A CONSIDERATION OF THE PHILOSOPHICAL ASSUMPTIONS UNDERLYING THE SEARCH FOR LIFE ELSEWHERE
Paul Charles William Davies (born 1946) is an English physicist, writer and broadcaster, who is currently a professor at Arizona State University as well as the Director of BEYOND: Center for Fundamental Concepts in Science. He has written many other books, such as 'The Mind of God: The Scientific Basis for a Rational World,' 'Are We Alone?: Philosophical Implications Of The Discovery Of Extraterrestrial Life,' 'The Fifth Miracle: The Search for the Origin and Meaning of Life,' 'God and the New Physics,' etc.
He wrote in the Preface to this 1995 book, "The question of whether or not mankind is alone in the universe is one of the oldest problems of philosophy, and has deep implications for our world view... I make no attempt at a complete survey of the subjects of exobiology, or the SETI programme as such... Instead, my concern is with the philosophical assumptions that underlie the belief in, and search for, life beyond the Earth, and the impact that the discovery of alien life forms would imply for our science, religion and beliefs about mankind...
"Contrary to popular belief, the possibility of extraterrestrials was often debated, and the ramifications analyzed, in previous ages... My book is an attempt to rekindle this debate, and place it in a modern scientific context, by charting what aspects of contemporary science, and of our belief systems in general, are at stake."
He notes, "It is possible that micro-organisms can survive quite lengthy sojourns in space if conveyed within protective rocks. During the past year or two, microbes have been discovered deep beneath the ground in terrestrial rocks... It is conceivable that life originated deep underground and migrated to the surface only when conditions became favourable." (Pg. 18)
He states, "it is the job of the scientist to try to explain the world without supernatural purposive manipulation, and a number of scientific responses have been made to the problem of the enormous odds discussed above. One of these is to appeal to a larger number of 'trials' to shorten the odds. This lies behind the panspermia theories. If Earthlife did not have to originate on Earth, then there may be trillions of planets on which molecular shuffling is taking place. Given enough planets and enough time, even the most improbable molecular processes will eventually occur somewhere." (Pg. 29)
He cautions, "It is important to realize that the discovery of an alien signal would not lead rapidly to radio dialogue between our civilizations. The nearest star is over four light years away. Even on the most optimistic assumptions, the probability of an alien civilization existing within 100 light years of Earth is remote. A message from aliens 100 light years away would take 100 years to reach us, and any reply would take another 100 years to get back to them. It would take some centuries before any concept of a two-way period of adjustment during the early phase, before such a dialogue, when we would need to evaluate the consequences of contact without the benefit of a meaningful exchange." (Pg. 41-42)
He argues, "It is important to realize we cannot use the fact that we exist to argue that the formation of intelligent life is probable, any more than the winner of a lottery can argue that most punters will be successful. However improbable intelligent life may be a priori, the fact is that we DO exist. From that starting point we may reason that whatever improbable steps may be necessary for the formation of intelligent life, those steps must have happened once. It does not follow that they must have happened more than once." (Pg. 64)
On the notion that we might send "supercomputers" into space, he observes: "the recent failure of the Mars Observer mission underscores how vulnerable technology is in space. The assumption that a man- (or alien-) made machine could operate flawlessly over millions of years in a hostile environment stretches credulity." (Pg. 72)
He suggests, "the general [evolutionary] trend from simple to complex, from microbes to mind, seems to me to be built into the laws of nature in a basic way. If so, then we would expect the same general trend that has led to the emergence of life and mind on Earth to take place elsewhere in the universe." (Pg. 80) He adds, "I believe that there's a sort of 'law of increasing organized complexity' operating in the universe. It's not quite a law in the same sense as, say, Newton's law of gravity, more like a tendency or trend, but its manifestation seems unmistakable. There really does seem to be a general tendency in nature for increasing organizational complexity [or depth]." (Pg. 105)
This is an excellent discussion of many of the key issues involved with the search for extraterrestrial life, and will be great value to anyone studying this issue.