Talk:Heat death of the universe/Archive 2

Maldek's Concerns Regarding This Article

1. I am extremely sorry that I kept messing up the equation 10^40 plus 1.7x 10^106. I finally understand that the correct value is 1.7 followed by 65 zeros and then a one x 10^106, a very insignificant number so I also agree that it should just be kept at 1.7x 10^106. I apologize again for the erroneous corrections I have about this subject matter. I began to understand it using large numbers. I understood that 10^106 is 10^66 times larger than 10^40 thus 10^40 only represented 0.followed by 65 zeros and 1. I understand my error, so I thank you for enlightening me but there is still one thing I do not understand. You say that “So, 3^3^3 is the same as 3^(3^3), and is not the same as (3^3)^3 = 3^9.” This is not true 3^3^3 equals 19683 and 3^(3^3) equals 7.62 x 10^12. Obviously the latter number is much larger. Just type it in a graphing calculator and you can see for yourself.

2. The Poncence Recurrence time was messed up so I changed it according to the offical sources. You can see for yourself.

3. The Black Hole Lifetimes should be kept there because it is relavent to the article since different black holes evaporate at different times. You yourself Spacepotatoe have agreed upon this table since you were the one who created it.

4. The lifetime of 1.7x 10^106 years for 20 trillon solar mass black holes, was a number that Spacepotatoe said he found in a reliable source. I had originally but 10^106 years as the lifetime of 20 trillion solar mass black holes but you, Spacepotatoe said that the correct number was 1.7x 10^106 according to your source which you said was much more reliable then mine, so I accepted your word. But now Ashill says there is no source for this and that 1.7x 10^106 is to accruate to be known. I wrote 10^106 years in the first place but Spacepotatoe said he had found a source much more reliable then this so I went with this word. So this 20 trillion solar mass black hole lifetime has been sourced by me and then resourced with Spacepotatoes “much more accurate” source. Ironic how Ashill now says 1.7 x 10^106 is too accurate when I put 10^106 all along and Spacepotatoe comes along and repeatedly changes it to 1.7 x 10^106 years because he says it is much more accurate then my source. So finally I just took Spacepotatoes word, but now Ashill doesn’t like it and says its not relevant and not sourced when it is in fact both relevant and sourced even reliably sourced by Spacepotatoe. Understand that most of the information in this article is from Spacepotatoes sources so I am not supplying these reliable sources.

5. I still don’t understand why I can’t add stars are flung from their orbits in 10^18 years. It is sourced so why can’t I put that in addition your new section about Galaxy Evaporation since stars being flung from their orbits in a prerequistie to Galaxy Evaporation? Could you please tell me?

6. Why are all of things that we agreed on now being changed and if the Coalasing of the Local Group does not relate to the topic then why would Spacepotatoe add it? Please let me know for this article is getting out of control and I need some answers as to why things are being changed so much such as Black Hole Lifetime table after it had been agreed upon for so many weeks and there has been consensus on it, and now all of the sudden Ashill wants it gone. And anyway it was Spacepotatoes idea for the Table so why would he add the table if it wasn’t relevant to the article? I just need some answers? Sorry for all the questions. Thank You for you cooperation. Thank YouMaldek (talk) 01:44, 17 July 2008 (UTC)

Spelling of name of User:Spacepotato
Spacepotato	Spacepotatoe
OK. Good. Right. Ça va pas mal. ¡Muy bien!	Not OK. Bad. Wrong. Tout est perdu. Estamos en el quinto coño.

1. My name is "Spacepotato", with no "e" on the end. Please refer to the table on the right for further clarification.
2. Re the Poincaré recurrence times, I evaluated the top power of 10 in the exponential towers to make displaying and comprehending the numbers easier:
   10^1010102.08 = 10^1010120,
   10^101010101.1 = 10^10101012.6.
   This does not change the values of the numbers (except for a slight change due to roundoff.)
3. Stars aren't flung from their orbits in 10¹⁸ years (at least, not with the most obvious meaning of "flung from their orbits.") If your source is Dyson, "Time without end", he doesn't say that.
4. Although I did add the table of black hole lifetimes to the article, I'm not sure it's really worth having.
5. As I said earlier, exponentiation associates to the right. I don't have a graphing calculator, but when I type 3^3^3 into PARI (a computer algebra system), it tells me it's 7625597484987 = 3^(3^3) = 3^27 and not 19683 = (3^3)^3 = 3^9.

Spacepotato (talk) 06:57, 17 July 2008 (UTC)

I think that wins best username spelling correction in Wikipedia's history! ;) Maldek, I would appreciate if you were to respond to Spacepotato's comment above pointedly and concisely. Thanks in advance. El_C 07:14, 17 July 2008 (UTC)

Oh, nonsense. We have Republicans in charge and Dan Quayle already settled on how to spell "potatoe" beyond all reasonable doubt. We'll see how hard the grammar terrorists are laughing next time they try to fly on an airplane... Wnt (talk) 17:30, 17 July 2008 (UTC)

Neutrino gravity and chemistry

[I transferred this question to Talk:Future of an expanding universe because although that article's content is a large portion of this one, the "heat death" scenario with maximal entropy is inconsistent with speculations about planets made out of neutrinos ;)] Wnt (talk) 17:19, 18 July 2008 (UTC)

The fate of the largest black holes: equilibrium with the CMB

What are the assumptions about the temperature of the Cosmic Microwave Background being made in the Black hole evaporation section ?

At the moment, according to black hole thermodynamics, a black hole with roughly the mass of the moon has a temperature equal to that of the CMB. Larger black holes are colder than that, so are currently consuming more energy from the CMB than they would be emitting through Hawking radiation.

As I wrote previously (above, in 2006) the projection for the CMB temperature would seem to depend strongly on the scenario chosen for the continued expansion of the universe. If the universe continues to expand, so the CMB continues to fall indefinitely, then it will eventually become colder than even the largest black holes. But this is the Big Freeze scenario. If, as some posters have suggested above, the Heat Death scenario is different, and represents everything coming to the same temperature (but not zero), then that temperature would be the temperature of the largest black holes, the coldest objects in the universe, in equilbrium with the CMB.

This could use some clarification in the article. Jheald (talk) 08:00, 17 July 2008 (UTC)

The timeline assumes that the universe continues to expand indefinitely. In this case, the CMBR will cool sufficiently so that it doesn't prolong the time it takes black holes to evaporate. Spacepotato (talk) 08:36, 17 July 2008 (UTC)

It would be useful then to state that explicitly, and identify when the temperature is assumed to have fallen to particular levels, and what the temperature is considered to be of the largest (so coldest) black holes. Jheald (talk) 08:55, 17 July 2008 (UTC)

Maldek's Deepest Apologies to Spacepotato

I am so sorry Spacepotato that I called you Spacepotatoe. Can you ever forgive me for calling you something so different from what your name is? I hope that this does not hurt our friendship and you can reach down into your energy reserves and find it in your big heart to forgive me. I made a big mistake and I am so very very sorry. And I promise you it will never happen again. I hope this does not affect our friendship and that we can continue to be best friends and best buddies despite this incident. Once again I am so sorry for calling you Spacepotaote, something so radically different from Spacepotato, and I implore you to find it in your heart to forgive me. I am so sorry, and I will make it up to you, please let us continue to be best friends. Thank YouMaldek (talk) 00:02, 19 July 2008 (UTC)

Timeline appropriate for this page or future of an expanding universe

My thought in creating the new article, future of an expanding universe, was that the material in the timeline that is unrelated to the heat death of the universe would be moved there. There was no opposition and some support in the discussion above, which I interpreted as a clear consensus in support of this move. However, the material on the Milky Way/Andromeda collision, the coalescence of the Local Supercluster, and the graphical timeline were re-added (diff). I undid the edit because I think the material is very clearly not on topic; am I mistaken?

I think that the timeline should be further trimmed, or maybe completely deleted, not re-expanded. I have dramatically trimmed the timeline section and renamed it "Timeframe for heat death" because I think rewriting will help to focus the section on the heat death, not possible futures of the universe. The section could probably use some expansion (there's more material in Adams & Lauglin §VID, for example), but I don't have time to work more now. —Alex (ASHill | talk | contribs) 22:02, 19 July 2008 (UTC)

I trimmed some more material. Also, I pointed the wikilink to Future of an expanding universe to the correct section—it's possible to do this even before the name of the section is known as one can create invisible anchors which can be linked to but whose names are not seen by the reader. Spacepotato (talk) 21:43, 20 July 2008 (UTC)

Timeline for heat death

I'm no Wikipedia formatting expert, so I'll just pose the question: is there a way to preserve the formatting in the "Timeline for heat death" in the table of contents on the main page? It looks like the black hole age is just 1040 years away, rather than 10^40 years away. Jyoshimi 18:42, 17 October 2006 (UTC)

You could just write 10E40 instead of 10⁴⁰. I assume most people would understand. (68.98.52.155 01:17, 1 November 2006 (UTC))

Actually it would be 1E40, not 10E40 --Charlesreid1 (talk) 08:40, 30 October 2010 (UTC)

I just changed all headers to the 10Exx format instead of the 10^xx format, this made the table of content more correct but a bit less pretty. Someone with knowledge might be needed to step in Lyml 15:02, 26 December 2006 (UTC)

I've replaced the 10Exx format with 10¹⁴, etc., using Unicode superscript characters (¹²³⁴⁵⁶⁷⁸⁹⁰) which looks better, but requires better Unicode support.—Ketil Trout 20:55, 7 February 2007 (UTC)

But what if the black hole age is a mere slightly over thousand years away?! Dun dun dun! Not only did I just break countless laws of thermodynamics, but we have less time than we thought to create a utopic society and learn everything we can about life, the universe, and everything! Pass it on through the generations, and mark it on the calendars of the future! There's only 1039 years left now! Shadow Scythe of Strongbadia?! (talk) 07:44, 23 November 2007 (UTC)

Awww...crap.

Yeah, keeping it at 1040 might scare some people. —Preceding unsigned comment added by 68.227.163.40 (talk) 03:14, 8 May 2008 (UTC)

question of empirical verifiability of the ultimate fate of the universe

Dear friend Spacepotato, the very article itself contains the relevant justification, if it were not obvious after a moment's reflection. Lord Kelvin is quoted as follows.

"The result would inevitably be a state of universal rest and death, if the universe were finite and left to obey existing laws. But it is impossible to conceive a limit to the extent of matter in the universe; and therefore science points rather to an endless progress, through an endless space, of action involving the transformation of potential energy into palpable motion and hence into heat, than to a single finite mechanism, running down like a clock, and stopping for ever."

This means that Kelvin simply does not know whether the universe is finite or not. He just says that it is impossible to conceive a limit to the extent of matter in the universe. He was writing before people had a sort of justification for an idea of a finite universe, inferred from the Einstein general theory of relativity and then the doctrine of the Big Bang. Kelvin's saying he cannot conceive of the contrary is his own admission that he is speculating wildly.

But then, it is literally true that the heat death of the universe is empirically unverifiable, for when it happens, there will be no one around to conduct the alleged empirical verification.

The article invites the reader to see also articles about the future of an expanding universe, quite outside the range of Kelvin's thinking. And to see articles about the big crunch, the big bounce, and the cyclic model. These are testimony to the deeply speculative nature of the grandiose conclusion that the universe will have a heat death.

The universe itself is, if it is tending to a heat death, not in thermodynamic equilibrium. But Kelvin had no definition the entropy of such a universe. He was speculating way beyond what he could prove. If one cannot see that for oneself, it would be good for one to have some warning from someone who can, by simply thinking carefully about what the article itself says.

It is not for the good of science for it to speculate and not tell people that it is doing so, but instead to give them the false impression that it is telling them about scientifically established fact.Chjoaygame (talk) 07:30, 1 October 2009 (UTC)

Science is a mixture of experiment and theory, so putting hypotheses to an empirical test usually requires more or fewer theoretical assumptions. For example, the observation of the cosmic background radiation is usually construed as being empirical verification for the Big Bang theory, in which the universe is expanding from a primordial hot, dense state, despite the fact that we can't observe this state directly (since it ended long ago) but only see remnant radiation that supposedly originated at this time. Similarly, observations which supported a cosmological model in which the universe ended in a high-entropy state of thermal equilibrium might give us more confidence that this will happen. Also, if it is possible to maintain an environment suitable for life in a small portion of the universe, we might in principle be able to observe the universe approaching heat death around us (a depressing sight.)

It's true that all of this is rather speculative, but it's not more so than some of our other articles on cosmological scenarios. Also, the article at the moment calls the heat death "possible" and a "hypothesis"—I don't think it calls it a fact, which as you correctly point out would be an unsupportable claim. Spacepotato (talk) 21:36, 1 October 2009 (UTC)

Thank you for your thoughts.Chjoaygame (talk) 01:17, 2 October 2009 (UTC)

A play about the heat death of the universe

I'm not sure it's worth adding a "references in popular culture" section to this article just for one item, but interestingly there is a play entitled Postponing the Heat Death of the Universe in which the protagonist lies perfectly still to postpone entropy. --WayneMokane (talk) 15:24, 7 October 2009 (UTC)

Fixed your link for you. Viriditas (talk) 13:04, 20 October 2009 (UTC)

Section "heat death vs cold death"

An anon removed this section. It was restored, but after reading the section and the source cited, I've reimplemented the removal.

The section's text did not match the source. Rather that describing "heat death", the first paragraph describes Olbers' paradox. The source cited attempts to make the point that a "heat death" doesn't imply a specific temperature, and that a big freeze isn't necessarily a heat death, but it does this poorly (that material is already better-covered elsewhere in the article).

End result: This subsection's first paragraph was misleading, and the second paragraph redundant. They didn't follow the source, and the material is already better-covered in other sections. So, I endorse the removal of this section. --Christopher Thomas (talk) 15:50, 14 May 2011 (UTC)

It may be poorly sourced, but it was factually correct. Olber's paradox and Kelvin's heat death were related. Now the article makes no attempt at describing the relationship between the heat death and the big freeze. Great. -- cheers, Michael C. Price ^talk 17:22, 14 May 2011 (UTC)

This is already discussed in the middle paragraph of the "Current Status" section, and (with clunky prose but a better reference) in "Time frame for heat death". --Christopher Thomas (talk) 19:55, 14 May 2011 (UTC)

No it isn't. -- cheers, Michael C. Price ^talk 22:38, 14 May 2011 (UTC)

The thermodynamic concept of "heat death" is described in detail. The Big Freeze is described in detail, with discussion of whether or not it actually reaches thermodynamic equilibrium. What exactly do you feel is missing, specifically? --Christopher Thomas (talk) 23:10, 14 May 2011 (UTC)

"freeze" (big or cold) nowhere appears in the article, nor is there an explanation of why the Hubble expansion has caused the freeze to supplant the heat death in terminology. No doubt it is an implication evident to expects, but the general reader will be left clueless. -- cheers, Michael C. Price ^talk 06:39, 15 May 2011 (UTC)

While I'm unconvinced that "Big Freeze" has supplanted "heat death" in terminology, I am quite sure that no classical thermodynamicist thought the universe was going to "heat up". The whole point of "heat death" was that all usable sources of heat would eventually be exhausted, resulting in "a state of universal rest and death". The assertion of universal heating in the deleted section appears to rest on an assumption that Kelvin thought stars were perpetual motion machines capable of producing heat forever. (Clearly not the case, since this would violate the very principles underpinning the "heat death" concept.) 214.4.238.180 (talk) 20:30, 24 May 2011 (UTC)

Kelvin's belief, which was widely shared, was that stars were heated by meteor impacts during formation. They were expected to cool down over a period of millions of years, and the rest of the universe would warm up. Eventually the two temperatures would be equal and life would cease - but it would be a very hot universe, since the mass of the stars dominates (they didn't know about dark matter). -- cheers, Michael C. Price ^talk 21:10, 24 May 2011 (UTC)

So you're suggesting that the fellow who said "This earth, certainly a moderate number of millions of years ago, was a red-hot globe ..." and thought he could calculate the earth's age based on this cooling -- also thought that the earth would start heating up again at some future date? 214.4.238.180 (talk) 19:22, 25 May 2011 (UTC)

OKay, that's a good point. Perhaps the stars would only warm the universe (as it was then believed) slightly. In Pamela Zoline's story, "The heat Death of the Universe", New York itself virtually melts.-- cheers, Michael C. Price ^talk 20:15, 26 May 2011 (UTC)

Per anon's response, I don't think the term "heat death" has been supplanted by anything. Certainly I've never seen other terms used in place of it, or vice versa. The heat death (or lack thereof) and the ending temperature of the universe (hot or cold) are different concepts. I've added a sentence to the lede to make this clear.

Regarding "big freeze", the middle paragraph of "current status" links the words "closed universe" to "big crunch" and "open or flat universe" to "big freeze", and describes the first as a situation where temperature increases without bound and the second as a situation where temperature approaches zero. If you fee that should be reworded, go ahead, but I really don't see what else can be added to it. --Christopher Thomas (talk) 23:53, 26 May 2011 (UTC)

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)

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)

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)

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)

Your opinion is completely irrelevant to the physical realities. And its not controversial at all. It follows thermodynamics which is a well understood phenomena. — Preceding unsigned comment added by 84.49.84.41 (talk) 14:14, 31 May 2013 (UTC)

Thermodynamics has little to say about such huge thing as the universe, and indeed the concept of the "heat death of the universe" is mostly a historical relic of untestable speculation, neither a physical reality nor an uncontroversial consequence of thermodynamics. It is a mistake to attribute to thermodynamics a supposed wide applicability that it does not have.Chjoaygame (talk) 22:10, 31 May 2013 (UTC)

relevance

I have undone the removal of a clause of a quotation. The reason given for the removal was that the clause is irrelevant to the article. But the clause modifies the meaning of the quoted words, and so is relevant to the article.

The underlying physical question is whether Clausius' use of the word universe in his famous aphorism is literally applicable to the whole actual physical universe, or whether it is simply rhetorical, "sybillic" in the words of Truesdell, or "poetic" in the words of Grandy.

Clausius is the author of the sybillic utterance, "The energy of the universe is constant; the entropy of the universe tends to a maximum." The objectives of continuum thermomechanics stop far short of explaining the "universe", but within that theory we may easily derive an explicit statement in some ways reminiscent of Clausius, but referring only to a modest object: an isolated body of finite size.

— Truesdell, C., Muncaster, R.G. (1980). Fundamentals of Maxwell's Kinetic Theory of a Simple Monatomic Gas, Treated as a Branch of Rational Mechanics, Academic Press, New York, ISBN0-12-701350-4, p.17.

This was expressed rather poetically by Clausius in his famous couplet reflecting the First and Second Laws: "Die Energie der Welt ist constant; Die Entropie der Welt strebt einem Maximum zu.

— Grandy, W.T., Jr (2008), Entropy and the Time Evolution of Macroscopic Systems, Oxford University Press, Oxford UK, ISBN 978-0-19-954617-6, p. 4.

The scope of the cited text on thermodynamics is relevant to the scope of the meaning of one of its sentences that is quoted.Chjoaygame (talk) 22:59, 25 August 2013 (UTC)

Move discussion in progress

There is a move discussion in progress on Talk:Age of the universe which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 22:15, 3 October 2013 (UTC)

Treatise on Thermodynamics

Where, exactly, does this source (Treatise on Thermodynamics) say that "the phrase 'entropy of the universe' has no meaning". I searched for this, but could not find it. 214.4.238.180 (talk) 13:17, 11 March 2014 (UTC)

Here, third sentence of § 135. It is admirable that you checked this. Thermodynamics is a laboratory science, not a cosmological one. Planck is recognized as perhaps the most reliable authority on thermodynamics, by J. Uffink, in 'Irreversibility and the Second Law of Thermodynamics', Chapter 7 of Entropy, Greven, A., Keller, G., Warnecke (editors) (2003), on page 131.Chjoaygame (talk) 13:56, 11 March 2014 (UTC)

Ludwig Boltzmann accomplished the feat of showing that the second law of thermodynamics is only a statistical fact.

With all respect to the editor who removed the paragraph that started "Ludwig Boltzmann accomplished the feat of showing that the second law of thermodynamics is only a statistical fact." The physical reality is that we have not the slightest idea of the remote future of the universe, and that talk of increase of entropy of a single object not in thermodynamic equilibrium is presumptuous at best. That the second law depends on an external driver, not present for the universe as a whole, is important to place some kind of reality check on talk of "the heat death of the universe". I think the added paragraph should stand, as a guide to the reader that we are here talking unverifiable speculation, if not nonsense.Chjoaygame (talk) 01:21, 10 February 2014 (UTC)

Boltzmann's undoubted accomplishments are not in and of themselves relevant to this article. Which reliable sources claim "that we are here talking unverifiable speculation, if not nonsense"? Paradoctor (talk) 08:46, 10 February 2014 (UTC)

You ask for comment on the talk page for reliable sources. Common editorial skill is enough for the talk pages, and that reveals that we are here talking unverifiable speculation, if not nonsense. As for the statement's inclusion of comment on Boltzmann's skill, I agree that is not immediately relevant. But the statistical nature of the law is very relevant; it tells about the reliability of the law. For the history of the universe, which is being discussed here, there is only one throw of the dice. n = 1.That is not an average of many outcomes, such as is predicted by the law. The disputed comment could be edited to remove the part about Boltzmann's skill, and then the edited disputed comment would be fully relevant.Chjoaygame (talk) 22:43, 10 February 2014 (UTC)

I'm afraid that, without WP:RS containing it, your argument constitutes WP:OR. As for "enough for the talk pages", please note that this is not a WP:FORUM. For more information on what is appropriate here, WP:TALK, and specifically WP:TALK#Use might be helpful. Paradoctor (talk) 07:22, 11 February 2014 (UTC)

No comment.Chjoaygame (talk) 23:32, 11 February 2014 (UTC)

Putting the irony aside, it would still be helpful to explain where you disagree. I'm afraid I don't see your problem here. Paradoctor (talk) 01:42, 12 February 2014 (UTC)

I don't have a problem here. It's the article that has a problem. It is written too nearly as if there is sound science in the "heat death of the universe" legend. The second law is not as straightforward as might be thought. The present lead Wikipedia statement of it is about the entropy of an isolated system. An isolated system has never ever been observed. Not isolated enough to test the second law to the level required for a prediction about the fate of the universe. Therefore it is speculation, and probably wrong speculation, that an isolated system will approach thermodynamic equilibrium, though many texts and Wikipedia editors rather carelessly assume that it will. Loschmidt's theoretical argument about an isolated system is correct, but is not specific for a system in thermodynamic equilibrium. The universe is not and never has been in thermodynamic equilibrium. There is no generally applicable definition of the entropy of a system that is not in thermodynamic equilibrium. People who don't know much about it suppose that there is a generally applicable definition, but that is because they don't know much about it. The second law can be stated in other ways, far more reliable, that do not depend on unproven speculation about isolated systems and do not depend on a definition of entropy for a system not in thermodynamic equilibrium. They do not imply anything about the heat death of the universe.Chjoaygame (talk) 12:35, 12 February 2014 (UTC)

Fine, so which sources say so? Paradoctor (talk) 20:43, 12 February 2014 (UTC)

My comment is a summary of many reliable sources. If I had time to put the content of my comment into the article as an edit, I would do so, citing a selected few of them. As it is, I commented on the talk page in support of another edit. That's all I have time for right now.Chjoaygame (talk) 00:10, 13 February 2014 (UTC)

"Despite the fact that most physicists believe in such a nonequilibrium entropy, it has so far proved impossible to define it in a clearly satisfactory way." Quote from Lieb, E.H., Yngvason, J. (2003). 'The entropy of classical thermodynamics', Chapter 8 of Greven, A., Keller, G., Warnecke (editors) (2003). Entropy, Princeton University Press, Princeton NJ, ISBN 0-691-11338-6, page 190. The reason for this is that entropy for a system in its own state of internal thermodynamic equilibrium refers to a system defined fully by state variables with no non-zero fluxes. In this sense, the equilibrium state is unique and absolute, so that its entropy is well defined. Whereas a non-equilibrium system has non-zero fluxes, which would need to be added to the list of state variables, but can hardly be fixed uniquely or absolutely. Entropy has then to be relative to the non-zero values of the flux variables, at least. So the entropy is not uniquely defined. In a physical system very far from thermodynamic equilibrium, such as in a shock wave, the very definition of the flux variables is unsafe.Chjoaygame (talk) 14:14, 11 March 2014 (UTC)

This article continues to be a drivel-magnet

The idea of heat death of the universe is of merely historical interest. The simple idea of heat death of the universe is no longer remotely tenable in serious physics, because the idea is meaningless. Yet this article continues to accumulate pretentious disorganized miscellaneous drivel as if the idea of heat death of the universe were currently a useful one. The article should confine its contents to simply historical accounts, mostly about nineteenth century thinking. Serious speculation about the remote future of the universe belongs elsewhere. For these reasons, as it stands, this article is a blot on the face of the Wikipedia.Chjoaygame (talk) 09:13, 11 June 2014 (UTC)

The see also section needs to be looked at.

The see also section has a lot of ill-relevant link and probably should be cleaned up.

Ke48273 (talk) 00:18, 28 August 2014 (UTC)

reasons for undo of good-faith edit

Don't get me wrong: I think this article is a drivel magnet and is mostly misconceived. But that's not what we are concerned with right here and now. Our present concern is with a question of grammar raised by this edit. I undid the edit because I think it did not improve the article.

The verb of the sentence is 'are thought'. The tense is present. I think the English language is flexible enough to let that cover whatever is thought. The edit was redundant.Chjoaygame (talk) 03:02, 10 January 2015 (UTC)

Eh, no this clearly a descriptive and not a prescriptive grammatical error. Here, not meaning to talk down to you, but let me walk you through it. Take out all of the other elements that have to agree with the tense of the copular verb and just focus on the one that is in conflict:

"Well into the future, matter and dark matter in the universe are thought to be concentrated in stars, galaxies, and galaxy clusters."

That is grammatically incorrect in a descriptive manner in that it pairs the present tense with a future context. The sentence (if we didn't have to add those other two time frames) would need to read:

"It is thought that, well into the future, matter and dark matter in the universe will be concentrated in stars, galaxies, and galaxy clusters."

Because three separate temporal distinctions were being referenced in the prepositional phrases which proceed the copula (one of which conflicts with the other two as to which tense it will accept) there is no way to get them to all agree with one tense inside of one clause, so I separated the sentence into two clauses, where tense and logic are consistent. Does that make sense? Because not only does the change I made improve the article, it's also absolutely demanded by the WP:MoS, and it seems you reverted it compulsively without fully understanding the issue. Having observed this behaviour and now come to the talk page to observe your disagreements with others here, I'm wondering if I can, without giving offense, suggest you take a look at WP:OWN, because you seem to have staked out a territorial claim on this subject matter (not withstanding your low regard for this article), and I see on your talk page references to similar incidents on similar pages. Snow talk 03:22, 10 January 2015 (UTC)

As I said, this article is drivel magnet. Your edit made it worse.Chjoaygame (talk) 03:40, 10 January 2015 (UTC)

You're entitled to your opinion on both matters, but as to this particular edit you are absolutely and un-ambiguously incorrect in your interpretation of how tense agreement works in the English language (and you have presented no counter-argument to my explanation above as to why the correction was necessary) so if you revert again, I'll take the matter to the appropriate forum to see to it that the edit warring does not persist. I think your behaviour here could use some oversight anyway. Snow talk 04:13, 10 January 2015 (UTC)

Significant sections poorly worded or placed

A lot of the later additions to this page are in poor English which creates ambiguity of meaning. They also seem to be worded more to win an argument with other editors than to contribute to a well-written article. Some are placed inappropriately to give more prominence to this argument (which is, as I understand it, that the idea of Heat Death is so clearly ridiculous that the page should make that clear from the start and throughout, or should not be here at all). The result actually weakens the article and the argument of the editor. More moderate and appropriate editing would improve both (if the argument has merit).

In a more recent view than Kelvin's, it has been recognized by a respected authority on thermodynamics, Max Planck, that the phrase 'entropy of the Universe' has no meaning because it admits of no accurate definition.[1][2] Kelvin's speculation falls with this recognition.

This has all of those problems:

1. It appears, with identical wording, in both the main article and the introduction. It is out of place in the introduction and could be replaced by a simple statement that the idea of a Heat Death has increasingly been questioned and cast into doubt (or discredited) over time. Those questions and criticism can then be developed in the rest of the article (or a specific section).
2. "In a more recent view than Kelvin's" - unnecessary. Obviously views on a hypothesis come after its proposition. Anybody following the link to Planck's page will find all the detail about dates and context that they need. Seems argumentative.
3. "it has been recognized". A counter argument has been made. Planck's reputation is enough to give good authority to that argument without just saying "It's a *fact* and Max says so".
4. "by a respected authority on thermodynamics" which is clear from the linked page on Planck, a link which would not survive here if the relevance and authority of Planck were not valid. This is just verbosity for the sake of argument.
5. "Kelvin's speculation falls with this recognition." The argument certainly challenges the hypothesis. Saying that a term is poorly defined is not in itself an absolute proof of the nullity of the hypothesis which uses it. The sources referenced in "Current Status" mostly label the hypothesis too vaguely defined rather than entirely, conclusively and provably wrong. This is just a (rather poorly worded) judgement by the editor.

The whole "Current Status" section is baggy, verbose and poorly structured. The sudden introduction of "Inflationary Cosmology", an allegedly common misunderstanding about that field and the refutation of that misunderstanding, seems to serve no purpose at all here other than rehearse arguments which annoy the editor. A series of sources are introduced mostly without any information about their authority. These would be better presented if grouped according to the main arguments they share. The section itself would also be better placed *after* the "Time Frame" section in which the idea is briefly developed. That would give more context for the counter-arguments.

The quality of this article has been damaged by the conviction of one editor that the hypothesis is not only wrong but laughable. If the counter-arguments were presented with better clarity and in a way that enhanced rather than confused the article's structure, the editor's argument would actually be better presented.

I'm going to leave this a few days to allow time for responses but then I'm going to clean this up.Itsbruce (talk) 12:55, 22 February 2015 (UTC)

It is good to see that you care about this article. I accept that my expressions of dissent are defective in rhetoric. A half-excuse for that is that one has to be cautious or indirect when dissenting from a more or less established conviction, such as I think this article largely expresses.

I don't think the idea was laughable when it was expressed a century ago. I don't think "the hypothesis is wrong". I think it is meaningless; to call it wrong would admit that it was meaningful. I didn't bring in the question of Inflationary cosmology; I think that was probably brought in by an editor more sympathetic to the main idea than I am.

It will be good if you really clean this up. That is a big task, too big for me to undertake.

I think that a main problem is that many people who have not studied thermodynamics closely imagine that there is some useful notion of "the entropy of the universe". They think it a kind of quibble to deny it. I say No, a reasonable starting point is that it is most probably nonsense to speak of 'the entropy of the universe'. If it is desired to speak of it, the first task is to argue for its meaningfulness; a hopeless undertaking, I think, but not quite a priori impossible. To start the article from the assumption that the phrase is meaningful is to condemn the article to being a drivel-magnet.

The lead's talk of absence of free energy is nonsense from a thermodynamic viewpoint; a use of terms that ignores their physical meaning and context. It sets the tone of the article.

As a trivial point, it is customary to speak of the first section of the article as 'the lead' (or as 'the lede' for some editors). Many articles have separately headed section entitled Introduction. I think that is a good custom.

At present the article is largely structured as if the idea of heat death were well founded a priori, and that dissent was quibbling. No, I think the idea needs positive construction and argument if it is to be taken seriously, other than as of historical interest.

The article should treat 'the heat death of the universe' as a notion of historical interest, but obsolete.Chjoaygame (talk) 15:17, 22 February 2015 (UTC)

I have no opinion on the science, but I agree the wording needs to be less definitive, and not attempt to take sides except where near-universal scientific consensus exists.[1]--Anders Feder (talk) 05:22, 5 April 2015 (UTC)

faulty claim of "original research"

An anonymous IP editor has here deleted the sentence "In other words, this writer is saying that when gravity is taken into account (which Kelvin did not), a prediction of heat death is not justified." The deletion is covered by the edit summary "I removed original research".

The edit is faulty, because the the removed sentence was not original research. The removed sentence was re-wording of the cited source to clarify for the reader the meaning of the cited passage. Such re-wording is not original research; no, it is good editing. The re-wording clarifies for the reader the precise relevance for the article of the cited passage.Chjoaygame (talk) 04:48, 3 April 2015 (UTC)

If we need to "clarify" or impose a certain meaning onto the cited passage for it to seem relevant, maybe it would be better to leave it out.--Anders Feder (talk) 05:59, 5 April 2015 (UTC)

further reading

Looking at the present entries in the Heat death of the universe#Further reading section, I feel that none of them are suitable to be recommended by Wikipedia for this article. I would like to delete them all.Chjoaygame (talk) 00:41, 1 April 2015 (UTC)

I agree completely, and will remove the section.[2]--Anders Feder (talk) 06:26, 5 April 2015 (UTC)

perspective on argument from authority

An edit here has an edit summary that warns against "argument from authority".

I don't intend to try to resist the author of that edit.

But it is worth noting in this context that the whole basis, without exception, of Wikipedia, is reliance on authority. It is known as the policy of reliable sourcing. Planck is a reliable source on the relevant matters. It is probably useful to bring that to the attention of a wavering reader, considering that the article partly relies on dubious sources, or even in places on no stated source.Chjoaygame (talk) 12:05, 5 April 2015 (UTC)

@Chjoaygame: It isn't useful. It's puffery, and it's editorializing. The reader has no need to know who you or I may or may not consider an "authority". Just present the neutral, reliable facts and leave the reader to make their own decision as to who they consider to be "authoritative". Nullius in verba. What are the sources in the article which you consider to be dubious? If there are any, let's throw them and the statements attributed to them out at once.--Anders Feder (talk) 20:08, 5 April 2015 (UTC)

I wrote that I don't intend to try to resist the author of the edit. Likewise, in making my above vague comment on this talk page, I am not tagging particular sentences in the actual article. The Wikipedia is not the Royal Society. The Wikipedia criterion for a reliable fact is that it comes from a reliable source, preferably a consensus of reliable sources. What is a reliable source? It is one that the editor has found to be reliable after a reasonable survey of sources in the light of his own reasonable level of background study, and that is accepted by other reasonable editors as such.Chjoaygame (talk) 00:13, 6 April 2015 (UTC)

Whether Wikipedia is the Royal Society or not is irrelevant. Wikipedia aspires to approximately the same standards as the Royal Society, even if it can never achieve them. "The tone of Wikipedia articles should be impartial, neither endorsing nor rejecting a particular point of view. Try not to quote directly from participants engaged in a heated dispute; instead, summarize and present the arguments in an impartial tone." WP:IMPARTIAL.--Anders Feder (talk) 01:43, 6 April 2015 (UTC)

Based on User talk:Chjoaygame, it appears that this person has a long history of topic bans relating to thermodynamics due to bias and vandalism AkariAkaori (talk) 15:35, 7 April 2015 (UTC)

Nevermind, I take that back, looks like it's mostly drama from the same person harassing him with sockpuppets AkariAkaori (talk) 16:14, 7 April 2015 (UTC)

reliable source

It was a well intended edit, but not an improvement, to remove the statement that Planck is a respective authority in this area. Planck is a reliable source, indeed "authoritative" according to another reliable source. To help remove the worry, I have quoted Uffink explicitly on the point of authority. Uffink is currently a reliable source on such matters, having been chosen by the editors to contribute to the book in which he writes. I have corrected the English of Uffink who is, I suppose, not a native English speaker. He wrote "underestimated" where 'overestimated' is the usual cliché and the only reading that makes sense. That error of English is quite common because the phrase is cliché and people often don't put their minds in gear when using it.Chjoaygame (talk) 08:36, 19 April 2015 (UTC)

@Chjoaygame: I completely agree with User:Astrokid's edit. What you are doing is not a "demonstration of reliable sourcing", but of possessiveness and the inability to engage in consensus-building. The citation you are offering seems to be a classic case of WP:SYNTH.--Anders Feder (talk) 00:46, 20 April 2015 (UTC)

I accept that my sentence "Kelvin's speculation falls with this recognition" is not sourced and so you can delete it. Hopefully the reader will join the dots.

You accuse me of failing to build consensus. So far, my efforts have been criticized along such ad hominem lines, but no substantial arguments have been raised against them. On such matters as the meaning of entropy, identification of reliable sources is not as easy as falling off a log. Indeed considerable care is needed for identification of reliable sources. In the general background of thinking, Wikipedia aims not to mislead readers; that is part of the reason for the reliable source policy.

"Consensus-building" is a good idea but it should not over-ride truth. Reliable sourcing over-rides all, but reliable sourcing is not guaranteed by consensus. A reliable source respects truth. It is possible for consensus to agree that black is white. It is possible for Wikilawyering to achieve things otherwise unattainable.

You write that what I did was not to demonstrate reliable sourcing but was to act possessively. I think you overstate your case. Kelvin's case rested on the concept of "the entropy of the universe". In his day, entropy was a new idea and was not understood as it is today by those best qualified to have opinions, such as for example Jos Uffink. Many people today mistakenly imagine that entropy is a relatively clearly defined thing that covers very kind of physical system and process. Since reliable sourcing is in effect argument from authority, and the degree of reliability of sources for this article is various, I think it appropriate to cite a reliable source saying that another source is authoritative.

I don't feel I own the article. If I did feel that I might be expected to very thoroughly reconstruct it, which I don't want or intend to do. I am not sufficiently interested in the subject to do the amount of source-surveying that I think would be needed to support a thorough reconstruction. But I do feel it right to put in the point of view of present day thermodynamics as distinct from looser thinking about "entropy", and to point out on this talk page that the article is partly built on the more or less unstated assumption that the loose thinking is right, and for that reason the article would well be reconstructed by editors who are willing to do the proper source-surveying.Chjoaygame (talk) 04:33, 20 April 2015 (UTC)

"I think it appropriate to cite a reliable source saying that another source is authoritative." Undoubtedly, that is what you think. The problem is that what you think is wrong.--Anders Feder (talk) 10:26, 20 April 2015 (UTC)

It seems to me that there are several issues for editors here. Our concern is to reliably inform Wikipedia readers. One issue for editors is as to the kind of notability that belongs to the doctrine of the heat death of the universe. Another issue for editors is as to the substantial validity of that doctrine. I suppose yet other issues may emerge.

As to the kind of notability of the doctrine. It is not notable as a subject of present mainstream thinking about the remote future of the universe. This is because nowadays large factors are considered important besides those covered by the second law. The doctrine rests on the second law alone. Consequently, people don't write much about it, and there is not much reliable sourcing, about the doctrine as a subject of current active research. The doctrine is notable because of its historical interest. This is where the article should concentrate.

As to the substantial validity of the doctrine, present day reliable sources, though few, are concurrent in the view that the present-day concept of entropy is tightly defined. The doctrine, however, relies on obsolete and loose thinking about entropy. Moreover, it fails to consider adequately the cosmological effects of gravity and its interaction with entropy, as stated in the body of the article. This is not to mention the doctrine's failure to consider factors such as dark matter and dark energy. For this reason, again the article should treat the doctrine primarily as of historical interest. It would mislead readers to give the impression that the doctrine is important and valid for present-day thinking about the remote future of the universe.

More immediately, the concept of entropy, as understood today, is of limited scope, and does not extend as far as Kelvin imagined, for example to allow a definition of the entropy of the universe. There is concurrence of reliable sources on this point. It has to be faced that entropy is a conceptual quantity, and that some sources are more reliable than others on the question of the scope of its definition. On this, readers should be guided to the more reliable sources.

The article should focus on the history of the doctrine.Chjoaygame (talk) 16:46, 20 April 2015 (UTC)

The way to focus the article on anything is to add properly sourced statements to that effect; not to editorialize or to synthesize original, unattributed claims. In fact, reading through the Max Planck source, it too seems a poor source for the view you are advocating: "If we say that the entropy of a system increases quite regardless of all outside changes, an error will, in general, be committed, but the more comprehensive the system, the smaller does the proportional error become." (p. 102) Though you want to use the Planck source to dispell the notion of universal heat death, the source does not discuss heat death at all, but only the related concepts of entropy and the laws of thermodynamics. Extrapolating the source to make a statement about the far-future evolution of the universe is another instance of SYNTH.--Anders Feder (talk) 10:50, 21 April 2015 (UTC)

Something about a research

http://www.theguardian.com/science/2015/aug/10/universe-slowly-dying-gama-old-stars-fade-faster-than-new-ones-born

http://edition.cnn.com/2015/08/10/us/universe-dying/index.html

http://www.latimes.com/science/sciencenow/la-sci-sn-universe-dying-astronomers-fading-light-20150810-story.html

(three sources from here: http://www.inquisitr.com/2328733/scientists-confirm-universe-is-dying/ )--Hienafant (talk) 23:14, 15 August 2015 (UTC)

Why was my image removed?

And why was I marked as a vandal? That illustration was in my math textbook, and is of decent historical interest. Laudiacay (talk) 16:02, 25 April 2016 (UTC)

I don't see Editor Laudiacay marked as a vandal. I removed the image because I don't see Wikipedia as an art gallery, and because I see the image as neither fitting nor illuminating the topic. It gives not the remotest insight into the idea of heat death of the universe.Chjoaygame (talk) 17:18, 25 April 2016 (UTC)

It's a hypothesis, not a theory.

As there are many scientific ideas about the fate of our universe, several of which have scientific backing, heat death is a hypothesis not a theory. — Preceding unsigned comment added by 51.9.160.162 (talk) 00:06, 1 April 2017 (UTC)

Statement about creating a new universe

The article states " Possibly another universe could be created by random quantum fluctuations or quantum tunneling in roughly $10^{10^{10^{56}}}$ years.". I have looked into the linked source, and think things got a lot simplified here. While not a being a physicist myself, I at least see only probability a value of $10^{-10^{10^{56}}}$ in the linked source without a the dimension "years" linked to the value (not that it matters a lot if you have years or seconds with this huge/tiny values). Its the propability within a "space-time volume" - whatever this is. Maybe this can be explained a little better. TTL (talk) 10:29, 3 September 2017 (UTC)

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Change of Phrasing in Beginning of Article

My recent edit is NOT intended to refute the Heath Death Scenario. However, it seems that there are many theories about how the universe evolves with time, some of which posit the idea of Cyclic universes and decaying cosmological constants. We might have theoretical reasons for believing the heat death scenario is true - and, if so, we should demonstrate those reasons in the article. However, it seems as if the jury might very well still be out about whether the universe ends in a heat death. If there is room for reasonable doubt about whether this scenario is true, then reasons for doubt are best indicated (as in the Controversies section).

There is a paper entitled "Current observations with a decaying cosmological constant allow for chaotic cyclic cosmology" and another paper entitled "Decay of the cosmological constant by Hawking radiation as quantum tunneling" which may be worth further reading.

Stating that the universe ends in Heat Death is not necessarily a proven fact (though I can certainly understand why many people would jump on the 'Heat Death' bandwagon - due to the Second Law of Thermodynamics). We could argue on the 'balance of probabilities' but this might lead to erroneous conclusions.

ASavantDude (talk) 18:07, 9 June 2018 (UTC)

Timeframe for heat death section does not answer the implied question of when heat death will occur

I.e. the specificity is zero. There is no number. When is heat death? Can you at least provide a distribution to extrapolate from? — Preceding unsigned comment added by 2601:648:8505:2CE0:E1BD:E283:6E14:D5B1 (talk) 00:55, 25 June 2019 (UTC)

Extremely slow mass evaporation leading to heat death??

A few years ago, I saw a documentary on the BBC, the details of which I can't remember. If I remember correctly, the documentary said that all of the mass in the universe is undergoing an extremely slow evaporation process which will eventually lead to a universe in which no particle exists other than photons. This will be the heat death of the universe.

Does anyone know exactly how this extremely slow evaporation process works? What actually happens to any particle of mass during this process?95.172.233.137 (talk) 12:51, 19 June 2018 (UTC)

This is not the place to ask. Here we discuss the article, not the subject—see wp:Talk page guidelines. Best place to go is wp:Reference desk/Science. Good luck. - DVdm (talk) 13:11, 19 June 2018 (UTC)

Well anyway not everything is a liquid, so the term is definitely incorrect. — Preceding unsigned comment added by 2601:648:8505:2CE0:E1BD:E283:6E14:D5B1 (talk) 00:57, 25 June 2019 (UTC)

Should there be more info here?

I think that there should be more info here such as examples, or, well, basically more info. What do you think? MercenaryFeet (talk) 09:44, 11 October 2020 (UTC)

"Big Freeze" listed at Redirects for discussion

A discussion is taking place to address the redirect Big Freeze. The discussion will occur at Wikipedia:Redirects for discussion/Log/2020 December 9#Big Freeze until a consensus is reached, and readers of this page are welcome to contribute to the discussion. MB 15:35, 9 December 2020 (UTC)

Sources mismatch

I noticed that, under the "Current status" section, a new paragraph was added about a recently published study. After cleaning up the grammar I looked to the actual source to read more, and I have noted that the quotes in that paragraph are not located anywhere within the academic paper that is that paragraph's sole source. In short, whoever added that section seems to have paraphrased a false quote not located within the published study (as far as I have been able to find as of yet). This should be handled and replaced with something more accurate from that study. Further, the quote by Yi-Kuan Chiang isn't located within the study either, and likely is from an entirely different source. Either way, it needs its own source as well. SpecialAgentCake (talk) 10:48, 16 December 2020 (UTC)

All the quotes seem to come from this news release: https://news.osu.edu/the-universe-is-getting-hot-hot-hot-a-new-study-suggests/ TChapProctor (talk) 19:57, 21 December 2020 (UTC)

Texas Freeze

let's assume this gets worse because of climate change?? MattClowers (talk) 16:14, 18 February 2021 (UTC)