Talk:Boltzmann brain

message: I wish people who tag articles with reference to the talk page would put a comment on the talk page saying what they were about. For the record, this article accurately describes its subject as far as I can see. Remove tags, anyone? PaddyLeahy 09:52, 9 May 2007 (UTC)
thread_title: Tags require talk page comment

message: I know, not a very eloquent question;  one clearly indicating a lack of enlightenment.  But I know some of you were thinking it too!  — Preceding unsigned comment added by 68.156.83.135 (talk) 12:51, 13 June 2011 (UTC)
replies: text: Actually, this article makes perfect sense to me, as opposed to the inaccuracies or failures of explanation in more technical articles. 178.38.152.228 (talk) 23:48, 20 November 2014 (UTC)

text: Well, so we have Boltzmann Brains - what about much simpler things, like Boltzmann Bananas? Boltzman Cheeze Puffs?  Boltzmann Ballpoint Pens?  These things are many, many orders of magnitude simpler - we should be awash in them, and all manner of other Boltzmann "products", one would think... 2601:195:C102:D940:B428:F646:B938:66E8 (talk) 21:36, 15 June 2022 (UTC)
thread_title: Exactly what was this guy smoking?

message: Surely the probability of an environment in which evolution could occur coming into existence it much lower than any of the produces of evolution coming into existence by chance?  Wouldn't this mean that any where a 'brain' had come in to existence, it would surely have happened this way?  —The preceding unsigned comment was added by 62.232.221.61 (talk) 16:20, August 22, 2007 (UTC) 
:Evolution requires a continuing flow of energy, which is happening now but won't be when any Boltzmann brain might appear in our cosmos.  If you're arguing that the "Big Bang" is less likely than the spontaneous appearance of a god-like Boltzmann brain, you might be right.  --Wfaxon 20:35, 22 August 2007 (UTC)
thread_title: Shouldn't Darwinian evolution come into this?

message: New Scientist did a cover on Boltzmann Brains.  It can be found here.  
http://www.newscientist.com/channel/fundamentals/mg19526171.100-spooks-in-space.html
It is from the 17 August Magazine. 203.98.31.34 23:01, 30 August 2007 (UTC)
replies: text: I also added that link to the Manifestation article, since the article discusses objects popping into existence as a result of Boltzman brains. 5Q5 (talk) 22:49, 20 December 2007 (UTC)
replies: text: Is it appropriate - or necessary/desirable - to add some indication that this article can only be viewed in full with a subscription to New Scientist (as seems to be the case for most if not all their items)? - Irdwrwyn (talk) 01:14, 31 August 2012 (UTC)

text: I don't think it's a good idea to link to a PAYwalled article, unless there are no free articles available. It just generates frustration. 84.117.18.221 (talk)   — Preceding undated comment added 03:46, 27 August 2014 (UTC)
thread_title: New Scientist

message: Doesn't this whole notion seem like a modern reformulation of Descartian dualism?  —Preceding unsigned comment added by 128.6.78.31 (talk) 16:05, 16 January 2008 (UTC)
replies: text: Interesting comparison.  One obvious difference is that Descartes envisaged a "separate but equal" dualism between mind and body.  What would the duality be here?  It wouldn't be much of a reformulation if it didn't retain the yin-yang character of Cartesian dualism, which seems more naturally related to the bra-ket notation of quantum mechanics than to Boltzmann brains. --Vaughan Pratt (talk) 19:37, 14 April 2008 (UTC)

text: It certainly brings to mind the "malicious demon" and other (universal?) belief falsifiers Jep1203 (talk) 00:53, 2 October 2023 (UTC)
thread_title: Descartes

message: The article asserts that Boltzmann advanced an idea: "that the known universe arose as a random fluctuation". I looked through the cited references that I could access and did not find a Boltzmann reference cited. I requested a citation to a published source that constitutes Boltzmann's idea, "that the known universe arose as a random fluctuation". KesheR removed my request for such a citation with the edit summary "request for facts makes no sense". It seems a simple matter of fact checking to find a citation to Boltzmann's works where he made this proposal. I'd like to see a direct quote from Boltzmann. Can anyone explain why "Disturbing Implications of a Cosmological Constant" is listed as a reference? I suggest that this Wikipedia article use numbered references and that the references be cited in the text of the article. Also, the sentence, "The idea is named for physicist Ludwig Boltzmann (1844 - 1906), who had advanced an idea that the known universe arose as a random fluctuation, similar to process through which Boltzmann brains might arise," does not seem grammatically correct, although I'm not sure what "similar to process through which Boltzmann brains might arise" is trying to say. Can a "random fluctuation" constitute a "process"? --JWSchmidt (talk) 17:04, 26 January 2008 (UTC)
replies: text: I second this.  Until someone produces some convincing documentation for the attribution to Boltzmann (which has been repeated so often that no one doubts it any more) it would be better if the article phrased the origin of the idea as "commonly attributed to Boltzmann."  (Not to say that the original idea was necessarily bad, but the form repeated retelling has given it might make Boltzmann turn in his grave.)  Secondly the originator of the supposed paradox also needs to be cited, particularly given that it is hard to see how such a statistical comparison can be justified without an assumption of independence similar to that made by EPR to support their paradox.  Like the EPR paradox, this alleged BB paradox goes away as soon as one allows for the possibility of correlation (entanglement or otherwise) between widely separated parts of the universe.  Thirdly the article speaks of entropy as though it were an absolute quantity, in the segue from "increasing entropy" to "low entropy".  Entropy is defined by the formula dS = dQ/T, which expresses a differential relationship between energy Q and entropy S mediated by temperature T---one can think of temperature as diluting the impact of energy change (power) on entropy change (bit rate), much as noise dilutes bit rate in an information channel for a given transmitter power (clearer when both sides are divided by dt as the time differential to give dS/dt = (dQ/dt)/T).  One can measure changes in entropy by integrating over time, so one can speak of increasing or decreasing entropy, but there is no formula for the constant of integration, whence there is no sensible notion of high entropy or low entropy, only higher or lower entropy.  --Vaughan Pratt (talk) 17:55, 14 April 2008 (UTC)
replies: text: ORLY? Entropy may be 'defined' as dS=dQ/T in classical (macroscopic) thermodynamics, but, as the best of my recollection goes, it was originally defined in a statistical mechanics framework (by Boltzmann himself) as S=k*log(Z), where Z is the number of microstates compatible with the observed macrostate, and k is a known constant, named, appropriately enough, 'Boltzmann's constant'. This is the actual definition of entropy, which can therefore be computed precisely, in absolute terms, at least for finite systems. By the way, the origin of the paradox's name is probably due to the concept of stochastic fluctuation in equilibrium systems, originally analyzed by Boltzmann with his distribution; it's not meant to imply he actually thought this up.  —Preceding unsigned comment added by 89.214.196.69 (talk) 05:08, 27 November 2008 (UTC)
thread_title:  references 

message: This doesn't make much sense that I can see. It seems far too verbose and vague. Surely the argument presented is not so complex that it cannot be summarized in a sentence or two? The introduction completely fails to present the argument. 
Is it about the likelihood of the existence of highly ordered regions (brains presumably being chosen solely for their alliterative properties, a choice with the dubious odour of a preacher's corny OHP slides)? What has that to do with physics? I'm not sure the argument is being correctly represented here either.
This article debunks one interpretation http://startswithabang.com/?p=12 and gives a reference to papers on the subject. I doubt the version currently is circulation has much to do with anything Boltzmann actually said or thought. 
This poster seems to get to grips with the concept more effectively, though the OP seems a bit clueless, viewing the notion like a Star Trek plot element: http://www.bautforum.com/questions-answers/63924-boltzmann-brains-question.html#post1057956
Another reference to a paper, maybe one of the same ones http://motls.blogspot.com/2007/01/boltzmanns-brain-and-low-entropy.html The discussion is mistaken on some points (e.g. he imagines something that is not a Boltzmann's brain as he initially describes it). The ref mentions "the Boltzmann-Penrose question of why the initial conditions for cosmology have low entropy. 
Mr. Jones (talk) 19:46, 13 June 2008 (UTC)
thread_title:  Badly written? 

message: Neo
* how close it this to a universe based on the Matrix movie?, there is no reality no individual just one big simulation.
Strange as it might sound i think a lot of budhisms might not find this whole concept that strange, no individual, no reality as we observe it, reality as a lie from which one needs to get free (enlighten)..  —Preceding unsigned comment added by 82.217.253.26 (talk) 11:41, 27 April 2009 (UTC)
thread_title:  matrix reality ? 

message: The "Boltzmann Brain Hypothesis" is referred to in this Dilbert cartoon strip.  I can't quite make it relevant enough to include, but add it here for the record. Earthlyreason (talk) 07:54, 27 April 2009 (UTC)
replies: text: It certainly had an imapct on the hits for this page - 9,400 against a background daily average of about 70-80 (). However I agree that a reference in one cartoon doesn't justify an "in popular culture" section. —  Tivedshambo  (t/c) 07:38, 28 April 2009 (UTC)
replies: text: Yes, we shold be careful. --94.79.152.113 (talk) 22:39, 1 September 2009 (UTC)

text: Never heard of "Boltzman Brains" but in a big 'aha" moment for me, I just realized that it is the origin of the famous whale appearing out of the quantum vacuum (with help from the infinite improbability drive) in the atmosphere of the planet in Douglas Adams' "The Hitchhikers Guide to the Galaxy".  — Preceding unsigned comment added by 98.111.255.217 (talk) 02:15, 5 September 2013 (UTC)

text: See WP:CULTURALREFS. If a review is found that says the comic is significant, then we can add it. But it needs to be a mainstream citation, not just someone's blog or reddit post. Richard-of-Earth (talk) 17:21, 8 May 2022 (UTC)

text: Hmm, I found a ref. Also Star Trek: Strange New Worlds#Episodes links to this article. We need to confirm that Screenrant.com is suitable as an WP:RS and write some prose. Richard-of-Earth (talk) 05:06, 24 June 2022 (UTC)
thread_title: Cultural reference

message: "[I]t is more likely that a brain randomly forms out of the chaos with false memories of its life than that the universe around us would have billions of self-aware brains." To me this nowhere approaches a statement that existence of a population of self aware entities, being highly improbable, must be the result of non-stochastic phenomenon. From "we seem to be unlikely" to "we must have been created" is a nonsequiter of order far beyond the watchmaker hypothesis. The logical conclusion I can derive follows thusly; 
1. A population of brains (say humanity) has been observed by a brain (say the reader of this text).
2. A single brain with false memories is more likely to form than a population of brains. 
Therefore
3. It is more likely the observed brains were false memories of the observing brain than that the observed brains ever existed.
Under this formalism the Boltzmann brain theory presents no paradoxical contradiction, and is nothing but a statistical argument for solipsism.
So what am I missing?97.83.161.77 (talk)  —Preceding undated comment added 22:37, 17 June 2009 (UTC)
replies: text: My question is why "solipsism" isn't even mentioned anywhere in this article?? At the very least it should be in the See Also section, it's more relevant than many of the things there. 71.238.12.254 (talk) 18:46, 17 January 2024 (UTC)
thread_title: What's So Paradoxical 'bout That?

message: This ignores the possibility that the probability of a universe in which a brain pops into existence, without any prior mechanism driving towards its creation, may be dwarfed by the probability of a universe in which there are active mechanisms which lead to processes of development  [...]
This misses the prohability of the initial condiditions. Because the entropy was extremly lower in the past (say, Big Bang) than it is today where all those brains exists, the initial conditions are extremly unlikely, in fact more unlikely than at any later point in time. The prior mechanism is just shaking some elementary particles. If you do this, it is more likely that some form of "brain" pops out than the extremly unlikely initial conditions of the big bang. Only if you get the initial conditions "for free" the cited argument holds, which may be true for the physic of the future.  —Preceding unsigned comment added by 92.72.94.97 (talk) 01:25, 30 August 2009 (UTC)
thread_title:  Last paragraph misses probability of initial conditions 

message: The article is interesting and useful, though rather speculative, and I further second the above requests for a reference to Boltzmann himself. Also, the main argument is probably incorrect, since it assumes that a selfaware brain could emerge without social interaction. Since all certainly selfaware animals (i.e. humans) have language,  selfawareness probably arises only socially. In other words, the intelligence that is needed for selfawareness may only be possible via social interaction (especially, linguistic). Indeed, until we understand what intelligence is, the matter remains obscure. 174.141.81.106 (talk) 12:37, 3 January 2011 (UTC)
replies: text: You are employing common-sense psychology in a thought experiment that turns on accepting a one-shot thermodynamic counterfactual at the very base of the physics, namely the low-entropy initial condition or fluctuation. But an ambient nebular plasmic Kaspar Hauser, like a typing monkey, might learn English by accident. Say 10-1000000000000000000. The thesis is that this is vastly more likely than the entire low entropy state of solar system, earth, water, iron and rivers that you require for the education of your African village child. The latter process unfolds in a more thermodynamically plausible way once it starts, but its initial condition is far less likely than a single nebular coincidence brain. That is the thesis anyway.178.38.152.228 (talk) 00:14, 21 November 2014 (UTC)
thread_title:  References and Criticisms 

message: "The usual resolution of the Boltzmann brain paradox is that we and our environment are the products of a long process of natural selection, which can produce complex and improbable outcomes without violating the laws of thermodynamics." 
How exactly does evolution theory "resolve" this "paradox" ? 
How does it prevent these "brains" to come to existence?
If there is no logical counter-argument to existence of these brains it should be noted, also it should be pointed out that if universe expansion is accelerating then the occurence of these brains is increasing and chance of concious beings to be Boltzmann's brain rather than anything else is increasing with it.  — Preceding unsigned comment added by Mentospech (talk • contribs) 09:58, 13 September 2013 (UTC)
thread_title:  Illogical statements 

message: "The idea is named for the physicist Ludwig Boltzmann (1844–1906), who advanced an idea that the known universe arose as a random fluctuation in the process of inflation, similar to a process through which Boltzmann brains might arise."
This seems like a pretty dubious claim.  In the linked article on inflation, inflation proper was postulated by Alan Guth in the 1980s, and the earliest inflation-like models came about in the 1930s.  Boltzmann died in 1906, long before any of this came to fruition.  In the (6 year old) discussion below, no sources for this were located
--Necroforest (talk) 04:24, 7 March 2014 (UTC)
thread_title:  Dubious Claims 

message: If no-one objects, I think we should remove the counter-argument paragraphs. Not only is it uncited, it doesn't actually counter the argument at all. It just states the process of evolution, which is beside the point: The Boltzmann brain is a counter to the anthropic principle, showing that selection bias means we should expect a Boltzmann brain universe rather than our vastly more complex universe. ··gracefool☺ 13:44, 30 May 2014 (UTC)
thread_title:  Actual counter-argument 

message: I propose to delete or shorten it since it is not just linked to many-worlds but also makes dubious claims like that quantum fluctuations don't exist without observers (many-worlds is observer independant as far as I know) I that nothing happen inside the wavefunction. It is also heavily criticized by Lubos Motl.Thundergodz (talk) 00:58, 29 April 2015 (UTC)
thread_title:  Sean Carroll resolution 

message: Is it a theory about the origin of God? That should be discussed, and as such this idea should be topic-boxed categorically along with other arguments for the existence of God. Does the term which is the title of this article apply just to Boltzmann's conception, or is there some allowance for expansion as such which keeps the idea alive, to include re-conceiving in the context of string theory, which is the highly validated theory of the fundamental quantum object being something elongated that constitutes everything including spacetime, but wasn't available to Boltzmann. The term "fatal flaw" in the introduction is biased form. -Inowen (nlfte) 09:12, 18 August 2018 (UTC)
thread_title:  What is it? 

message: The section with this title does not state what "problems" there are.  This renders the text puzzling, at least to some readers (like me).  It would be helpful to know what the section is talking about.  That should be stated clearly.  Zaslav (talk) 05:39, 3 September 2019 (UTC)
thread_title:  Modern Boltzmann brain problems? 

message: I spot a serious inconsistency between the Boltzmann brain concept with the simulation hypothesis.
Assuming a highly compressed (== minimal entropy dip) universe implies the need for a "decompression process" to be "spawned".
And identifying that "decompression process" with the "program" in the simulation hypothesis (program = boundary conditions plus generating function - bootstrap compressed - maybe more like an observation consistent equivalence class of programs). 
That "decompression program"  that spawns the whole universe may well require an enormously smaller entropy dip than a single human brain (with all its lifelong experiences) totally cropped out of context from the rest of the universe or any other nontrivial crop-out.
Given that: 
* even a few lines of code can generate something as complex as the mandelbrot set and 
* even a few hundred MB of DNA can generate something as complex as a human being (looking aside epigenetics the microbiome and other stuff) 
This shouldn't be all too surprising.
I think without examples like the two above most people will perceive statements like 
"the lifelong experiences of a single human may be much more complex than the essence of the whole universe" as illogical, stupid and 
paradox because of the false human bias of "size equates to complexity".
I could discuss my deeper thoughts on this in more detail here but Wikipedia is not the place for hyper speculative essays.
So since I doubt I'm the first one to notice this, maybe someone knows of existing literature that is discussing this topic or has time to look it up
and integrate these thoughts plus references into the article.
Login Mechadense (talk) 13:32, 4 December 2019 (UTC)
thread_title:  Perceived inconsistency with the simulation hypothesis 

message: The last paragraph/sentence currently states "in a Boltzmann-dominated Universe, most Boltzmann brains have "abnormal" experiences, but most observers with only "normal" experiences are Boltzmann brains". This doesn't make a lot of sense. I couldn't read the full source, but the abstract puts it in the terms "most Fs are Gs, this is an F, so it’s probably a G; because I also know this F is an FH, and most FHs are not Gs..." (shortened a bit). I thought this could be fixed by replacing "are" with "aren't", but the follow up also seems oversimplified to the point of being simply wrong (the amount of Boltzmann brains with "abnormal" experiences and their ratio to brains with "normal" experiences supports the argument, the overall number still works in the opposite direction). Personuser (talk) 06:13, 3 June 2021 (UTC)
thread_title:  Are/aren't and other problems in the last paragraph 

message: No, it would not have any coherent thought, it would disappear in 10^{-23} seconds, right? Zalán Hári (talk) 10:50, 7 April 2023 (UTC)
replies: text: The citation abstract says "last at least long enough to think a few thoughts". Do you have some citation that says otherwise? The whole thing is theoretical anyways, is it not? Richard-of-Earth (talk) 02:39, 9 April 2023 (UTC)
replies: text: There is a formula: https://math.ucr.edu/home/baez/uncertainty.html. ΔH should be greater than 938 MeV, because the brain must contain protons, and the energy from mass of a proton is 938 MeV https://quarknet.fnal.gov/toolkits/new/gevanswers.html. It is approximately 1.5 \cdot 10^{-10} joule. The half of the Planck constant is approximately 3.313  \cdot 10^{-34} https://physics.nist.gov/cgi-bin/cuu/Value?h.\frac {3.313  \cdot 10^{-34}}{1.5 \cdot 10^{-10}}. Its order is 10^{-23}. Zalán Hári (talk) 04:17, 10 April 2023 (UTC)
replies: text: Okay, well thanks for bringing it to our attention, however, you need to look at WP:OR. Someone needs to write a paper about that and get it published in a peer-reviewed journal and then we might consider adding it to the article. Until then, we should stick to what the already published reference says. That said, it looks like the cited article is a pre-print that was not peer-reviewed nor published in a journal, so we could be justified in removing the whole section, That is, if you feel the section is misinformation. I do not mind it being there, myself. Richard-of-Earth (talk) 07:15, 10 April 2023 (UTC)
replies: text: Sorry, the original resource rule of the Hungarian Wikipedia (where I mostly edit) is a less strict rule, I did not know it. Zalán Hári (talk) 08:03, 10 April 2023 (UTC)
thread_title:  "... remain only long enough to have a single coherent thought or observation, and then disappear into the vacuum as suddenly as it appeared" 

message: I was confused by the possible error referred to in the first sentence of this section. An error in what exactly? Our model of the universe, I assume, but could this be made less vague?
Apologies if this the wrong forum or format. DCT667 (talk) 09:08, 8 July 2023 (UTC)
thread_title:  Modern reactions to the Boltzmann brain problem