In his first book ever, the father of string theory reinvents the world's concept of the known universe and man's unique place within it. Line drawings.
As modern physics has developed a better understanding of how the universe operates at its most fundamental levels, one thing has become increasingly clear: we're damned lucky to be here at all. The laws of physics are precariously balanced, and were the value of one constant slightly different, life as we know it wouldn't exist. To explain the ridiculous improbability of it all, some physicists have turned to the "Anthropic Principle": the universe seems perfectly tailored to us because if it weren't, we wouldn't be here to observe it. The underlying rationale for this argument involves the "landscape" of potential laws of physics (which, it turns out, aren't so immutable after all), a whole bunch of extra dimensions and lots of particle physics. Luckily, Susskind the father of string theory does the job right, guiding readers through the current controversy over the Anthropic Principle. Make no mistake: this is the cutting edge of physics as described by one of the sharpest scientific minds around. While the subtitle is a bit misleading (this isn't about intelligent design in the Kansas Board of Education sense, but actually a controversy at once bigger and less prominent), persistent readers will finish this book understanding and caring about contemporary physics in ways both unexpected and gratifying.
A clear if not somewhat redundant discourse.
The breadth of plain language examples is easy to follow. However, the number of examples got a little tedious.
Unnecessarily Incomprehensible Due to Poor Use of Language
No-one doubts Professor Susskind’s brilliance as a physicist, but his flaws as a writer and/or philosopher of language make this book, and his main thesis, much harder to understand than necessary. My first recommendation, which I wish I’d known enough to follow, is to read the Note on Terminology and the glossary, at the end of the book, _first_. That might make it easier to follow his deliberate misuses of ordinary English. (I think I at least meet the minimum requirements for this book; I didn’t end up as a physics major, but did reasonably well in undergraduate quantum mechanics and philosophy of quantum mechanics, and graduate electrodynamics.) But even so, note that the glossary does not define some key terms, such as “universe,” though he does define “pocket universe” in terms of it.
In particular, I’m still not sure when, and with what term, he’s talking about our universe in what I think is the normal use of the term, i.e. a contiguous volume of space in which the laws of physics (in the normal sense) are constant. He does warn us that he’s violating normal usage when he says “The Laws of Physics are determined by the environment.” I’m not sure if he’s deliberately violating it when he writes “But as we move through the Landscape,” or is simply being sloppy with “move.” And any discussion of any aspect of existence is rendered less clear by his early declaration that “… mean by the term exist is that the object in question can exist theoretically.”
There are genuine extreme realists about the existence of other universes, not normally accessible from ours, and with different physical laws, e.g. some modal logicians, and some who believe that quantum computing’s supposed power relies on computations performed partly in those other universes. Such a belief is also helpful for some versions of the Anthropic Principle. I still can’t tell whether Professor Susskind agrees with them.