1
Four Laws that Drive the Universe By Peter Atkins. Oxford University Press, Oxford 2007. 130 pp., hardcover $ 19.95.—ISBN 978-0-19-923236-9 Much to my surprise, I quite enjoyed this little book. Having struggled myself with the fundamentals of thermodynam- ics—both as teacher and student—I can appreciate the conceptual difficulties, and Peter Atkins has done a good job here in helping to de-mystify the subject and make it seem like (almost) common sense. This is as one might expect from a prolific author whose more formal text- books now dominate the teaching of undergraduate physical chemistry. The approach is almost entirely classical. Separate chapters are dedicated to each of the four laws of thermodynamics in sequence, showing how each in turn can lead logically to the necessary existence of quantities such as temper- ature (from the Zeroth Law), energy (1st Law), and entropy (2nd Law), with the 3rd Law drawing a line under what is achievable in terms of temperature and entropy. Free energies (Gibbs, Helm- holtz) are introduced in a separate chapter, despite being described (merely?) as “… just convenient accounting quantities, not new funda- mental concepts” (p. 103). Not everyone would agree with this, but it does make some sort of sense in the classical approach presented here, and the rela- tionship between free energy and work is handled nicely. And I guess that it is a reflection of the power and beauty of thermodynamics that, starting from alternative/different postulates, one can arrive at the same overall conclusions. Naturally, there are some parts of the book that I felt I might disagree with—that)s part of the fun, especially for the (supposedly expert) reviewer. The treatment is almost entirely non- mathematical, and none the worse for that, given the likely intended audi- ence—though the introduction of an exponential function as early as page 13 might discourage nonspecialist read- ers, and is perhaps unnecessary. Some of the arguments can seem a little pedantic and disruptive of the flow. For example, the digression on the word “heat” might be a little disconcerting to the new- comer, by stating that : “… heat is not an entity or even a form of energy: heat is a mode of transfer of energy. It is not a form of energy …” (p.30), then reverting to a more commonplace usage of the term for the rest of the book. Elsewhere (p. 45) it was nice to be reminded of Emmy Noether)s theorem regarding the relationship between conserved quanti- ties and symmetry (and also nice to discover that she was a woman), but does that really mean “… the shape of the universe we inhabit. In the particular case of the conservation of energy, the symmetry is that of the shape of time”. I am not sure I would have followed that if I hadn)t already encountered it else- where. My own understanding is that it is the invariance (i.e., symmetry) of the laws of physics with respect to time that makes energy conservation obligatory. (In the same way that spatial transla- tional or rotational invariance leads to conservation of linear or angular momentum, and so forth). In other words, it is the shape of the laws, not the shape of the universe, that is signifi- cant here. Equally disconcerting might be the tantalizing references to thermo- dynamic fluctuations and the fluctua- tion-dissipation theorem (p. 42), which hint at the potentially (to some scien- tists) more satisfying molecular statisti- cal approach. Molecular interpretations don)t get much of a show here. For example, just why is it that water has such a high heat capacity (p. 44)? And just where did that connection between entropy and disorder creep in (p. 66)? OK—most of us professionals and (we hope) our students know why, but do others? And this leads on to the underlying question regarding the intended target audience for this book. Professor Atkins reminds us of C. P. Snow)s famous 1950s dictum (in The Two Cultures) that ignorance of the second law of thermo- dynamics is akin to never having read a work of Shakespeare—a reflection of the arts-versus-science divide that still persists to some extent more than 50 years later. But I can feel some sympa- thy for the nonscientists here. Thermo- dynamics has been a victim of its own history : a remarkably successful product of 19th century science, logically consis- tent and complete without the need to invoke concepts of atoms or molecules. But, as conventionally taught, and as mostly described in this book, it is based on abstract notions derived from the workings of steam engines and related devices that are increasingly unfamiliar to present generations. Since we cannot “unlearn” atoms and molecules, a much more overtly molecular approach to thermodynamics might be more helpful nowadays for nonspecialists. Despite these caveats, this is a nice book—an entertaining and illuminating read for those who have struggled with classical thermodynamics, and a reasonable chal- lenge for others who want to get some grasp of this most difficult topic. Alan Cooper WestChem Department of Chemistry University of Glasgow (Scotland, UK) DOI: 10.1002/anie.200785577 Books 3088 # 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Angew. Chem. Int. Ed. 2008, 47, 3088 – 3089

Four Laws that Drive the Universe. By Peter Atkins

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Page 1: Four Laws that Drive the Universe. By Peter Atkins

Four Laws that Drive the Universe

By Peter Atkins.Oxford UniversityPress, Oxford 2007.130 pp., hardcover$ 19.95.—ISBN978-0-19-923236-9

Much to my surprise, I quite enjoyedthis little book. Having struggled myselfwith the fundamentals of thermodynam-ics—both as teacher and student—I canappreciate the conceptual difficulties,and Peter Atkins has done a good jobhere in helping to de-mystify the subjectand make it seem like (almost) commonsense. This is as one might expect from aprolific author whose more formal text-books now dominate the teaching ofundergraduate physical chemistry. Theapproach is almost entirely classical.Separate chapters are dedicated toeach of the four laws of thermodynamicsin sequence, showing how each in turncan lead logically to the necessaryexistence of quantities such as temper-ature (from the Zeroth Law), energy(1st Law), and entropy (2nd Law), withthe 3rd Law drawing a line under what isachievable in terms of temperature andentropy. Free energies (Gibbs, Helm-holtz) are introduced in a separatechapter, despite being described(merely?) as “… just convenientaccounting quantities, not new funda-mental concepts” (p. 103). Not everyonewould agree with this, but it does makesome sort of sense in the classicalapproach presented here, and the rela-

tionship between free energy and workis handled nicely. And I guess that it is areflection of the power and beauty ofthermodynamics that, starting fromalternative/different postulates, one canarrive at the same overall conclusions.

Naturally, there are some parts ofthe book that I felt I might disagreewith—that6s part of the fun, especiallyfor the (supposedly expert) reviewer.The treatment is almost entirely non-mathematical, and none the worse forthat, given the likely intended audi-ence—though the introduction of anexponential function as early as page13 might discourage nonspecialist read-ers, and is perhaps unnecessary. Some ofthe arguments can seem a little pedanticand disruptive of the flow. For example,the digression on the word “heat” mightbe a little disconcerting to the new-comer, by stating that: “… heat is not anentity or even a form of energy: heat is amode of transfer of energy. It is not aform of energy …” (p.30), then revertingto a more commonplace usage of theterm for the rest of the book. Elsewhere(p. 45) it was nice to be reminded ofEmmy Noether6s theorem regarding therelationship between conserved quanti-ties and symmetry (and also nice todiscover that she was a woman), butdoes that really mean “… the shape ofthe universe we inhabit. In the particularcase of the conservation of energy, thesymmetry is that of the shape of time”. Iam not sure I would have followed thatif I hadn6t already encountered it else-where. My own understanding is that itis the invariance (i.e., symmetry) of thelaws of physics with respect to time thatmakes energy conservation obligatory.(In the same way that spatial transla-tional or rotational invariance leads toconservation of linear or angularmomentum, and so forth). In otherwords, it is the shape of the laws, notthe shape of the universe, that is signifi-cant here. Equally disconcerting mightbe the tantalizing references to thermo-dynamic fluctuations and the fluctua-tion-dissipation theorem (p. 42), whichhint at the potentially (to some scien-tists) more satisfying molecular statisti-cal approach. Molecular interpretationsdon6t get much of a show here. Forexample, just why is it that water hassuch a high heat capacity (p. 44)? Andjust where did that connection between

entropy and disorder creep in (p. 66)?OK—most of us professionals and (wehope) our students know why, but doothers?

And this leads on to the underlyingquestion regarding the intended targetaudience for this book. Professor Atkinsreminds us of C. P. Snow6s famous 1950sdictum (in The Two Cultures) thatignorance of the second law of thermo-dynamics is akin to never having read awork of Shakespeare—a reflection ofthe arts-versus-science divide that stillpersists to some extent more than 50years later. But I can feel some sympa-thy for the nonscientists here. Thermo-dynamics has been a victim of its ownhistory: a remarkably successful productof 19th century science, logically consis-tent and complete without the need toinvoke concepts of atoms or molecules.But, as conventionally taught, and asmostly described in this book, it is basedon abstract notions derived from theworkings of steam engines and relateddevices that are increasingly unfamiliarto present generations. Since we cannot“unlearn” atoms and molecules, a muchmore overtly molecular approach tothermodynamics might be more helpfulnowadays for nonspecialists. Despitethese caveats, this is a nice book—anentertaining and illuminating read forthose who have struggled with classicalthermodynamics, and a reasonable chal-lenge for others who want to get somegrasp of this most difficult topic.

Alan CooperWestChem Department of ChemistryUniversity of Glasgow (Scotland, UK)

DOI: 10.1002/anie.200785577

Books

3088 1 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Angew. Chem. Int. Ed. 2008, 47, 3088 – 3089