Short Book Reviews

There’s now a fairly long list of books that I’ve found worthwhile recently and wanted to write about here, making it unlikely I’ll have time to write in detail about them. Instead, here are some short reviews:

• More than seven years ago I wrote very critically here about Leonard Susskind’s The Cosmic Landscape. That book struck me as embodying the worst aspects of where string theory has ended up, promoting to the public in a high-profile way a dangerously pseudo-scientific excuse for string theory’s failure. Debate about the anthropic landscape has now been going on for nearly a decade, with mixed results. This ideology still has its believers and gets taken seriously, but I think it’s fair to say that interest has dwindled as it has become clear that no one has a serious idea about how to use it to make any kind of scientific prediction. For both proponents and opponents, it’s now old news, hard to get interested in talking about, especially since the lack of any evidence (pro or con, now or forever) seems guaranteed.

  Luckily for all of us, Susskind has moved on to much more promising topics. He has a new popular book out which is quite good, entitled The Theoretical Minimum. It’s basically a textbook on classical mechanics, written at a level appropriate for someone who has had a calculus class, but not necessarily any more physics or mathematics than that. The style is breezy and colloquial, with lots of nice explanations of some of the basic concepts of physics. It’s wonderful to see Poisson brackets appearing and nicely explained in a popular book destined to be displayed at bookstores everywhere.

  The book is based on one of several series of lectures given by Susskind as part of Stanford University’s Continuing Studies program, all of which are available on video at YouTube (see here for a list). The writing of the book is a joint effort of Susskind and George Hrabovsky, who started the project of turning Susskind’s lectures into book form.

• While selling popular books with equations in them is a new concept in the US, it’s not so unusual in France. When last in Paris I picked up a copy in a non-scientific bookstore of Cédric Villani’s Théorème Vivant, which includes equations I can’t even follow. It’s basically a fascinating journal he kept during 2008-2011, focused on a problem he was working on during this period with his collaborator Clément Mouhot. It provides a good picture of what it’s like to be a top-class analyst working on a difficult problem. During this period, Villani was very much aware that he might be a candidate for a Fields Medal, which provided some motivation for him to push forward. If you want to know what it’s like to really want a Fields Medal, to work hard to get it and succeed, this is the book for you.

  A large part of this work took place during a year when Villani was holed up at the Institute in Princeton, and this is described in detail. Difficult working conditions included lack of access to good bread or cheese, a major reason Villani turned down efforts by Princeton to keep him there and returned to France, where he is now Director of the Institut Henri Poincaré in Paris. He also maintains a blog here where you can keep up with his activities.

• Steven Weinberg’s Lectures on Quantum Mechanics is based on graduate-level quantum mechanics courses he has taught over the years. It covers concisely and well most of the standard topics that are make up a quantum mechanics course at this level (this is definitely not a beginning QM book). It does differ from most QM books though in providing a high-level and serious discussion of the question of interpretations of quantum mechanics, a topic about which Weinberg has thought deeply. After explaining carefully the issues, he ends up with:
  

  My own conclusion (not universally shared) is that today there is no interpretation of quantum mechanics that does not have serious flaws, and that we ought to take seriously the possibility of finding some more satisfactory other theory, to which quantum mechanics is merely a good approximation

  I fear I’m with those who don’t share this conclusion, but his arguments are well-worth paying attention to. For someone else who has thought deeply about all this, and come to conclusions closer to my own less well-considered ones, see this recent blog entry by John Preskill (don’t miss the discussion in the comments).

  The book ends with a modern but very short chapter on entanglement, Bell inequalities and quantum computation.

• I’ve recently gotten a copy of a wonderful new quantum field theory textbook, Anthony Duncan’s The Conceptual Framework of Quantum Field Theory. It’s a long, fat book, packed with material that doesn’t appear in other QFT books. Most modern QFT books stay focused on the goal of writing down the Standard Model and giving the details of how to do perturbative calculations in the theory. Duncan instead devotes most of the book to a careful investigation of the basic issues raised when one works with a theory of quantized fields and tries to understand exactly how such objects are connected to the particle states and their scattering that we see in the real world.

  Besides the close attention to thorny conceptual problems normally glossed over, Duncan also gives a long discussion of the early history of the subject, a time in which the conceptual problems were being thought about by the leading figures in the field. Probably every one who has learned quantum field theory in one way or another could benefit by going through this book and picking up some insight into all the questions that were ignored in whatever other book they learned the subject from.

• Finally, for those already fluent in quantum mechanics and quantum field theory, there is Mikhail Shifman’s Advanced Topics in Quantum Field Theory, published last year. It concentrates on methods for understanding the non-perturbative behavior of QFTs, especially gauge theories. A major topic is semi-classical methods and the art of extracting non-perturbative information about the QFT from interesting solutions to the classical equations of motions (e.g. instantons and solitons). The latter part of the book focuses on supersymmetric theories, where supersymmetry can be used to get further insight into the non-perturbative behavior. In recent years, much of the research interest in SUSY has moved away from the idea of using it for Beyond Standard Model physics (a trend likely to accelerate with the failure of SUSY to show up at the LHC), and towards thinking of it as a tool for studying QFTs. Shifman’s book gives a good introduction to the basic examples of how this works.

Update: Lev Okun sent me a copy of his ABC of Physics: A very brief guide. It’s a remarkable document, managing to cover all of fundamental physics in about 120 pages, from the simplest topics in high school physics to the Higgs and superstring theory (the latter treated with appropriate skepticism). If you want an overview of the subject that is as short as possible, this is for you.