As per Japanese physicist (Masahiro Hotta), energy teleporation is possible

[yoron]

No, I'm not taking it too seriously, I hope? It just bugs me :
And yes, I also wondered about it DA.

But assuming both in uniform motion and that 'locality' of 'c' holds (using 'c' as your 'clock'), and that 'B' doesn't start measuring until he gets the message defining the 'time rate' from 'A'. Starting from its arrival for example. Then it seems to me that as 'B' receives the message from 'A', they have a 'timing' protocol that will work relative those two? That is, they have set up a 'causality chain' of sorts, that will hold relative them.

That we can have a third observer defining it differently doesn't change the relation in between 'A' and 'B', does it? Neither does it change the way they now can 'time it' from the arrival of that message, assuming them both moving uniformly. To assume that this relation won't hold seems, to me, to imply that 'B' can answer 'A' and that 'A' then could get this answer even before he sent his message in a worst case. And that one can't be correct.

As for the entanglement? Doesn't the measurement define all of it? If 'A' measure a momentum, won't 'A:s' interaction with the entanglement, measuring it, impart a added momentum, and also redefine the momentum for 'B' after he received the message that he can start his?

I'm ignoring the Hotta injection for this, just asking if you can define it otherwise than that A:s interaction measuring the momentum will add a momentum from A:s measurement, that is valid for the whole entanglement? No matter how HUP treats it, the idea should hold, or?
==

To make it somewhat easier to think about, let us assume that they are uniformly moving, of a identical mass distribution/gravity, and at rest relative each other. 'Time dilations' are hard to avoid :)

 

[DevilsAvocado]

No, I'm not taking it too seriously, I hope? It just bugs me :

No worries mate.

But assuming both in uniform motion and that 'locality' of 'c' holds, and that 'B' doesn't start measuring until he gets the message defining the 'time rate' from 'A'. Starting from its arrival for example. Then it seems to me that as 'B' receives the message from 'A', they have a 'timing' protocol that will work relative those two? That is, they have set up a 'causality chain' of sorts, that will hold relative them.

Okay, but for how long? Clocks will always drift no matter what... The safest way must be to create (let’s say) 100 entangled pairs, let A do her measurements, and then send the 'twins' to B for an "energy measurement"... but then you could use DrC’s "Laser Gadget" instead... cheaper, safer and simpler...

That we can have a third observer defining it differently doesn't change the relation in between 'A' and 'B', does it? Neither does it change the way they now can 'time it' from the arrival of that message, assuming them both moving uniformly. To assume that this relation won't hold seems, to me, to imply that 'B' can answer 'A' and that 'A' then could get this answer even before he sent his message in a worst case. And that one can't be correct.

But this reasoning builds on that you are sending something beforehand in a "classical channel" ≤ c, right? And then were back to the "Laser Gadget"...

If you don’t do that, and are using entanglement (at least 10,000 times c), and try to define a 'causality chain' you’re in for a real treat...

The fact is, that if a "peak of energy" was about to propagate (like a bullet) from A to B at FTL, you couldn’t even agree on the direction! Some would be certain it was going from B to A!

Fredrik has constructed a very nice "Computer Paradox" https://www.physicsforums.com/showthread.php?p=2588832#post2588832". It is nuts! :yuck:

As for the entanglement? Doesn't the measurement define all of it? If 'A' measure a momentum, won't 'A:s' interaction with the entanglement, measuring it, impart a added momentum, and also redefine the momentum for 'B' after he received the message that he can start his?

I’m not sure I understand... in real EPR-Bell experiments with a BBO crystal, entanglement happens at random and is very rare. The only way to ensure that you are measuring the same pair is thru time tagging and coincidence counting (slot). If you use so-called "perfect correlations", i.e. put the measuring apparatus at the same angle, you will always know the exact outcome for B, if A is measured first.

But this knowledge (about B) can only be transmitted at ≤ c.

EDIT: And of course you cannot enforce the outcome of A (and hence B), it will always be 50/50 random up/down.

I'm ignoring the Hotta injection for this, just asking if you can define it otherwise than that A:s interaction measuring the momentum will add a momentum from A:s measurement, that is valid for the whole entanglement? No matter how HUP treats it, the idea should hold, or?

Generally, there is absolutely no way for A or B to tell if something was 'done' in the other end, like a measurement. All A and B will see from their measurements is random noise. Finally, when they get together and compare their data, a pattern of correlations will emerge from the two separate measurements. That’s all you get, but to me it’s pretty cool as it is!

 

[DrChinese]

...

As for the entanglement? Doesn't the measurement define all of it? If 'A' measure a momentum, won't 'A:s' interaction with the entanglement, measuring it, impart a added momentum, and also redefine the momentum for 'B' after he received the message that he can start his?

1. The RESULTS of Bob's measurement is 100% predictable if made after Alice's, and 100% UNpredictable if made before Alice's. That assumes they are measuring on the SAME BASIS. This is simply a restatement of the HUP.

2. On the other hand, when measuring on a different (non-commuting) basis: The RESULTS of Bob's measurement is 100% UNpredictable (i.e. no better than chance) even if made AFTER Alice's and you send Alice's results to Bob in advance. This is too simply a restatement of the HUP.

3. QM says that the results of measurements of entangled A and B are themselves independent of time ordering. This has been experimentally verified. See 1. again and you will realize that when you combine Alice's and Bob's results, this is ALWAYS the case. That is because when they measure on the same basis, the results are completely redundant! When they measure on a different basis, the results are completely random! So ordering obviously does not change the outcome.

4. Keep in mind that every pair of A and B is fully independent of all other A+B pairs. So if you need information for 1 pair, you will need to get fresh information for other pairs. That is because each pair has random values, I am sure you can see this will be true if they are entangled (it is practically definitional).

5. There is NO ENERGY BEING INJECTED AND TELEPORTED ANYWHERE FROM A MEASUREMENT APPARATUS. That is a misunderstanding, plain and simple, despite what you are reading from Hotta. Again, the terminology is what is confusing. You cannot push A and feel it at B, or something similar. This is NOT a part of QM, and there is no evidence or hint of evidence for this concept. The "energy" being teleported has to do with the system of A+B, and has nothing to do with the measuring device at A injecting something into that system which is received at B. I believe that in the example, we are talking about a measuring device which is simply a passive polarizer - which is obviously incapable of adding energy.

 

[yoron]

As for "There is NO ENERGY BEING INJECTED AND TELEPORTED ANYWHERE FROM A MEASUREMENT APPARATUS." I agree totally, never have said anything else? What I'm talking about is not Hotta there, just about what happens as you measure a entanglement, that is 'interact' with it.

I assume that the interaction will add a momentum to your entanglement, and also, as you can't differ/split the 'wave function' without interfering, that this 'added momentum' will exist at all 'places' of the entanglement, meaning 'both sides'. I'm not discussing Hotta at all there.

The question is: is it so that a measurement of a entanglement will add a momentum in the interaction by your measuring.

If not, how do it do it?

If it do, then it seems to me that we always inject 'momentum/energy' in our measurements.
=

When it comes to injecting 'energy' in general.

I presume that you see 2. "On the other hand, when measuring on a different (non-commuting) basis: The RESULTS of Bob's measurement is 100% UNpredictable (i.e. no better than chance) even if made AFTER Alice's and you send Alice's results to Bob in advance. This is too simply a restatement of the HUP." as the definition of why a 'timer' won't work here?

When it comes to sending a code, or something where a 'decoder' is needed you always need a sub channel for each entanglement. I'm just not sure that this argument works for 'work', as this 'energy seems to become in his description? There is no decoder needed as I think of it, what is needed is just knowing the intervals between measuring the entanglements for the 'receiver', relative the 'sender'.

 

[yoron]

Yeah DA, better see this as an 'idealised' thought experiment. It's extremely hard to imagine it any other way as gravity is 'everywhere', and clocks will differ relative the observer. So, uniformly moving, at rest with each other, of the exact same gravity, etc :)

As for entanglements 'propagating information' I never said they did? The initial 'message' I'm discussing is through a sub-channel, slower that light, or lights speed in a vacuum.

I don't see a entanglement that way, as I said a description I like was the one of 'one particle'. I can go with a 'wave function' describing it too though, as long as we then assume it to be in a pristine 'superposition' prior to the measurement, with 'both sides' falling out in the interaction/measurement, no matter if the side not making that initial measuring, will measure it later, or not.

 

[DrChinese]

...I assume that the interaction will add a momentum to your entanglement, and also, as you can't differ/split the 'wave function' without interfering, that this 'added momentum' will exist at all 'places' of the entanglement, meaning 'both sides'. I'm not discussing Hotta at all there.

The question is: is it so that a measurement of a entanglement will add a momentum in the interaction by your measuring.

Nope, generally this is not the case (although there are some complex exceptions that are really not relevant to this discussion). Once there is a measurement on an entangled particle, it ceases to act entangled! (At the very least, on that basis.) So you might potentially get a new entangled pair [A plus its measuring apparatus] but that does not make [A plus its measuring apparatus plus B] become entangled. Instead, you terminate the entangled connection between A and B.

You cannot EVER say specifically that you can do something to entangled A that changes B in any specific way. For all the evidence, you can just as easily say B changed A in EVERY case! This is regardless of the ordering, as I keep pointing out. There is NO sense in QM entanglement that ordering changes anything in the results of measurements. Again, this has been demonstrated experimentally.

My last paragraph, if you accept it, should convince you that your hypothesis is untenable. Because you are thinking measuring A can impart momentum to the A+B system, when I say it is just as likely that it would be B's later measurement doing the same thing. (Of course neither happens in this sense.) Because time ordering is irrelevant in QM but would need to matter to make your idea be feasible.

 

[pranj5]

There is no science - theory or experiment - indicating there is a technique for pulling useful energy from the vacuum. Nothing you quoted or elsewhere in the literature contradicts this statement. The law of conservation of total energy forbids this. You cannot end up with more energy than you started with, and nowhere has Hotta suggested otherwise.

Nobody denies that. Hotta clearly said that energy at B can be extracted only when there is an input at A. SO, WHY ARGUING?

There is no science - theory or experiment - indicating there is a technique for "teleporting" useful energy from point A to point B faster than light. Nothing you quoted or elsewhere in the literature contradicts this statement. Hotta's technique for "quantum energy teleportation" requires a classical communication channel to function. To quote Hotta: "Recently, negative energy physics has yielded a quantum protocol called quantum energy teleportation (QET) in which energy can be transported using only local operations and classical communication (LOCC) without breaking causality and local energy conservation."

Another quote from Hotta"

Amazingly, the QET protocol can transport energy from A to B in a time scale much shorter than that of the usual transportation.

On the other hand, there is theory and experiment for "teleporting" useful energy from point A to point B at speeds at or near the speed of light, and those have been known for decades. An example is a laser, which has been around for about 50 years.

We are discussing quantum energy teleportation here, NOT CLASSICAL.

pranj5, there is a difference between accepted science (what I have given above) and your speculation based on Hotta's work. I can cite you plenty of papers that give exciting and interesting results which hint of all kinds of things - such as retrocausal action. And yet there is still no theoretical assertions that retrocausal action is possible. That is simply a parallel. In the case of Hotta, we are fascinated by the idea that essentially, you invest something into the vacuum at one point and extract it at another. And Hotta shows that is in keeping with QM. If so, fine, but understand that the principles of QM are respected at all times - including conservation and classical limits of causality.

You need to either accept that yours is pure speculation, or stop talking about it here. PhysicsForums is for science.

Before Fermi made the first atomic energy based experimental power plant, E=MC2 was also a "speculation" as per your terminology, BUT SPECULATION BASED ON SCIENCE.
Well, can you explain how Quantum computers respect "classical limits of causality". As per wikipedia, Quantum Computers can perform computation much much faster than classical computers and it need a classical computer of huge memory and RAM to perform the same actions which are just unachievable with present technologies.

 

[DrChinese]

Before Fermi made the first atomic energy based experimental power plant, E=MC2 was also a "speculation" as per your terminology, BUT SPECULATION BASED ON SCIENCE.

Hey, you aren't Fermi. Or Einstein. :tongue: And there is not a lick of science to support your speculations (which is not Hotta's, as he is not prone to the speculation you seem to employ).

 

[yoron]

You wrote "You cannot EVER say specifically that you can do something to entangled A that changes B in any specific way. For all the evidence, you can just as easily say B changed A in EVERY case! This is regardless of the ordering, as I keep pointing out. There is NO sense in QM entanglement that ordering changes anything in the results of measurements. Again, this has been demonstrated experimentally."

So if I choose to measure its momentum I don't define it in a special way, as compared to measuring a spin for example? Mixing in relativity we can get a uncertanity relative a third observer, but his relation as a observer seems to me weaker than the role 'A' and 'B' takes measuring. And between 'A' and 'B', that do the actual deed, there should be no confusion to whom was the first to do it, assuming 'A' informing 'B' via a sub-channel as he do the initial measuring.

Looked at as a wave function you collapse it in your initial measurement, that sets the 'state' for the whole entanglement, as I see it (or 'particle':) and if a measurement exert a 'force' on what it measures (interaction) then I wonder where that momentum goes, if it doesn't exist on 'both sides'. Seems like a collision of terms if you want a interaction as a measurement to exist, without it imparting any momentum/energy? But I'm not sure, and if you know how to define a interaction without imparting a momentum I'm curious.

 

[yoron]

The point I see here is that we're talking about 'energy'. It is a addition of 'work' for 'B', assuming that 'A:s' measurement indeed impart a momentum/energy in the collapse of the wave function. And energy is something you can use, not needing it to 'make sense' first, as I think of it that is. And that's where the 'timer' comes in for me, relative a initial sub-channel light message. Assuming only one entanglement, and message, you only need to define if there is, or is not, a addition of momentum in the entanglement through the initial measurement though.

It might be that there are different definitions, in where we always need to 'make sense' of it, before using it though, but then I would like a example showing me why, and how, we do that. And it's not really Hotta, although he had some ideas of how to lift that 'energy' out.

 

[bohm2]

This is confusing me. With respect to quantum teleportation, the advantage would be one can quickly and reliably move around quantum information via electromagnetic signals and material particles (electrons, light, etc.). That would be useful in the future in stuff like quantum computers, etc. If accurate, what would be the implications of quantum energy teleportation with respect to using this "energy" be? Would it be for long-distance transportation of quantum information in quantum computers, quantum nanodevices, etc.?

 

[aspades]

Since this paper has been published new scientist published an article saying light has been transported across a room through pairs of entangled particles.

 

[DrChinese]

You wrote "You cannot EVER say specifically that you can do something to entangled A that changes B in any specific way. For all the evidence, you can just as easily say B changed A in EVERY case! This is regardless of the ordering, as I keep pointing out. There is NO sense in QM entanglement that ordering changes anything in the results of measurements. Again, this has been demonstrated experimentally."

So if I choose to measure its momentum I don't define it in a special way, as compared to measuring a spin for example? Mixing in relativity we can get a uncertanity relative a third observer, but his relation as a observer seems to me weaker than the role 'A' and 'B' takes measuring. And between 'A' and 'B', that do the actual deed, there should be no confusion to whom was the first to do it, assuming 'A' informing 'B' via a sub-channel as he do the initial measuring.

Looked at as a wave function you collapse it in your initial measurement, that sets the 'state' for the whole entanglement, as I see it (or 'particle':) and if a measurement exert a 'force' on what it measures (interaction) then I wonder where that momentum goes, if it doesn't exist on 'both sides'. Seems like a collision of terms if you want a interaction as a measurement to exist, without it imparting any momentum/energy? But I'm not sure, and if you know how to define a interaction without imparting a momentum I'm curious.

The issue is that your idea of entanglement does not mesh with what actually happens. If you do something to A, nothing changes at B. Ever - at least as far as we know. All you can say is that the results from measurements at A and B will be consistent with the Heisenberg Uncertainty Principle (HUP). Measurements at A and B can be at any time or place, and this will be true.

It is true that when A collapses first, it sets the wave state for B. However, and this is the point that is hard to grasp, it is equally true that when B is measured AFTER A, B sets the wave state for A. There is no possible experiment which will yield a different result. Any other description is one which a convenience for our language. A does not "cause" B in any strict meaningful sense of the word. Only the entire context matters, and that is why order of measurements is not important.

If you work through an actual example using 2 polarization entangled photons, it will probably be easier to follow. Then you will see better WHY I am repeating the points I keep making. Would you like me to show you?

 

[bohm2]

Since this paper has been published new scientist published an article saying light has been transported across a room through pairs of entangled particles.

Is it this one?

Teleportation of Nonclassical Wave Packets of Light

We report on the experimental quantum teleportation of strongly nonclassical wave packets of light. To perform this full quantum operation while preserving and retrieving the fragile nonclassicality of the input state, we have developed a broadband, zero-dispersion teleportation apparatus that works in conjunction with time-resolved state preparation equipment. Our approach brings within experimental reach a whole new set of hybrid protocols involving discrete- and continuous-variable techniques in quantum information processing for optical sciences.

http://www.sciencemag.org/content/332/6027/330.abstract

 

[DrChinese]

This is confusing me. With respect to quantum teleportation, the advantage would be one can quickly and reliably move around quantum information via electromagnetic signals and material particles (electrons, light, etc.). That would be useful in the future in stuff like quantum computers, etc. If accurate, what would be the implications of quantum energy teleportation with respect to using this "energy" be? Would it be for long-distance transportation of quantum information in quantum computers, quantum nanodevices, etc.?

It is not clear to me that there is an implication, because there are already experiments which show a lot of quantum FTL effects (entanglement swapping being an example). Hotta seems to see an angle I don't, but that is hardly surprising (he's the expert). I would strongly urge everyone following this thread to be very cautious with the term "quantum energy teleportation" as this is seriously misleading.

 

[bohm2]

Hotta seems to see an angle I don't, but that is hardly surprising (he's the expert). I would strongly urge everyone following this thread to be very cautious with the term "quantum energy teleportation" as this is seriously misleading.

I'm lost. What is your hunch about their meaning of "quantum energy"? Don't they mean the zero-point energy? I'm asking because this is what they write:

In this counterintuitive protocol, the counterpart of the classical "transmission line" is a quantum mechanical many-body system in the vacuum state (i.e., a correlated system formed by vacuum state entanglement. The key lies using this correlated system (hereinafter, the quantum correlation channel) to exploit the zero-point energy of the vacuum state, which stems from zero-point fluctuations (i.e., nonvanishing vacuum fluctuations) originating from the uncertainty principle. This energy, however, cannot be conventionally extracted as that would require a state with lower energy than vacuum—a contradiction. In fact, no local operation can extract energy from vacuum, but must instead inject energy; this property is called passivity. According to QET, however, if we limit only the local vacuum state instead of all the vacuum states, the passivity of the local vacuum state can be destroyed and a part of the zero-point energy can in fact be extracted.

http://arxiv.org/PS_cache/arxiv/pdf/1109/1109.2203v1.pdf

 

[pranj5]

Hey, you aren't Fermi. Or Einstein. :tongue: And there is not a lick of science to support your speculations (which is not Hotta's, as he is not prone to the speculation you seem to employ).

And you are not the ultimate authority to announce what is "science" and what is "speculation". Just keep that to yourself.

 

[M.Hotta]

Hi! I'm Hotta. My friend emailed me about this thread. I'm glad to know you all have interest of my QET. However, you seem confused a little bit. Dr.Chinese looks like understand fairly well, though some part he also misunderstands.

I'm a theorist, not an experimentalist. I can not do experiments to verify my QET theory. My colleagues have a plan to do the exp, but, unfortunately, on 3.11 of this year, our university was severely affected by an big earthquake. This generated a big tsunami that killed a lot of people and a serious nuclear power plant accident. Now we are doing much effort to recover our research activity, though that seems very long-way. It is good for me that somebody will try the QET experiment in USA or other countries.

In order to understand QET precisely, please read my review article: http://www.tuhep.phys.tohoku.ac.jp/~hotta/extended-version-qet-review.pdf
The energy is 'teleported', just in an operational sense, as seen in p6-p8 of the above review.
If you see a process described in the pages, you say the energy is truly 'teleported' from a viewpoint of users, don't you? (Please see page 21.) The energy of information carriers, which Dr.Chinese worried about, is not important. Bob obtains energy of information carriers plus additional energy from local vacuum by generating a negative-energy wave packet of the quantum field.

In order to understand the meaning of the teleported energy deeply, we should recall two points, I think. The first is the fact that any energy has no tag which shows where it was stored, just like pure water. (Anyone cannot make distinction between pure water on Earth and pure water on moon.) The second is the famous Wheeler's viewpoint about many particles. J. A. Wheeler came up with an exotic idea about electron and positron (anti-electron), and proposed it to Feynman. He imagined that one particle is doing a zigzag motion in our spacetime, and that it is electrons when it propagates forward in time, positrons when propagates backward in time. Actually, we have many electrons and positrons in our world, but he said they are a single particle. His picture could explain why all electrons have the same mass and charge. (As you know, the current precise explanation about that is provided by quantum field theory, not his own idea. ) In a similar way, we can regard a part of the energy Alice injects as the energy Bob extracts. Let us imagine that, after a one-round protocol of QET, the negative energy that Bob generates in the quantum field moves to the positive energy injected by Alice and merges ( partially pair-annihilated ). Then, the energy shows a zig-zag motion in the spacetime, like the electron of Wheeler. In this sence, it becomes meaningless to discuss distinction between the energy Bob obtains and a part of the energy Alice injects. What we can do is just to say that energy is transported in an operational sense via classical communication. Thus, I called this as energy teleportation. (As you know, a very similar situation happens when you say that energy of the Hawking radiation comes from inside a black hole event horizon and the black hole loses its energy.)

I would like to respond all comments here, but have no enough time. Please email me if you have a question about QET, though afraid that the response delay will often takes place, sorry.

 

[pranj5]

Hi! I'm Hotta. My friend emailed me about this thread. I'm glad to know you all have interest of my QET. However, you seem confused a little bit. Dr.Chinese looks like understand fairly well, though some part he also misunderstands.

I'm a theorist, not an experimentalist. I can not do experiments to verify my QET theory. My colleagues have a plan to do the exp, but, unfortunately, on 3.11 of this year, our university was severely affected by an big earthquake. This generated a big tsunami that killed a lot of people and a serious nuclear power plant accident. Now we are doing much effort to recover our research activity, though that seems very long-way. It is good for me that somebody will try the QET experiment in USA or other countries.

In order to understand QET precisely, please read my review article: http://www.tuhep.phys.tohoku.ac.jp/~hotta/extended-version-qet-review.pdf
The energy is 'teleported', just in a operational sense, as seen p6-p8 of the above review.
If you see a process described in the pages, you say the energy is truly 'teleported' from a viewpoint of users, don't you? (Please see page 21.) The energy of information carriers, which Dr.Chinese worried about, is not important. Bob obtains energy of information carriers plus additional energy from local vacuum by generating a negative-energy wave packet of the quantum field.

In order to understand the meaning of the teleported energy deeply, we should recall two points, I think. The first is the fact that any energy has no tag which shows where it was stored, just like pure water. (Anyone cannot make distinction between pure water on Earth and pure water on moon.) The second is the famous Wheeler's viewpoint about many particles. J. A. Wheeler came up with an exotic idea about electron and positron (anti-electron), and proposed it to Feynman. He imagined that one particle is doing a zigzag motion in our spacetime, and that it is electrons when it propagates forward in time, positrons when propagates backward in time. Actually, we have many electrons and positrons in our world, but he said they are a single particle. His picture could explain why all electrons have the same mass and charge. (As you know, the current precise explanation about that is provided by quantum field theory, not his own idea. ) In a similar way, we can regard a part of the energy Alice injects as the energy Bob extracts. Let us imagine that, after a one-round protocol of QET, the negative energy that Bob generates in the quantum field moves to the positive energy injected by Alice and merges ( partially pair-annihilated ). Then, the energy shows a zig-zag motion in the spacetime, like the electron of Wheeler. In this sence, it becomes meaningless to discuss distinction between the energy Bob obtains and a part of the energy Alice injects. What we can do is just to say that energy is transported in an operational sense via classical communication. Thus, I called this as energy teleportation. (As you know, a very similar situation happens when you say that energy of the Hawking radiation comes from inside a black hole event horizon and the black hole loses its energy.)

I would like to respond all comments here, but have no enough time. Please email me if you have a question about QET, though afraid that the response delay will often takes place, sorry.

Hello Prof. Hotta,
Glad to have you in this forum. Whatsoever, I want to ask you the same question that I have asked you in my e-mail to you (to the e-mail address given on your papers). I am curious to know that 1) whether this QET phenomenon can be used as substitute to classical channel communication and 2) whether the classical channel is an integral part of the process or not. If Alice can inject energy at A and Bob can extract that at B and if the process is continuous i.e. Alice just started his "energy" pumping apparatus and Bob kept his own machine on, then why every time some kind of classical communication is necessary. Just think of a scenario when Alice just communicated to Bob (via classical channel) that "I have started" and Bob started his own apparatus. Then is the classical channel necessary after every pulse of energy injection?

 

[M.Hotta]

1) whether this QET phenomenon can be used as substitute to classical channel communication

ANS. The amount of 'teleported' energy becomes quite small, as the distance becomes macroscopically large. Thus, QET is not suitalble for macroscopic energy transfer like classical channel communication. QET is a small-world phenomenon, like processes in quantum devices.

2) whether the classical channel is an integral part of the process or not.
ANS. The classical channel for announcement of the measurement result is one of key ingredients of QET. This ensures that QET satisfies causality and prohibits superluminal (faster-than-light) energy transfer. What Dr.Chinese said about that is precisely correct.

 

[DevilsAvocado]

1) whether this QET phenomenon can be used as substitute to classical channel communication

ANS. The amount of 'teleported' energy becomes quite small, as the distance becomes macroscopically large. Thus, QET is not suitalble for macroscopic energy transfer like classical channel communication. QET is a small-world phenomenon, like processes in quantum devices.

2) whether the classical channel is an integral part of the process or not.
ANS. The classical channel for announcement of the measurement result is one of key ingredients of QET. This ensures that QET satisfies causality and prohibits superluminal (faster-than-light) energy transfer. What Dr.Chinese said about that is precisely correct.

Thanks a lot Hotta!

This explains a lot, and I guess "Mars Power Plants" is out of the question!

Explanation: We have "one guy" here who says dogs can fly, but not by themselves.

 

[pranj5]

1) whether this QET phenomenon can be used as substitute to classical channel communication

ANS. The amount of 'teleported' energy becomes quite small, as the distance becomes macroscopically large. Thus, QET is not suitalble for macroscopic energy transfer like classical channel communication. QET is a small-world phenomenon, like processes in quantum devices.

Well, from your answers, it seems that this phenomenon is useless beyond the volume of a hydrogen atom. In your papers, you have said about the damping factors, can you say something about that? I mean what are those damping factors that prevent QET to transfer large amount of energy to macroscopic distances.

2) whether the classical channel is an integral part of the process or not.
ANS. The classical channel for announcement of the measurement result is one of key ingredients of QET. This ensures that QET satisfies causality and prohibits superluminal (faster-than-light) energy transfer. What Dr.Chinese said about that is precisely correct.

Well, as per the paper you have mentioned in your first post, how big can the amount of energy that Alice can sent to Bob by thins method.

 

[DevilsAvocado]

Obviously not big enough for a power plant on Mars! :rofl:

 

[yoron]

Nice, and thanks a lot for taking a interest Mr. Hotta. How do you view the interaction taken in measuring a entanglement? Do it impart a momentum as it measures? Will the momentum imparted, if existing, exist over the whole of the entanglement?

As for describing it as existing in a 'time symmetry', I don't know? Macroscopically there always should be someone initialising it, at least under our arrow of time. And when it comes to a controlled entanglement it is easy to define who's 'involved'. It all seems to fall back to what 'time' should be seen as, though? But as all theories it has to fit what we observe, and I do not know of any experiments made in 'reversed time'? To me they all have a causality chain following our macroscopic arrow of time, whether it is observing positrons or electrons?

To say that nothing happens to 'B' after me measuring 'A' gets me confused. It may be semantics, but as I understands it we define a entanglement as something being 'together', where an action taken on 'A' having a instantaneous effect on 'B'? I don't see how you can expect that to be true, at the same time as you define it as noting can have happened at 'B', until you measure it?

This one you need to explain MRChinese :)

"It is true that when A collapses first, it sets the wave state for B. However, and this is the point that is hard to grasp, it is equally true that when B is measured AFTER A, B sets the wave state for A."

Is that from the idea of a symmetric 'time'? If I use a beam splitter and split a 'photon' in two A and B. Then proceed to measure A after that go on to measure B, are they reversible? In 'time' that is?

What I mean here is that the action is taken on 'A' before the action taken on 'B'. That they are identical, and would give identical relations, no matter on which 'side' I started to measure don't invalidate the arrow I measured them under, well, as I see it?
=

And yes Mr Hotta

"The first is the fact that any energy has no tag which shows where it was stored, just like pure water. (Anyone cannot make distinction between pure water on Earth and pure water on moon.)"

That's how I think of it too. And then it to me become a question of what we mean by 'information' in this case?

 

[yoron]

To me it would have to be a very 'still' universe, if I define particles and anti particles this way, Almost like a lightcone of 'relations' stretching both forward and backward in 'time', not 'moving' in themselves as they exist simultaneously, using the eye of God. Which then should become a question about why we have a macroscopic arrow. If I get it right here.

 

[DevilsAvocado]

To say that nothing happens to 'B' after me measuring 'A' gets me confused. It may be semantics, but as I understands it we define a entanglement as something being 'together', where an action taken on 'A' having a instantaneous effect on 'B'? I don't see how you can expect that to be true, at the same time as you define it as noting can have happened at 'B', until you measure it?

Nothing final happens to B until you measure it. [In most cases] there is always a large amount of 'randomness' involved in EPR-Bell experiments when getting the final outcome. For instance, the angle is random and should be set in the very last moment (outside A’s light-cone) to do it properly. And depending on the relative angle a-b, you get very different probabilities for the final outcome. Malus' law: cos^2(a-b) gives you the probabilities. Hence, you cannot claim that A has an instant effect on B, what happens is that the shared wavefunction decohere/collapse and this sets the 'prerequisites' for the final outcome, but B isn’t 'materialized' until the measurement is performed.

This one you need to explain MRChinese :)

"It is true that when A collapses first, it sets the wave state for B. However, and this is the point that is hard to grasp, it is equally true that when B is measured AFTER A, B sets the wave state for A."

I think this falls back on our previous discussion on SR and RoS...

There’s absolutely no doubt that the entangled pair of photons share the one and only wavefunction, period.

Could one wavefunction decohere/collapse/branch twice?? Answer: NO

Now, suppose you want to decide which one of Alice & Bob do actually decohere the wavefunction and sets the state, given they have equal opportunities; it will be impossible to tell according to RoS.

(And this time it is 'bulletproof', no "timer" in the world could save you. )

However, if you arrange so that you first measure A, to let say spin up, and then take this result to Bob and do the B measurement – this will of course not have any possibility to change the A measurement (in retrospect) to spin down... that’s impossible.

 

[DrChinese]

Well, from your answers, it seems that this phenomenon is useless beyond the volume of a hydrogen atom. ...
Well, as per the paper you have mentioned in your first post, how big can the amount of energy that Alice can sent to Bob by thins method.

First, thanks to M. Hotta for the time to help us better understand QET!

pranj5, thanks for bring Hotta into the discussion, but you are still missing the big picture here. Hotta's work is theoretical, it doesn't really matter how much energy is teleported by the process. That there is a possibility that ANY could be shifted is a good result in itself (in my opinion).

I think most would understand that it's not likely this would be a net positive teleportation in the end (although I can't be sure). As mentioned previously, we already have practical devices that can do the same thing.

What I have been trying to tell you is that the speculative ideas you advanced early on are not appropriate for this forum. While yours is not science, Hotta's is. If you follow the following link, you will see that there were over 1000 papers written this year alone on theoretical AND experimental developments in entanglement. Many of the results presented are amazing papers, I think if you scan a few you will see all kinds of exotic terms and ideas mentioned that shed important new light on the quantum world. Every one is a step forward. This is how science works, it takes time and a bit of luck every now and then.

http://arxiv.org/find/quant-ph/1/abs:+OR+entanglement+OR+bell+epr/0/1/0/2011/0/1?per_page=100

Skip the sci fi speculation, it doesn't really do anyone any good.

 

[M.Hotta]

Dear all, thank you so much for your responces. I have no time to reply them in detail. I think DrChinese has ability of explanation about that. (He is one of the best persons who understand physics quite well among this thread participants, I think. ) Please ask him to discuss about that.

If you want to know about the effect of quantum measurement, please read my review:http://www.tuhep.phys.tohoku.ac.jp/~hotta/extended-version-qet-review.pdf
In particular, p29 and p36-38. Time dependence of switch on-off of measurement devices always excites quantum fields in the vacuum state locally.


Description about the distance and energy scale of QET exp using quantum Hall systems can be found in our recent paper publsihed in Physical Review A. (You can see it via
http://xxx.yukawa.kyoto-u.ac.jp/abs/1109.2203 .) The typical length scale of QET systems is 10μm and the order of teleported energy is estimated as 100μeV.

The amount of teleported energy per one QET channel is quite small. However, if you consider huge numbers of QET channels paralley laid, the total amount of energy becomes large, in principle. Therefore it is valid to apply the QET argument to various gedanken experiments with cosmological distance scales or black hole physics, by taking a large N limit in terms of the number of quantum matter fields. The total amount of teleported energy can be N-times enhanced. About this, please see the above review (p51) and my recent paper published in Physical Review D.(You can see it via http://xxx.yukawa.kyoto-u.ac.jp/abs/0907.1378 .)

About the case with many people who extract energy using Alice's information, please see p49-50 of the above review.

 

[yoron]

DA :)

It's about definitions I think. To me causality exist in SpaceTime. Although you might want to define it as times arrow can take on different values, when comparing 'frames of reference', to me it have only one direction, into the future. Locally your clock always will be the same (relative your heartbeats, as a weak example), and that is enough to prove a casualty chain at the local plane.

On the conceptual plane, comparing frames of reference, you can find some other clock to, possibly, become unmeasurable, not ticking at all as you observe it. But you will nowhere find a 'clock' that, relative your local 'clock' ticks backward.

And that's where you make your experiments, inside SpaceTime.

"In relativistic QFT, all particles (and antiparticles) travel forward
in time, corresponding to timelike or lightlike momenta.
(Only 'virtual' particles may have unrestricted momenta; but these are
unobservable artifacts of perturbation theory.)

The need for antiparticles is in QFT instead revealed by the fact that
they are necessary to construct operators with causal (anti)commutation
relations, in connection with the spin-statistic theorem. See, e.g.,
Volume 1 of Weinberg's quantum field theory book."

So it is a question of 'definitions' to me. The same will be true with how you define that 'wave function' collapsing. As I understand it we can talk of a entanglement as existing as one wave function only, same as you described it. Assuming a arrow of time pointing one way, and with causality chains defined as above I expect us to be able to define who measured first, ignoring simultaneous measurements. Although there always will exist a doubt from a third observer, not involved in the process, we can, assuming that Lorentz transformations hold for defining a 'same universe' use those to prove who did what relative their own frames of reference.

Failing that, assuming that there is no coherent background, even though Lorentz transformations exist and work, we will have to look at the persons involved here, 'A' and 'B' and then define it as the measuring they do relative each other, as well as the message received, will define who did what, relative the relation created in their measuring, and messaging. Assuming no message but still a measurement we will have to define whom is observing them both, and then also 'measuring' their respective measurements ( in time :)

Why I discussed a 'timer' was just the remarkable definitions 'energy' has, which I'm still not sure of how to see. But I'm pretty sure that a measurement should impart a momentum, and as I expect, be present in all of it, not only one side. Whether you choose to measure that or something else, and no matter whether HUP treats it one way or another, I still would expect a addition by that measurments momentum.

As for it falling out, when it does it should to me be defined by one who did it first, even though there is a 'time symmetry' assumed in physics. And 'first' will easiest be defined relative a 'relation' as in a communication by message. Without it we fall back on defining a observer and his relation to those doing the experiment, or possibly assume that they was watching each other, and then use Lorentz transformations for defining who did it 'first'.

What I mean is that from the entanglements side there can be no two interactions on it, only one, if we define it as a 'wave collapse'.

 

[bohm2]

Thanks to everyone. This was a very useful thread and also a lesson to me to read the original papers more carefully and not through secondary sources. Because M. Hotta did suggest possible uses of QET on p. 50:

Much after the transportation, dynamical evolution of the system begins and then heat is generated. Thus, the time scale for effective energy transportation by QET is much shorter than that of heat generation. This property is one of the remarkable advantages of QET. Due to this property, QET in expected to find use use as an energy distribution scheme inside quantum devices that avoids thermal decoherence and would thus assist in the development of quantum computers.

 

[DevilsAvocado]

Dear all, thank you so much for your responces.

Thanks again, for taking your time explaining QET!

 

[DevilsAvocado]

... and also a lesson to me to read the original papers more carefully and not through secondary sources

extremely good point, thanks...

 

[DevilsAvocado]

It's about definitions I think.

It’s all about definitions!

And I admit being a bit 'sloppy'... this is no easy matters. Fact: We know that Local Realism is a dead parrot (99%), what’s left is the Grand Funeral. Then we have 3 options left on how the world works at the fundamental level:

• non-local + realism
• local + non-realism
• non-local + non-realism

It’s only in solutions containing non-locality you get this tension between SR and QM. However, if you accept the Many-worlds interpretation (MWI), this tension is gone immediately.

If you are still left, we can start the 'fight'!

Although there always will exist a doubt from a third observer, not involved in the process, we can, assuming that Lorentz transformations hold for defining a 'same universe' use those to prove who did what relative their own frames of reference.

I don’t agree that you need a third observer to get problems with RoS, and I think Einstein is on my side...

Einstein's old train thought experiment from 1917:

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I don’t want to make a big fuss over this; although I find it very interesting, with the tension between SR and QM (in case of confirmed non-locality), because here we have an experiment, alive and kicking, that could be performed in the undergraduate laboratory, which is much easier than travel back to Big Bang and t0!

But I can promise you – this is not my 'idea'.

A few months before John Stewart Bell died he held a lecture where he expressed his thoughts around the incompatibility between SR and QM, when it comes to non-locality. You can also find it the literature:

http://books.google.com/books?id=BaOoqbLrXK8C&dq=ladyman+every+thing+ross&hl=en

Every Thing Must Go - Metaphysics Naturalized (2007)
James Ladyman, Don Ross, David Spurrett, John Gordon Collier

(Page 165)

The upshot seems to be that the status of the arrow of time in QM is open. The tension between SR and QM is made into a definite contradiction if collapse of the wave function is regarded as an objective physical process, as in the dynamical collapse theories along the lines developed by Ghiradi et al. (1986), or if non-local hidden variables are introduced as in Bohm theory, since both imply action at a distance and pick out a preferred foliation of spacetime (Timpson and Brown forthcoming, Maudlin 1994). The real questions concern what happens to time if quantum theory is married with GR, and we return to that issue below. (Since relativistic quantum field theory is based on the background of Minkowski spacetime the status of time in the former is the same as in SR.)

But I'm pretty sure that a measurement should impart a momentum, and as I expect, be present in all of it, not only one side.

I’m not sure what you mean... did you get my explanation of a standard EPR-Bell experiment with entangled photons measuring a superposition of spin, in https://www.physicsforums.com/showpost.php?p=3612060&postcount=96"?

I can’t tell to you what to do, but my 'recommendation' is to leave momentum out of it for the moment, and make sure you got the "EPRB standard experiment" right... (it’s complex as it is)

What I mean is that from the entanglements side there can be no two interactions on it, only one, if we define it as a 'wave collapse'.

Yep! That’s my point also:

There’s absolutely no doubt that the entangled pair of photons share the one and only wavefunction, period.

Could one wavefunction decohere/collapse/branch twice?? Answer: NO

 

[bohm2]

It’s all about definitions!

And I admit being a bit 'sloppy'... this is no easy matters. Fact: We know that Local Realism is a dead parrot (99%), what’s left is the Grand Funeral. Then we have 3 options left on how the world works at the fundamental level:

• non-local + realism
• local + non-realism
• non-local + non-realism

I never understood non-local or local non-realism. If there's no reality/realism (non-realism) what does the local or non-local part refer to?

 

[DevilsAvocado]

I never understood non-local or local non-realism. If there's no reality/realism (non-realism) what does the local or non-local part refer to?

Very good question (but I was hoping no one should ask... ).

Seriously, I can’t give a straight answer (maybe DrC can?), but according to RUTA (PhD) you could exchange non-realism for http://plato.stanford.edu/entries/physics-holism/" .

That’s all help I can give you at the moment, sorry...