Book review: "Impossibility" by John D. Barrow

Impossibility: The Limits of Science and the Science of Limits
John D. Barrow
Oxford University Press (1999)

In his book "Impossibility: The Limits of Science and the Science of Limits" John Barrow has carried together everything that sheds light on the tricky question what is possible, practically as well as conceptually. It is an extensive answer to the question of FQXi's 2009 essay contest "What is ultimately possible in physics?" but takes into account more than just physics. Barrow also covers economical, biological and, most importantly, mathematical aspects of the question what we can and can't do, what we can and can't know.

The book discusses paradoxa, timetravel, computabily, complexity and the multiverse, though Barrow never uses the word multiverse. The book was written somewhat more than a decade ago, but the summary of eternal inflation and bubble universes, varying constants and the question if it is still science to speculate about something that's unobservable is timely, and Lee Smolin's cosmological natural selection also makes an appearance. Barrow does mention some of his own work (on varying constants and universes with non-trivial topologies) but only in a paragraph or two.

Barrow briefly introduces most of the concepts he needs, but I suspect if you don't already have a rough idea what cosmology and quantum mechanics is about, some sections will not make a lot of sense. He mentions for example the many worlds interpretation in the passing without ever explaining what it is, and has the possibly shortest explanation of inflation and the expanding universe I've ever seen. But if you've read one or the other book that covers these topics you might (as I) be relieved Barrow keeps it short.

The presentation is very non-judgmental. Barrow essentially goes through all aspects of the issue and reports who has contributed what to the discussion, without imposing an opinion on the reader. He also gives an interesting historical perspective on how our view on these questions has changed esp. with Gödel's contributions. However, the writing reads more like a review than a book in that it lacks a narrative, and Barrow also doesn't offer own conclusions, he just summarizes others' arguments. I don't mind so very much about the lack of narrative since I have grown a little tired by the current pop sci fashion to make up a story around the facts so it sells better, but I'd have expected some original thoughts here or there. It is also unfortunate that the book is very superficial on some topics, for example time travel and free will, and if you know a little about that already you won't hear anything new. On the other hand, if you just want a flavor and some references for further reading, Barrow does a good job. I ceartainly learned about some aspects of the possible and impossible that I hadn't thought about before.

Barrow's book is well structured with a summary at the end of each chapter and a final summary in the last chapter. This is very convenient if you put the book down and only pick it up again a few months later and need a reminder what you've already read.

I've been reading for a while on this book. Since 2008 in fact, if I believe the receipt. The reason it took me so long has very little to do with the actual content of the book which, now that I managed to finish it I like very much, and more mundanely with the representation of that content. The book is printed in tiny and in addition the print is crappy, so I get tired just by opening it and looking at a page. It has a few illustrations that are very helpful and to the point, but not particularly inspired. There are also a few photos. As you can guess however, Hubble Deep Field in a crappy black and white print on some square inch isn't too compelling, and it's difficult to see the Château in Magritte's Château de Pyrénées.

Taken together, you may enjoy this book if you are interested in a summary of aspects of the possible and impossible, but you would be disappointed if you're looking for an in-depth treatment of any particular aspect. The book is well written, though not very inspired, and the scientific explanations are well referenced and, for all I can tell, flawless. I'd give four out of five stars if I had stars to give.