Superstrings: A Theory of Everything? (Canto) [Englisch] [Taschenbuch]

The book starts with the best crash-course I have read of modern physics. In just 60 pages, you are introduced to supersymmetry, relativity theory, quantum mechanics, particle physics, superstrings, and other conceptual issues. The main body of the book however, involves interviews with various physicists concerning superstrung theory. Green, Gross, Witten, Feynmann, Salam, weinberg among others all give their points of view of this putative "theory of everything". They talk about the structure of the theory, its limitations in experimentation, its main obstacles, and their personal views of what lies in the future for superstrings.

Some main issues come up regularily, like the multidimensional aspect of the theory, the fact that there are various diferent superstring theories, and issues on topology. Unfortunately this was before some very interesting results that clarify some of these issues. For example, Calibi-Yau spaces were not in the spotlight, as they currently are. Also, all of this is pre "M-theory". That is, the 5 kinds of theory described (E8*E8 for example) are now linked through "M-theory", so there is no real problem of unification anymore (aty least one could see how it comes together, but this issues are still controversial).Also, current theories sometimes use 11 dimensions, whereas in the book 10 dimensions seemed to be the standard. Holographic principles could also enlighten some of the discussed problems in the book.

Another great aspect of the book is that it includes internal critics as well. Richard Feynmann for exaple, does not feel superstring is going to save physics, and does not share the same kind of enthusiasm as say, Edward Witten. The main points are the fact that superstring theory is so far from being directly testable (PLank lenght experiments would require 10 light year long particle accelerators!), and other philosophical issues. Of course, there is circunstancial evidence, but some see that superstring theory resembles pseudo-science in not being directly testable. This is certainly an issue.

Wether theory of everything or not, superstring theory is here to stay, so one might as well read this book to get a larger scale view of the field, before reading more modern or popular texts.

But there is a limit to what you can do in words to convey mathematical ideas. A book on physics with no mathematics at all CAN work if the subject treatment is broad rather than deep, and good metaphors employed. By contrast, the focus of this book is narrow and shallow. There is no mathematics, and not too many metaphors to help us bridge the gap. Plus, on occasion, the interviewees sound pompous and patronizing. A major part of the problem seems to be that the interviews are mostly statements of personal position on the nature of strings, and personal role in their development, rather than an attempt to educate. Anyhow, I was left hungry and disappointed that I had not learned more.

I recommend the introduction (70-pages - presumably by Davies). It is a very well written and educative layman's survey of modern physics leading up to strings. The book may be worth buying just for that.