Since I was a boy, I have been a Star Trek fan. I would sit in front of the TV watching Captain Kirk and the crew of the Starship Enterprise explore a galaxy teeming with alien life of all shapes and sizes and colors. Seeking out new life and new civilizations was the exciting challenge in the Star Trek universe, and civilizations built by intelligent humanoids were practically everywhere. Could such a vision of the cosmos be true? Is there intelligent life out there?
Polls indicate that anywhere from 60-80% of Americans believe there is intelligent life somewhere in the universe. On a basic level, this makes much sense. Our galaxy is vast and there are an estimated 100 billion galaxies out there in the heavens. One doesn't have to be a Ph.D in mathematics to draw the obvious conclusion that intelligent life has evolved elsewhere. Unlike the Star Trek universe, life may not be teeming throughout the cosmos, but surely we earthlings are not alone as the only civilization.
Well, enter someone who dares to challenge the conventional wisdom and who mounts quite an argument for the very real possibility that we are indeed the only intelligent life that exists anywhere. Astrophysicist, John Gribbin in his book, Alone in the Universe: Why Our Planet Is Unique, writes, that while the galaxy might be a giant warehouse containing all the spare parts needed for life,
...it seems likely that earth-like planets are rare. But even if other earths were common, my view is that while life itself may be common, the kind of intelligent, technological civilization that has emerged on Earth may be unique, at least in our Milky Way Galaxy.... The Milky Way contains a few hundred billion stars, but almost certainly contains only one intelligent civilization. In that sense, our civilization is alone and special (pp. xiv-xv).
So what evidence leads Gribbin to what seems to so many to be a counter-intuitive conclusion? Quite simply, it's the unique events throughout the evolutionary process in our part of the galaxy and on earth as well and how those events uniquely came together to create the conditions necessary for intelligent life to evolve. In chapter after chapter Gribbon makes a compelling case (to this novice anyway) that our existence is not ordinary, but rather quite amazingly extraordinary. Not only did the formation of our solar system happen at just the right time, the earth was also fortunate enough to be in a stable solar system at that with planets in basically stable orbits. Indeed, those stable orbits would not have been possible without the influence of the gas giant Jupiter over millions of years. Without Jupiter there would be no life on earth. Also, our sun is just the right size and age for life to develop and without the moon and all that it has contributed, our existence would never have been possible.
Moreover, there were the necessary events that needed to take place to make the earth rich in minerals and fossil fuels that was singularly necessary for technological civilizations to develop. Such minerals may be present throughout the universe, but lots of different things need to come together to make a world rich in such many and various metals. And without life in plant and animal form, there are no fossil fuels. That too is extraordinary. And while we shudder to think that earth may collide with a large asteroid in the future, it was such collisions in the past that paved the way for intelligent life to evolve. An asteroid may have killed off the dinosaurs, but it gave mammals the upper hand in the evolutionary process. And if all of this isn't incredible enough, the evolution of life on earth could have taken a very different turn producing no intelligent beings had it not been for other unique events coming together in quite timely fashion. In other words, Gribbin is arguing that winning the lottery is a sure bet compared to what needs to happen to produce an intelligent civilization on any planet. I simply have given a brief and selective summary of the unique billions of years scenario Gribbin takes us through in his book. As the evidence mounts throughout the book, Gribbin's argument becomes more and more convincing.
Gribbin does not deal with the God question in his book and he gives no clue as to his metaphysical convictions if any, but he does write the following in the Preface,
Whether or not you see the hand of God in any of this, it would mean that we are the most technologically advanced civilization in the Universe, and the only witnesses with an understanding of the origin and nature of the Universe itself (p. xv).
As I read Alone in the Universe I thought several times of Psalm 8 which recognizes human smallness in vastness of the cosmos, while at the same time occupying a unique place in the sight of God.
When I look at your heavens, the work of your fingers,
the moon and the stars that you have established;
4 what are human beings that you are mindful of them,
mortals* that you care for them?
Yet you have made them a little lower than God,*
and crowned them with glory and honour.
6 You have given them dominion over the works of your hands;
you have put all things under their feet,
7 all sheep and oxen,
and also the beasts of the field,
8 the birds of the air, and the fish of the sea,
whatever passes along the paths of the seas.
While intelligent life elsewhere in the universe cannot be ruled out, Gribbin doesn't think we should be too optimistic. And if there are intelligent and technologically advanced civilizations out there somewhere in the heavens, and if we could board a starship and visit them, we would likely find out that our cosmos is quite unlike the Star Trek universe where life is literally everywhere in the Milky Way.
For some the idea of being alone in the universe may be rather depressing, but at least a future Captain Kirk will not have to worry too often about violating the Prime Directive.