Top critical review
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a dangerous little book
on 27 May 2013
Having a large number of thermodynamics books already, I was moved to buy this one because of a comment in one of the reviews; a comment relating to negative temperatures which I did not believe would reflect the content of the book. When I received the book, I found, to my horror, that the review was correct and the author did refer to negative temperatures as being below absolute zero; that is, colder than positive temperatures. As anyone who has worked in the field knows, because of the way in which temperature was defined historically, negative temperatures are, in fact, hotter than positive temperatures in the sense that, when two systems with temperatures of unequal signs are brought into contact, heat will flow from the negative temperature one to that at positive temperature. This point is explained very clearly in Buchdahl's book on thermodynamics (p78) and in books by such as Landsberg, Landau & Lifshitz etc. Somewhat technically, if, as was claimed by Atkins, a system had been cooled to a temperature below absolute zero, it would have been necessary for that system to have passed through absolute zero. That, in turn, would have meant that, at some point, the said system had been at absolute zero in violation of one popular form of the Third Law of Thermodynamics. Possibly more importantly, however, if absolute zero is in fact an accessible temperature, that could lead to violations of the Second Law. This is seen easily by considering a Carnot cycle in which one of the isotherms is at absolute zero. However, the isotherm at absolute zero is also an adiabatic and so, the mentioned Carnot cycle could be viewed as consisting of one isotherm at some positive temperature and three adiabatics. In such a set-up, it is straightforward to see that the end result would be the conversion of a quantity of heat entirely into work in a cyclic process in the absence of other effects; that is, a direct violation of Kelvin's form of the Second Law.
Also, most importantly, on page 42, Atkins fails to make absolutely clear that the statement of the Clausius form of the Second Law is, like the Kelvin form, solely concerned with cyclic processes. His suggested 'new' Second Law introduced on page 49, is at best a deduction from the true Second Laws - that is, those of Kelvin and Clausius or even that of Caratheodory - and possibly not even that because there is still great uncertainty over what entropy really is. Certainly, the expression Atkins introduces on page 54 is nothing to do with thermodynamics but is rather a purely statistical concept which may, or may not, be the same as the thermodynamic entropy which arises purely as a mathematical deduction from the traditional statements of the Second Law.
No; there are sections of this book which are dangerous for students and anyone else interested in learning more about this basic topic in physics. Such people might be better advised to search for a good used copy of the little Methuen Monograph on Thermodynamics by A. W. Porter.