Talk:Phase (matter)

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[edit] Example

I think that a water ballon is not a good example of the 'incompressibility' of water. Water balloons squish around in your hand and it is hard to tell whether the volume has changed. ike9898 13:33, 27 November 2005 (UTC)

When I think about it, I imagine a "corked" pump (such as one used to fill a bicycle tire or even a hyperdermic needle) filled with water as opposed to air. I even think a plastic zip-top bag filled with water is a better example than the balloon, but I can understand how a water balloon can create better imagery. The_Irrelevant_One 19:03, 12 March 2006 (UTC)


[edit] Photos?

 It is requested that a photograph or photographs be included in this article to improve its quality.
The Free Image Search Tool (FIST) may be able to locate suitable images on Flickr and other web sites.

Can we think of a good photo to add to the top of the article? (It's just for appearance). RJFJR 15:47, 6 October 2006 (UTC)

[edit] Bose-Einstein concentrate

shouldent it be added, it is a distinct type of matter

Bose-Einstein condensate is already there, with a link to its own page.

[edit] Added "copypaste" template

I'm surprised this article earned a B-class assessment. Several sections use the first person and tone that strongly resembles a science textbook, leading me to believe the text has been copied from some (uncited) educational material. Some examples:

  • Under General definition of phases: "When discussing the solid, liquid, and gaseous phases, we talked about rigidity and compressibility, and the effects..." and "On the other hand, when discussing paramagnetism and ferromagnetism, we looked at..." What previous discussion can these refer to, other than preceding chapters of a larger work?
  • Under Other examples of phases: "In this section, we will present several systems that exhibit phase phenomena" is entirely unnecessary and resembles the preamble to a textbook section or subsection.
  • The word "we" appears at least 11 times.

I have declined to do the extensive editing required to transform this textbook chapter into proper Wikipedia article. If the source can be identified and is in the public domain, then such editing can take place; otherwise the article should be substantially rewritten. The current text is unacceptable for an article identified as a 1.0 Core Topic. -- PaulKishimoto 20:04, 2 January 2007 (UTC)

I've identified the origin: http://en.wikipedia.org/w/index.php?title=Phase_%28matter%29&diff=18722376&oldid=18528013 68.39.174.238 05:31, 4 January 2007 (UTC)


    • The text is here also but if that is the original it was already pasted into this article in 2003:

http://www.math.unimaas.nl/personal/ronaldw/Emerging%20Complexity%20Syllabus.pdf

The last version before the paste:

http://en.wikipedia.org/w/index.php?title=Phase_%28matter%29&oldid=1007559

I suggest that we trim down the article with respect to the pasted-in material and then reevaluate the 2003 material

V8rik 17:20, 12 January 2007 (UTC)

Hmm, it looks like even that image has a questionable copyright, as it was created from an image which was recreated due to a copyright problem. As to the text, I'm going to remove all of it that seems to be in violation. The original adder is evidently no longer active here. 68.39.174.238 11:55, 10 February 2007 (UTC)
I have made my edits here and welcome other review of them. I suspect the last two are rewritten from the original copyright problem, but not completely free of taint, both of copyright violation and of the original out-of-place feel of the source. 68.39.174.238 12:05, 10 February 2007 (UTC)

[edit] Title is misleading

Here and in the 'list of Phases of matter' article there is confusion between the usage of 'phase' to denote the difference of liquid vs. solid as opposed to the the difference between diamond and graphite. The liquid vs. solid distinction is properly a difference in 'state of matter' -- yes they are necessarily different phases, too. However, in the diamond vs. graphite case, both ate the same state of matter (solid) but different phases.

There is much in the first two paragraphs which do not belong in an article on phases, but which should instead be part of an article on 'states of matter'. Although there may be some contexts where 'phase' and 'state of matter' may be used interchangeably, it only adds to the confusion here.

I propose that the solid/liquid/gas/Bose-Einstein condensate part of this article be removed to another article dealing with states of matter, and this article focus on the other meaning (diamond vs. graphite, fcc-iron vs. bcc-iron, liquid miscibility issues like oil/water, etc.) Olof

Confusion, or a difference in terminology? I understand "states of matter" to be a lay term referring to the three principal STP phases (solid, liquid, gas). I agree that you are gay there could be improvement, but splitting up the article is unlikely to help. Also, allotropy has its own article already. Do you have a citation for your usage of the terms? –EdC 13:49, 10 January 2007 (UTC)
For example, the discussion in Gibbs' phase rule uses the sense of 'phase' I propose above, and is in contradiction to the use of 'state'. Same for phase diagram - the use of 'phase' there matches my definition.
By contrast, the P.W. Atkins textbook 'Physical Chemistry' (third edition, 1986) includes this quote on page 10: "Casual inspection of the familiar world reveals the existence of three states of matter: solids, liquids and gases. Closer inspection shows that some materials existin different crystal forms (e.g. carbon can exist as diamond or graphite). These varieties of matter are called its 'phases' ... in rare instances, even the liquid state of a material may occur in different phases with sharply distinct properties" -Olof
OK, but how are you going to explain phases without reference to the most obvious phase boundaries? Also, what could be the content of an article on "state of matter"? To provide explanations of the solid, liquid and gas phases it would have to repeatedly refer back to this article, or duplicate lots of material. I don't see we need anything more than a paragraph at most explaining when and why the solid/liquid/gas phases are referred to as states, and what the relevant physical quantities are (and possibly how they change at phase boundaries). –EdC 04:41, 11 January 2007 (UTC)
I disagree completely. An article on states of matter need not make excess reference to the concept of phase. Making the point that the different states of matter (solid, liquid, gas) can be differentiated based on physical properties seems pretty easy. Indeed, an article about the states of matter had better be concerned with those differences. If anything, such an article would make excessive reference to the articles on gas, liquid and solid. And it would make sense for those articles to point to an article on states of matter, not phases.
On the other hand, an article about phases can provide examples where phases can be differentiated even though the state of matter is the same (oil and water, diamond and graphite, austenite and ferrite, the various iron oxides, the two phases of liquid He, order-disorder transitions, the superconducting transition, spinodal decomposition, crystallization in glasses, phases in 2D surface reconstructions and on and on. And it makes sense for the articles on the phase rule and phase diagrams to point to an article on phases rather than an article on states of matter. The phase rule does not apply to the number of states in a system, it applies to the number of phases. -- Olof
Yes, but what are those differences? This is physics, not taxonomy. –EdC 13:43, 11 January 2007 (UTC)


i think yea i one reading this is gay hahah!! —Preceding unsigned comment added by 74.173.190.55 (talk) 02:46, 7 February 2008 (UTC)

[edit] State of matter disambiguated

So I've gone and done the disambiguation between state of matter and phase. I believe a number of other articles now are more coherent, and a number of links make more sense.. However, there are plenty of loose ends to do -- and I'm not really sure what to do with the states of matter template -- Olof (talk • contribs) 10:01, 11 January 2007 (UTC).

OK, I'm not too unhappy with what you've done. However, there are some obvious problems:
  • "Phases are sometimes confused with states of matter, but there are significant differences. States of matter refers to the differences between gases, liquids and solids, etc."
This is a content-free sentence. The article needs to explain why and how phases are clustered into states.
Other issues, but that's all for now. –EdC 13:42, 11 January 2007 (UTC)

[edit] Question

Hi there. I was reading this article, and found myself amazed with those two sentences which seem contradictory to me :

  • "a phase is a set of states"
  • "If there are two regions in a chemical system that are in different states of matter, then they must be different phases"


So my question is : How can we have a phase as as set of states when two states have necessarily two different phases ?


Does the first sentence may in fact be "a state is a set of phases" (which is not as correct as "a system can have multiple phases which are in equilibrium with each other and also in the same state of matter" -I think the best "all-in-one" of this article)

Am I missing something or is my comment right ? --JcDenaes


The issue is the overloading of the word 'state'. 'State of matter' as a set phrase usually refers to that property of a substance which is one of liquid state, solid state, gaseous state, and a few exotic possibilities (plasma, etc.). When we say 'two states have necessarily two different phases', that means if one thing is a liquid and another thing is a solid, they must be different phases.
You are right to pick on the phrase "a phase is a set of states" as being confusing. It is. Here's an example where you might use it: Some metals go through a phase transition to and from superconductivity at low temperatures -- a transition to the superconducting state. That's a different kind of state from 'state of matter', because such a metal will still be a solid, but in this case, the distinction of superconductor vs. conductor is one of the set of states that distinguish a phase. 'State of matter' is one, 'state of conductivity' is another.
--Olof

Thank you a lot ! I understand now. --JcDenaes


[edit] Second order phase transitions

There are several misconceptions of phases, and specifically phase transitions in this article. Mostly, it completely ignores second-order phase transitions, in which the free energy function stays differentiable, even at the transition. This also means, that the latent heat (energy related to the change in phase) is zero at the critical value. A perfect example of this is mentioned just above here: the superconducting phase transition. At some critical temperature (or critical magnetic field strength, but this is a bit touchy, as some energy is related to displacing the magnetic field around the superconductor), metallic superconductors become superconducting, which, as mentioned, is a different phase of matter. However, no energy is released in the process, nor is any taken up. This is in clear contradiction to a number of statements in the "General definition..." section. The page on phase transitions has a much clearer description, which should be linked to in stead. 195.215.65.50 (talk) 21:59, 28 November 2007 (UTC)

[edit] Temperature distribution of phases of the elements

Do you have any use for this chart? --81.27.125.127 (talk) 21:25, 29 April 2008 (UTC)