Physics Today Nonlinear Physics of Ecosystems Hugo Fort Citation: Physics Today 68(10), 46 (2015); doi: 10.1063/PT.3.2949 View online: http://dx.doi.org/10.1063/PT.3.2949 View Table of Contents: http://scitation.aip.org/content/aip/magazine/physicstoday/68/10?ver=pdfcov Published by the AIP Publishing This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 164.73.83.101 On: Thu, 01 Oct 2015 22:06:59 books The allure of the aesthetic A Beautiful Question its extension to general relativ- physical theories. More than ity, quantum mechanics, and 20 years have passed since Finding Nature’s Deep ultimately the standard model Weinberg wrote his book, but Design of particle physics. He touches the dream is still as elusive Frank Wilczek briefly on condensed-matter today as it was back then. Penguin Press, 2015. $29.95 physics—graphene in particu- For all its elaboration on the (430 pp.). ISBN 978-1-59420-526-2 lar—and takes an interesting beauty of symmetry, Wilczek’s detour into the human eye’s book falls short of spelling out Reviewed by Sabine Hossenfelder limited ability to decode visual a conundrum physicists face My four-year-old daughter recently dis- information. today: We have no reason to be confi- covered that equilateral triangles com- In the last chapters of the book, dent that the laws of nature yet to be bine to form larger equilateral triangles. Wilczek goes into quite some detail discovered will conform to the human When I caught a distracted glimpse of about the particle content of the stan- sense of beauty. Nor does Wilczek her artwork, I thought she had drawn dard model and how, it seems, the spend many words on aspects of beauty the baryon decuplet, an often-used dia- model is not as beautiful as one may beyond symmetry; he only briefly gram to depict relations between some have hoped. He introduces the reader touches on fractals, and never goes into of the particles composed of three to extended theories such as grand the rich appeal of chaos and complexity. quarks. unification and also supersymmetry, My mother used to say that “sym- The baryon decuplet doesn’t come which was invented to remedy some metry is the art of the dumb,” a criticism easy to humans, but the beauty of sym- of the supposed shortcomings of the perhaps too harsh to level at the stan- metry does. And how amazing it is that standard model. The reader unfamiliar dard model. But seeing that reliance on physicists have found symmetry tightly with the quantum numbers used to beauty has not helped us in the past two woven into the fabric of nature itself: classify elementary particles will likely decades, maybe it is time to consider Both the standard model of particle find some parts of that section a bit that a beautiful answer might not reveal physics and general relativity, currently demanding. itself as effortlessly as does the appeal our most fundamental theories, are in But whether or not one makes the of plane tilings to a four-year-old. essence mathematically precise imple- effort to follow the details, Wilczek gets Maybe the inevitable subjectivity in our mentations of symmetry requirements. his message across clearly: Striving for sense of aesthetic appeal will turn out Next to being instrumental for the beauty in natural law has been a useful to be a curse, misleading us as to where accurate description of nature, symme- guide, and he expects it to remain one. the answers lie. tries are also universally appealing to He is, however, careful to note that Wilczek’s book contains something humans, as reflected in art and design relying on beauty has, on various occa- for every reader, from the physicist who across cultures. For the physicist, it is sions, led to plainly wrong theories, wants to learn how a Nobel Prize win- second nature to see the equations be- such as an explanation of planetary ner thinks of the connection between hind the art. Indeed, having that ability orbits in terms of Platonic solids or a ideas and reality to the layman who may be considered either a curse or a theory of atoms based on the mathe- wants to know more about the structure blessing. matics of knots. of fundamental laws. A Beautiful Ques- To Frank Wilczek, it clearly is a bless- A Beautiful Question is a skillfully tion reminds us of the many ways that ing. In A Beautiful Question: Finding written reflection, or “meditation,” as science connects to the arts, and it in- Nature’s Deep Design he highlights the Wilczek puts it. It is well structured and vites us to marvel at the success our success of symmetries in physics and accompanied by many figures, includ- species has had in unraveling the mys- goes on to answer the question of ing two inserts with color prints. The teries of nature. whether “the world embodies beautiful book also contains an extensive glos- ideas” with an emphatic “Yes.” Wilczek sary, recommendations for further starts from the discovery of basic math- reading, and a timeline of discoveries Nonlinear Physics of ematical relationships like Pythagoras’s mentioned in the text. Ecosystems theorem (and doesn’t shy away from The content of the book is unique Ehud Meron proving it!) and proceeds through the in the genre of popular works. Dave CRC Press, 2015. $89.95 (344 pp.). Goldberg’s The Universe in the Rearview history of physics, stopping to consider ISBN 978-1-4398-2631-7 such milestone topics as musical har- Mirror: How Hidden Symmetries Shape monies, the nature of light and the Reality (Dutton, 2013), for example, also Many concepts and methods from non- basics of optics, Newtonian gravity and discusses the role of symmetries in fun- linear physics have proved to be useful damental physics, but Wilczek gives for addressing important problems in Sabine Hossenfelder is an assistant more space to the connection between ecology. Indeed, a growing number of professor of high-energy physics at Nordita, aesthetics in art and science. A Beautiful physicists are working with ecologists the Nordic Institute for Theoretical Physics, Question picks up and expands on the and are making significant contribu- in Stockholm. She works on physics beyond theme of Steven Weinberg’s book, tions to ecology. Pattern formation and the standard model and on quantum- Dreams of a Final Theory (Pantheon, spatial ecology—how those patterns are gravity phenomenology, and she blogs 1992), which also expounds on the rel- related to ecological phenomena—are at http://backreaction.blogspot.com. evance of beauty in the development of particular research areas that benefit 46 October 2015 Physics Today www.physicstoday.org This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 164.73.83.101 On: Thu, 01 Oct 2015 22:06:59 from the interdisciplinary inter- pose is to fill that gap; in ecological problems presented in the actions. For example, field ob- essence, part two is the book’s first part, including desertification and servations of vegetation pat- nucleus. The author presents biodiversity loss in changing environ- terns in arid and semiarid basic and advanced methods ments. I enjoyed reading the two final regions have revealed patterns related to the main types of chapters—11 and 12—which cover similar to ones found in fluid pattern formation mechanisms. topics I have been working on, namely, dynamics and nonlinear optics. Among the plethora of struc- regime shifts, desertification, and Any book that attempts to tures are stripe and hexagonal species coexistence and diversity in bridge ecology and nonlinear patterns, scale-free patterns, plant communities. Particularly well physics would be welcomed by scien- and spiral waves. done were the discussions on different tists who work at the intersection of The third part considers different early warning signals of regime shifts both fields. In my own work, I have col- applications of pattern formation the- and their spatial aspects. I enjoyed the laborated with ecologists to develop ory to spatial ecology. The author ex- explanation of species coexistence in- quantitative methods and models to plains the significance of self- organized duced by plants that act as ecosystem address biodiversity dynamics and vegetation patchiness to paramount engineers by modifying their physical spatiotemporal early warning signals of catastrophic shifts in ecosystems. I have also taught courses for mixed audiences of agronomists, ecologists, NEW VERSION and physicists. I was greatly impressed by the vari- ety of topics covered in Ehud Meron’s Nonlinear Physics of Ecosystems and by the depth in which they are discussed. The author’s introduction to each topic is clear, and the book’s overall organiza- tion makes it easily readable. At the be- ginning of each chapter is an outline of the major points treated, and at the end, a summary of the key ideas that were developed. The bibliography is exten- sive and comprehensive. I found few omissions. The most significant one would be James Murray’s classic text Mathematical Biology II: Spatial Models and Biomedical Applications (Springer, 2003), which, although it does not focus on spatial ecology, has substantial over- lap with this book. Nonlinear Physics of Ecosystems also contains many figures and photos that help readers to visual- ize spatial patterns in real eco systems. All that makes Meron’s book an im - portant reference, particularly for re- searchers of spatial self-organization and spatial ecology.