Radioactive decay and the myth of randomness
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From: John Jones on 15 Nov 2009 14:45 David C. Ullrich wrote: > On Sun, 15 Nov 2009 03:30:06 +0000, John Jones > <jonescardiff(a)btinternet.com> wrote: > >> David C. Ullrich wrote: >>> On Fri, 13 Nov 2009 14:56:33 +0000, John Jones >>> <jonescardiff(a)btinternet.com> wrote: >>> >>>> Quantum mechanics says that there is no way to predict when an atom will >>>> decay radioactively. >>>> >>>> This doesn't mean that the decay is random. We wouldn't, for example, >>>> claim that a person who suddenly appears from behind a bus is exhibiting >>>> a new, mysterious, physical state called randomness. >>>> >>>> So! - why would we say that the appearance of an outcome of hidden >>>> quantum events is random? Quantum events are necessarily hidden because >>>> physical space itself hides very small objects - but they are still only >>>> "hidden", like the man behind the bus. >>>> >>>> I rest my case. >>> You rest your case in spite of the fact that you've given no argument >>> in support of your thesis, just bare assertion. >> I asserted nothing. I examined the grammar. > > You think we're all blind? You asserted 'but they are still only > "hidden", like the man behind the bus', right there where anyone > can see. That assertion is simply false - you think it's so because > you know nothing about the topic you're discussing. as usual. > >>> You're simply ignorant of the actual physics. >> Physics has nothing to do with it. The problem is grammatical. Quantum mechanics employs everyday terms to support its mathematical structure. My complaint, a valid one, is that these terms are no longer employed with their standard meanings, thus making Quantum theory meaningfully vacuous. THus Quantum mechanics is a pragmatic, predictive tool only, for which "understanding" and sense are no longer required.
From: Jim Burns on 15 Nov 2009 15:24 tg wrote: > I'm fascinated by JJ's ability to elicit responses > with his language which closely approaches quantum > randomness. However, there is a reasonable underlying > language/philosophical question. I agree that these questions about quantum randomness and others like them are reasonable. But the program of consulting our intuition about their answers has expired, has ceased to be: it is an ex-program. The assumptions of Bell's Theorem are that the outcome of a quantum measurement is (i) determined by properties of the particle and apparatus (whether or not we can measure the properties themselves), and (ii) /not/ affected by anything that happens at some arbitrarily large distance (which are often abbreviated as "local reality" and may, for many purposes, be referred to as "our intuition"). The theorem puts a limit on how strongly correlated certain pairs of widely separated measurements can be. Quantum mechanics claims that some of these measurements will break those limits. It turns out experimentally that quantum mechanics is right and "local reality" (AKA "our intuition") is wrong. > We believe that there is no cause that can effect > the lifetime of the decay of a particle. So it seems > to me that we could attribute a label of > 'hidden variable' to that information itself. IOW, > while we do not claim a cause, we could argue that > the lifetime could as easily be *determined* at the > instant of creation of the particle as at the instant > of decay. So there would be a piece of information > about the particle which is inaccessible rather than > non-existent. I'm afraid I don't find your description of this whatever-it-is (that does not cause the particle's decay but does determine it) to be very coherent. If the time of the decay of the particle is a function of this 'hidden variable', then the conditions of Bell's Theorem are met and there is a limit on correlations between widely separated measurements which is at least sometimes broken by our measurements. I take this to mean that there is, in fact, no such hidden variable, whether or not we can access it. Someone might object that we don't know that the results of the intuition-destroying experiments apply to decaying atoms as well as pairs of gamma rays. Personally, I find experimental results that dodge our constraints but only when we can't see them doing so to be considerably less intuitive than the loss of local reality. Perhaps a better answer would be to point out that the way physics proceeds, the way science proceeds is to generalize alleged laws to the utmost extent ("Energy is conserved everywhere in the universe.") and then wait for contradictions to pour in from the experimentalists. ("But, wait! I've got some radium that behaves very oddly.") Is there some contradiction, some troubling experimental result that makes it necessary to suppose there is this 'hidden variable'? Jim Burns http://en.wikipedia.org/wiki/Bell%27s_theorem#Importance_of_the_theorem
From: Marshall on 15 Nov 2009 16:11 On Nov 15, 11:40 am, John Jones <jonescard...(a)btinternet.com> wrote: > Virgil wrote: > > > One normally asserts something in words. > > But without position and momentum there is nothing substantial to assert. I question this: you yourself take a position, and you post so much as to have a certain momentum, and yet you still have nothing substantial to assert. Marshall
From: John Jones on 15 Nov 2009 16:13 Jim Burns wrote: > tg wrote: > >> I'm fascinated by JJ's ability to elicit responses >> with his language which closely approaches quantum >> randomness. However, there is a reasonable underlying >> language/philosophical question. > > I agree that these questions about quantum randomness > and others like them are reasonable. But the program of > consulting our intuition about their answers has expired, > has ceased to be: it is an ex-program. > > The assumptions of Bell's Theorem are that the > outcome of a quantum measurement is (i) determined > by properties of the particle and apparatus > (whether or not we can measure the properties > themselves), and (ii) /not/ affected by anything > that happens at some arbitrarily large distance > (which are often abbreviated as "local reality" > and may, for many purposes, be referred to as > "our intuition"). > > The theorem puts a limit on how strongly correlated > certain pairs of widely separated measurements > can be. Quantum mechanics claims that some of these > measurements will break those limits. It turns out > experimentally that quantum mechanics is right and > "local reality" (AKA "our intuition") is wrong. > >> We believe that there is no cause that can effect >> the lifetime of the decay of a particle. So it seems >> to me that we could attribute a label of >> 'hidden variable' to that information itself. IOW, >> while we do not claim a cause, we could argue that >> the lifetime could as easily be *determined* at the >> instant of creation of the particle as at the instant >> of decay. So there would be a piece of information >> about the particle which is inaccessible rather than >> non-existent. > > I'm afraid I don't find your description of this > whatever-it-is (that does not cause the particle's > decay but does determine it) to be very coherent. > > If the time of the decay of the particle is a function > of this 'hidden variable', then the conditions > of Bell's Theorem are met and there is a limit on > correlations between widely separated measurements > which is at least sometimes broken by our measurements. > I take this to mean that there is, in fact, no such > hidden variable, whether or not we can access it. > > Someone might object that we don't know that the > results of the intuition-destroying experiments > apply to decaying atoms as well as pairs of > gamma rays. Personally, I find experimental > results that dodge our constraints but only > when we can't see them doing so to be considerably > less intuitive than the loss of local reality. > > Perhaps a better answer would be to point out > that the way physics proceeds, the way science > proceeds is to generalize alleged laws to the > utmost extent ("Energy is conserved everywhere > in the universe.") and then wait for contradictions > to pour in from the experimentalists. ("But, wait! > I've got some radium that behaves very oddly.") > Is there some contradiction, some troubling > experimental result that makes it necessary to > suppose there is this 'hidden variable'? > > Jim Burns > > > http://en.wikipedia.org/wiki/Bell%27s_theorem#Importance_of_the_theorem > The idea of a hidden variable is a grammatical consequence of any quantum theory, as I argued.
From: Marshall on 15 Nov 2009 16:19
On Nov 15, 11:45 am, John Jones <jonescard...(a)btinternet.com> wrote: > > Quantum mechanics employs everyday terms to support its mathematical > structure. My complaint, a valid one, is that these terms are no longer > employed with their standard meanings, thus making Quantum theory > meaningfully vacuous. That's obviously bullshit. If attempting to use a word in more than one way were to be any impediment to meaning, then nothing would mean anything. Every word is used more than one way; some words are used dozens if not hundreds of different ways. Hell, *every* field of human endeavor uses everyday terms in idiomatic ways. The closest true thing to what you wrote above is that if one enters a new field, one has to learn the field-specific meanings for its terms, and that can confuse the ignorant and the indolent. (Since you're both, this is a particularly heavy burden in your case.) Bleah, I'm replying seriously to a troll; I need to go wash my hands. Marshall |