Talk:Absolute zero

message: At the top of the article, it's stated that in 2003 MIT reached "500 pK (.5*10^-9)", but at the bottom it says they achieved 450 pK (4.5*10^-10). I just realized the magnitude of the two is the same, but which value is it, 450, or 500? SpartanMurph117 (talk) 01:11, 31 January 2008 (UTC)
thread_title:  MIT Temperature discrepancy 

message: "It is an infinite number of orders of magnitude below any attainable temperature.  It is by definition unachievable (after all, T appears in the denominator of many equations of thermodynamics), ..."
:I can only speculate as to what an infinite number of orders of magnitude means. That absolute zero is practically unachievable is the third law of thermodynamics and not inherent in the definition. Cutler 17:41, 17 January 2006 (UTC)
thread_title:  Edited intro 

message: I started thinking about 100 Kelvin, if it exists; and I was wondering...
When you start a particle vibrating, raising its temperature, its position
in space decreases in size. If you could create such high temperatures that the
particles poition in space is a singularity, its temperature zould be infinite,
no? But if its position is a singularity, would it have the room to vibrate, to
produce heat?
:Um... first of all, a single particle does not have a temperature; see the intro to the article Temperature. Second, increasing the energy of a particle does not necessarily decrease its "size", and certainly not for a harmonic oscillator; see for example the figures in the article Quantum harmonic oscillator. You might be thinking of the uncertainty principle, which says something else. Melchoir 22:43, 27 February 2006 (UTC)
thread_title:  Theory 

message: I reckon that at least with the "low temperature records", a Celsius conversion should be applied, as Kelvin is used by physicists resp., in general, scientists only. A Celsius value (like -272.95 °C) would be far more imaginable for so-called "ordinary people" than the Kelvin value would. -andy 217.91.47.231 12:08, 7 April 2006 (UTC)
replies: text: As far a general understanding goes, the difference between any temperature here and -270 °C won't affect the general understanding.  I can see no benefit whatsoever of listing temperatures such as -273.14999999955 °C. Gene Nygaard 13:03, 7 April 2006 (UTC)
thread_title:  Celsius conversions should be applied 

message: I would just like to point out, that this listed as fourth reference on the page seems to be inacurate to the point of being pseudo-scientific nonsence. 
"500 GHz is more than 250 times faster than today's cell phones, which typically operate at approximately 2 GHz."
When giving comparison of the clock speed of the processors in the article, it relates them to operating frequency ranges of cell phones. Obviously no processor in any modern cell phone runs at 2Ghz, but it is their band frequency. I think the segment that references the article and the article itelf should be removed from the page as grossly innacurate and misleading. Tani unit 13:54, 22 June 2006 (UTC)
replies: text: Tani unit: You gotta forgive the New York Times because the Georgia Tech's press release uses similar language: Silicon-germanium transistor operates 250 times faster than average cell phone.  Your opposition to the statement presumes a bit more than is directly stated in the Times article.  The NY Times didn't say microprocessor chips; just chips.  And this is technically true since there are solid-state devices within a cell phone that oscillate at 2 GHz in order to generate the RF.  Having an entire microprocessor running at 250X these speeds and not vaporize into a flash of x-rays is quite an accomplishment.  Given that the NY Times' article isn't factually incorrect still means it might be misleading to some, but it can't fairly be characterized as "grossly innacurate [sic]" as you stated.  Greg L 22:12, 20 July 2006 (UTC)
replies: text:  I think the point here is that the statement is pretty much meaningless.  It is an apples to oranges comparison, and while technically true, not enlightening in any way. —The preceding unsigned comment was added by 66.102.196.37 (talk) 04:46, 4 April 2007 (UTC)
thread_title:  Source inaccuracy 

message: Glossando: Regarding your having converted the Boomerang Nebula paragraph to past-tense form (you justified doing so by stating in your Edit Summary in the History section that “we are viewing the existence of something as it was thousands of years ago”): This is confusing, unnecessary, and unsupportable. Unless an astronomy topic is directed strictly to the origins of the universe (such as the Big Bang or the Cosmic Microwave Background), relatively nearby events are always dated as Earth-receive time.  For instance, Supernova 1987A and the 1054 supernova producing the Crab Nebula are events that are dated Earth-receive time.  Supernova 1987 is said to have occurred 19 years ago.  Any mention of when it "really" occurred is added parenthetically.  This sort of distinction properly belongs in articles such as Light year (where it is undoubtedly covered in great detail). You also used past-tense language for the very existence of a heavenly object (the Boomerang Nebula) when you wrote “and existed in the constellation Centaurus” (my emphasis). While you are clearly very bright to have recognized how everything seen in the heavens is actually seen as it occurred at some point in the past, I sure wouldn't have gone out on such a limb as you did trying to emphasis this point; particularly since there is zero evidence that the Boomerang Nebula no longer exists or no longer is still (Boomerang transmission time) the coldest observable object in the heavens. This is about as logical as saying the Crab Nebula “existed” in the sky or that the Voyager spacecraft "used" to exist when they broadcast information (that takes many hours to reach Earth) regarding the edge of the heliosphere that also "used to exist".   Greg L 20:47, 26 October 2006 (UTC)
replies: text: Although I don't think mentioning something that only takes hours to view after it occurred is a good example to give to argue against something we are actually viewing thousands of years after it happened, I think what you are saying is fair enough. It would surely become too cumbersome to find the right past-tense wording every time we are speaking of such a thing that many light years away. I agree that sort of distinction more properly belongs in articles such as in Light year. --Glossando 21:39, 26 October 2006 (UTC)

text: Note: 500,000 kilometers per hour, not per second.  The speed of light is about 300,000 kilometers per second. --Trovatore (talk) 16:39, 31 March 2013 (UTC)
thread_title:  The Boomerang Nebula: Event timing in the heavens 

message: My friend says that you can get colder than absolute zero. I say you can't. Who is right? Tell me on my user page.(search my username)Caleb M. 23:19, 12 February 2007 (UTC)
replies: text: You are. Maybe surprisingly, it is possible to have negative absolute temperature, a temperature that's a negative number on the Kelvin scale. But this is not extremely cold but rather extremely hot. --Trovatore 23:22, 12 February 2007 (UTC)

text: I think it's already cold enough. Ilyajedi96 (talk) 16:16, 18 May 2010 (UTC)

text: When we speak about absolute zero we speak about atoms with zero kinetic energy. But what about energy of subatomic fractions. For example electrons are composed of smaller fractions, that are active in still atom, even if electrons are stopped.  —Preceding unsigned comment added by 193.200.189.4 (talk) 12:59, 5 March 2010 (UTC)
replies: text:  I'm not really sure what you're getting at here.  But it's important to emphasize this:  Atoms have nonzero kinetic energy at absolute zero, because of quantum effects.  It's even more important to emphasize this:  Temperature is not not not about kinetic energy!  Temperature is a statistical-mechanics thing; it's about the relationship between entropy and internal energy.  That's why InternetFoundation is wrong in his remarks above.  --Trovatore (talk) 19:42, 18 May 2010 (UTC)

text: There has to be a simpler way to explain this. What about Maxwell's Demon? If you were to create an area of the universe that was at absolute zero, the absolute zero collapses as every non-absolute zero temperature source filled it in. Im not really sure if this would be a good description of how things work. But I didnt se it on here so I thought id add it. 74.132.249.206 (talk) 20:23, 24 August 2011 (UTC)
replies: text:  The definition of temperature is the derivative of the absolute energy in function of the entropy at constant volume and number particles. Also the  entropy increases with the number of states of a system. In some quantum systems it is possible for the system to be in a state so that when the temperature increases the number of states decreases, giving rise to a negative temperature. This states are, however, hotter than state with positive temperatures. Maybe we should add a section about this.  — Preceding unsigned comment added by BrunoGCoutinho (talk • contribs) 08:40, 4 May 2015 (UTC)
thread_title:  Colder? 

message: What would happen if a load was applied to (say) hydrogen at absolute zero?  Could it be compressed?  Does it depend upon whether the substance has more than one (meta)stable state at that temperature?
— DIV (128.250.204.118 02:57, 28 September 2007 (UTC)
thread_title:  Compression 

message: Couldnt it say that absolute zero is the point at which the atoms stop moving entirely? Cause that's kinda what it is.  —Preceding unsigned comment added by 74.135.7.26 (talk) 21:27, 20 October 2007 (UTC)
replies: text: "Kinda" in the sense of "not really". See zero-point energy. --Trovatore 22:05, 26 October 2007 (UTC)
replies: text:  Shouldn't the intro say something in layman's terms also, something along the lines of "theoretically the coldest temperature that any object can achieve (although in reality, the laws of thermodynamics preclude actually reaching absolute zero)." Also some reference somewhere to the temperature of deep space in relation to absolute zero. The Yeti (talk) 12:35, 22 October 2008 (UTC)
thread_title: What it actually is

message: If a particle completely stopped moving and had no energy, wouldn't the electrons stop orbiting and be attracted and collide with the nucleus?  Is this theoretically possible?  and if so wouldn't it cause some sort of singularity or black hole type thing?71.190.143.208 22:02, 26 October 2007 (UTC)
replies: text: The electrons don't stop moving. No, it isn't theoretically possible for the electrons to be bound to the nucleus and yet unmoving (in the sense of having zero expected momentum). --Trovatore 22:09, 26 October 2007 (UTC)
thread_title:  Black Hole? 

message: Is it relevant to mention that MIT got to 500pK in 2003, when Helsinki University of Technology were more successful before then? Halsteadk (talk) 12:51, 20 April 2008 (UTC)
thread_title:  Intro section - researchers 

message: "...It is at this point the laws of thermodynamics become very important."
Surely the laws of thermodynamics are important at all temperatures?  —Preceding unsigned comment added by 86.16.167.203 (talk) 23:02, 20 July 2008 (UTC)
thread_title:  Relation with Bose Einstein Condensates 

message: Wouldn’t it be simpler to say that absolute zero is the point at which there is no heat?  —Preceding unsigned comment added by 71.107.132.94 (talk) 09:04, 22 September 2008 (UTC)
replies: text: Heat and Temperature are two very different things. Temperature is not a measure of heat; therefore, temperature should not be defined in terms of heat. by hajatvrc at 03:19, 12 December 2009 (UTC)
thread_title:  Definition 

message: Possible effect of achieving the zero temperature could be:
irreversibility:
Because of achieving *absolute* 0 temperature, we would be unable to force the "system" to move again. Because we would need absolure force to make it move. I suppose, that even all the energy of universe shouldn't be enough to reanimate the *frozen* system.
problems with artifical achieving:
The system cannot be artifically frozen down to absolute 0 temperature. Because we add energy even upon measurement (the machine/lab should be absolute 0 temperature already, otherwise it will add an extra energy).
mass vanishment:
The mass should vanish. Because of absence of movement in the elementary particles. Electrons, protons, neutrons, even quarks in the atomic nucleus.  Even we could have obstacles to recognise electrons and/or quarks and other particles. Because of absence of movement, we could hardly determine their position. Thus we couldn't use electron bombing reactions or particle accelerators. In simply way, we would unable to recognise the mass, should it have absolute 0 temperature.  —Preceding unsigned comment added by Janmojzis (talk • contribs) 21:38, 15 October 2008 (UTC)
thread_title:  achieving absolute zero is irreversible and can cause mass vanishment 

message: "... and −459.67 degrees on the Fahrenheit scale" (Absolute zero)
"Absolute zero is −523.67 °F ..." (Fahrenheit)
Surely there must be something wrong here :)
: Actually the article's correct. Forbes72 (talk) 00:08, 27 January 2012 (UTC)
thread_title:  Absolute zero in degrees Fahrenheit 

message: "...a column of mercury was sustained by a certain mass of air..."  
What does "sustained" mean in this context?
"...the volume or 'spring' which of course varied with the heat to which it was exposed. Amontons therefore argued that the zero of his thermometer would be that temperature at which the spring of the air in it was reduced to nothing." 
In other words, absolute zero would be the point at which the volume of air had "shrunk to nothing"?  Wouldn't that mean that the mercury was expanding, the opposite of what it should be doing in the cold?  I can't visualize what's going on here.  Nine9s (talk) 00:11, 28 November 2008 (UTC)
thread_title:  Section on Guillaume Amontons is unclear 

message: This section of the page is currently showing this text:
* At temperatures near 0 K, nearly all molecular motion ceases and Failed to parse (Cannot write to or create math output directory): \Delta S = 0 for any adiabatic process. Pure substances can (ideally) form perfect crystals as TFailed to parse (Cannot write to or create math output directory): \to 0. Max Planck's strong form of the third law of thermodynamics states the entropy of a perfect crystal vanishes at absolute zero. The original Nernst heat theorem makes the weaker and less controversial claim that the entropy change for any isothermal process approaches zero as TFailed to parse (Cannot write to or create math output directory): \to 0  —Preceding unsigned comment added by 72.204.113.140 (talk) 11:15, 8 December 2008 (UTC)
thread_title:  Thermodynamics near absolute zero "Syntax Errors" 

message: InternetFoundation (talk) 01:33, 28 July 2009 (UTC)
thread_title:  Fermi Temperature, Zero of Temperature Paradox 

message: Answering Kevin: The claim that "all molecular motion stops at absolute zero" is simply incorrect.  It's correct in the classical approximation, but according to quantum mechanics, it's just wrong. --Trovatore (talk) 22:20, 27 July 2009 (UTC)
thread_title:  Trovatore's reply to Kevin 

message: This article needs copy editing. It contains a lot of undefined terminology, or uses new terms before defining them. The progression of ideas is not coherent, and sometimes sentences are not even grammatical!Wwallacee (talk) 21:30, 24 September 2009 (UTC)
replies: text: WP:BOLD.—Tetracube (talk) 21:35, 24 September 2009 (UTC)
thread_title:  Request for copy editing 

message: Please, somebody with normal language skills rework the introductory paragraph!!!
The opening sentence is clear enough, but then it all goes to hell after that, and continues on with all the clarity of a mind-numbing technical paper. When writing an article for wikipedia always ask yourself the question: Who is your audience?
Apire for greatness. Think Loren Eisley or John McPhee. Ask yourself: "what would they do with the subject?"...And then go from there. Try Try Try.  —Preceding unsigned comment added by 24.241.235.92 (talk) 03:05, 27 November 2009 (UTC)
thread_title: Intro paragraph

message: In the Very Low Temperatures, this article says "Record temperature" twice.
22:28, 30 July 2010 (UTC)
thread_title: Contradictions

message: It starts mentioning variables S and T but doesn't say what they are intended to represent.  For example it says: "when entropy = S, ΔS = 0".  Is S supposed to represent entropy?  Or is this an equation that is only applicable in the case when S (whatever that is) has the same magnitude as the entropy? -- DBooth (talk) 17:50, 26 December 2010 (UTC)
thread_title:  Section on "Thermodynamics near absolute zero" needs variables defined 

message: The document cites that the coldest temperature recorded is at 1K, but the article it uses as a reference says that they Boomerang Nebula absorbs 3K microwave waves. This does not appear correct and should be removed if evidence cannot be found to support it.
--174.69.9.141 (talk) 01:44, 14 July 2011 (UTC)
replies: text: Good point. Happy editing, hajatvrc with WikiLove @ 23:31, 14 July 2011 (UTC)
thread_title:  Coldest Temperature Recorded 

message: About this edit: 
* 85.64.251.156 says "Undid revision 522335558 by Hhhippo (talk). He did erase some links that are needed".
* Wikipedia's Manual of Style says "Generally, a link should appear only once in an article, but if helpful for readers, links may be repeated in infoboxes, tables, image captions, footnotes, and at the first occurrence after the lead."
I would suggest to restore only those links that are needed (preferably explaining why they are needed) and that are not violating the Manual of Style. I'm not re-reverting for now in case someone else has an opinion on this. — HHHIPPO 18:31, 26 November 2012 (UTC)
thread_title:  Overlinking 

message: A couple of editors (well, could be the same editor for all I know, but at widely varying times) have changed the opening sentence from "lowest possible temperature" to "lowest temperature".  To my ear that just doesn't work in English.  Lowest temperature of what?
The most recent edit raised the point that absolute zero isn't "possible".  I think that's actually an error — there is no process that will lower an object's temperature to absolute zero, but it is not in fact impossible for a sufficiently small object to reach absolute zero by chance, if it radiates out its last quantum of heat energy without absorbing another one.
But that's a little beside the point, which is really a linguistic one — what we want, conceptually, is to say that it's the greatest lower bound of all possible temperatures, but without bringing up greatest lower bounds.  I think "lowest possible temperature" is a reasonable realization of that goal.  It's certainly no worse than "lowest temperature"; it's not clear how "lowest temperature" expresses a greatest lower bound any better than "lowest possible temperature" does.  --Trovatore (talk) 03:15, 29 November 2012 (UTC)
thread_title:  "possible" 

message: OK, I asked the IP to comment here saying there was already a section about it, but I had forgotten that the name of the section was something you wouldn't obviously connect with negative temperature.  Hopefully this is clearer. --Trovatore (talk) 21:40, 13 January 2013 (UTC)
replies: text: When you google "below absolute zero" (in quotes) you get lots of hits, as I understand it. They are adding energy to a gas at the cusp of absolute zero, so regardless of what is claimed/true, a mention in the header is probably appropriate. It came up in an conversation at my office, and we are not theoretical physicists. JeepdaySock (AKA, Jeepday) 14:27, 18 January 2013 (UTC)
replies: text: Hmm, fair enough, but a detailed mention needs to wait for someone who understands the result.  I think I could probably follow the paper if I put enough effort into it, but I don't know when I might get around to doing that.  I'll try to think of some generic language that isn't actively misleading. --Trovatore (talk) 20:41, 18 January 2013 (UTC)
thread_title:  Negative temperature result in lead 

message: Shouldn't it be "100 picokelvin" and not "100 picokelvins?" --coolbho3000 (talk) 19:44, 17 February 2013 (UTC)
replies: text: I believe the SI standard is to treat the kelvin like any other unit, so if you'd say "100 picometers", you should also say "100 picokelvins".  I don't really care much which one is used, but certainly there's at least a reasonable basis for the current choice. --Trovatore (talk) 23:23, 17 February 2013 (UTC)
thread_title:  "Kelvins" vs "Kelvin" 

message: In the thermodynamics near absolute zero section, there are some strange citations that instead of being a reference like one would normally find on Wikipedia, e.g. a superscript that links to the reference, are an "inline" type of citation (for lack of a better term), such as:
:(≈ Callen, pp. 189–190)
Is there a reason for these being present, or should these just be made into the standard citations?
:-5donuts (talk) 18:19, 19 February 2014 (UTC)
replies: text: The person who included these probably didn't know how to do it properly.  Come to think of it, I don't know the procedure myself.  If you fix it, I will watch and learn! --guyvan52 (talk) 02:13, 20 February 2014 (UTC)
thread_title:  Bizarre Citations 

message: Substituted at 06:32, 29 April 2016 (UTC)
thread_title: Assessment comment

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thread_title:  External links modified 

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thread_title:  External links modified 

message: There is a move discussion in progress on Talk:Absolute Zero (disambiguation) which affects this page. Please participate on that page and not in this talk page section. Thank you.  —RMCD bot 09:01, 11 September 2019 (UTC)
thread_title:  Move discussion in progress 

message: In this section, the first point says:
The current world record was set in 1999 at 100 picokelvins (pK), or 0.0000000001 of a kelvin, by cooling the nuclear spins in a piece of rhodium metal.
But by the bullet points below that one, this is clearly no longer the case, right? Take e.g. the last bullet point:
[...] In a space-based laboratory, temperatures as low as 10 picokelvin ( 10 − 12 {\displaystyle 10^{-12}} 10^{-12} K) temperatures have been achieved,  [...]
Well, according to this source: https://www.ctvnews.ca/sci-tech/scientists-create-coldest-temperature-ever-in-a-lab-to-help-understand-quantum-mechanics-1.5632054 (and among many others) say that in 2021 the record was 38 trillionths above -273.15C. So, we should make a change on that.  — Preceding unsigned comment added by 2601:5C7:4100:3600:259F:CC85:5F10:EECE (talk) 19:17, 25 November 2022 (UTC)
thread_title:  Very low temperatures. 

message: What is the difference between a temperature of 0 and the minimum kinetic energy as detailed in the discoeries section in 2000.
What are the degrees of freedom in addition to nuclear spin?
Which degree of fredom is easiset to constrain?
ScientistBuilder (talk) 18:53, 8 February 2022 (UTC)
thread_title: Absolute Zero and Degrees of Freedom

message: According to this link The Challenge of Discovering Absolute Zero or -273.15 Degrees Celsius, the now official value of 0 °K = -273.15°C was first determined by Masao Kinoshita and Jiro Oishi of Tokyo Tech, Japan in 1938, and their result was finally recognised by the Consultative Committee for Thermometry of the International Committee for Weights and Measures in 1952.
The article includes additional information on how the temperature of absolute zero was determined, citing also work in the USA and Germany.  I think use of the information in this article would be a useful addition to the History section.
As I am neither a Wikipedia editor nor an expert on this subject, I leave it to others to edit the actual page section.
--195.213.152.87 (talk) 12:51, 22 June 2022 (UTC)
thread_title:  History 

message: I was curious why William Francis Giauque is not featured anywhere in this article? 1949 Nobel laureate recognized for his studies in the properties of matter at temperatures close to absolute zero.  — Preceding unsigned comment added by 142.113.219.114 (talk) 15:50, 30 November 2022 (UTC)
thread_title:  William Francis Giauque 

message: Perhaps a small section on the 2019 redefinition of the Kelvin scale is in order? it is no longer defined by the triple point of water, rather by the boltzmann constant. 137.248.1.6 (talk) 13:19, 25 September 2023 (UTC)
replies: text: This article is not about the kelvin, and it doesn't mention the triple point of water, except in "see also" and in one note.  I think it would be fine to edit the note to remove that mention; it was probably never appropriate anyway. --Trovatore (talk) 20:11, 25 September 2023 (UTC)
replies: text:  I got rid of the note, replaced it with a quote from the current SI brochure. Mathnerd314159 (talk) 23:03, 25 September 2023 (UTC)
replies: text:  Thanks! --Trovatore (talk) 01:35, 26 September 2023 (UTC)
thread_title:  Redefinition of the Kelvin