Quantum ghosts are helpful

(PhysOrg.com) -- The idea that far distant particles can somehow 'talk' to each other worried Einstein so much that he called it 'spooky action at a distance'.

Having confirmed its existence, scientists today are learning how to use this 'spooky action' as a helpful tool. Now a team of physicists at the University of Bristol and Imperial College London have harnessed this phenomenon to shed light on another unusual and previously difficult aspect of quantum physics - that of distinguishing between two similar quantum devices.

In the everyday world any process can be considered as a black box device with an input and an output; if you wish to identify the device you simply apply inputs, measure the outputs and determine what must have happened in between.

But quantum black boxes are different. Distinguishing between them is impossible using only single particle inputs because the outputs are not distinguishable: a fundamental consequence of the laws of quantum mechanics is that only very few states of a quantum particle can be reliably distinguished from one another.

The Bristol-Imperial team has shown how to get around this problem using 'spooky action'.

Anthony Laing, PhD student in the Department of Physics, who performed the study, said: "Apart from providing insight into the fundamentals of quantum physics, this work may be crucial for future quantum technologies.

"How else could a future quantum engineer build a quantum computer if they can't tell which circuits they have?"

The new findings have implications for our understanding of quantum mechanics as well as the emerging potential of quantum information science.

More information: The paper in Physical Review Letters is published online ahead of print, 24 April 2009, http://link.aps.org/abstract/PRL/v102/e160502 .

Source: University of Bristol (news : web)

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LuckyBrandon

5 / 5 (1) Apr 27, 2009

maybe the spooky action at a distance philosophy also speaks to why we get a gut feeling when our kids are up to no good :D

laserdaveb

5 / 5 (2) Apr 27, 2009

alas..PRL.."moving physics forward"... for a price
this report tells us nothing

Auxon

not rated yet Apr 27, 2009

Yeah, I was going to say basically the same thing. The article says, "entanglement could be used to figure out things about quantum states which we can't figure out yet." Sad ... not even a hint of how it would be used.

holoman

This might give a hint of what direction things
might go.

http://colossalst...gled.htm

Alizee

3 / 5 (2) Apr 27, 2009

.."entanglement could be used to figure out things about quantum states which we can't figure out yet."..

You're right, but you can read about Aether based interpretation of quantum entanglement http://tinyurl.com/cqh389

By AWT entanglement can be demonstrated even for undulating droplets floating in low gravity conditions (i.e. the oil droplets inside of lava lamp, for example). When we split such undulating droplet into two halves by wire, the resulting parts will remain undulate at phase with respect to the center of their common mass. The smaller dropplets will therefore remember the state of the original droplet in certain extent, so they can serve as a memory. Such pair will create their own "inertial reference frame" and/or "local universe" by Everett interpretation. As you can see, nothing "spooky" is on such entaglement, in fact.

Note that even though you can combine the different droplet pairs with the same surface amplitude or even frequency, such reconnection will not restore the original surface wave, until the phase of the surface waves will not remain exactly the same - from this the quantum cryptography follows.

The explanation of entanglement is related to wave function collapse. Try to imagine, you're a sailor, who is staying on the end of floating wharf, to which some boat is attached. Because the sea is stormy, everything (both sailor, wharf and boat) are wobbling up and down, but in different phases. From the perspective of sailor the boat sways randomly.

The observation of quantum particle is analogous to situation, when sailor touches the boat for a moment, thus exchanging some kinetic energy with it. What will happen, after then? The wharf and boat will start to oscillate at phase. It means, the sailor will keep his relative position with respect to boat, so he cannot detect any boat wobbling anymore, because he moves by the same way. We can say, the wave function of boat has collapsed from perspective of that sailor.

In AWT both particles of observer, both particle of observed object are formed by dense nested clusters of another undulating particles, recursivelly. At the moment, observed object exchanges some energy with particles of observer during process of observation, the undulations of both systems aren't independent anymore: their internal fluctuations will undulate at phase, too. Briefly speaking, the observer will get entangled with the particle observed. As the particle doesn't undulate independently from this moment, the corresponding part of their mutual undulations will disappear from observation, because the internal motion of both systems has been synchronized.

This is what we are calling a collapse of wave function (of object). The observer and object are now undulating like single body - the common center of mass of both objects is forming a private reference frame, a sort of independent island of reality inside of wave ocean - from this idea the concept of many worlds follows.

"The observation of quantum particle is analogous to situation, when sailor touches the boat for a moment, thus exchanging some kinetic energy with it. What will happen, after then? The wharf and boat will start to oscillate at phase. It means, the sailor will keep his relative position with respect to boat, so he cannot detect any boat wobbling anymore, because he moves by the same way. We can say, the wave function of boat has collapsed from perspective of that sailor."

This is not true...get on a boat and hold the side, you damn sure still feel the movement of the boat, and see it, it is only your perception that has changed, because you have changed the angle of which you are viewing the boat. Ask anyone who has ever gotten sea sick...they stand at the rails, and they dont feel better, they still puke all over the side of that fresh white paint. Get on a boat and try it. If htis were true, they should feel better at the rails, and no longer ralph all over anyone or anything near them. No matter what the tiresome AWT says, you cannot change the fact that there is NO change in the movement or oscillation of the boat when someoen touches the rail, in order to do that, youd have to invoke newtons laws that state that an object in motion stays in motion until acted upon by an outside force...more important than that, that force must be equal to or greater than he force creating the movement to begin with, or else it is simply knocked aside as if it wasnt there. Think of a soccer ball that was just kicked...the grass doesnt stop the movement (immediately anyways, given enough time, drag and friction kick in stopping it of course) or oscillate with the movement of the ball, which gives much more resistence than a sailor touching the rails of a boat, instead, the grass gives way to the ball until the next player kicks it again, beginning the momentum all over.

Alizee with her boat examples...lol

You cannot bypass known laws of motion by using AWT. At a quantum level, I don't think something like AWT is worth anything, as it cannot be used to explain the physical and quantum worlds, as they are too different to do that with.

I am sick of the phrase "by AWT", i swear...

...Alizee with her boat examples...

I see, a legend has born..

...get on a boat and hold the side...

You cannot go inside of particle during their observations, so your analogy doesn't work in this moment.

...youd have to invoke newtons laws...

That's correct, in QM every observation is followed by some energy transfer.

....the grass doesnt stop the movement...

Such analogy exists even in quantum mechanics, too - for example you can prepare spin separated electrons by magnetic field in Mosbauer experiment - even though by quantum principle every attempt to localise electron would lead to violation of spin state and vice-versa. But because the path of every electron is modified just very slightly like by touch of grass, you can achieve a separation of electrons by their spin. This is a principle of so called "weak measurements", BTW...

...I am sick of the phrase "by AWT"..

Why? If nothing else, we should separate well confirmed ideas and theories from those private ones with respect to another layman readers, who aren't familiar with subject so well.

Main problem of boat-sailor analogy is in absence of quantization - but whereas water droplets can undulate in standing waves, the quantization of energy transfer can still take place in second example. As you can see, even such simple model can cover the entanglement, collapse of wave function, decoherence and quantum cryptography and seamlessly reconcile Copenhagen and many worlds intepretations of quantum mechanics in few sentences.

Dont worry Alizee, I always like your analogies and explanations :)

Heres my responses for ya :)

A legend has indeed been born, as I always remember you for your boat analogies, and my quotes of the past of you liking the boat analogies. Legend by any definition within my memory :)

From a particle and quantum level, I admit, the analogy doesnt work so well. I do figure at some point though, since the quantum and physical world are entangled, and we will discover one day how, that the analogy in 20 yrs may very well be valid :) Lets wait 20 and see then :)

Good explanation of the grass movement analogy..I like

The reason I'm sick of the "By AWT" quote is because everyone defending/introducing/speaking to AWT begins their sentence in the exact same way. It would be nice to see it start with something like "Within the aether wave theory" or something of the like, just for a change. Merely a grammatical preference there is all.

My thought on your last post though, is that weight attributed to the sailors body mass does in fact change things, but my point was that his movement, and sense of movement, will not change just because hes on the rails.

Its my 8th wedding anniversary though, and I'm drunker n drunker the more I type, so maybe that doesnt make sense :)

SmartK8

not rated yet Apr 28, 2009

LuckBrandon: Well said! Let's wait and see. Maybe the next generation religion prayers will start with "By holy AWT..".

Alexa

5 / 5 (1) Apr 28, 2009

. we will discover one day how..

It's discovered already. After all - if you don't believe in boats and droplets, here are experiments, which are confirming this model directly.

http://www.physor...511.html

. next generation religion prayers..

Well, on the contrary. AWT forces you to understand things, not to believe in abstract postulates. AWT is nothing for religious physicists, but for people, who are able to explain things in illustrative way.

..it would be nice to see ..

Maybe it would be nice for you, but not for Google keyword searchers, for example. My congrats. 4 your 8th wedding anniversary anyway.

Frankly, I don't understand the people, why they're so hostile against every new interpretation of quantum mechanics. If nothing else, it would enable you to think about it in new way at the moment, when intuitive insight is missing.

One would expect, people like you should be thankful - not impertinent.

Oh I will read everything and make determinitations. I'm not against one way or another. If I can put it in a lab and reproduce it, or observe it with little room for mistaken identidy in whats being observed, then I am all for calling something a fact.

superhuman

not rated yet May 01, 2009

The observation of quantum particle is analogous to situation, when sailor touches the boat for a moment, thus exchanging some kinetic energy with it. What will happen, after then? The wharf and boat will start to oscillate at phase.

There are problems with this analogy.

As boats and wharfs are much bigger then water wave lengths they will oscillate with their own specific frequencies depending on their dimensions and mass among other things, it is certainly not a trivial situation to model.

The sailor will have to act with a significant and periodically changing force to keep the two bodies oscillations in phase, in reality he would probably have to weld them together. In any case the phase would start to deviate the moment the boat and the wharf are no longer linked.

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