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

In summary, the conversation discusses the concept of quantum energy teleportation (QET) and the work of Masahiro Hotta on the subject. Hotta suggests that energy can be transported from one point to another through entanglement and that a classical correlation between the two points is sufficient for QET to occur. The conversation also mentions the potential use of this phenomenon for information exchange, but notes that it has not yet been tested in experiments. The cited paper and Hotta's work in general are described as deep theoretical work and not easily accessible. The conversation also raises some doubts and questions about the practicality and feasibility of Hotta's claims, and suggests that experimental proof is needed.
  • #106
bohm2 said:
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?

That reality is completely local but happens/takes place as you go(i.e. not pre-existing). This is thought by some to be at least theoretically plausible as it allows doing local physics without magical influences. But this is philosophy, as is much of QM(actually anything out of the formalism). The difficulty seems to reside not in terms like local, non-local, real or non-real and their combinations but in what we mean by "to understand" and what it is that understands and how it understands. The other difficulty resides in constructing an incomprehensible model of the world and calling it "The World". It's likely not the world but a limited and crippled model of the world. You won't experience these problems if you regard matter as that which you observe(if you observe it, it must be real in a certain sense) and the formalism as that which makes predictions.
 
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  • #107
I reckon I already defined my position :)

To me the question is about indeterminism and superposition's, on a quantum level. Macroscopically we have no difficulties defining what is 'real' and 'imaginary' locally, well as I see it. In my view one can use locality as a 'golden rule', measuring all other frames of reference macroscopically. And assuming that we all can do so, even if getting to different results relative each others definitions of time and distance we have to find what join those definitions. And that would to me be radiation, describing what we see, and 'gravity' defining a metric for space.

Can you expand on how you define that 'Local realism' a little DA? As expressions of 'conceptually made' comparisons of different 'frames of reference', or as doubting what radiation tells you locally? Or maybe you are thinking of something entirely different there.
=

Eh, I'm presuming a arrow of time too, the 'exact same' locally, measured as a 'clock', as 'c' is to us locally. And the really interesting part of assuming it to be this way, is that we then find a 'invariant local time' for all, joining us through the radiation communicating between 'frames of reference'. That makes 'c' my 'clock of choice', not only its 'speed'.
 
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  • #108
DevilsAvocado said:
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.



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.

Yep but it is there we don't agree, unless you can give me a experiment on entanglements showing that they fall out differently, if measuring a 'spin' for example. And if you can then I would start to wonder how a 'entanglement' can describe two things/spins in this case. What you can say about different measurements is that they are dependent on the one measuring and that they seem to share a connection to how you define the circumstances for your measuring. But that is no different than saying the exact same about lights duality.
 
  • #109
yoron said:
Yep but it is there we don't agree, unless you can give me a experiment on entanglements showing that they fall out differently, if measuring a 'spin' for example. And if you can then I would start to wonder how a 'entanglement' can describe two things/spins in this case. What you can say about different measurements is that they are dependent on the one measuring and that they seem to share a connection to how you define the circumstances for your measuring. But that is no different than saying the exact same about lights duality.

Not true! Bell's Theorem shows us differently.

The ONLY variable known to be relevant to outcomes of any two spin (polarization) measurements on entangled photons is the RELATIVE different of their measurement angle. The reality of one is dependent on the nature of a measurement of the other, and vice versa, in accordance with the predictions of QM - and completely in opposition to LR (local realism).
 
  • #110
What I was thinking of was the Quantum eraser experiment, when I spoke of the experimenter as part of the entanglement DRc. As for "The reality of one is dependent on the nature of a measurement of the other, and vice versa, in accordance with the predictions of QM - and completely in opposition to LR (local realism)"

I don't know what 'local realism' should be seen as? Even macroscopically, in relativity, you have Lorentz contractions. If you define them as real, which I do, then there is no such thing as a 'defined distance' globally, Lorentz transformations non-withstanding, I differ between 'conceptual comparisons', and what you see locally. I also define it such as 'what you see is what you got', meaning that if you're 'speeding away' like a muon the Lorentz contraction I expect you to see will be as 'real' as it can be in this 'reality', for you.

If you mean that I state that we can know the spin before measuring? Or that I think that "all objects must objectively have a pre-existing value for any possible measurement before the measurement is made." then I sincerely doubt that one.

I expect the observer to define his reality through his local observations, and as he compares that to other frames of reference, then use his local definitions. Just as any experimenter does, using his own 'clock' defining a time for example. But I don't expect a entanglement to be known before the measurement?

Also I expect a outcome to be defined by the relations circumstancing it, including the experimenter, and his choice of measuring, set-up etc.

As I understand it Aspect proved that there was no such thing, as pre-existing values? That doesn't mean that I'm wrong in defining it from locality. And it doesn't mean that I necessarily must be wrong in saying that that the experimenter defines the experiment, as in the delayed choice quantum eraser.

In it they say "Some have interpreted this result to mean that the delayed choice to observe or not observe the path of the idler photon will change the outcome of an event in the past. However, an interference pattern may only be observed after the idlers have been detected (i.e., at D1 or D2)." as the signal photon reach D0 before the idler, due to a shorter 'path'.

But it will still be the experimenters choice that defines what there is to see, "the choice of whether to preserve or erase the which-path information of the idler need not be made until after the position of the signal photon has already been measured by D0."

And it is a still a function of both photons in the entanglement, meaning that your choice defines the outcome for the whole entanglement.
 
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  • #111
yoron said:
To me the question is about indeterminism and superposition's, on a quantum level. Macroscopically we have no difficulties defining what is 'real' and 'imaginary' locally, well as I see it. In my view one can use locality as a 'golden rule', measuring all other frames of reference macroscopically. And assuming that we all can do so, even if getting to different results relative each others definitions of time and distance we have to find what join those definitions. And that would to me be radiation, describing what we see, and 'gravity' defining a metric for space.

Yeah sure, but now we are talking about the fundamental properties at the fundamental level = QM. The macroscopic world 'behaves' different, to us, but in the end it’s the same thing, more or less 'screened off'. (Yep, elephants could probably be entangled too, but it’s very hard trick! :smile:)

yoron said:
Can you expand on how you define that 'Local realism' a little DA? As expressions of 'conceptually made' comparisons of different 'frames of reference', or as doubting what radiation tells you locally? Or maybe you are thinking of something entirely different there.

DrC is the real expert on this subject, but I’ll give it a try (and maybe he could fill in 'the blanks'):

Local Realism is the view of Einstein; there is a world of pre-existing particles (objects) in the microscopic world, having pre-existing values for any possible measurement before the measurement is made (=realism), and these 'real' particles is influenced directly only by its immediate surroundings, at speed ≤ c (=locality).

yoron said:
Eh, I'm presuming a arrow of time too, the 'exact same' locally, measured as a 'clock', as 'c' is to us locally.

Yup, that’s what we do in the macroscopic world, however if you build the same assumptions for QM you will run into difficulties...
 
  • #112
yoron said:
Yep but it is there we don't agree, unless you can give me a experiment on entanglements showing that they fall out differently, if measuring a 'spin' for example. And if you can then I would start to wonder how a 'entanglement' can describe two things/spins in this case.

DrC already explained it clearly; the 'magic thing' is the relative angle between the two detectors at Alice & Bob. If Alice’s detector is finally set to +30° and Bob’s detector is finally set to 0° and, you get sin^2(+30°) = 25% discordance (i.e. the number of measurements where we get a randomly mismatching outcome up/down).

If Alice’s detector is finally set to 0° and Bob’s detector is finally set to -30° and, you get sin^2(-30°) = 25% discordance, same as above.

And now comes "the genius move" of John Bell.

In a world of Local Realism you would expect that if Alice’s detector is finally set to +30° and Bob’s detector is finally set to -30° you could predict the outcome from the measurements above, right? All logic in the world says that if the relative angle between Alice & Bob is 60°, we could just double the values from the 30° and get 50%, right?

EDIT: The explanation above isn’t perfect... Maybe it’s better to think of it like "anything you do in the 'other end' shouldn’t make any difference to Alice or Bob". When they are set to 0° this should be 'obvious', and when they are not, you just take their "local" values and add them together.

Here’s the formula for this Bell Inequality:

N(+30°, -30°) ≤ N(+30°, 0°) + N(0°, -30°)

There’s only one 'little' problem... if you actually perform the experiment and do the math, you get:

sin^2(60°) = 75%

This is the 'magic'!

There is no way for Alice or Bob to get this information about the other detector before the final measurement is carried out, since they are (should be) outside each other’s light cone.

2wr1cgm.jpg
 
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  • #113
yoron said:
If you mean that I state that we can know the spin before measuring? Or that I think that "all objects must objectively have a pre-existing value for any possible measurement before the measurement is made." then I sincerely doubt that one.

That's realism! Once you throw that out, you are good to go. :smile:
 
  • #114
Maui said:
That reality is completely local but happens/takes place as you go(i.e. not pre-existing).

What does that "reality" that is not pre-existing but becomes "actualized" then refer to?
 
  • #115
bohm2 said:
What does that "reality" that is not pre-existing but becomes "actualized" then refer to?


Good question, but it belongs in the Philosophy forum. It's not an easier task to make sense of a pre-existing reality with instantaneous influences across it either. Perhaps it's true that mathematics and relationships underlie reality and are more fundamental than our crippled attempts to make sense of it(esp. with the clasicallity baggage and its preconceptions). I see it as a biological problem of how the brain was wired, its task has never been to make sense of the universe in its entirety, so maybe we should be more modest at this point.
 
  • #116
Yes, DA I agree to both your definitions above. But I can't see where I go wrong in assuming that a wave function is set, no matter if you never look at the second entangled photon. As for the formalism defining different outcomes I have no argument, I think :) I better think some more there.

Look at it this way, Bell proved that there was no hidden causality as I understands it. That is okay with me. Either the wavefunction sets for 'both' and in that case the result is defined. Then it still will be a matter of how you choose to measure as I see it. But I can't see where Bells theorem demands that you must measure both particles before defining that collapse?
 
  • #117
yoron said:
Look at it this way, Bell proved that there was no hidden causality as I understands it. That is okay with me. Either the wavefunction sets for 'both' and in that case the result is defined. Then it still will be a matter of how you choose to measure as I see it. But I can't see where Bells theorem demands that you must measure both particles before defining that collapse?

Bell doesn't demand such an interpretation. You could define the collapse as occurring when the first particle is measured. There is no difference in the predicted outcomes, per QM, as to the ordering. The relevant issue is that outcome stats are related to the two angle settings alone, exposing a relationship between them. Bell simply shows that this relationship cannot be one in which all possible angle settings were locally predetermined.
 
  • #118
hehe DrC is always *fast*... anyway... :)
yoron said:
Yes, DA I agree to both your definitions above. But I can't see where I go wrong in assuming that a wave function is set, no matter if you never look at the second entangled photon

The one and only shared wavefunction decohere/collapse at measurement.

yoron said:
Look at it this way, Bell proved that there was no hidden causality as I understands it.

Bell proved that Local Realism is not compatible with the predictions of QM.

yoron said:
That is okay with me. Either the wavefunction sets for 'both' and in that case the result is defined.

Nope! The final results of the measurements can never be pre-defined; they are always 100% random up/down. What the collapse of the wavefunction does is setting the probabilities for the final correlations (up/down).

yoron said:
But I can't see where Bells theorem demands that you must measure both particles before defining that collapse?

I don’t think it does... :bugeye:
 
  • #119
"The final results of the measurements can never be pre-defined; they are always 100% random up/down. What the collapse of the wavefunction does is setting the probabilities for the final correlations (up/down)."

Maybe that is it?

Assume that I set up a entanglement by a beam splitter (A&B). Then I measure the spin for A to 'up'. Have I set the wave function then, or not?

According to how I think of it I now 'know' the spin of B, as it has to be the opposite. I see no probability for that spin to be anything else?
 
  • #120
yoron said:
According to how I think of it I now 'know' the spin of B, as it has to be the opposite. I see no probability for that spin to be anything else?

You sure? Because that can be erased by bringing A's beamsplitter outputs back together again in a suitable manner. So that implies that you must wait and evaluate the final context as a whole. As I have said over and over again, you cannot say the first measurement causes collapse. It might be the last one that does that. No one really understands the mechanism. You're way of thinking of it works most of the time and is the easiest to use - it's what I do most of the time. But that is just a tool.
 
  • #121
"Because that can be erased by bringing A's beamsplitter outputs back together again in a suitable manner. "

You lose me there DrC :)

If I measure A, how can I bring it back? If we're talking about photons A will annihilate in a direct measurement. Is it 'weak measurements' you are thinking of there? Or is it another type of experiment?

But it seems to be where we don't agree? So if you have a nice simple explanation I would be very interested.
 
  • #122
yoron said:
"Because that can be erased by bringing A's beamsplitter outputs back together again in a suitable manner. "

You lose me there DrC :)

If I measure A, how can I bring it back? If we're talking about photons A will annihilate in a direct measurement. Is it 'weak measurements' you are thinking of there? Or is it another type of experiment?

http://www.optics.rochester.edu/~stroud/cqi/rochester/UR19.pdf

See figure 1. You have a photon go into a beamsplitter and follow that with a reverse PBS. The final reconstructed beam is still entangled.

So is the first beamsplitter a measurement if the beam is reassembled later? The entire context must be considered to get the correct answer. And that context gives NO preference for ordering.
 
  • #123
I think I see your argument there, but a beam splitter isn't defined as the 'measuring', is it? Although I've wondered about that one before :)

What 'sets a state', is it when a 'photon' is annihilated, or do I need both the annihilation, and observer, to 'set' it? Or is it enough to let it pass something that will define a polarisation, even if I don't know what that polarisation is.

But no matter what manipulations I do on it, when I measure one of them, as in annihilate it, will be the moment I know the other ones state too, would you agree on that?
 
  • #124
yoron said:
Maybe that is it?

Assume that I set up a entanglement by a beam splitter (A&B). Then I measure the spin for A to 'up'. Have I set the wave function then, or not?

According to how I think of it I now 'know' the spin of B, as it has to be the opposite. I see no probability for that spin to be anything else?

Wake up yoron, it’s 2011! :smile:

Seriously, they way you see it, is exactly the way Einstein & Bohr debated it for 20 years... let’s not repeat this 'mistake'! :wink:

If you lock Alice & Bob’s both detectors at angle 0° and measure Alice photon first – then yes you will know the result of Bob’s measurement!

But that’s no fun, is it...? Einstein would just say:

– He he, my dear lad, you are cheating, bechause zhis was all setup from tse beginning, nööö??

albert-einstein5_115383074_136702853.jpg

And this could go on for another 20 years... :biggrin:

The WHOLE POINT in Bell’s breakthrough is that you use ALL angles 0-360° to get out of the Einstein-Bohr-deadlock!

And when you do that, you have no "pre-existing idea" (except for 0° and 180°) about the outcome for either Alice or Bob, no matter if you make sure to measure Alice first.

It’s completely 100% random, trust me!
 
  • #125
Trust is a dangerous thing DA :)

Lovely picture. And yes, entanglements is one of, or, the most confusing thing I know of. I used to be very interested in it some year(s)? ago, but then I got this headache :) that didn't let up, until I let it rest. And now I'm back, again :)

How about what's setting a entanglement? The beam splitter does it, but I can't know the polarisation/spin without first measuring, right? Now assume that I switch A:s polarisation/spin, not knowing what it is, I can still switch it right :) Will 'B' 'know' this in your definition, or is it the 'measurement' I do that 'force' it to 'know'?
 
  • #126
One other thing that makes this interesting, even though it might be slightly outside this conversation? Is 'Interaction Free Measurements'. And it has a relevance, as I see it, to how we define this 'wave collapse'. Because that's the first step for me ever going to see what a entanglement might be.


"Another very interesting topic is that of a quantum object, i.e., one that can be in a superposition of being "there" and "not there". One such example is an atom in an atom interferometer, which simultaneously exists in both arms. Another is the recent separated-ion demonstration by Wineland et al., in which a single ion in a trap is made to coexist at two separated points in space.

If such systems are evaluated using the interaction-free measurement schemes, then the two sub-systems -- the quantum object and the interrogating light -- become entangled. In fact, although we have not discussed it at all here, for sufficiently large N, the interaction-free measurement methods even work for multiple-photon states, even for dim classical pulses.

Therefore, combining such an input with a quantum object, one is able to transfer the quantum superposition of the latter onto the former. In other words, one could make superpositions of "bunches" of photons; for example, one could prepare a pulse of light with an average of 20 photons in it, all of whom were horizontal, or all of whom were vertical, and yet until a measurement was made, none of them would have a definite polarization. Such a peculiar state of affairs would be a modest example of a Schroedinger cat."

http://physics.illinois.edu/people/kwiat/interaction-free-measurements.asp
 
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  • #127
yoron said:
Trust is a dangerous thing DA :)

Yup, absolutely! But you can always trust a mushy avocado, yummy! :smile:

yoron said:
Lovely picture. And yes, entanglements is one of, or, the most confusing thing I know of.

Agree, the only consolation is that we’re in good company, no one understands entanglement 100%!
(As I see it, you’ve got all 'weirdness' in QM in one place; the measurement problem, wave/particles, probability, non-locality, HUP, RoS – and it’s just wonderful! :smile:)

yoron said:
How about what's setting a entanglement? The beam splitter does it, but I can't know the polarisation/spin without first measuring, right?

Well... eh... um... actually, you can’t say that it does... :rolleyes:

We could agree that a photon 'bouncing' in a mirror is kinda 'measured', right? But what about a photon going just straight thru a mirror (BS)? That can’t be a 'measurement'... or? :rolleyes:

Check this out:
350px-Beam_Split_and_fuse.svg.png

Photons are emitted one at a time from the yellow star. They each pass through a 50% beam splitter (green) that reflects 1/2 of the photons, which gives two possible (red/blue) traveling paths.

In the top picture it’s no doubt which path the photon took, right?

But what happens when you insert another beam splitter, as in the lower picture? Well if the length of the path is exactly equal (through + reflected / reflected + through) – you can’t tell which path! :bugeye:

This is a standard setup for Alice’s and Bob two detectors:

sketch.jpg


To be absolutely "sure" (if this is 'feasible' in QM I don’t know... ;), you have to wait for the "click" in the yellow detectors.

... and then you can start the fight with Einstein, on who "did it" first! :wink:

Here’s a video on a standard EPR-Bell experiment:

http://www.youtube.com/watch?v=c8J0SNAOXBg&hd=1
https://www.youtube.com/watch?v=c8J0SNAOXBg

And here’s an 'interactive' http://www.didaktik.physik.uni-erlangen.de/quantumlab/english/".

372px-SPDC_figure.png


[PLAIN]http://www.pienkow.com/img/science/dnconv.jpg

[URL]http://www.tongue-twister.net/mr/physics/bbophoto.jpg[/URL]
http://www.tongue-twister.net/mr/physics/entangled.htm"
 
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  • #131
  • #132
Well, it's true with present day technology. But, the question is whether it's theoretically impossible to create macroscopic objects or future technologies can be able to do that.
 
  • #133
Forgive me for jumping in here with questions, I have not read the entire thread, or much about your theory other than what came from technology review website. My question is probably asked a lot so here goes. If you can teleport energy over unlimited distances, light years, than could you somehow relay messages utilizing this theory?

I envision something like a binary code for passing on messages this way, this could be significant for obvious reasons. Do entangled protons occur in space, and if so would you be able to find one and look for messages from other parts of space?

If you can make a binary system that sends 1 entangled proton for 0 and 2 entangled for 1, then you'd be able to interpret this and create a binary message capable of interstellar travel, and maybe intergalatic.

It could also be used to create a high tech internet system, and much more here in our own solar system. You could power drones in space remotely, and have nearly instant communications.
 
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  • #134
D.Blackburn said:
Forgive me for jumping in here with questions, I have not read the entire thread, or much about your theory other than what came from technology review website. My question is probably asked a lot so here goes. If you can teleport energy over unlimited distances, light years, than could you somehow relay messages utilizing this theory?

Welcome to PhysicsForums, D.Blackburn!

This thread should really be closed and a new one started.

The short answer is: energy cannot be teleported in the manner in which you envision, nor in the manner you might conclude from the original post. That is simply incorrect.

Additionally, you cannot signal faster than c using entanglement or any other know mechanism.

Again, start a new thread to discuss further if needed. We don't need to re-hash discredited ideas.
 
  • #135
DrChinese said:
Welcome to PhysicsForums, D.Blackburn!

This thread should really be closed and a new one started.

The short answer is: energy cannot be teleported in the manner in which you envision, nor in the manner you might conclude from the original post. That is simply incorrect.

Additionally, you cannot signal faster than c using entanglement or any other know mechanism.

Again, start a new thread to discuss further if needed. We don't need to re-hash discredited ideas.

http://www.technologyreview.com/view/523716/energy-teleportation-overcomes-distance-limit/

According to this article they claim he can send electricity almost any distance.
 
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  • #136
D.Blackburn said:
http://www.technologyreview.com/view/523716/energy-teleportation-overcomes-distance-limit/

According to this article they claim he can send electricity almost any distance.

That article is an inadequate source by forum rules. See:

https://www.physicsforums.com/showthread.php?t=414380

Even as a newbie, I think you know that energy cannot be teleported as implied by the article. That is because the direction and amount of energy nets to zero every time. There are conservation considerations, among others.

I am recommending this thread be closed. If you have a suitable subject to discuss, please open a new thread. But please do not reference this article again.
 
  • #137
DrChinese said:
This thread should really be closed and a new one started.
...
Again, start a new thread to discuss further if needed. We don't need to re-hash discredited ideas.
Agreed.

Note also that the reference is a pop-sci reference and that the arxiv article that it references is unpublished. That is not up to the PF standards, particularly since it seems to conflict with known physics.
 

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