Monday 27 January 2014

The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory - Brian Greene (1999, 2003 with new preface)

Calabi-Yau shapes in action

One of the rotating quotes on Brian Greene’s website states that: “Brian Greene is the new Hawking, only better.” This quote comes from the Times, but what do they mean by better? Is Greene better at popularizing difficult physics concepts, or is he simply a better scientist? In any case The Elegant Universe is certainly well written and stands as a fine popular science text for the curious to begin to understand string theory. Greene does a fine job of explaining both the history of the theory, its principle concepts and its potential to be the long sort after theory of everything. String theory has its origins in the late 1960’s, but really came to the fore as a significant theory in the 1980’s. String theory posits that the smallest fundamental bits of nature are not particles, but are in fact tiny vibrating strings of energy. Intrigued? Then The Elegant Universe is the book for you. 

One of the great things about The Elegant Universe is that before you get to the chapters that focus on string theory Greene presents an overview of some of the major theories and discoveries in physics. I’ve read many quality physics books about Einstein’s special and general theories of relativity and also quantum theory, but I was particularly impressed with Greene’s ability to explain tricky concepts with well chosen analogies. Greene’s overview of the weird world of quantum mechanics, including Heisenberg’s uncertainty principle, wave particle duality, and quantum tunneling, is particularly impressive. 

Greene’s thorough explanations of the principles of both relativity and quantum physics lead to a detailed and complex explanation of string theory. Greene makes it clear why string theory is, at the moment, the best candidate to reconcile the problems of uniting relativity and quantum theory. Perhaps the most fascinating aspect of string theory is how it convincingly suggests that there are other dimensions curled up as small as the Planck length. Things get really tricky when Greene takes you through extra dimensional curled up Calabi-Yau shapes. However Calabi-Yau shapes are nothing compared to the sections dealing with space tearing flop transitions, which is a specialty of Greene’s. But wait, you then have your mind blown by the second superstring revolution in the form of M-theory. Phew! Are you totally put off the idea of reading this book? Don’t be, it might be important for you to know what a flop transition is one day, and Calabi-Yau shapes? Your arm just passed over a few trillion a moment ago.

The argument for string theory as the ultimate theory of everything is certainly compelling, however lurking in the background is the problem that unlike relativity and quantum theory, string theory is extremely difficult to test experimentally. Greene does acknowledge this problem and devotes a whole chapter to the issue. The Elegant Universe was first published in 1999 and since then the Large Hadron Collider has been built and used successfully to find the so called ‘god particle,’ the Higgs Boson, which is a massively significant achievement. However the collider is yet to turn up any evidence of extra dimensions or supersymmetry particles, both of which would give string theory a massive boost of credibility. At the moment the Large Hadron Collider is undergoing upgrades to make it even more powerful. Will Greene be updating The Elegant Universe in a few years time following the great news that string theory has been verified? Just how string theory theorists will be regarded in the future compared to such giants as Heisenberg, Einstein and Bohr may depend upon it. String theory does have many supporters, such as Hawking, but it also has its fair share of detractors and until there is some experimental proof it runs the risk of losing ground as other avenues are pursued. Personally Greene has convinced me of string theory’s worth, but I just hope that’s he’s right about the integrity of those space tearing flop transitions, otherwise we are all really in trouble.

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