Talk:Heat death of the universe

History Confusion

The history of the heat death of the universe confuses Thomson's principle of least dissipation of energy and Clausius's principle that the entropy of the universe tends to a maximum. It was Boltzmann in his public lectures who popularized the idea of the end of the universe in a heat death. P. G. Tait in his first edition of "Sketch of Thermodynamics" (1867) tried to make the principle of least dissipation stick, but it was later superseded by Clausius's principle [cf. his second edition]. Bernhlav (talk) 07:21, 4 September 2012 (UTC)

entropy and the future of the universe as stated in this article

This article is at present heavily biased to make it seem as if there is definite physical meaning in the idea of the heat death of the universe, when that is not so. My edits were intended to bring some scientific accuracy to the article. They were reverted by someone who is apparently imbued with the bias that now pervades the article.

The celebrated statements by Clausius about the energy and entropy of the universe are regarded by thermodynamicists as poetic or metaphorical, but are mistakenly taken as categorical and physically well defined by the mindset that biases the present article. This mindset is a kind of 'fundamentalism', so to speak, not in a conventional religion, but in what would like to be taken as science, but is really pseudo-science.

The concept of entropy rests on two bases. One is the definition of entropy by Clausius, in directly physical terms. It refers only to the states of systems consisting of matter and energy that are in a condition of thermodynamic equilibrium. "The universe" is not, and has never been, understood well enough to justify a statement that it is in thermodynamic equilibrium. There is no generally recognized and understood physical definition of the entropy of such vast and ill-understood entities as "the universe". The present article gives no hint of this. The other definition of entropy is much more recent, far more abstract, and not widely used. In this definition, entropy is proportional to the amount of information needed to take one's knowledge of a system, from a state of knowledge defined by the values of a set of macroscopic variables, to a state of knowledge defined by a detailed and exhaustive description of the state of the system in terms of its microscopic and elementary particulate constituents. It is not of such close relevance to the present article, but in the case of equilibrium thermodynamics it is in logical agreement with the Clausius physical definition.

The article as it stands is full of half-baked slip-shod pseudo-thinking.Chjoaygame (talk) 21:20, 10 September 2012 (UTC)

Please discuss the article, not contributors. In particular, you are unlikely to achieve consensus by attacking other editors based on your assumptions about their motivations.

Your edits to the article, and your comments above, are written in an argumentative tone that is not appropriate for the article's voice. Given that, even assuming you have a valid point about the content, your edits will need a substantial amount of work before they make suitable article text. If you can find sources that express this view, and establish their notability, then we can present it with appropriate weight. --Amble (talk) 21:26, 10 September 2012 (UTC)

There were also quite a few things in your edits that weren't adequately sourced: your evaluation of one author as widely respected; the deprecation of other authors as having less expertise; and your use of the content of a book to evaluate other research that isn't directly mentioned in the book. Even if your judgements on these subjects is correct, it constitutes original synthesis, which is problematic for sourcing in Wikipedia. --Amble (talk) 21:35, 10 September 2012 (UTC)

Thank you for your valuable advice, Amble. Indeed thank you for your further advice.

The present voice of the article needs changing.

The article at present does not attach word 'speculative' to the concept of the entropy of the universe, but that word is clearly present in the Adams and Laughlin article that is cited four times in the article. The Adams and Laughlin article writes: "Classical heat death is thus manifestly avoided." There is no hint of this in the Wikipedia article that cites it. Moreover the article by Adams and Laughlin concludes: "In other words, interesting things can continue to happen at the increasingly low levels of energy and entropy available in the universe of the future." The Wikipedia article presents the Adams and Laughlin article as supportive of the heat death story, which is a thorough misrepresentation of the Adams and Laughlin article.

My edits were based on an authoritative and reliable expert source, explicitly quoted verbatim, and in summary, with a internet link, and they accurately represent its content. The present weight of the article is slight. If the present "we" will read and think about the source of my edits, then the present "we" will be able to put in something much like my reverted edits, to bring some real weight to the article. I do not have the heart to spend time trying to swim against a tide such as the present article's "voice".Chjoaygame (talk) 22:00, 10 September 2012 (UTC)

I'm sorry, I haven't had much time to come back to this discussion. The Adams and Laughlin paper seems rather dated now, as it predates the discovery of accelerating expansion. The distinction it makes between classical heat death and cosmological heat death involves a fair amount of subtlety. Are there later reviews that cite this work and bring it into line with the later concordance cosmology?

Using an authoritative and reliable expert source is, of course, highly desirable. However, your edits included a lot of additional commentary on your evaluation of the source, and on other authors, that were not themselves sourced. It's usually easy enough to avoid that kind of problem by avoiding such commentary and focusing on the material itself. --Amble (talk) 02:25, 5 October 2012 (UTC)

This article is built on historically early ideas about thermodynamics, one might say about classical thermodynamics. In particular, classical thermodynamics may fairly also be called equilibrium thermodynamics, as it is in the titles of some books on the subject. The early thinkers, such as Clausius and Kelvin, did not for the present context adequately grasp that the concept of entropy is initially restricted to systems in thermodynamic equilibrium. Today it is very far from agreed how, even it is possible, to give a general definition of the entropy of a system that is not in thermodynamic equilibrium. The universe has never been in thermodynamic equilibrium. Thermodynamics is a laboratory-based science. It is not built on cosmological concepts. The concept of heat, considered precisely in thermodynamic terms, refers only to flows of energy between closed systems. The idea of dividing the universe up into closed systems is mind-boggling. It follows that the idea of the "heat death of the universe", when read strictly in terms of thermodynamics, which is the only source that supplies the notion of physical entropy, is nonsense.Chjoaygame (talk) 04:06, 5 October 2012 (UTC)

"[T]hermodynamics, which is the only source that supplies the notion of physical entropy, [...]" -- Hmm? Why do you exclude statistical mechanics? And it's not entirely clear to me that it's justified to say that "[t]he universe has never been in thermodynamic equilibrium." Anyway, what we really need are not arguments here about the merits of the science, but review papers and other sources that give a broad overview of the subject. --Amble (talk) 04:54, 5 October 2012 (UTC)

Perhaps I could have worded it more elaborately. Thermodynamics is the source of the idea of physical entropy. Statistical mechanics provides explanations and calculations of estimates of it. Statistical mechanics cannot provide a valid notion of entropy beyond what is provided by thermodynamics because entropy is essentially defined by macroscopic quantities. As for the question of whether the universe has ever been in thermodynamic equibilibrium: an isolated system in thermodynamic equilibrium never leaves it. I doubt that you will find overviews on this subject adequate for your demands; but at least you are agreeing that you don't have them already. I have indicated Grandy to you.Chjoaygame (talk) 13:55, 5 October 2012 (UTC)

I think at root you're trying to point out that there's more subtlety here that's not adequately reflected in the article; in that sense you are surely correct. However, you end up making very blanket statements that appear to go too far. The Universe has certainly not been in thermal equilibrium in the sense that its gravitational state has been far from equilibrium; it has been in states that can be understood as a self-gravitating system in which certain other degrees of freedom are in equilibrium. I've looked the Grandy book, but the author contents himself with giving reasons why he declines to make statements about the long-term fate of the universe. I'm not sure we can get from there to usable article text without engaging in original synthesis. --Amble (talk) 19:39, 5 October 2012 (UTC)

You say I'm trying to point to a lack of subtlety. You think my statements go too far. Nice try. I don't have time to debate this with you. Feel free to shield yourself from reality by minimizing what I say. Grandy's book explains his reasons clearly enough. They are, more or less, that the idea of the entropy of the universe is a nearly nonsensical phrase. That is not a reason for you to dismiss Grandy. If you applied such high standards, as you are now demanding, to the article as it stands, you would delete from it nearly all beyond the historical sections. As I mentioned before, I do not have the heart to try to edit the article swimming against the tide.Chjoaygame (talk) 23:19, 5 October 2012 (UTC)

The personal stuff doesn't help your argument any. And discussion is how this place works. I haven't dismiss Grandy, but I have questioned whether his book adequately supports your edits. In particular, if you apply your understanding of Grandy's book to make a critique of other works, you're walking onto shaky ground with regard to original synthesis. --Amble (talk) 00:17, 6 October 2012 (UTC)

Beyond the historical parts, the present article rests not on merely shaky ground, but on quicksand or less.Chjoaygame (talk) 04:06, 6 October 2012 (UTC)

heat death controversy

I know a lot of predictions have been proven but how the heck is heat gonna cause the death of the universe. I personally believe that the universe is gonna exist for eternity. The universe has been expanding since the big bang, what makes you think it's gonna come to an end. It's possible that it will end, but in my opinion if it will end it won't end for billions of years. — Preceding unsigned comment added by Anastronomer (talk • contribs) 15:48, 20 October 2012 (UTC)

lead is nonsense

The first sentence of the lead finishes as follows: "the universe has diminished to a state of no thermodynamic free energy and therefore can no longer sustain processes that consume energy (including computation and life)." As it stands this seems to be a statement in terms of thermodynamics but in those terms it is nonsense; yes, utter nonsense; that is to say, it has no physical meaning. To find out why this is so, one must read a little thermodynamics.Chjoaygame (talk) 17:39, 25 October 2012 (UTC)

Actually it's a perfectly sound statement.89.99.122.33 (talk) 13:13, 5 May 2013 (UTC)

link to Logopolis misleading

The present article is borderline. It tries to pass off a historical or very speculative and ultimately nearly nonsensical idea as if it were more or less reliable science. It needs be edited further to indicate just how far is the idea of "heat death of the universe" from reliable science.

To add to this by a link to an account of a science fantasy gives too much credibility to that fantasy, and adds to the feeling of licence that this article has that one can talk in the Wikipedia with such a blurring of the borderline between science and fantasy.

Perhaps I went too far in calling the link vandalism. I would still remove it on the ground that it is misleading by supporting confusion of thought.Chjoaygame (talk) 00:45, 10 December 2012 (UTC)Chjoaygame (talk) 00:47, 10 December 2012 (UTC)

Go ahead. But personally I'd remove like a half of the "See also" section; the links there are either only tangenially related or should be linked within the article. For example, I'd replace most of the links with a single one, Ultimate fate of the universe. Matma Rex pl.wiki talk 06:54, 10 December 2012 (UTC)

I don't think this article is worth an argument about this. I will do nothing about it.Chjoaygame (talk) 13:14, 10 December 2012 (UTC)