Talk:Phase space

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Contents 1 Work in Progress 2 The Images 3 quantization 4 State Space 5 Phase space and Parameter space 6 WikiProject class rating 7 Contrast with configuration space 8 dynamical

[edit] Work in Progress

To make Phase Space the main article on the (p, q) space of dynamical systems, and Phase diagram mainly on the physical chemistry uses of that term Linuxlad 23:48, 19 Feb 2005 (UTC)

Speaking of that, it looks like someone erroneously linked the English article on Phase Space with the French article on Phase Diagrams... Ed Sanville 18:56, 26 July 2005 (UTC)

[edit] The Images

The images require labels on their axes. The first image has none. The second image's resolution is too poor to decipher the axis labels.

[edit] quantization

The statement on quantisation needs a tidy - it's the product p.q which has the dimensions of action surely. (so from memory, dp.dq = h) Bob aka Linuxlad

Done. Howeever, I was sloppy with the links, some may be disambig pages. I have to run ... linas 16:24, 13 March 2006 (UTC)

Now, the statement on quantisation is better: no one will understand, who not already knows! It's a pity! ErNa 07:48, 14 March 2006 (UTC)

[edit] State Space

Isn't "Phase space" = "State space"? They both are the space of all possible states, aren't they? --Javalenok 19:48, 3 May 2006 (UTC)

No, "state space" is a synonym for Configuration space, which is a related but different concept. -- Four Dog Night 02:48, 25 August 2006 (UTC)

for a classical system with N particles, each point in the 3N + 3N dimensional phase space is a possible configuration of the system. in statistical mechanics, a "state" is then a probability distribution (in mathematical terms, a probability measure) on the phase space. so the state space is the family of probability distributions. for example, the microcanonical ensemble is a state; it corresponds to the distribution that is constant everywhere on some constant-enery surface of the phase space. Mct mht 04:47, 25 August 2006 (UTC)

... and zero everywhere else. Ed Sanville 10:29, 25 August 2006 (UTC)

Another related category: "Dimensional analysis" Vugluskr 11:30, 29 December 2006 (UTC)

[edit] Phase space and Parameter space

"In a phase space, every degree of freedom or parameter of the system is represented as an axis of a multidimensional space" I think this phrase is misleading. There is a difference between phase space as defined here and parameter space. The phase space is all the possible states of a given system (usually over time for different initial conditions). Changing the parameters of a system (for example the stiffness of a spring) can give a different phase space. If we allow the parameters to be changed then we obtain a family of phase spaces. Usually, if the system has fixed points one can study the evolution of this fixed points when changing the parameters of the system, leading to the bifurcation diagram in which the parameters of the system are the axes of the plot. To summarize, in the phase space you do not represent the parameters as an axis. If the parameter has dynamics then ti can be considered a degree of freedom of the system. JuanPi —Preceding comment was added at 12:40, 20 February 2008 (UTC)

[edit] WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 10:01, 10 November 2007 (UTC)

[edit] Contrast with configuration space

I think it might be helpful to contrast phase space with configuration space, or at least link to that article at some point. Steve Avery (talk) 02:20, 14 January 2008 (UTC)

[edit] dynamical

I assume all of those "dynamical" and "thermodynamical" should actually be "dynamic" and "thermodynamic"? Didn't change them in case it's some weird mathematical usage. —Preceding unsigned comment added by 196.30.245.149 (talk) 14:22, 4 March 2008 (UTC)