Science has peered outward and found that there are as many as 200 billion galaxies in the observable universe. There are some 100 billion stars in our own galaxy, the Milky Way. Our own star, the sun, is very, very average in size and age, and exists in the humdrum outer reaches of a plain-vanilla spiral galaxy. Yet it has just one inhabited planet, as far as we know: earth.
We have lately discovered planets around other stars in the galaxy, though we can't as yet detect any planets as small as ours. So we have not yet confirmed the existence of planets elsewhere whose conditions can be considred ripe for the evolution of life. I assume, however, that innumerable such planets exist, and the question is, are any of them inhabited by intelligent life forms?
In his Cosmos TV series and book, the late astronomer Carl Sagan presented the Drake equation giving an estimate of the potential number of extraterrestrial civilizations in the Milky Way galaxy. Frank Drake, an American astronomer and astrophysicist, devised the equation to take into account:
- the average yearly rate of star formation in the galaxy
- the fraction of those stars that have planets
- the average number of planets per star that can potentially support life
- the fraction that actually develop life at some point
- the fraction of life-bearing planets that develop intelligent life, and therefore civilizations
- the fraction of civilizations that develop a technology that gives off detectable signs of their existence into space
- the length of time such civilizations give off detectable signals into space (as they may cease doing so for a number of reasons, including self-destruction via, say, nuclear weapons)
These imprecise factors were estimated by Drake in such a way as to yield a result of just 10 civilizations in our galaxy with which communication might be possible.
Of course, if there are 200 billion galaxies out there, by such estimates there may be on the order of 10 x 200 billion, or 2,000 billion planets in the cosmos that can give off signs of intelligent life. In SETI, the Search for Extra-Terrestrial Intelligence, we have been searching for such signs for the last fifty years. So far, nothing.
Meanwhile, Sagan in his Cosmos series was openly skeptical about such things as UFOs and alien abductions. There is no hard evidence, he said, that any earthling has ever encountered beings from outer space.
My guess, in view of all the above, is that we're alone. If I'm right, then what does that say to us?
I personally believe in evolution. Life somehow began on earth and then evolved, producing (among countless other species) us. No one in the scientific community knows for sure how life began on earth. Darwin himself simply assumed that it began in ways that lie outside the scope of his theory of evolution.
Logically, if life began in the same way on Planet X, a planet enough like ours to allow intelligent life to evolve in the ordinary way, then there must be some non-zero probability, however tiny, that intelligent life would evolve on that Planet X. The "however tiny" probability factor here relates closely to Drake's fraction of life-bearing planets that develop intelligent life, and therefore civilizations.
So, if there are really 10 planets in the galaxy that have undergone earth-like evolution leading to currently existing species whose individual members possess minds, then on each of those 10 planets there must have been Darwinian evolution by natural selection from simple, original life forms that lack minds.
Yet we have yet to see any signs whatsoever of "little green men". Where are they?
If they are nowhere, then intelligent life has developed, from an original life form we cannot as yet explain, on earth alone. How decidely odd. Sagan and other scientists have emphasized how ordinary our planet, sun, solar system, and galaxy are. If that's right, then our being absolutely alone (if we indeed are) must mean sommething.
To me, it means there is a Creator God. This God, whatever else is true about Him, Her, or It, must be capable of mighty works: the creation of life. Moreover, He/She/It must be capable of intentionally deciding to create life in just one of numberless hospitable habitats in the physical universe.
We generally say that any being capable of having and expressing such discrimination of intent is a "person" with a "will". So the fact that we are alone implies, to me, a mighty Creator God who is a person with a will. I'll call that person male by convention and use the masculine pronoun accordingly.
If there were more than one such creative Deity, then we would expect more than one instance of intelligent life in the universe. Hence, our Creator God is most likely also alone.
All this says nothing whatever about how the universe itself came to be. It might have existed always and forever. It might have come to be as the result of a big bang, which may or may not imply divine agency, depending on who you ask. My argument sidesteps that discussion entirely. All I'm saying is that, if we're alone in an otherwise vast and fecund universe whose laws are wholly consistent with the sustenance of life and the evolution of intelligence, then maybe that's because the spark of life on our planet came from a God whose intent was to make us His unique creatures.
