Aliens: Can We Make Contact with Extraterrestrial Intelligence?
by Andrew J H Clark and David H Clark
Fromm International, $25.00, ISBN 0880642335
This book is by a father (David) and son team who, between them, possess expertise in astronomy, physics and philosophy. It starts well, with a prologue full of marvellous withering scorn for the alien abductions and other nonsense surrounding the subject. There is, the authors say, no certain evidence that extraterrestrials have ever visited Earth, and the rest of the book, making clear the vast distances there must be between intelligent species, if indeed there are any others, demonstrates why this is almost certainly so. And that is a big ‘if ’: there is a nice illustration of the fallacy of the “in the vastness of the universe there must be other intelligent beings” argument with an analogy with a shoe shop offering 12,000 pairs.
The authors admit that no definitive evidence of extraterrestrial intelligence (ETI) has been found, but emphasise how small the effort to find it has so far been. They illustrate the vastness of the task with another nice analogy, on how long it would take to ask everyone on Earth their cola preference – at 10 seconds per person, all day every day – 1,000 years! But that would be only 1.5% of the challenge of surveying every star in the Galaxy. The McCrea Question (“If life in some elementary form that we know about is available on every planet in the cosmos, what is the chance that creatures like humans will evolve elsewhere?”), and the Fermi Question (more usually called the Fermi Paradox – if there are intelligent beings elsewhere why do we see no evidence of them, given that some might be expected to be much more advanced than us and therefore to have developed interstellar travel, or as the Clarks put it more economically: “If they are there, why aren’t they here?”) are naturally discussed. The book ends with an epilogue, glossary, bibliography, and advice on how to become a SETI scientist.
