Random transfer in entanglement

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Discussion Overview

The discussion revolves around the nature of entanglement in quantum mechanics, particularly whether randomness or energy can be transferred between entangled particles without violating the principles of relativity. Participants explore concepts related to correlations, entropy, and the implications of Bell's theorem, with references to thought experiments and interpretations of quantum mechanics.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants question whether random energy can be transferred in entangled systems, suggesting scenarios where entropy decreases at one end and increases at another.
  • Others assert that while correlations exist, no information is transferred, emphasizing that measurements at one end do not affect the statistics at the other end.
  • One participant compares the situation to red and green slips of paper, arguing that correlations do not imply transfer of information.
  • There is a discussion about Bell's theorem and its implications, with references to the need for faster-than-light (FTL) communication if one assumes properties exist prior to measurement.
  • Some participants propose that the correlation might be a result of information in the wave function, while others challenge this notion, insisting that the wave function's reality is debatable.
  • Several participants express the need for experimental evidence to support claims regarding entanglement and correlations.

Areas of Agreement / Disagreement

Participants generally disagree on the implications of entanglement, particularly regarding the transfer of energy and the nature of information in quantum mechanics. There is no consensus on whether randomness or correlations can be interpreted as a form of information transfer.

Contextual Notes

Limitations include the dependence on interpretations of quantum mechanics, such as Bohmian mechanics (BM), and the unresolved nature of discussions surrounding the reality of the wave function and its implications for information transfer.

fanieh
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It is said that entanglement doesn't violate relativity because there is no information transferred. Ther reasoning being Bob and Alice only get randomness even if there is correlation. But can random energy be transferred as it is still random? For example. Entropy decreasing at one place and increasing at another place in the entangled ends? What experiments have discounted (or proven) this?
 
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fanieh said:
It is said that entanglement doesn't violate relativity because there is no information transferred. Ther reasoning being Bob and Alice only get randomness even if there is correlation. But can random energy be transferred as it is still random? For example. Entropy decreasing at one place and increasing at another place in the entangled ends? What experiments have discounted (or proven) this?

Or random energy transfer in the entangled ends. For example. Bob in Europa. Alice on earth. Alice will transfer heat to the Bob location in the moon Europa. Bob won't be able to get any information because Alice would send the heat random. Therefore can entanglement be used to teleport heat to another location?
 
No.
 
secur said:
No.

You are not sending information but random correlations.. please show an experiment that discounted that even sending random correlation is not allowed.
 
Put a red slip in an envelope, green in another. Open one and you automatically know the other. Its just correlated and that is all the this Bell-EPR stuff is. It just has slightly different statistical properties. Nothing is transferred - you simply correlated the systems. If you insist QM is like the red and green slips that remain red and green at all times then Bell says something is transferred - but only if you insist its like that. Don't insist - no problem.

Read Bells original paper where red and green slips have been replaced by Bertelmans socks:
https://cds.cern.ch/record/142461/files/198009299.pdf

Thanks
Bill
 
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fanieh said:
You are not sending information but random correlations.. please show an experiment that discounted that even sending random correlation is not allowed.
No. This answer should be worked out, theoretically, using QM formalism. Given QM is one of many theories used in science I would have thought proposing a new model of how the universe works would be needed to accommodate your thought experiment.
 
bhobba said:
Put a red slip in an envelope, green in another. Open one and you automatically know the other. Its just correlated and that is all the this Bell-EPR stuff is. It just has slightly different statistical properties. Nothing is transferred - you simply correlated the systems. If you insist QM is like the red and green slips that remain red and green at all times then Bell says something is transferred - but only if you insist its like that. Don't insist - no problem.

Read Bells original paper where red and green slips have been replaced by Bertelmans socks:
https://cds.cern.ch/record/142461/files/198009299.pdf

Thanks
Bill

They have setup where this can be disproven.. they showed that prior to measurement, the red and green slip doesn't even exist in the envelope. Something about Bell's Inequality equation that is violated. I'll take a look at it later and let you know when I found the reference.
 
fanieh said:
They have setup where this can be disproven.. they showed that prior to measurement, the red and green slip doesn't even exist in the envelope. Something about Bell's Inequality equation that is violated. I'll take a look at it later and let you know when I found the reference.

There is no experiment ever that has shown for red and green slips they did not exist prior to measurement - that would be classically absurd and slips of paper are classical objects.

What Bell shows is if you want properties to exist prior to measurement then you need FTL. QM is silent on such things - but places restrictions. Bell and Kochen-Specker are the main ones.

It would be wise if using experimental evidence to support a position to actually reference the experiment.

Thanks
Bill
 
bhobba said:
There is no experiment ever that has shown for red and green slips they did not exist prior to measurement - that would be classically absurd and slips of paper are classical objects.

What Bell shows is if you want properties to exist prior to measurement then you need FTL. QM is silent on such things - but places restrictions. Bell and Kochen-Specker are the main ones.

It would be wise if using experimental evidence to support a position to actually reference the experiment.

Thanks
Bill

Yes, Bell and Kochen-Specker are the main ones. But earlier.. why did you that "Put a red slip in an envelope, green in another. Open one and you automatically know the other. Its just correlated and that is all the this Bell-EPR stuff is"? It's not Kochen-Specker but the old argument by Einstein handled already by Bohr nearly a century ago.
 
  • #10
fanieh said:
For example. Entropy decreasing at one place and increasing at another place in the entangled ends?

We don't really need to do an experiment to disprove this. The observed statistics at one end are unaffected by measurement at the other - so there is no experimental way to detect a 'decrease' of entropy at either end. As far as the endpoints are concerned there is nothing that can be measured at that endpoint that will tell whether an experiment at the other endpoint has been performed or not - it's only when we compare the results do we see the correlation.

As Bhobba said - it's simply a pre-existing correlation - nothing is 'transferred' in the measurement process.
 
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  • #11
fanieh said:
It's not Kochen-Specker but the old argument by Einstein handled already by Bohr nearly a century ago.

Its a correlation like Bell. Simply another example of the Bertelmans socks type situation which is also a correlation. That's all EPR, Bell etc is. It just has statistical properties different to classical - but that changes nothing - you know one and hence the the other because they are correlated. No information etc passed. With one caveat - if you want it to be like Beterlmans socks or the slips of paper and have properties at all times then FTL communication is required - but only if that is what you want.

If you want to discuss if energy is passed you need to reference a particular interpretation like BM. We have at least one expert here in it - but I am not one.

Thanks
Bill
 
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  • #12
bhobba said:
Its a correlation like Bell. Simply another example of the Bertelmans socks type situation which is also a correlation. That's all EPR, Bell etc is. It just has statistical properties different to classical - but that changes nothing - you know one and hence the the other because they are correlated. No information etc passed. With one caveat - if you want it to be like Beterlmans socks or the slips of paper and have properties at all times then FTL communication is required - but only if that is what you want.

If you want to discuss if energy is passed you need to reference a particular interpretation like BM. We have at least one expert here in it - but I am not one.

Thanks
Bill

Ok. No information is passed because the spin up or spin down properties don't exist before measurement.. but can't we say the correlation is caused by information in the wave function that is omnipresent? There is still information involved that is holistic.

You can numb it down by saying the wave function is not real and there is not even information that is involved.. but the simple fact there is correlation means there should be information involved.
 
  • #13
fanieh said:
Ok. No information is passed because the spin up or spin down properties don't exist before measurement.. but can't we say the correlation is caused by information in the wave function that is omnipresent?

I think you need to spell out the detail of EXACTLY what you mean.

The correlation is usually a result of conservation principles.

Thanks
Bill
 
  • #14
bhobba said:
I think you need to spell out the detail of EXACTLY what you mean.

The correlation is usually a result of conservation principles.

Thanks
Bill

Correlation in the Bell Aspect-like experiments can be changed or the setup influenced after the photons already left the emitter.. so the correlations involved is really something not classical (I think everyone knows this). Do you claim the Aspect correlation really classical and just some conservation principles? please elaborate your context.
 
  • #15
fanieh said:
Correlation in the Bell Aspect-like experiments can be changed or the setup influenced after the photons already left the emitter.. so the correlations involved is really something not classical (I think everyone knows this). Do you claim the Aspect correlation really classical and just some conservation principles? please elaborate your context.

You seem to be jumping all over the place,

I specifically claimed:
bhobba said:
It just has slightly different statistical properties.

If you don't get to the point you are trying to make then the mods will, correctly, shut this down.

Thanks
Bill
 
  • #16
bhobba said:
You seem to be jumping all over the place,

I specifically claimed:If you don't get to the point you are trying to make then the mods will, correctly, shut this down.

Thanks
Bill

It just has slightly different statistical properties... but there is correlation that can be adjusted instantaneous as per Aspect experiment. What I was describing is the standard belief. Maybe you also agree with me and we just have semantics mismatched. What is your point anyway (please get to the point)?
 
  • #17
fanieh said:
What is your point anyway (please get to the point)?

I was explicit.

This is my last comment. Its simply a correlation. No random energy is transferred.

Thanks
Bill
 
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  • #18
bhobba said:
I was explicit.

This is my last comment. Its simply a correlation. No random energy is transferred.

Thanks
Bill

Ok. I got your ideas anyways. I was thinking if there are ways for energy to be transferred.. but you said for the Bohmians.. energy may be passed. So let's give the floor to the Bohmians.
 
  • #19
fanieh said:
There is still information involved that is holistic.

Yes, but I think that view depends on some assumption about the 'reality' of the wavefunction. It is the view to which I subscribe - but I also recognize the serious limitations with this perspective.

If we work out the mutual information of the entangled state we find it's 2 bits. A classical 'Bertlmann's socks' type of correlation has a mutual information of 1 bit.

The quantum state permits stronger correlations than a conventional classical counterpart of that state. I would view this by saying the quantum entangled state contains twice as much information in its correlation and see the things we can do with entanglement as a consequence of this extra information resource - but this 'ontic' perspective is not necessary.

One thing we can say is that a hidden variable model has to access at least 2 bits of randomness if it is to reproduce the predictions of QM (we know this because spin-x and spin-z measurements at either end generate 2 bits of entropy and a hidden variable model has to reproduce ALL the predictions of QM not just the highly correlated ones) - so any hidden variable model based on a single binary random variable will not achieve its goal.

We can attempt to view things in a holistic and ontic way by thinking of the collapse of some wavefunction caused by measurement at either end (and ignore the obvious relativistic problems) but there is no possibility of using this process to transmit information. In other words there can be no measureable consequence that will inform someone at one end whether an experiment has been done at the other. That includes no measureable consequence for 'energy' or 'entropy' - so to answer your question there's no transfer of anything physically measurable.
 
  • #20
We've supplied a number of "no" answers in this thread, and it is time to close it.

As always, it can be reopened to allow further on-topic and helpful points to be made.
 
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