QM randomness...

Discussion in 'Physics & Math' started by Seattle, Jun 2, 2017.

  1. The God Valued Senior Member

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    There is an inherent contradiction here. True randomness means coming to know only when happened, so cannot be predicted. (But I do get the drift what you are talking about).
     
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  3. river

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    Agreed
     
    Last edited: Jul 13, 2017
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  5. iceaura Valued Senior Member

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    It's not a contradiction, but an observation: That's the prediction criterion that works. When measuring quantum states, your measurement outcomes will be those you would get if you could not know, if knowing was impossible, until you measured - just as the theory describes.

    You cannot, even in theory, discover a cause and use it to predict a measurement outcome. If there were any such cause, your measurement outcomes would obey Bell's Inequality.
     
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  7. The God Valued Senior Member

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    But Bell's inequality violation, if any, will also be causal.
     
  8. iceaura Valued Senior Member

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    With no possible cause? How would that work?

    And what do you mean by "if any"? You've already got dozens of them on your , and anybody can set up another one whenever they want to.
     
  9. The God Valued Senior Member

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    There is a cause for Bell's inequality violation, who says it is acausal? It is just that we don't know.

    "If any", I used, because IMO this Bells inequality violation may have explanation somewhere else.
     
  10. iceaura Valued Senior Member

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    It's not just that we don't know. It's also that the requirements for a "cause" rule out anything normally earning the label.

    For instance: normally with a cause the statement "If {the cause}, then {either the effect or not the effect}" makes sense. If A then B or not B is normally an essential aspect of saying that A causes B. But such statements and the reasoning from them conflict with violations of Bell's Inequality.
    That won't make it go away.
     
  11. The God Valued Senior Member

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    Bell's inequality violation may not be there. It's quite likely that we do not know what we are talking about. In experimental set up first we find out the Bell's limit by some mathematics which is full of assumption (not straightforward like your simple ABC example), so there could be first loophole here, then we measure something, there could be issues in measurement at quantum level. Our prevalent interpretation of QM may need a paradigm shift to resolve these issues, but we are not prepared for that yet.

    I flaged a paper which talks of violation at macro level, I will see what is that all about and get back.
     
  12. iceaura Valued Senior Member

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    If you are simply going to deny the uncontradicted findings of dozens of replicated experiments and demonstrations, you aren't doing science any more.
    The problem is not the interpretation - which we don't really have yet - but the theory itself. The equations, the arithmetic. It predicts violations of Bell's Inequality. And experiment agrees with it.
     
  13. John.P Registered Member

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    I think you are saying that things that seem totally random may end up not being so random as knowledge increases? If so then I sort of agree.
     
  14. iceaura Valued Senior Member

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    The theory says they are random - the one theory standing, the most thoroughly vetted theory in all of science, the most accurately and the most reliably predicting theory science currently employs.

    So we are talking about replacing this paragon of a theory - and we have no discrepancies of data, no anomalous facts stubbornly refusing to be incorporated, to indicate there is anything wrong with it - because we are mentally uncomfortable with our philosophical interpretations of it.

    We demand that cause and effect be fundamental and constitutive at the subatomic level, rather than derivative and ad hoc as we know it to be macroscopically, on philosophical grounds we inherited from Bronze Age Greece.

    That seems unwise.
     
  15. The God Valued Senior Member

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    This is religious fanaticism.
     
  16. John.P Registered Member

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    I am not so sure I even understood the post , probably better I did not understand.
    I am certainly struggling to even understand what you just ''said''. True randomness has an infinite form, where a ''random'' sequence has parameters of a start point and end point of numbers or symbols in the sequence. This inevitably giving repeat values in a continuous sequence. So although the sequence is ''random'' , we can predict repeats within a time period although not strictly exact.
     
  17. iceaura Valued Senior Member

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    ?
    Are you claiming that the mathematical formulation of QED is religious dogma?
    That the complete agreement of QED with observation and experiment for decades now is a matter of faith?

    Have I made any claim that is not immediately verifiable, and quite ordinary, fact? Please be specific.

    I am simply pointing out the nature of your objections to QED, the current theory governing very small phenomena of the real, physical world. I'm not worshipping the damn theory, I'm just making clear what it is you think will be superseded by some other theory that accounts for some unspecified new information you expect to acquire in the future.

    And what the apparent motives are, for wanting it replaced. Because failure to account for, predict, model, and describe, physical reality - the supposed role of physical theory - is not one of them. QED does its job, as a scientific theory, very very well.

    The violations of Bell's Inequality are measured. They are experimental results, from dozens of replications and different approaches over a couple of decades now. QED not only accounts for them, but predicted them to several decimal points - a remarkable event, in many ways deeper and more astounding than Relativity Theory's prediction of the bending of light by gravity. Your new theory is going to have to account for them, while at the same time matching QED's record of agreement with experiment in all other fields.

    That's not going to be easy.
    It's found in (and modeled by) many simple and finite mathematical formulations. Probability theory is a standard topic in school.
     
    Last edited: Jul 14, 2017
  18. The God Valued Senior Member

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    Such a strong belief in any scientific theory is unwarranted. Fine, QM/QED are well established but even then they are open to ideas and meaningful debates.
     
  19. John.P Registered Member

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    That answer tells me that you do not have the ability to discuss randomness in great detail, if for example you think a coin toss is unpredictable you would be incorrect but the prediction would not be precise but within the defined parameters.
     
  20. iceaura Valued Senior Member

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    No such "belief" is or ever has been any part of my understanding. No statement of "belief" appears in any of my posts, except possibly an allusion to my as yet unformulated sense that the "superdeterminism" interpretation of the quantum world has been underestimated and misunderstood.
    Contrast that with your repeated assertion that causal explanations for the Bell violations are just around the corner, requiring only some more information. You have no evidence for that - it's a claim of pure belief unsupported by anything except your intuitive sense of how the world has to be.
    Of course. And the meaning of the debate is the central matter of my posting here.
    I can teach probability theory at the college level. Does that count?
     
    Last edited: Jul 14, 2017
  21. The God Valued Senior Member

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    3,546

    May I respectfully ask you what in your opinion "True Random" means?
     
  22. John.P Registered Member

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    It only counts if you understand what probability is. Probability works within limits of the defined parameters. Outside these limits probability function breaks down. In example imagine we have 5 boxes and in one box was a prize.

    We have 1/5 chance of picking the correct box with the prize in. Now this only applies because we have defined the parameters and limit. Beyond 5 boxes becomes an uncertainty because we have no information beyond the defined limit.

    Beyond the finite possibilities (limit) , is then infinite possibilities.
     
  23. iceaura Valued Senior Member

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    It's not a technical term, in this thread. Who's using it? Ask them.
    QED works, as a theory, over the entire field of interest in this thread. Its predictions of Bell violations are not breakdowns in the theory, but consequences of it.
     

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