Talk:State variable

Much More Information Required

This article hasn't explained what a state variable is. Equally important, it hasn't explained what a state variable is not. What does it mean to be a state variable? What do temperature, pressure, and all the other variables listed have in common?

My engineering text book

My Engineering Dynamics text book has an entire chapter devoted to the "State variable" approach. I was reading this article and wondering of the material I have been learning about in school would belong here. The essential concept is that newton's laws are based on a second order differential equations, and the first step in creating using the state variable approach is to convert all the differential equations into coupled first order differential equations. When this is done, the equations are written in "Standard state variable form" which I am not really seeing in this article just yet. Well I am off to class right now, but I am thinking that I have some sourced material to contribute to this article. One problem is that the word "state variable" is used in a number of different fields, and I fear that I might momentarily add to much content on the definition of state variable from a mechanical context, and I would also add that "State variables" I believe also are found in thermodynamics and quantum mechanics, and so at some point someone more well schooled in content organization will need to contribute to these efforts.

   With this being said, I am off to my classes, but would like to get some feed back from others before considering adding any content here.  I also would like to take some time to re-read the text I am studying and see what portions of it are suitable for an encyclopedia of this nature.  So what does every body else think, back soon with some well referenced material for addition to this fine article.