Bookmarks: Brief reviews of new and overlooked books

The Cosmic Landscape: String Theory and the Illusion of Intelligent Design
by Leonard Susskind
Little, Brown / December 2005, 416 pages, $24.95

If theoretical physicists are among the most intelligent people on the planet — in the history of the planet — it does not necessarily follow that they must be adept communicators. Trying to explain concepts and ideas that only really exist in the Platonic realm of mathematics is one of the trickiest feats possible for a scientist. Metaphor is one of the most basic concepts in human existence, but verbal metaphor can only go so far towards explaining ideas which are properly expressed in numbers — numbers which are themselves metaphors, but metaphors which are hard and precise where words are soft and porous. It’s easy to explain Euclidean geometry in terms of the world around us all, but what about when we get to higher (or lower) frames of reference, where everything we may presume to understand in regards to the physical world around us breaks down?

This is where the imagination of our scientific guide comes into play. Thankfully, while Leonard Susskind is one of the leading theoretical physicists in the world, he’s also very good at explaining these concepts to the rest of us — that is, the vast majority of the world who do not understand advanced quantum mechanics and string theory. Anyone who has ever struggled through Stephen Hawking’s A Brief History of Time knows how frustrating this kind of endeavor can be. Hawking’s book is actually written quite well, but even the best written approach to pop physics is still bound to be a demanding experience for the layman reader. The Cosmic Landscape succeeds quite well without markedly dumbing-down the material (at least not so much as my ignorant self could detect) or losing the reader in clouds of obfuscation. Insomuch as you can hope to understand something as complex as string theory without a background in mathematics, it’s hard to imagine a better guidebook than the one Susskind has provided us.

Mathematicians and their ilk get a bad rap, and in my limited experience it is at least partially unearned. While there are almost certainly distracted and antisocial mad scientists lurking around the corners of academia, some of the best minds in science are also witty and approachable — something that probably comes at least in part from the rigors of having to teach an idea instead of simply comprehending it. To judge by the evidence of this book, Susskind appears to be the kind of eminently knowledgeable raconteur who makes us garden-variety autodidacts look bad. He seems to have an instinctive feel — a skill undoubtedly gained through a lifetime of teaching — for knowing exactly how to mix the hard science with explanatory metaphor and analogy as well as history in just such a fashion as to keep his audience involved at every step of the narrative. The word “narrative” is not too strong here: more than simply an examination of the ideas behind our current understanding of the universe, this is also the story of those ideas, written by a man intimately involved for the past forty years in the discovery and elucidation of those ideas. Although the vast majority of names dropped in this book will be of opaque significance to the vast majority of the world, it is impressive enough that for every significant theory discovered in his lifetime, Susskind has probably sat across a conference table from the person who discovered it at some point in time.

The book begins at the beginning, really, the only possible beginning: “elementary” particles such as those which compose atoms, the type of which we should all (hopefully) remember from high school chemistry. The most brilliant feat in The Cosmic Landscape is how every development in Susskind’s story of physics proceeds logically from a previous development, so that even if we don’t understand the math, the reader still is able to comprehend how the properties of elementary particles can be seen in the properties of immeasurably vast cosmological distances, how the very basic theory of general relativity (which is explained in an extremely cogent manner) led to the creation of modern astrophysics, and the evolution of string theory from Einstein’s quantum mechanics. Of course, the narrative inevitably breaks down towards the end of the book, when the far reaches of modern science simply outstrip the ability of conceptual language to adequately describe phenomena. From what Susskind says it does not appear that there is any rational way to make concepts such as Black Hole Complementarity and the Holographic Principle sensible for a layman audience: both ideas depend on a very basic assumption that the world does not actually operate on the basis of the laws of conventional physics — the conservation of matter and energy is apparently a relative concept, because new matter and energy appear out of nowhere at many points in Susskind’s cosmology, sometimes in outrageous quantities. Short of spending the next decade or more in post-graduate math studies I don’t know if I could ever understand how the universe is actually supposed to be a two-dimensional holograph created out of pixels one Planck-length long. I will have to take his word for that one.

Surprisingly, however, the most important concept in the book is not really a scientific concept at all but a philosophical idea known as the anthropic principle. The notion has created as much furor in advanced physics as the so-called theory of “Intelligent Design” has in biology and anthropology, and for much the same reasons — it is seen by many as a cop-out, an admission of God into the deliberations of science. Essentially, if the universe needs to be so incredibly finely-tuned in order to support life, why do we exist? There must be some concrete reason why the universe — our type of universe, a universe where all the properties of elementary forces and particles are composed just so as to provide for the existence of life — exists as it does, and not in one of a literally infinite number of alternative configurations which would make life (at least carbon-based life such as ourselves) flat-out impossible. One of the great frustrations of physics over the last few decades has been the realization that there is apparently no reason at all why the universe is exactly the way it is. Short of ascribing the situation to dumb luck (which would be statistically absurd), or ceding the problem to a higher power, how do you explain the fact that we exist? The answer is simple enough as to be practically a tautology: we exist because the universe is composed in such a way as to allow us to exist. Modern physics implies the existence of an almost infinite variety of alternative universes having been created and constantly being created in the context of a vast landscape composed of every possible statistical variation, so the existence of a universe containing just the right environment to lead to the formation of galaxies and stars and heavy elements is practically inevitable. It’s not that we’re necessarily special, we’re simply a strong statistical probability. Some scientists still rebel against the notion, branding it essentially unscientific for the very simple reason that it defies any kind of fasifiable experimental analysis — and while this is certainly a valid complaint, Susskind makes a strong argument for the fact that the numbers support this incomprehensibly large megaversal model. What we do know, in other words, strongly implies the existence of what we don’t know, and for the time being that may have to be enough.

It is to Susskind’s credit that he is able to elaborate on such thorny issues without getting bogged down in metaphysical mud. The boundary between physics and metaphysics has traditionally been the province of late-night bull-sessions on college compuses across the globe, but the distinctions have once again become vital to any coherent conception of the universe. There is no need to posit the existence of God — an empirically unprovable assumption if ever there was one — to believe that the universe is still stranger and more mysterious than any human intellect will probably ever hope to understand. From the looks of things, the physicists will be busy for quite some time to come.

Tim O’Neil Amazon

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