Critical Phenomena A Heuristic Discussion

We are all familiar with the gas-liquid phase transition undergone by water. In such a transition, a plot of density versus temperature shows a distinct discontinuity at the critical temperature marking the transition point. There are many other common examples of similar phase transitions. 

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In this chapter we provide a heuristic introduction to scaling procedures that characterize properties of systems close to their critical point. The objective is to provide some general insights and to convey the flavor of the methodology. Much of the treatment of critical phenomena falls into the province of statistical mechanics, well outside the confines of classical thermodynamics. However, certain illuminating aspects that can be discussed without having to resort to statistical approaches will be taken up below. We center the discussion on critical exponents and the Landau theory of critical phenomena. For a proper exposition of the subject the reader is referred to several sources in the literature. ... 

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