Intelligent Life Among The Stars?

Press, Volume CV, Issue 31047, 30 April 1966, Page 4

Intelligent Life Among The Stars?

We Are Not Alone. By Walter Sullivan. Hodder and Stoughton. 291 pp. Index. Is there intelligent life elsewhere in the universe, or is man unique? This has perplexed man from the dawn of civilisation, and in “We Are Not Alone,” Mr Sullivan gives what is probably the best contemporary account of the problem. Many scientists today, and Mr Sullivan himself, firmly believe that intelligent life does exist elsewhere in the universe, and from a careful consideration of the facts presented in this book, the conclusion seems to be inescapable. Inquires into the possibility of extra-terrestrial life frequently degenerate into a mixture of fact and unsupported belief, but Mr Sullivan carefully avoids such a fruitless procedure. His method, the only 'satisfactory one, is to present all the relevant scientific data, together with the opinions and theories of reputable scientists. The result is an impressive, stimu-

lating and immensely readable book. Walter Sullivan is science editor of the “New York Times” and one of the foremost journalists in the United States. He is also one of the few men capable of explaining the complexities of modern science to the layman, and as such, he has earned the confidence and respect of scientists all over the world. Having given a brief history of man’s varying conceptions of the universe. Mr Sullivan proceeds to examine the implications of our present view. The first pre-requisite for the existence of life (in any conceivable form) is a suitable planet. With this in mind, the question of whether planetary systems are common or scarce, whether our solar system is the exception or the rule, is considered, together with the related problem of the origin of planetary systems. The suitability or otherwise of different star-types for supporting life is also examined. Mr Sullivan carefully points out the paucity of our knowledge in these areas before concluding that planets capable of supporting life are, in all probability, quite common. The question of whether living organisms evolved or were created is of major importance. The traditional belief is that life was created, but modern developments in science, and the creation of some of the basic molecules of life, have given support to the evolutionary theory. If living cells can be synthesised, it might indicate that life would evolve on any planet where the chemical

environment was suitable. But some researchers believe that the probability of complex life forms evolving, even in a favourable chemical environment, is very low, in which case intelligent life would be comparatively rare in the universe. It has been calculated that 1000 or more visitors from space arrive on our planet every year. These are meteorites, and in recent years some of them have been subjected to careful analysis in an attempt to find indications of life in them. Of particular interest are the extremely rare carbonaceous chondrite meteorites. These are rich in carbon compounds, and they respond to analysis in much the same way as humus, the mixture of decayed vegetable and ani-

mal matter that enriches our soil. But the question of whether it is. in fact, humus or some other mixture of organic compounds is hotly debated. A search for radio signals transmitted by intelligent beings on other worlds has been undertaken in recent years. A pioneer attempt was Project Ozma, carried out at the National Radio Astronomy Observatory at Green Bank, West Virginia, in 1960 The search was concentrated on two stars which seemed likely candidates, Tau Ceti and Epsilon Eridani, both of which are about 11 light years away. Although this is very close by interstellar standards, a radio signa! travelling at the speed of light (186,000 miles a second) would take about 11 years to reach the Earth from either of them, with the result that if contact was established, attempts at Intelligent “conversation” would have to proceed at an extremely leisurely pace. Mr Sullivan’s book is systematic and comprehensive throughout. It is an excellent exposition of one of the most fascinating searches ever undertaken by science, and many readers will echo the author’s concluding words: “The universe that lies about us, visible only in the privacy, the intimacy of night. Is incomprehensibly vast. Yet the conclusion that life exists across this vastness seems inescapable. We cannot yet be sure whether or not it lies within reach, but in any case we are a part of it all: we are not alone!"