## Warped Passages - Lisa Randall

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**Aug. 11th, 2008 | 08:28 am**

"Every now and then a man's mind is stretched by a new idea or sensation, and never shrinks back to its former dimensions." (O.W. Holmes, Sr. 1858)

Holmes would, I think, have agreed that this book is a provider of such mind-stretching ideas. Here you'll find an excellent discussion of some of the more radical new ideas from the model-building camp of theoretical physics. Taking ideas of higher dimensions and branes borrowed from string theory, Prof. Randall and co-researchers have produced interesting models of physics in which the extra dimensions of string theory are shown to not all necessarily be miniscule curled-up planck-scale regions beyond experimental probing. She demonstrates possibilities for larger additional dimensions the existence of which might be experimentally verified when the Large Hadron Collider swings into action, and alternative possibilities to supersymmetry for unification of the forces of nature.

There's not very much cosmology in this book. It mainly concentrates on spatial geometry, particle physics, quantum field theory and the (possible) relationships between them. Of course the obligatory explanations of relativity, quantum mechanics and the standard model of fundamental particles and forces, all de rigueur for any pop science tract, comprise the first half of the book.

Don't be fooled by the reassuring commentary by newspaper reviewers on the cover about how this book is 'remarkably clear'. No journalist wants to admit that they can't make head nor tail of a 'pop' science book. Though Randall steers clear of mathematics there are many abstract concepts in this book that are not at all easy to grasp, especially the idea of non-spatial symmetries and symmetry breaking. 'Remarkably clear' is a very relative term here - in that, given the inherent difficulty in explaining these subjects to the uninitiated, yes, she's done a great job; but that doesn't mean it's easy-going or accessible. In fact I would have preferred more mathematics to give a structure to hang the conceptual understanding on and give it shape - without the maths there are parts of the book that come across as a formless mass of phrases like 'inter-brane communication of symmetry breaking' - OK, I have a grasp of the ideas of symmetry and broken symmetries and branes but I can't see how or why symmetry breaking can or needs to be 'communicated' - I sort of imagined it was something that happened spontaneously, as in the well-known theoretical physics phrase 'spontaneous symmetry breaking'. But when you bring maths into a book you are always faced with the question 'Where do I start? How much do my audience know already?' so I can understand her reasons for avoiding mathematical descriptions.

I liked her sections on the Standard Model which go into more detail than Brian Greene's books. I think this book was tougher going than his books 'The Elegant Universe' or 'The Fabric of the Cosmos'. This is partly because Greene, I think, is slightly more adept at the use of analogies, and partly because Randall goes into more depth because this book is more specific in its focus than his works.

Lisa Randall has actually made a very brave move in publishing this work, because her conjectures might be disproved or at least thrown into doubt by the results of LHC experiments (whereas - contrary to what some people on the interweb seem to believe - string theory as a general concept will neither be proved nor disproved because the LHC doesn't probe anywhere near the energy scales needed to do so conclusively). More power to her elbow for doing so.

Holmes would, I think, have agreed that this book is a provider of such mind-stretching ideas. Here you'll find an excellent discussion of some of the more radical new ideas from the model-building camp of theoretical physics. Taking ideas of higher dimensions and branes borrowed from string theory, Prof. Randall and co-researchers have produced interesting models of physics in which the extra dimensions of string theory are shown to not all necessarily be miniscule curled-up planck-scale regions beyond experimental probing. She demonstrates possibilities for larger additional dimensions the existence of which might be experimentally verified when the Large Hadron Collider swings into action, and alternative possibilities to supersymmetry for unification of the forces of nature.

There's not very much cosmology in this book. It mainly concentrates on spatial geometry, particle physics, quantum field theory and the (possible) relationships between them. Of course the obligatory explanations of relativity, quantum mechanics and the standard model of fundamental particles and forces, all de rigueur for any pop science tract, comprise the first half of the book.

Don't be fooled by the reassuring commentary by newspaper reviewers on the cover about how this book is 'remarkably clear'. No journalist wants to admit that they can't make head nor tail of a 'pop' science book. Though Randall steers clear of mathematics there are many abstract concepts in this book that are not at all easy to grasp, especially the idea of non-spatial symmetries and symmetry breaking. 'Remarkably clear' is a very relative term here - in that, given the inherent difficulty in explaining these subjects to the uninitiated, yes, she's done a great job; but that doesn't mean it's easy-going or accessible. In fact I would have preferred more mathematics to give a structure to hang the conceptual understanding on and give it shape - without the maths there are parts of the book that come across as a formless mass of phrases like 'inter-brane communication of symmetry breaking' - OK, I have a grasp of the ideas of symmetry and broken symmetries and branes but I can't see how or why symmetry breaking can or needs to be 'communicated' - I sort of imagined it was something that happened spontaneously, as in the well-known theoretical physics phrase 'spontaneous symmetry breaking'. But when you bring maths into a book you are always faced with the question 'Where do I start? How much do my audience know already?' so I can understand her reasons for avoiding mathematical descriptions.

I liked her sections on the Standard Model which go into more detail than Brian Greene's books. I think this book was tougher going than his books 'The Elegant Universe' or 'The Fabric of the Cosmos'. This is partly because Greene, I think, is slightly more adept at the use of analogies, and partly because Randall goes into more depth because this book is more specific in its focus than his works.

Lisa Randall has actually made a very brave move in publishing this work, because her conjectures might be disproved or at least thrown into doubt by the results of LHC experiments (whereas - contrary to what some people on the interweb seem to believe - string theory as a general concept will neither be proved nor disproved because the LHC doesn't probe anywhere near the energy scales needed to do so conclusively). More power to her elbow for doing so.