Thursday, September 3, 2009 1:29 PM

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Uva's Science Book Reviews

Rereading a few good books should at times take priority over reading new ones.

Are We Alone? Philosophical Implications Of The Discovery Of Extraterrestrial Life

Paul Davies

Basic Books 1996

The author of this well-written book is Paul Davies, an Arizona State University physicist who is also the director of BEYOND. Through workshops and research programs, BEYOND tackles fundamental questions that still lack definitive answers: How did the universe come to exist? Is ours the only universe? Why are the laws of physics suited for life? Why is nature mathematical? How did life begin?

In this book, he addresses the popular question about whether life has relatives beyond the boundaries of our planet. He argues that finding extraterrestrial life would be at least as momentous as the 16th century realization that the earth is not at the universe’s centre.

There have been, however, three major arguments against the existence of intelligent life elsewhere in the universe:

  1. The creation of life only occurs towards the end of a solar system’s evolution, making the window of opportunity very narrow.
  2. Fermi’s “Where are they?” argument about how the earth is much younger than the universe. This would have given alien intelligences ample time to spread and flourish elsewhere.
  3. The Neo-Darwininian contingency argument that intelligence is just one of a multitude of life’s adaptations and basically a fluke.

But for each viewpoint, Davies presents some strong counterarguments. Unfortunately, in spite of many efforts, no evidence of alien intelligence has surfaced yet.

Is there at least evidence for microbial life elsewhere in the universe? While my wife was attending the University of Hawaii in the fall of 1996, I attended a public lecture on the possibility of life on Mars. A meteorite of Martian origin ALH 84001 had been found in Antarctica in 1984, and in August of 1996 NASA held a press conference about the presence of polycyclic aromatic hydrocarbons and how it suggested that there was once microbial life on Mars. The U of Hawaii professor, like several other scientists, was sceptical because he felt that the microfossils in the stony meteorite were far too small to be living cells. As Paul Davies points out, since then, nanobacteria that are similar in size to the suspected fossils in the meteorite have been discovered. The debate is ongoing because there is still the possibility that the hydrocarbons could have been formed by inorganic processes. Although it may be farfetched I like Davies’ suggestion that life could have hitchhiked from Earth to Mars after a large meteor impact and then could have returned via a similar route.

Davies writing also exposes the reader to intriguing ideas about life’s origins such as those of Stuart Kauffman discussed in At Home in the Universe. He argues that before natural selection has a chance to act as an architect in shaping life, there are self-organizing principles at play. Self-catalyzing networks could be common preparatory stages for the origin of life, increasing its likelihood. Similarly, the other organizing principles may be responsible for life’s complexity.