The maximum size of an object which can be teleported

[Dmitry67]

I suspect that there is a limit of a size of an object which can be teleported. And that limit is not instrumental, but it is theoretical (and is very small – dozens of atoms)

Say, we have a blob of atoms. We need to ‘scan’ that blob somehow. There are 2 options, either we do it instantly (t in range of (diameter of an object)/c) or we scan from the surface, removing atoms, digging deeper and deeper.

If we scan from the surface, and as a teleportation is destructive, we begin to heat layers of an object, and that heat propagates inside at c, changing an object. If object is big enough, it’s inner parts would become different (and overheated) when ‘scanning’ finally reaches it.

If we scan an object ‘instantly’, we need some agent delicate enough to go thru the outer parts, but somehow interfering with the inner parts. But as all QM particles have identical properties such agent can’t exist.

There is also a limit how much information one particle can carry away. As volume (and the number of atoms) grows as R^3 while for the surface it is only R^2 for the bigger objects one scanning particle must carry more and more information (which is impossible) or we must throw more and more scanning particles on the same trajectory. But again, if means that these particles have magical properties: they can

 

[ZapperZ]

Before even discussing the limit to the size of the object, shouldn't you first need show some kind of experimental evidence that an object (not just the quantum state) can be teleported? Isn't this putting the cart waaaaay before the horse?

Zz.

 

[Dmitry67]

On the contrary: if we show that theoretical limit exists, that NO-GO theorem would save a lot of useless efforts.

 

[ZapperZ]

On the contrary: if we show that theoretical limit exists, that NO-GO theorem would save a lot of useless efforts.

I guess that's why I'm not a theorist.

Zz.

 

[bobbytkc]

On the contrary: if we show that theoretical limit exists, that NO-GO theorem would save a lot of useless efforts.

It probably does not exist, in my opinion.

For example, it is in principle, possible to have a macroscopic lattice of spin particles in a pure state with all its spin pointing in the same (but unknown direction). In this case, the state is expressible in exactly the same way as a single particle with spin. Therefore, the teleportation protocol proposed by Bennett can be performed in much the same manner. Such a physical situation is practically impossible, but it illustrates that size is probably not really the issue. The issue I feel most likely lies in the scalability of the teleportation protocol itself to large number of particles, and decoherence effects.

 

[Dmitry67]

pure state with all its spin pointing in the same (but unknown direction).

But it changes the system
What happens to your brain if you point all spins into the same direction?
Holodeck, we have a problem :)

 

[bobbytkc]

But it changes the system
What happens to your brain if you point all spins into the same direction?
Holodeck, we have a problem :)

No, you are specifically saying that teleportation is not possible due to the size of the object. I simply presented a counter example where teleportation is possible even if you have millions of particles, suggesting perhaps that simply the size alone is not enough to prevent teleportation from happening. If quantum teleportation has a limit, it seems to me that the underlying reasons, to me, probably lie elsewhere.

 

[JesseM]

Before even discussing the limit to the size of the object, shouldn't you first need show some kind of experimental evidence that an object (not just the quantum state) can be teleported? Isn't this putting the cart waaaaay before the horse?

Zz.

How would you distinguish "an object" from its quantum state? Are you assuming (implicitly or explicitly) there are hidden variables associated with a system that go beyond the system's complete quantum state? As I'm sure you know, in QM indistinguishable particles don't have distinct "identities", if you measure two electrons at positions A and B, and later measure the electrons at positions C and B, without hidden variables there can be no fact of the matter about whether the electron that was originally at A later went to C or if it later went to D, if you're doing a path integral you have to consider both types of paths and they interfere with one another so it's not just a statistical ensemble of different possibilities (assuming there's a 'real truth' about which type of path actually occurred would be like assuming there's a 'real truth' about which slit an electron went through in the double-slit experiment with no detectors present)

 

[Dmitry67]

No, you are specifically saying that teleportation is not possible due to the size of the object. I simply presented a counter example where teleportation is possible even if you have millions of particles, suggesting perhaps that simply the size alone is not enough to prevent teleportation from happening. If quantum teleportation has a limit, it seems to me that the underlying reasons, to me, probably lie elsewhere.

You use a specially prepared object.
To clarify my claim: I claim that beginning from some size, objects can't be teleported in general (so you can't create a device which can teleport ANY object), while, of course, you can teleport SOME specially prepared objects.

Hence this:

is not possible in principle.

 

[ZapperZ]

How would you distinguish "an object" from its quantum state? Are you assuming (implicitly or explicitly) there are hidden variables associated with a system that go beyond the system's complete quantum state? As I'm sure you know, in QM indistinguishable particles don't have distinct "identities", if you measure two electrons at positions A and B, and later measure the electrons at positions C and B, without hidden variables there can be no fact of the matter about whether the electron that was originally at A later went to C or if it later went to D, if you're doing a path integral you have to consider both types of paths and they interfere with one another so it's not just a statistical ensemble of different possibilities (assuming there's a 'real truth' about which type of path actually occurred would be like assuming there's a 'real truth' about which slit an electron went through in the double-slit experiment with no detectors present)

A electron has a "spin" state. But the spin state is not the electron.

The quantum teleportation experiments that have been done only teleported the quantum state of the entangled ensemble. It does not teleport the object itself.

Zz.

 

[JesseM]

A electron has a "spin" state. But the spin state is not the electron.

But that's not the complete quantum state of the electron, i.e. the total state vector of the electron which assigns amplitudes to observables other than spin. Isn't it possible (theoretically at least, I don't know what's been done experimentally) to teleport the complete quantum state of a system? Although now that I think of it the complete state vector would include position probabilities, if position was one of the observables being measured I suppose there would have to be a displacement added.

 

[ZapperZ]

But that's not the complete quantum state of the electron, i.e. the total state vector of the electron which assigns amplitudes to observables other than spin. Isn't it possible (theoretically at least, I don't know what's been done experimentally) to teleport the complete quantum state of a system? Although now that I think of it the complete state vector would include position probabilities, if position was one of the observables being measured I suppose there would have to be a displacement added.

If it is "possible", it hasn't been done. What we do know how is that we can teleport ONE quantum state. We haven't shown anything beyond that. And note that that is the case that I made, that we have not shown the ability to teleport whole particles. I don't believe I'm making an erroneous statement there.

Note also that teleporting whole particles requires energy "creation" at a particular location, i.e. no particle at one instant, and a particle appears at that instant. Now this does not necessarily violate conservation of energy, but it requires energy conversion into a particle as depicted in Star Trek. This is quite different than what has been accomplished so far in the EPR-type experiments.

Zz.

 

[JesseM]

If it is "possible", it hasn't been done.

OK, but I'm not really interested in the experimental question, just the theoretical question about what should be possible according to QM. I assume there is some well-defined answer to this theoretical question of whether quantum teleportation allows teleporting of arbitrary observables or whether it's confined to spin...reading popular articles on the subject written by physicists, several seemed to suggest that sci-fi style teleportation of all properties of a macroscopic system was possible in theory, even if wildly impractical (akin to how backwards time travel via wormholes is possible in theory according to general relativity).

Note also that teleporting whole particles requires energy "creation" at a particular location, i.e. no particle at one instant, and a particle appears at that instant.

That's not the model I've seen, rather the idea was that you would have a system composed of the same numbers of different types of particles as the system to be "teleported" but in a completely different state, then you would transfer the state from one to the other. As I said in my first post on the thread, if you transfer the entire quantum state it would seem meaningless in QM to say this isn't "real" teleportation since that would suggest identical particles have distinct "identities".

 

[ZapperZ]

OK, but I'm not really interested in the experimental question, just the theoretical question about what should be possible according to QM. I assume there is some well-defined answer to this theoretical question of whether quantum teleportation allows teleporting of arbitrary observables or whether it's confined to spin...reading popular articles on the subject written by physicists, several seemed to suggest that sci-fi style teleportation of all properties of a macroscopic system was possible in theory, even if wildly impractical (akin to how backwards time travel via wormholes is possible in theory according to general relativity).

But this is the identical issue with the question on whether a tennis ball can tunnel through a wall. We've had this discussion before. If the probability of something to occur is so small, that the probability of it happening requires a time period longer than the age of the universe, then what good is something like that?

Just because something is possible, on paper, doesn't mean that it has be considered. The Higgs is MORE than just possible. Yet, we still need to make sure it is verified before we take it seriously.

That's not the model I've seen, rather the idea was that you would have a system composed of the same numbers of different types of particles as the system to be "teleported" but in a completely different state, then you would transfer the state from one to the other. As I said in my first post on the thread, if you transfer the entire quantum state it would seem meaningless in QM to say this isn't "real" teleportation since that would suggest identical particles have distinct "identities".

Transfer the entire quantum state to WHAT? I take an electron's quantum states, and where do I sent it to? And what do I get?

Zz.

 

[JesseM]

But this is the identical issue with the question on whether a tennis ball can tunnel through a wall.

I don't think the issues are really "identical", because in that case the small probability is due to fundamental physics, where in the case of quantum teleportation of large objects we are talking about a different sort of "improbability", one concerning the likelihood that humans will ever develop a technology that will ever allow them to read out the full quantum state of a macroscopic object and teleport it using the methods of quantum teleportation. Again think of the comparison to traversable wormholes manipulated to allow backwards time travel--even if they are not forbidden by the fundamental laws of physics (which is an open question since general relativity is not expected to be true exactly), the likelihood that we humans will ever build such a thing is probably very small, but if we assume it was already present as a fait accompli there wouldn't be any issues of it being "improbable" for anyone to use it to go back in time. I think the same is true for a hypothetical technology to allow quantum teleportation of macro objects (which might also require assuming that while the laws of physics are the same, the external conditions around the experiment are far emptier than would be possible anywhere in our actual universe, to prevent decoherence and allow the macro object to be in a pure quantum state), but it's not true of the tennis-ball-through-the-wall scenario since the laws of fundamental physics don't allow you to change the probability of that event from astronomically small to highly probable.

Just because something is possible, on paper, doesn't mean that it has be considered. The Higgs is MORE than just possible. Yet, we still need to make sure it is verified before we take it seriously.

"Has to be considered" for what purpose? No one says we "have to" consider an issue like macro teleportation or closed timelike curves through traversable wormholes, but certainly a number of physicists consider the latter possibility to be an interesting issue from a theoretical point of view, would you tell them they "have to" stop wasting their time with the issue since it's not feasible to explore the problem experimentally anytime soon?

Transfer the entire quantum state to WHAT? I take an electron's quantum states, and where do I sent it to? And what do I get?

As I understand it, you would take your electron #1 in an unknown initial quantum state S, then perform some type of joint measurement (or "Bell-state measurement") on the electron #1 and some other electron #2 which entangles them (and scrambles the state of your original electron #1), then send both electron #2 and some classical information about the results of your joint measurement to me, I would then use the classical information to pick a type of joint measurement on electron #2 and my own electron #3 which will cause my electron #3 to go into state S. As you said existing experiments have only dealt with transferring a spin state, but I think in principle the laws of physics would allow for a transfer of other aspects of the quantum state, and would also allow for transferring the quantum state of a system composed of multiple particles. See for example the Scientific American article by Anton Zeilinger (a physicist known for his work in quantum teleportation, among other subjects) which starts on p. 9 http://www.scribd.com/doc/47422884/Extreme-Physics-Scientific-American-February-2004 , the illustrations at the bottom of pp. 10-13 show conceptually how quantum teleportation would work for a macro object like a person (they note this is "impossible in practice but a good example to aid the imagination"), and the "Skeptic's Corner" sidebar on p. 15 where "the author answers common teleportation questions" seems to say that the problems with teleportation of macro objects are practical ones like preventing decoherence and storing the vast amount of classical information that would be needed, but doesn't suggest any fundamental theoretical problems with the idea:

Can we really hope to teleport a complicated object?
There are many severe obstacles. First, the object has to be in a pure quantum state, and such states are very fragile. Photons don't interact with air much, so our experiments can be done in the open, but experiments with atoms and larger objects must be done in the open, but experiments with atoms and larger objects must be done in a vacuum to avoid collisions with gas molecules. Also, the larger an object becomes, the easier it is to disturb its quantum state. A tiny lump of matter would be disturbed even by thermal radiation from the walls of the apparatus. This is why we do not routinely see quantum effects in our everyday world.

Quantum interference, an easier effect to produce than entanglement or teleportation, has been demonstrated with buckyballs, spheres made of 60 carbon atoms. Such work will proceed to larger objects, perhaps even small viruses, but don't hold your breath for it to be repeated with full-size soccer balls!

Another problem is the Bell-state measurement. What would it mean to do a Bell-state measurement of a virus consisting of say, 10⁷ atoms? How would we extract the 10⁸ bits of information that such a measurement would generate? For an object of just a few grams the numbers become impossible: 10²⁴ bits of data.

He also notes on the same page (but outside the "Skeptic's Corner" sidebar) that "the entanglement of molecules and then their teleportation may reasonably be expected within the next decade", so clearly he doesn't think it's in principle impossible to teleport the quantum state of multiparticle systems, it just becomes progressively more difficult as the number of particles increases due to problems like environmental decoherence and the need to entangle the system with a collection of exactly the same types of particles in the same numbers.

 

[Matterwave]

Doesn't the no-clone theorem prohibit one from making a particle identically like another? I'm not very well versed in this though...

 

[JesseM]

Doesn't the no-clone theorem prohibit one from making a particle identically like another? I'm not very well versed in this though...

Quantum teleportation is different from cloning, because the state of the original particle (or system) is disrupted by the initial Bell-state measurement, so it's no longer in the same state...that was this step in my summary:

As I understand it, you would take your electron #1 in an unknown initial quantum state S, then perform some type of joint measurement (or "Bell-state measurement") on the electron #1 and some other electron #2 which entangles them (and scrambles the state of your original electron #1)

 

[ZapperZ]

I don't think the issues are really "identical", because in that case the small probability is due to fundamental physics, where in the case of quantum teleportation of large objects we are talking about a different sort of "improbability", one concerning the likelihood that humans will ever develop a technology that will ever allow them to read out the full quantum state of a macroscopic object and teleport it using the methods of quantum teleportation. Again think of the comparison to traversable wormholes manipulated to allow backwards time travel--even if they are not forbidden by the fundamental laws of physics (which is an open question since general relativity is not expected to be true exactly), the likelihood that we humans will ever build such a thing is probably very small, but if we assume it was already present as a fait accompli there wouldn't be any issues of it being "improbable" for anyone to use it to go back in time. I think the same is true for a hypothetical technology to allow quantum teleportation of macro objects (which might also require assuming that while the laws of physics are the same, the external conditions around the experiment are far emptier than would be possible anywhere in our actual universe, to prevent decoherence and allow the macro object to be in a pure quantum state), but it's not true of the tennis-ball-through-the-wall scenario since the laws of fundamental physics don't allow you to change the probability of that event from astronomically small to highly probable.

"Has to be considered" for what purpose? No one says we "have to" consider an issue like macro teleportation or closed timelike curves through traversable wormholes, but certainly a number of physicists consider the latter possibility to be an interesting issue from a theoretical point of view, would you tell them they "have to" stop wasting their time with the issue since it's not feasible to explore the problem experimentally anytime soon?

As I understand it, you would take your electron #1 in an unknown initial quantum state S, then perform some type of joint measurement (or "Bell-state measurement") on the electron #1 and some other electron #2 which entangles them (and scrambles the state of your original electron #1), then send both electron #2 and some classical information about the results of your joint measurement to me, I would then use the classical information to pick a type of joint measurement on electron #2 and my own electron #3 which will cause my electron #3 to go into state S. As you said existing experiments have only dealt with transferring a spin state, but I think in principle the laws of physics would allow for a transfer of other aspects of the quantum state, and would also allow for transferring the quantum state of a system composed of multiple particles. See for example the Scientific American article by Anton Zeilinger (a physicist known for his work in quantum teleportation, among other subjects) which starts on p. 9 http://www.scribd.com/doc/47422884/Extreme-Physics-Scientific-American-February-2004 , the illustrations at the bottom of pp. 10-13 show conceptually how quantum teleportation would work for a macro object like a person (they note this is "impossible in practice but a good example to aid the imagination"), and the "Skeptic's Corner" sidebar on p. 15 where "the author answers common teleportation questions" seems to say that the problems with teleportation of macro objects are practical ones like preventing decoherence and storing the vast amount of classical information that would be needed, but doesn't suggest any fundamental theoretical problems with the idea:

But the Star Trek teleportation is NOT quantum teleportation! That's my whole point here! Teleportation, where objects are created as a distant location, is not the same as quantum teleportation! You are trying to convince me that it is possible to do quantum teleportation of a number of quantum states. That is not what I'm arguing, even though I haven't seen the experimental evidence yet. What I'm arguing is the physical creation of objects at a remote location.

Do you now see the difference? We're not even talking about "decoherence" yet.

Zz.

 

[Dmitry67]

So the realistic version of the Star trek teleportation:

1. When people get teleported, they don't dissapear, instead, there is a blob of something smelling funny remains. After every use of a teleporting cabin a serious cleaning will be required!

2. On a distant location to receive an information, an apparatus is filled with some substance. That substance is 'formatted' when information is received.

In any case, how do you know how many atoms of each sort must be prepared? ANd their location? You can't scan the location of atoms in the original objects without destructively overheating it. Such teleporation is even more difficult than makin a 2-slit experiment on alive humans.

 

[JesseM]

But the Star Trek teleportation is NOT quantum teleportation!

I never said anything about Star Trek teleportation and neither did the original post, Dmitry did use an image from Star Trek in post #9 but I didn't take that image to mean he was literally asking if teleportation that exactly matched the way it worked in Star Trek was possible, I thought it was just a humorous way of asking whether quantum teleportation of macroscopic objects could ever happen. Besides it isn't even clear that Star Trek involves new matter/energy being created out of nothing at a distant location, you could interpret "beaming" to mean they are sending a beam of high-energy particles to the location they want to "beam down to" and then somehow causing them to rearrange themselves into the person being beamed on arrival (obviously this still isn't much like quantum teleportation since there appears to be no need for a receiving device). Anyway, I agree that actually causing new matter/energy to pop into existence from nothing at a distant location isn't possible under any known theory, but I didn't think that was the question, maybe Dmitry can clarify though...

 

[JesseM]

So the realistic version of the Star trek teleportation:

1. When people get teleported, they don't dissapear, instead, there is a blob of something smelling funny remains. After every use of a teleporting cabin a serious cleaning will be required!

2. On a distant location to receive an information, an apparatus is filled with some substance. That substance is 'formatted' when information is received.

Yeah, that would be the most "realistic" version.

In any case, how do you know how many atoms of each sort must be prepared? ANd their location? You can't scan the location of atoms in the original objects without destructively overheating it. Such teleporation is even more difficult than makin a 2-slit experiment on alive humans.

I agree there are probably good reasons this will never be possible in practice, but I wouldn't say this argument shows it's definitely impossible in principle, after all the original joint measurement isn't supposed to preserve the original state of the system whose state you want to teleport...I don't know what teleportation of a multiparticle system would look like according to the theory, but the initial entanglement + joint measurement might well completely disrupt the original arrangement of particles. I suspect the whole thing would have to be almost instantaneously brief if you wanted to teleport the state of the original system at a particular moment in time, so maybe it would be something like sending a bunch of high-energy particles at the object which would rip it apart almost instantly, then immediately doing a measurement on the scattering particles, after which you'd send information about the results of that measurement along with the scattered particles to the location where you wanted to teleport the object (obviously this is just a guess!)

 

[Dmitry67]

Yes, I tried to explain it in post #19

What I want to say:


People usually say: yes, it is possible in theory, even very difficult to do it in practice, because there are so many obstacles.

But my point is that these obstacles are FATAL. You can't extract 10^HUGE number of bits from the human body without overheating it. Overheating so fast, that water in your brain will start to boil when the device will just start scanning your skin, and will evaporate when it will proceed to the bones.

It is an illusionary hope. No, teleportation of macroscopic objects is not possible There is an almost equivalent problem called “Mind uploading”.( http://en.wikipedia.org/wiki/Mind_uploading ) I believe it is also not possible for the same reasons.

 

[ZapperZ]

I never said anything about Star Trek teleportation and neither did the original post, Dmitry did use an image from Star Trek in post #9 but I didn't take that image to mean he was literally asking if teleportation that exactly matched the way it worked in Star Trek was possible, I thought it was just a humorous way of asking whether quantum teleportation of macroscopic objects could ever happen. Besides it isn't even clear that Star Trek involves new matter/energy being created out of nothing at a distant location, you could interpret "beaming" to mean they are sending a beam of high-energy particles to the location they want to "beam down to" and then somehow causing them to rearrange themselves into the person being beamed on arrival (obviously this still isn't much like quantum teleportation since there appears to be no need for a receiving device). Anyway, I agree that actually causing new matter/energy to pop into existence from nothing at a distant location isn't possible under any known theory, but I didn't think that was the question, maybe Dmitry can clarify though...

Then you and I read different things. Here's the original post, and Dmitry can clarify what exactly his intention was:

I suspect that there is a limit of a size of an object which can be teleported. And that limit is not instrumental, but it is theoretical (and is very small – dozens of atoms)

[Say, we have a blob of atoms. We need to ‘scan’ that blob somehow. There are 2 options, either we do it instantly (t in range of (diameter of an object)/c) or we scan from the surface, removing atoms, digging deeper and deeper.

If we scan from the surface, and as a teleportation is destructive, we begin to heat layers of an object, and that heat propagates inside at c, changing an object. If object is big enough, it’s inner parts would become different (and overheated) when ‘scanning’ finally reaches it.

If we scan an object ‘instantly’, we need some agent delicate enough to go thru the outer parts, but somehow interfering with the inner parts. But as all QM particles have identical properties such agent can’t exist.

There is also a limit how much information one particle can carry away. As volume (and the number of atoms) grows as R^3 while for the surface it is only R^2 for the bigger objects one scanning particle must carry more and more information (which is impossible) or we must throw more and more scanning particles on the same trajectory. But again, if means that these particles have magical properties: they can

All those highlighted statements pointed to me that this IS the teleporation as in Star Trek, NOT quantum teleportation. It was already discussed in Penrose's "Emperor's New Mind".

Zz.

 

[ZapperZ]

Yes, I tried to explain it in post #19

What I want to say:


People usually say: yes, it is possible in theory, even very difficult to do it in practice, because there are so many obstacles.

But my point is that these obstacles are FATAL. You can't extract 10^HUGE number of bits from the human body without overheating it. Overheating so fast, that water in your brain will start to boil when the device will just start scanning your skin, and will evaporate when it will proceed to the bones.

It is an illusionary hope. No, teleportation of macroscopic objects is not possible There is an almost equivalent problem called “Mind uploading”.( http://en.wikipedia.org/wiki/Mind_uploading ) I believe it is also not possible for the same reasons.

This is puzzling. First you wanted to talk about "theoretical limits" to such possibility. But now, you're describing practical limits such as "overheating". You are shifting.

But logically, it still doesn't negate the possibility of object teleportation. An electron has no "human body" to overheat. So just because you've argued that a human may not survive such teleporation, it doesn't rule out the ability to do that with an electron, proton, etc. On the contrary, if one can show that it cannot be done with an electron, proton, etc., then one can understandably argue that it won't happen with anything larger.

Zz.

 

[Dmitry67]

Sorry for not being clear.

Remember the "heisenberg microscope" as a naive explanation, why you can't observe the trajectory of an electron? And proving that the limitation is not instrumental?

Or the "maxwell demon" which is impossible - no matter how tiny detectors can be created.

My point is that impossibility to "scan" or to "teleport" macroscopic objects only appears to be instrumental, while in fact it is theoretical.

Saying "what's the problem with heating, may be in the future we will develop the devices which will be able..." might be the same is saying "may be we will make detectors so sensitive and tiny that maxwell's demon can be created". As you remember, the problem with the Maxwell demon is that is must be made of the same atom obeying the same laws. Excatly the same with scanning device, we scanbody particles with the same particles.

I hope I explained it better now.

P.S.
When you locate atoms in your body with some precision you add momentum randomly, heating them.
Heat propagates at c (infrared light)
When you start scanning skin, you have body radius/c time to complete the procedure, or the result will be inaccurate.
So you have to extract R^3 info in R/c time.

 

[ZapperZ]

But you never seem to have addressed on why this "heating" problem would apply to, say, an electron.

Zz.

 

[Dmitry67]

Lets forget about spins.

Say, you have a box 1m x 1m x 1m
You have 10^6 atoms of different sorts there.
You don't know where they are.
learning about the positions of the individual atoms leads to the heating of the system.
If links between the atoms are weaker than additional heat, created by the measurement, they will be broken.

 

[Rebooter]

Before even discussing the limit to the size of the object, shouldn't you first need show some kind of experimental evidence that an object (not just the quantum state) can be teleported? Isn't this putting the cart waaaaay before the horse?

Zz.

http://www.switched.com/2009/01/26/scientists-succeed-with-teleportation-experiment/

 

[ZapperZ]

http://www.switched.com/2009/01/26/scientists-succeed-with-teleportation-experiment/

You need to read this whole thread and figure out the difference between the Star Trek teleportation and quantum teleportation. Quantum entanglement does NOT teleport objects.

Zz.

 

[ZapperZ]

Lets forget about spins.

Say, you have a box 1m x 1m x 1m
You have 10^6 atoms of different sorts there.
You don't know where they are.
learning about the positions of the individual atoms leads to the heating of the system.
If links between the atoms are weaker than additional heat, created by the measurement, they will be broken.

Let's say you have ONE electron. Now tell me how you can have heating problems the way you described it.

Zz.

 

[yoda jedi]

A electron has a "spin" state. But the spin state is not the electron.

The quantum teleportation experiments that have been done only teleported the quantum state of the entangled ensemble. It does not teleport the object itself.

Zz.

i agree.



----------------------------------
What is actually teleported?
A. Peres
...There are no "unknown quantum states." The phrase is self-contradictory. Moreover, Alice and Bob are only inanimate objects: They know nothing. What is teleported instantaneously from one system (Alice) to another system (Bob) is the applicability of the preparer's knowledge of the state of a particular qubit in the systems...




------------------
C.Fuchs
...07 December 1998, and to the other teleporters, “Swedish Bikini Team”
The Swedish television crew came and went yesterday with little incident. No questions at all
about the soul this time: I was spared (and maybe so were you). But I didn’t pass up the chance to try to get an unsuspecting audience to think deeply about the wave function. (This audience, in fact, really will be unsuspecting: the footage was for a Swedish children’s show.)
The question came, “What material is teleported? What is it that is transported instantaneously
from Alice to Bob?”
I said, “The only thing that is teleported in quantum teleportation is what the preparer HAS
THE RIGHT TO SAY about Bob’s system. It is his description, his predictions, that jump instantaneously from one system to the other.”
A blank stare, “But what MATERIAL is teleported?”
“That is the material.”
He seemed pleased and left it at that. When he left, I had a look at my atlas to refresh the old
memory: Sweden was indeed not so very far from Copenhagen...