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Entropy
Oct 30, 2014 16:11:28 GMT 1
Post by abacus9900 on Oct 30, 2014 16:11:28 GMT 1
mrsonde, we all know entropy is a measure of the disorganiztion in a system, so why the big song and dance? What has this got to do with crystallography BTW?
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Entropy
Oct 30, 2014 18:32:22 GMT 1
Post by mrsonde on Oct 30, 2014 18:32:22 GMT 1
mrsonde, we all know entropy is a measure of the disorganiztion in a system You might think you "know" that, but you're wrong. How are you ever going to "measure" such a nebulous concept? What you can measure in infrmation terms is the dissipation of coherent distinctions - distinctions that you have specified in the first place, it hardly needs saying. You can call that "disorganisation" if you like, if you want to use it in that very specific sense. As I said, the problem arises when it is used in a very vague, unspecified and unspecifiable sense, and projected out from such specific circumstances as a precisely defined closed system onto the entire workings of the universe. What song and dance? You mean the corrections of your misunderstanding? That's what you asked for in your opening post, remember? I think Alan explained himself well enough - he was correcting your misunderstanding. I must say, you don't seem at all grateful for our efforts.
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Entropy
Oct 31, 2014 18:50:00 GMT 1
Post by alancalverd on Oct 31, 2014 18:50:00 GMT 1
Crystallography isn't the subject we are discussing. It just happens to provide the definitive counterexample to the notion that entropy is randomness or disorganisation. If you rule out all counterexamples, you can end up believing anything, but this is supposed to be a science forum.
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Post by abacus9900 on Nov 1, 2014 10:01:50 GMT 1
Look chaps, when I look up the definition of entropy at the online version of the Merriam Webster Dictionary I get the following: 1 : a measure of the unavailable energy in a closed thermodynamic system that is also usually considered to be a measure of the system's disorder, that is a property of the system's state, and that varies directly with any reversible change in heat in the system and inversely with the temperature of the system; broadly : the degree of disorder or uncertainty in a system. 2 a : the degradation of the matter and energy in the universe to an ultimate state of inert uniformity b : a process of degradation or running down or a trend to disorder. 3 : chaos, disorganization, randomness. www.merriam-webster.com/dictionary/entropySo, in future can you please indicate which particular definition you are referring to. Thank you.
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Post by abacus9900 on Nov 1, 2014 10:13:26 GMT 1
quote timestamp="1414681888" source="/post/23906/thread" author=" abacus9900"]mrsonde, we all know entropy is a measure of the disorganiztion in a system Well, frankly, I'm no more informed than I was before because you refuse to give me a straightforward definition of entropy. At this point, it is of little value going into the finer points of the concept because that will just lead to confusion. Are you doing it on purpose? Yes, I'm misunderstanding but that is because I have been given confusing information. I'm sure Alan is a nice enough bloke but he seems rather vague in his replies. He has yet to elucidate about the relationship between entropy and crystals. For example, he states: "It just happens to provide the definitive counterexample to the notion that entropy is randomness or disorganisation. If you rule out all counterexamples, you can end up believing anything, but this is supposed to be a science forum". This is not a very helpful statement.
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Post by mrsonde on Nov 2, 2014 7:25:56 GMT 1
Look chaps, when I look up the definition of entropy at the online version of the Merriam Webster Dictionary I get the following: 1 : a measure of the unavailable energy in a closed thermodynamic system Obviously wrong. It's a measure of the energy put into a closed (specifically defined beforehand) system and through dissipation not usable for work. The total unavailable energy not pre-specified in this way in, say, a steam engine, would probably be enough to generate the daily electricity use of the entire world. Using the term in the very specific sense that I pinpointed. It does not mean "disorder", or its opposite, in the ordinary everyday sense at all. And even in that very specific sense, it's a concept derived from information theory, not thermodynamics. Obviously wrong. "Disorder", in the very specific sense I've outlined - and not a concept usefully transposed from information theory to thermodynamics. In information theory, however, the concept of order has some parallel with its ordinary meaning, so it's understandable why Shannon borrowed it. As I said, this is where the difficulties arise. No empirical basis for this piece of theorising at all. At last - a reasonably accurate definition. That's it - all that need be said. This is what it means, scientifically. This is not a scientific (empirical) definition, as Alan pointed out to you. Again - not a scientific sense. Euphemistically, maybe. Like words might have weight, or situations have gravity. 2b is the only scientific definition there - which is what you asked for in your OP; and what you've been given.
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Post by mrsonde on Nov 2, 2014 7:47:36 GMT 1
quote timestamp="1414681888" source="/post/23906/thread" author=" abacus9900"]Well, frankly, I'm no more informed than I was before because you refuse to give me a straightforward definition of entropy. I gave you a straightforward definiton in my first post, #5: What? You asked what the term meant scientifically. I told you. You then used it in senses that are not scientifically correct, and Alan and I tried to put you straight. If you're confused because of that - well, that's hardly our fault. No doubt - there's probably more nonsense talked about entropy by popular science writers than any other concept in science. It always was the case, when Spencer, Spengler and Eddington started it. Since then we've had a generation of physics graduates who have learned what it means from them; and become the educators of another generation; and again, at least three times; so even professional physicists have the same pseudo-philosophical nonsense floating around their heads. It seems a good enough elucidation to me. What he's counteracting is your contention that "nature tends towards disorganisation", remember? He has helpfully pointed out one very important aspect of nature where this is simply not true. And nothing vague about it, was there? You do understand that a crystal has more organisation than a random distribution of particles, don't you? And now please note: as the concept is used in thermodynamics, crystallisation is fine, as is the return to a liquid or gaseous phase. That's why your dictionary definition 1 above is wrong - in the second part, after the colon(as a general aside, it's not a very sensible policy to try to educate yourself scientifically by reading dictionary definitions - especially of words with multiple meanings, and especially in a third-rate free online source). There is no trend to disorder or increase in the degree of uncertainty in this natural process: quite the contrary. One could say the same about elementary particles, of course; or of atoms - protons and electrons and the atoms they form are to all intents and purposes immortal: theoretically, they do break down, some at least, given enough time - but not through entropic processes. On the contrary, nature displays a strikingly evident tendency for them to agglomerate and organise themselves yet further - heavier and heavier atoms, molecules, polymers, amino acids, proteins, lifeforms &c &c
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Post by abacus9900 on Nov 3, 2014 9:44:27 GMT 1
mrsonde, it appears to me you are attempting to splt hairs, and in doing so are confusing yourself, as well as me. You don't seem very fond of words, much preferring mathematical definitions no doubt. However, different words often mean essentially the same thing and trying to pretend they don't is pretentious, to say the least and I suggest you are intentionally taking them out of context - a very easy thing to do when one is seeking to obfuscate. Alan also seems to have a tendency to do this.
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Post by alancalverd on Nov 5, 2014 18:32:49 GMT 1
a : the degradation of the matter and energy in the universe to an ultimate state of inert uniformity As we remove the energy from a gas, it turns into a liquid then a crystal - it can't get any more inert or uniform, but it is highly ordered. So you have a problem in that Webster's definitions seem to be mutually contradictory.
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Post by Progenitor A on Nov 5, 2014 18:56:28 GMT 1
As we remove the energy from a gas, it turns into a liquid then a crystal - it can't get any more inert or uniform, but it is highly ordered. So you have a problem in that Webster's definitions seem to be mutually contradictory. Probably why Bolzman committed suicide. He was counfounded by entropy Anyway uniformity is ordered - the sameness of Zero K throughout the universe would be the ultimate uniformity To say that the ultimate in uniformity is complete disorder is gibberish except for the thermal entropy bit
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Entropy
Nov 11, 2014 17:42:53 GMT 1
Post by mrsonde on Nov 11, 2014 17:42:53 GMT 1
mrsonde, it appears to me you are attempting to splt hairs, and in doing so are confusing yourself, as well as me. You don't seem very fond of words, much preferring mathematical definitions no doubt. However, different words often mean essentially the same thing and trying to pretend they don't is pretentious, to say the least and I suggest you are intentionally taking them out of context - a very easy thing to do when one is seeking to obfuscate. Alan also seems to have a tendency to do this. No "splitting hairs" about it. You claimed Entropy refers to a tendency in nature to disorganisation. Alan and I pointed out that this was quite evidently factually wrong. Okay? Where's the "hair"? Your understanding is wrong, full stop - you have a mistaken understanding of the concept in your head. And, apparently, you're very resistant to having it dislodged. Fine - no skin off my nose.
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Entropy
Nov 11, 2014 17:51:49 GMT 1
Post by mrsonde on Nov 11, 2014 17:51:49 GMT 1
Anyway uniformity is ordered - the sameness of Zero K throughout the universe would be the ultimate uniformity Ah - but this is not how the term "order" is used in information theory. Or anywhere else, come to that, as far as I'm aware. Not as the concept is used in Information - no distinctions to be drawn, therefore no order (i.e. complete disorder.) The same thing applies to the state of the Big Bang prior to the quark epoch. Exactly. Which is why I said it is not a concept usefully transposed from information theory to thermodynamics (which it was, regrettably.) There's an interesting historical accident behind tht error - a misunderstanding by cyberneticists of what Entropy meant in thermodynamics. They got it the wrong way around - or the thermodynamicists did, take your pick. For a few decades at least you has two completely separate and distinct branches of science using the same word with diametrically opposed meanings - high entropy meant a high degree of order for one branch, for the other it meant the complete opposite (as it still does - a physicist would claim, bizarrely, that the Big Bang was a time of maximum "order", and the universe has been running down ever since; a cyberneticist the exact opposite. The Information theorist is correct, in my view - it makes no sense to me to claim before there were quarks, when there was supposedly just undifferentiated energy, with no distinguishable boundries or connections (no space and time), this was in any intelligible sense a state of maximum "order". The point is there was no order at all.
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