: A quantum 'entangled' state means that two systems are in an 'undefined' state in the quantum sense, that are interdependent.
When one is measured, the other one will _instantanously_ adopt whatever state is 'required' to complement the other one. So one 'knows' instantly what the other is doing, so to speak. Which means a sort of information has been transferred at FTL speed.
The reason why this can't actually be used for communication is twofold: One is exactly as you said: Because you can't know which state you'll measure, you can't transfer information through that alone. The second reason is that, an entanglement between two systems occurs only if there's an (unmeasured) interaction between them.
That means you either separate the two systems from each other (as in the classic example of entangled photons moving apart), or as in this case, by letting them interact with photons - that travel at light speed. Either way though, light speed is the best you can do.
Re:Sounds neat, but parent needs a MOD UP (Score:2)
Thank you for the explanation, that was very helpful.
One more question, about measurement. Is there any way to know that measurement has taken place at the other end and your local qubit has collapsed? Or would determining that constitute a measurement in and of itself, meaning if it hadn't been collapsed it then would be so you wouldn't know what happened? I mean, I know the answer is you can't communicate instantly, I'm just figuring out why (mostly to help explain to people with roughly my same layman
Re:Sounds neat, but parent needs a MOD UP (Score:5, Informative)
Is there any way to know that measurement has taken place at the other end and your local qubit has collapsed?
Crash course in quantum mechanics, perhaps this explains it: a binary quantum mechanical system is in a linear superposition of states A and B. That is, it is either 100% A, or 100% B, or anything in between; for example 70% A and 30% B.
Now if you measure, you would only get "pure" results, i.e. purely A or purely B. If the system was pure (i.e. 100% B) before the measurement, you get what it was. If the system was mixed (say, 70-30), and you had the chance to measure the system more than once, then you get A in 70% of the cases, or B in 30%. For example: make 1000 copies of the system, and measure each of them. Roughly 700 (give/take a few) would be A, roughly 300 would be B.
The biggest problem is that you don't have 1000 exact copies -- unlike with classical information, basic QM forbids cloning of a system. So you basically have one shot, and if you happen to measure B, you'll never know whether it was because of a 100% pure B state, or simply because you "got lucky".
I mean, I know the answer is you can't communicate instantly, I'm just figuring out why (mostly to help explain to people with roughly my same layman's understanding of physics why instant communication is impossible).
While the "quantum information" is being transfered instantaneously, the problem is that the quantum state is not transfered 1:1 onto the target. It is ... "twisted". Imagine that like x*A+y*B (-> teleport ->) y*A+x*B. Now you know that the numbers x and y mean the same in both systems -- you just don't know exactly how they would be twisted after the teleportation. There are 4 possibilities how they can be twisted, and all 4 are equally probable, there's nothing you can do to favor the one over the other.
However, after the teleportation, the guy at the source can tell how they have been twisted (because the teleportation act itself is a measurement, which's result tells him exactly what happened), but the guy at the target does not.
So at first, even if the guy at the target knows that the atom has been "teleported", he stil doesn't know which one of the 4 twisted flavors of the original atom he got. If he just takes a "wild guess" and tries to measure, he'll get a statistical result which reveals absolutely no information about the actual coefficients.
The target-guy needs the source-guy to tell him which of the 4 twists occured, or in short: needs an information transfer in order to be able to "untwist" his atom and have an exact copy.
Again, the important part is that if the target-guy does not "untwist" his atom, but instead decides to go away and measure it anyway, he'll have an overall chance of 50-50 (regardless of the original x and y) to measure either A or B, so there's no information whatsoever that he could gain, not even from repeating the experiment.
It's the "twist" that makes the twist with teleportation... :-)
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Cracking explanation. Cheers!
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Hmm.
Is there any way this could be used, not for sending FTL messages, but exchanging a cipher? You said you can't know which state you'll measure, but if you can measure some as-yet-unknown random state at one end and measure the corresponding state at the other end, then you should be able to use this random pattern of bits to encode a message, which would then be transferred through traditional (light speed or slower) means. The message could be intercepted in transmission, but the cipher couldn't be.
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I assume you could, but then wouldn't it be the same as just taking a disk with one-time pads with you?
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Although the state of one atom, once measured, will affect the other atom instantaneously, there's no possibility for FTL communication.
The one part of that conclusion I don't get (and I've seen it several times to this point in the thread) is this: Why can't it relay binary information? If I entangle them, separate them, then either DO or DO NOT measure the first, and then measure the second, won't that tell me if the first one was measured or not?
Hmmm thinking on this I have to ask for clarification on t
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No, it doesn't. View it from the perspective of the two measuring parties. We'll call them Abe and Bob.
Each particle has a 50% chance of being in one of two states, + or -. Entanglement means that if Abe's particle is +, Bob's is -, and vice versa.
Abe measures his particle. Regardless of if his particle is + or -, that doesn't tell him if Bob measured his particle or not. While the values of the measurements are dependent on one another, without information from the other measuring party, the measurer can't
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Let me tell you why the whole thing is bullshit. It's bullshit because if it was true they absolutely _could_ send information with it - yet they hadn't.
Let me tell you how - time. You and I will come to an agreement. We shall entangle two particles and you shall have one and I shall have one. You will "collapse the waveform" or whatever these Star Trek raised modern physicists want to call it on an even second to send a "1" and on an odd second to send a "0". Since I will instantly see the change on m
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Wrong.
The only way to tell if your waveform has collapsed is by measuring it. And measuring it collapses it.
Thus *every* time you check to see if yours has been collapsed, it will always show as collapsed.
Go look at yourself in a mirror.
Now close your eyes.
Now, you cannot tell when your reflection has opened its eyes, unless you open yours, and if you open yours, the reflection will have its eyes open.
Same with the waveforms. No matter what, if you look, it'll be collapsed, and you can't tell if it was coll
Basically (Score:2)
Suppose Bob and Amy entangle 2 coins so if one comes up heads, the other comes up tails. Now they go away from each other and each flip their coin. All they know is that the other's coin came up opposite to that, and which way the two together came up is random. If they want the way the two came up to 'mean' something, they have to agree on that meaning BEFORE they go apart (or by radio etc). THAT is the information, and it wasn't transmitted 'faster than light', it was carried in their heads or it was carr
How fast is it really? (Score:2)
TFA (The Science News article) states 'instantly' and I can't actually read the academic paper (bugmenot doesn't seem to have a working login) but does anyone who's more familiar with this area know whether or not it's actually limited to the speed of light, or if we're actually seeing something that's capable of moving faster.
The article makes it sound as though it's instantaneous, but has this actually been measured to show that it's instantaneous or is the relatively short distance at which the "teleport
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Any use of the word "instantly" is, quite simply, hype. It's instantaneous like an "instant message" is instantaneous. Not that this isn't a cool discovery; it is. But it's not teleportation and it's not instant communication.
No, "spooky action at a distance" is indeed instantaneous. It's a quantum phenomena - it's not based on the information being transmitted (which would indeed be limited to the speed of light).
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You most certainly can measure the propagation time of light over distances of one meter. It takes on the order of 10^-8 seconds for light to travel 1 m, and we have time measurement devices better than ns. (Actually, using clever techniques, you can do way better than meters.)
A question that maybe someone might answer... (Score:2)
From the article they are saying that the entanglement has occurred, etc.... they also say that they know the entanglement occurs 1/100M times or so.
My question... If observation destroys the situation they describe, how to they know the entanglement happened at all?
Anyone know?
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IANAP Questions for someone who is. (Score:2)
Okay I am not a physicist, but am interested in understanding a bit more about what is going on here.
Is the following description (model) a reaonably accurate portrayal of what is happening here?
We have two atoms (A1 & A2) that are in two different (non-entangled) quantum states (Q1 & Q2), at two locations (L1 & L2) separated by 1 m, at which point we allow A1 to interact (quantum mechanically) with a photon which then is 'transmitted' along the vector (L2-L1) and is then 'received' at L2 and al
Bah! (Score:5, Funny)
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A New Form of Wireless (Score:3)
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Absolutely. Quantum computing aside, the idea of wireless communications via entanglement is absolutely fascinating. It could lead to instant communication with anyone, just about anywhere in the universe! No towers, no RFI, and absolutely secure from point to point. The major downside is that you probably have to have a centralized "entanglement switchboards" to actually relay the communications from one person to another, since you can't entangle every device to every other possible device. So that w
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And it begins.... (Score:2)
Just think, if they can figure out how this works or at least how to exploit it. You could use these for secure long distance communication. No more cell towers, just entangle some particles, put one in a rack and the other in the cell phone.
I am curious to know if this "spooky action at a distance" as Einstein referred to it, is faster than light communication. We won't know this until we put one in a Mars rover and launch it. I would also be interested to know if these particles are entangled in anot
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It is not faster-than-light communication. We will know immediately, and do. (You don't need large time scales to test "immediate" communications -- we can measure that to sufficient resolution on Earth.)
I'm not sure your statement on "if [they] are entangled in another dimension" is really meaningful. Entanglement is a property of objects in quantum states.
You can already exploit it, though -- it's fairly similar to the basis for quantum "encryption" (by one definition), which is not encryption at all, but
Damn... (Score:4, Funny)
Ok, who voted for the beammeupscotty tag?
I can't think of a worse place to be beamed, than 'up scotty'.
O, how about this for an explanation? (Score:2)
You have two entangled particles A and B and send particle B somewhere else. Then you take a reading of A and call this reading X. You don't really know what is the meaning of X - did you observe it first or did someone else observed B first but you do know that if someone observed B next he will certainly get reading X back to him. Thus it's useless for communication.
The only way this seems useful to me is if we need to keep something perfectly identical to something else, but it can't work that way either
what, no glitter involved? (Score:2)
Hey physics types: So I take it this can in no way lead to the future development of the transporter [wikipedia.org]?
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E=mc^2
Only works if you destroy the original.
unmolested??? (Score:2)
Holy crap! The feminism thing is a tad too much to digest:
Scientists have previously teleported unmolested qubits
Unmolested?? Where they expecting that these female ions would be molested by male ions on their way to their homes???
Why The Fuck they can't use normal words like "unchanged", "bit copy".
This feminism thing has gone too far...
I hope we go back to the pre-WW2 era when women were easier to control and men worked...
Interstellar communication. (Score:2)
Assuming something like this works at much longer distances, this could be applied to interplanetary and interstellar communication.
Imagine a martian colony being seamlessly connected to the internet on earth through circuits which utilize this kind of information.
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Quantum entanglement cannot be used for classical information.
when last I heard of this on a documentary, it had to do with two particles mirroring each other's spin, and when that spin changed, it was mirrored.
Sounds like binary to me.
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No, it cannot be used for classical information due to the basic principles of quantum entanglement. You cannot send information over a channel when you don't know the spin of either entangled particle: this is equivalent to sending random binary data, because while you know the particle the other guy gets is going to be the opposite of yours, you don't know what particle you have.
Think of it like this: you're a kid, you have a friend, Santa Claus has only two presents: a Game Boy and a rock. Christmas Day,
The question (Score:2)
How much it faster then speed of light?
The Ansible (Score:2)
Best science PR stunt ever ... (Score:2)
to call quantum entanglement "teleportation".
Implications for quantum encryption... (Score:2)
The researchers then measured the first atom, thus destroying the delicate quantum information it contained, and also destroying the entanglement. That left the original qubit intact in only the second, recipient atom, completing the teleportation.
If this works, then theoretically couldn't an attacker entangle a third qubit with the original two, measure that (and destroy the entanglement), and leave the two originals unchanged?
(yes I know there's a prodigious amount of handwaving here, but it's *entangled*
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An indiscrete physicist.
Re:A quantum physicist? (Score:5, Funny)
You mean a qubit molester?
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Re: (Score:3, Insightful)
The teleportation is instantaneous. (A philosophy-inclined physicist might object to you applying the label "instantaneous", since it implies a signal is propagating instantaneously -- but there's no signal at all.) However, the teleportation cannot be used for communication without information transfer -- which means the communication is bound by the speed you can transfer that information (which is lightspeed).
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In all seriousness, we could indeed be frickin' teleporting to work in the next 100 years. Or shorter. Let's hope we invent time travel first, so we don't have to.
What makes you think there's a difference? Walking across town would appear instantaneous if you went back the precise amount of time it takes you to walk there, except that you'd be that much older when you arrived.
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