Radioactive decay and the myth of randomness
in [Logic]
|
Prev: Can we predict the outcome of a tossed coin?
Next: group of formal differences vs. Grothendieck group
From: John Jones on 17 Nov 2009 23:11 haiku jones wrote: > On Nov 15, 2:13 pm, John Jones <jonescard...(a)btinternet.com> wrote: >> 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. > > Alas, the universe disagrees. > > > > Haiku Jones Fine. Oh great. I'll tell my mum.
From: John Jones on 17 Nov 2009 23:12 Jim Burns wrote: > tg wrote: >> On Nov 15, 3:24 pm, Jim Burns <burns...(a)osu.edu> 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. >>> >> >> I wrote rather quickly but I thought it was >> understandable; let me try again: >> >> 1) I do not claim that something causes the >> particle's decay. >> >> 2) That nothing causes the particle's decay does >> not mean that the lifetime is not determined at the >> creation of the particle. By determined I only mean >> that it is inevitable, that there is nothing that >> can change it. > > Here is my understanding of /randomness/: the outcome of > an experiment (like rolling a die) is /random/ if, in all > the possible worlds that are /identical/, there is more > than one outcome (more than one face lands up). By > /identical/ I mean that /everything we know/ about > all the causal paths leading to our experimental > outcome is the same in each possible world. > > My understanding of /quantum randomness/ is that we > consider all the possible worlds where /everything/ > is identical, instead of /everything we know/, but > there is still more than one outcome of the experiment. > > I see two interpretations that you might intend (and > a third option -- that I just don't get it). > > (1) If we draw a box around the space-time just before > the decay of the atom, we can look at all the possible > worlds where the contents of the box is identical. > Because the decay of the atom has quantum randomness, > there are still different times of decay for the atom > in different possible worlds. HOWEVER, if we, in our > imaginations, mark the time of the decay on the box > (our hidden variable -- hidden because it plays no > part in the physics, being imaginary), then we can > further subdivide the possible worlds so that boxes > marked with the same time are grouped together. > Presto! The outcome is no longer random, because > these groups of possible worlds all have single outcomes > (the atom decays at the same time in each possible > world -- /within each subgroup/, that is). > > Under this view, I suppose there is no quantum > randomness, but there is no randomness either, > nor any probability except 0 and 100%. There are no > uncertain outcomes because every outcome will be what > it will be, tautologically. I don't know, but this > view may be logically consistent, but it seems to > me completely useless. It certainly isn't physics. > > (2) We have almost the same situation as before: > a box around the space-time just before the decay > of the atom, a collection of all the possible worlds > where the contents are identical. Except that, under > this view, in stead of marking the time of decay > on the outside of the box, it's placed inside the > box, inside a lockbox, let us say, so that we know > it can't be used in the processes leading to the outcome. > > I think this might qualify as a physical theory, > but this is also the sort of situation that > Bell's theorem applies to. It doesn't matter that > the decay time written inside the lockbox does > not participate. The theorem does not ask whether > a particular parameter /participates/, just as the > theorem does not ask whether /we know the value of/ a > particular parameter. > >> 3) If you believe that this would violate QM, >> then you should be able to describe a hypothetical >> experiment whose outcome would be different >> if my proposed conjecture is incorrect. > > I think the experimental verification of quantum mechanics > over local reality are what you are asking for. If you > are considering scenario 2 above, then you are trying > to fix local reality by partitioning the possible worlds > finely enough that the outcome appears non-random. > > I don't think local reality is fixable. > > >> It seems to me that the best argument against >> what I am suggesting is that it is not parsimonious, >> but I'm not even sure that such a position holds up. >> As I said in the first place, this is a question >> of language and philosophy, not physics. I find >> the use of decay as the knee-jerk example to explain >> randomness to be facile. > > If what you describe is only a question of > language and philosophy, then maybe my first > interpretation is the correct one. If that is so, > then the point you are making is that it is > possible to change the meaning of > "quantum randomness" so that what you have > turned it into does not exist. > I don't find that a very interesting point. > > Jim Burns YOu never read the original post did you.
From: John Jones on 17 Nov 2009 23:13 kunzmilan wrote: > On 13 lis, 15:56, John Jones <jonescard...(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. But ponder this...wasn't the scientific term "random" >> invented to support a verbal fantasy world created by the quantum >> physicists? It's understandable. After all, every discipline, including >> maths, likes to have its own non-religious menagerie of supernatural >> objects and processes, where infinities abound far beyond the mortal >> realms of grammar and sense. > > The first study of random events was Poisson's study of deaths of > French cavaliers by falling from their horses. What makes a difference > between hidden causes of a death of a man and of an atom? > kunzmilan Quite right.
From: David C. Ullrich on 18 Nov 2009 06:48 On Wed, 18 Nov 2009 04:10:57 +0000, John Jones <jonescardiff(a)btinternet.com> wrote: >Marshall wrote: >> 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. > >It's obviously NOT. It's self-evident. Look at it! am I talking to Mr. >stupido? If you describe something in non-meaningful terms then it is >meaningfully vacuous. Comprende? Sometimes you seem stupid. "no longer employed with their standard meanings" is not the same as "non-meaningful". > >> 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; > >No. So far wrong it's a long time getting back. >A word is a sign. The sign does not have a meaning. The meaning we >'give' the sign is nothing that the sign displays to us. > > >> 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 > >And how many on the other side feel sick? David C. Ullrich "Understanding Godel isn't about following his formal proof. That would make a mockery of everything Godel was up to." (John Jones, "My talk about Godel to the post-grads." in sci.logic.)
From: haiku jones on 18 Nov 2009 09:02
On Nov 17, 9:10 pm, John Jones <jonescard...(a)btinternet.com> wrote: > Marshall wrote: > > 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. > > It's obviously NOT. It obviously is. If I use the noun "set", it can mean one thing to a mathematician, another thing to a tennis pro, a third to a theatrical designer, and a fourth to a dog breeder. None of these is "meaningfully vacuous", you just have to derive the current meaning from the current context -- something speakers of English do all day long, generally effortlessly, unless they happen to wander into an area in which they are technically ignorant. Haiku Jones > It's self-evident. Look at it! am I talking to Mr. > stupido? If you describe something in non-meaningful terms then it is > meaningfully vacuous. Comprende? > > > 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; > > No. So far wrong it's a long time getting back. > A word is a sign. The sign does not have a meaning. The meaning we > 'give' the sign is nothing that the sign displays to us. > > > 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 > > And how many on the other side feel sick? |