Lenny The Plumber

Leonard Susskind is a noted theoretical physicist who is one of the founding fathers of string theory and who has contributed important ideas to particle physics and quantum gravity. He also has a somewhat unusual CV, having spent five years working as a plumber before entering graduate school.

When I bought his book, The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics, I didn't really have very high hopes for it. For one thing, there was the title - just a bit too self-congratulatory. For another, I had read some of his quotes on string theory, and they seemed redolent of string chauvinism.

I am happy to say that these fears proved quite unfounded. To be sure, he isn't a prose stylist at the same level as some other physics popularizers, and he does have this sometimes annoying chip on his shoulder - repeatedly giving into the temptation to dis other physicists: "Einstein pompously declared..." Actually though, it's rather Feynman and Gell-Mannish - less amusing than Feynman but not quite as creepy as Gell-Mann, and can be seen as an almost endearing tough kid from NYC act.

These flaws are minor, though, compared to the book's great virtues. Susskind has a very deep, clear, and pictorial way of describing how nature works - he is a superb explainer. He is a big fan of the crucial thought experiment, and describes some of the notatable such in the history of physics, including several of his own. This is very natural to my own way of thinking, though, of course, to be useful, these thought experiments have to be coupled with some calculation - not my forte.

The central theme of the book is Hawking's black hole information loss puzzle - the notion that the unitarity of the S-matrix is destroyed when matter falls into a black hole and the BH subsequently radiates its energy. This bothered the heck out of Susskind, who saw that it gave birth to even more disturbing paradoxes in our attempt to make sense of the Universe. Relatively few of his colleagues were equally bothered, Gerhard 't Hooft being the most prominent exception.

The resolution of this paradox leads by strange paths through black hole complementarity, string theory, and the holographic principle. I have to say that I consider the successful resolution to be the strongest argument for string theory that I have heard yet. Strings, it seems, not only explain much of the strange goings on near the BH horizon, but do so quantitatively, at least for some intriguing special cases.

Because Susskind is writing for the general audience, large portions of the book are devoted to explaining things that are very familiar even to physicists who know little about string theory or black holes. This part is not as wasted as I expected. Looking at the familiar through the eyes of a deep thinker can be a revelation even if you were sure you understood that all along.

Highly recommended to those interested in black holes, string theory, Hawking's puzzle, and how the deep down things really work. It's also a good look into the head of an original and deeply insightful thinker.