Talk:Maxwell's demon

From RationalWiki
Jump to: navigation, search

Is it really pseuodoscience? I thought it was a valid thought experiment. Is Schrodinger's cat, then, pseuodoscience?--"Shut up, Brx." 15:41, 13 December 2011 (UTC)

Do you have a mental deficiency that prevents you from reading wikipedia? ArchieGoodwin (talk) 15:58, 13 December 2011 (UTC)
I think he's probably just incapable of sitting still for the 2 seconds it takes to think things through or refrain from holding court on every single inane thing that pops into his head. It's probably pseudoscience but the point is broader. The article presents it as an illustration of a principle of pseudoscience at work, e.g. the demon is only capable of effecting a violation of the 2nd Law of Thermodynamics if that's how you define it. According to Maxwell's original formulation, the demon is not considered part of the closed system of the divided box, thus he is capable of changing the temperature and regulating pressure "without expenditure of work." The standard criticism, and I think the way this article intends to present the issue albeit poorly, is that it's inaccurate to describe a being interacting with a system without affecting its net energy. Thus, the broad point is that it's analogous to the kind of slippery games creationists play in essentially assuming into existence the conclusions they've put at issue by building them into the definitions they (mis)use in debating their positions. I'm sure there are more profound ways to put it but that's what you get while I'm sitting here waiting to get out of an appt. Nutty Roux100x100 anarchy symbol.svg 16:28, 13 December 2011 (UTC)
I've taken out references to pseudoscience. I'm not Jesus (talk) 16:57, 13 December 2011 (UTC)
I did read the wikipedia article, long before I'd read this one and again before I left my comment. Maxwell's demon, while disproved, is still a valid part of science and is used in lessons even today. Just because it was found to be false doesn't mean it's pseudoscience. Science corrects itself. Also, it doesn't fit a stricter definition of pseuodscience- the guy who came up with it was a physicist himself who presented it to other physicists.--"Shut up, Brx." 19:18, 13 December 2011 (UTC)
I take it back. You're a cretin and you have the attention span and focus of a gnat. Nutty Roux100x100 anarchy symbol.svg 20:09, 13 December 2011 (UTC)

[edit] Category:Pseudoscience

I can see why this can be considered pseudoscience, but I'm under the impression Maxwell wasn't aware of the solution. If people still try to push this thought experiment as pseudoscience today then I think we should keep the category, but if we don't document that in the article I don't think we need the category. True, it gave rise to pseudoscientific Morton's demon, but it isn't Morton's demon, so I don't feel at the moment that we need the category. Sam Tally-ho! 04:19, 15 December 2011 (UTC)

Any theory involving demons is not science today and was not science in Maxwell's time. Mjollnir.svgListenerXTalkerX 04:21, 15 December 2011 (UTC)
But it's a though experiment. Was he actually trying to make a scientific theory involving demons? Sam Tally-ho! 04:24, 15 December 2011 (UTC)
(Edit conflict) It was a thought experiment. Maxwell didn't deny Thermodynamics, he was just questioning it (and no, he wasn't JAQing off, he ws legitmately curious). The thought experiment remains in physics education today and can help to understand the subject. Just because it was proven wrong doesn't mean it was pseudoscience. Only if people had kept propounding it, which they haven't.--"Shut up, Brx." 04:25, 15 December 2011 (UTC)
Stop edit warring, Brxbrx. Who cares if he was curious or not. Maxwell's idea is discredited as hokum. It's used, if at all, as an example of hokum. He couldn't have known why it was hokum, but that's also irrelevant. Redefining terms to create such an alternate reality is the very essence of pseudoscientific hokum. I have no idea what your prior point about Maxwell being a physicist presenting the idea to other physicists has to do with the issue. And your final assertion that it's not pseudoscience unless people continue propounding it is idiotic. If you were right, we'd never be able to cover one off cranks pretending they've got cold fusion all worked out. Knock it off. Nutty Roux100x100 anarchy symbol.svg 04:30, 15 December 2011 (UTC)
Scientific thought experiments still have to stay within the bounds of methodological naturalism, at the very least; Schrödinger's Cat, for example. Mjollnir.svgListenerXTalkerX 04:33, 15 December 2011 (UTC)
Wasn't Schrödinger's Cat making fun of quantum theory, though? As in, it was less a legitimate thought experiment and more a parody of a particular line of thought. Star of David.png Radioactive Misanthrope 04:39, 15 December 2011 (UTC)
My understanding is that it's a legitimate illustration of at least the Copenhagen interpretation of quantum theory that has it possible to calculate the probability that photons will pass through either slit in the double slit experiment as if they were in 2 places at one, based on theoretically tracing the path of a particle as if it were a wave function by its amplitude. This makes sense to me but I'm sure I'm getting it desperately wrong. Nutty Roux100x100 anarchy symbol.svg 05:10, 15 December 2011 (UTC)
It would be hokum if Maxwell said "there is a demon that can do this to violate thermodynamics". Thought experiments don't have to stay within the bounds of methodological naturalism, because you can use them to prove points about why methodological naturalism has to be maintained. That the demon does do work in opening a gate wasn't the relevant point; it was that the demon would have to be processing information to complete the task. This started the ball rolling to get information tied into thermodynamics and entropy. To call it "discredited" is really to miss the point entirely. Scarlet A.pngpathetic 16:46, 15 December 2011 (UTC)
Thank you! I was worried that if you did come into this discussion, you'd get your whole obtuse on, but I'm glad I was wrong.--"Shut up, Brx." 16:49, 15 December 2011 (UTC)
This article might help. Scarlet A.pngbomination 16:50, 15 December 2011 (UTC)
Wait a sec... did people seriously think Maxwell was trying to invent a perpetual motion engine by summoning up an genuine supernatural demon? Scarlet A.pngbomination 17:18, 15 December 2011 (UTC)
That's the Diskworld version. Bad Faith (talk) 17:31, 15 December 2011 (UTC)
Give me a break. Maxwell never said there is a "demon" (and actually never used that term) because the "demon" was merely a means of discussing the actual question he was asking, which gets left out of the thought experiment as it's commonly quoted. Beyond the conceit of the illustration, he was absolutely proposing a possibility that he viewed as within the bounds of methodological naturalism. The actual question he asked was whether the Second Law of Thermodynamics was something that emerged from a statistical understanding of the motion of molecules rather than from the motions of individual molecules. You point relates to subsequent understandings of the problem, but has nothing to do with what Maxwell's actual point was, a point that we obviously now know is bunk.

Let's look at exactly what Maxwell says since people seem to be looking at only part of the section from his 1872 book Light and Heat, and I think missing the actual point he was making:

One of the best established facts in thermodynamics is that it is impossible in a system enclosed in an envelope which permits neither change of volume nor passage of heat, and in which both the temperature and the pressure are everywhere the same, to produce any inequality of temperature or of pressure without the expenditure of work. This is the second law of thermodynamics, and it is undoubtedly true as long as we can deal with bodies only in mass, and have no power of perceiving or handling the separate molecules of which they are made up. But if we conceive a being whose faculties are so sharpened that he can follow every molecule in its course, such a being, whose attributes are still as essentially finite as our own, would be able to do what is at present impossible to us. For we have seen that the molecules in a vessel full of air at uniform temperature are moving with velocities by no means uniform, though the mean velocity of any great number of them, arbitrarily selected, is almost exactly uniform. Now let us suppose that such a vessel is divided into two portions, A and B, by a division in which there is a small hole, and that a being, who can see the individual molecules, opens and closes this hole, so as to allow only the swifter molecules to pass from A to B, and only the swifter molecules to pass from A to B, and only the slower ones to pass from B to A. He will thus, without expenditure of work, raise the temperature of B and lower that of A, in contradiction to the second law of thermodynamics.

This is only one of the instances in which conclusions which we have drawn from our experience of bodies consisting of an immense number of molecules may be found not to be applicable to the more delicate observations and experiments which we may suppose made by one who can perceive and handle the individual molecules which we deal with only in large masses.

In dealing with masses of matter, while we do not perceive the individual molecules, we are compelled to adopt what I have described as the statistical method of calculation, and to abandon the strict dynamical method, in which we follow every motion by the calculus.

It would be interesting to enquire how far those ideas about the nature and methods of science which have been derived from examples of scientific investigation in which the dynamical method is followed are applicable to our actual knowledge of concrete things, which, as we have seen, is of an essentially statistical nature, because no one has yet discovered any practical method of tracing the path of a molecule, or of identifying it at different times.[1] (my emphasis)

The actual question Maxwell asked has been answered in the negative in a variety of ways; but allowing the possibility of perpetual energy, as Maxwell did, is now known to be pseudoscience. The entire point of discussing the thought experiment now versus then is to illustrate what became a well-known principle that was unknowable, or at least unknown, to Maxwell. The pseudoscience category refers to the fact that the thought experiment admits of a possibility that we now know doesn't exist. It's not pejorative; it simply is what it is: no agent can act upon a system without doing work as part of the system ("the system enclosed in an envelope"). Nutty Roux100x100 anarchy symbol.svg 17:49, 15 December 2011 (UTC)

Yes, but "wrong" is not the same as pseudoscience and neither is "falsified". Things that are "wrong" or "falsified" are just that. I don't think it fits the description as outlined in our article on Pseudoscience.--BobSpring is sprung! 20:53, 15 December 2011 (UTC)
(EC, but also "what Bob said") So any time a scientist says "hmm, here's an idea..." it's pseudoscience if it doesn't work? We have no proof that the laws of thermodynamics are truly unbreakable, they're empirically observed and more than likely they are unbreakable - but there's nothing that says they CERTAINLY cannot be broken if we find the right method. That was true when Maxwell was working, it's still pretty much true now. It's asking the question "Could this work? And if not, why not?" and science does this all the time. Our understanding of mass-energy equiverlence and how information theory ties into entropy didn't exist when Maxwell asked that. So I don't see why the pseudoscience tag is there, no one else describes it as bunk psuedoscience as it's a question, not "this will work and I don't care what evidence you're going to put in front of me" as cranks do. If you presented Maxwell with mass-energy equivalence and information-entropy relationships to disprove the conjecture he'd be pretty happy with that. If that's pseudoscience then all of science is pseudoscience. Scarlet A.pngpathetic 20:58, 15 December 2011 (UTC)
I think his hate-on for me was making him want to prove me wrong. He can't be that dense--"Shut up, Brx." 21:17, 15 December 2011 (UTC)
I think Brxbrx just called me dense because a few people disagree with me. The irony meter supplier will be exhausted of his remaining stock. Anyway, once again I'm not suggesting that Maxwell was engaged in pseudoscience. I would have preferred it in the pseudoscience category because, while Maxwell didn't know he was wrong, redefining the laws of physics as he proposed very nicely illustrates the kind of thinking that goes into pseudoscience and the category provided a good jumping off point from which to explore the subject. The mention of perpetual motion machines amplifies that point but could be strengthened. Nutty Roux100x100 anarchy symbol.svg 22:03, 15 December 2011 (UTC)
Personal tools
Namespaces

Variants
Actions
Navigation
Community
Toolbox
support