This book tackles a large question in cosmology: Is the Universe designed for life? To which I am tempted to add my own query: is that question posed with sufficient clarity to inform rational inquiry? Carlos Calle believes it is. He is a research physicist at the Nasa Kennedy Space Center, and the author of three popular books on relativity and particle physics. This account traces our attempts to understand the Universe from Babylonian times to the present day.
The author sets the scene by reviewing the historical background. Although the technical content is explained clearly, I found myself distracted by a number of slips that should have been caught in copy editing. "If, as Augustine said two centuries ago ..." is the surprising opening to the section titled "What about God?"; and Galileo's major experiments in mechanics were actually performed in Padua rather than Pisa. Meanwhile the father of Big Bang cosmology, Georges Lemaitre, is correctly spelled on p21, but becomes Lamaitre for the rest of the book.
Fortunately the author redeems the situation when he gets into modern times, where his talent for explaining difficult physics to a lay readership shines through. By turns he introduces the major breakthroughs in 20th-century astrophysics: the discovery of the cosmic microwave background radiation, a fossil from the hot Big Bang; the startling inflationary theory of the Universe, in which its extent doubled 100 times in almost no time at all; confirmation that unseen dark matter outweighs visible matter by a factor of ten or more in clusters of galaxies; and the realisation that six billion years ago the expansion of the Universe began to accelerate in a cosmic jerk in which mysterious dark energy made itself felt as a version of anti-gravity. In addition to astrophysics, Calle introduces the fundamental aspects of sub-atomic physics, as well as good descriptions of attempts to unify the four forces of nature.
By assembling a mass of evidence from physics and astrophysics, the author is in a position to ask if the Universe is fine-tuned for the origin of life. This is actually an old question, but it has become a pressing issue because the former large uncertainties in the value of cosmological parameters have now been eliminated. The arrival of precision cosmology has fuelled the growth of the intelligent design bandwagon, the movement that uses probabilities to claim that our Universe had a supernatural creator.
Calle tackles intelligent design with some flair by invoking the latest cosmological models that arise from string theory, which suggests that our Universe may be just one among an unimaginable number of universes, each of which has its own set of physical laws. This, of course, turns the probability argument on its head: yes, life is improbable, just as winning the Lotto jackpot is improbable, but jackpots get won, and life exists somewhere if we posit endless cycles of universe creation or we accept the multiverse concept where we can have as many universes as we please in order to get one that is lively.
This account is outstanding in terms of setting out the issues objectively, and thus allowing readers to reach their own conclusions. Those who reject intelligent design are in good intellectual company: Pierre-Simon Laplace famously said to Napoleon, "I had no need for that hypothesis". There is plenty of food for thought in this book.
The Universe: Order Without Design
By Carlos I. Calle
Published 30 June 2009