"Where Are They?" - Enrico Fermi
I highly doubt there are other technological civilizations in the galaxy. Obviously, some other folks believe (hope, wish) there are. If they want to spend their own money on a fairly scientific research program, so be it. Admittedly, I do benefit from learning about their negative results. On the remote chance that they are right, I would certainly learn something. Our collective resources could be probably be invested more wisely, but that could be said about a great many things in a free society.
When I was eleven I attended a planetarium lecture on the origin, age and future of the universe. At the bus stop going home I got to thinking that even if I lived to be a hundred, the chance of the current moment in the history of the universe also being a moment in my life was pitifully small. While the odds of my being alive at that moment were weak, nevertheless I knew I could only consider the problem during my lifetime. Logic trumps probability. Matter and energy may have had to jump through countless high and tiny hoops to produce mankind. But despite the odds, they obviously succeeded at least once. Although that it no way proves it happened twice or was even likely to have occurred elsewhere. There may be a zillion planets out there, but that does not imply that technological civilizations “must have” evolved on some of them.
We are a result of a process of biological evolution. Genes protect their own kind and destroy those that directly threaten them or compete for resources. The fittest survive. Our own species has engaged in war and genocide right up to the modern era, not to mention what we do to other species. We likely disposed of the Neanderthals and other humanoids. Yet we are more closely related to a blade of grass, than to any extraterrestrial, no matter how intelligent it might be.
I would be concerned about the designs of a race of technological extraterrestrials that became aware of our existence. It may be unfortunate, but those who assume (hope, wish) that evolution will eventually lead to harmony and brotherhood among all intelligent creatures are probably kidding themselves. Survival is what matters, and its means may not be what some Pollyanna thinks it should be. Yet I submit that it is often (not always) Pollyanna who is searching for extraterrestrial intelligence. Polly is relatively harmless as long as she only attempts to receive signals and not send them.
To some the notion that intelligent extraterrestrials would come to guide us, gives them almost religious comfort even if they have abandoned traditional religions. Yet this is a motivation for many (not all) SETI people. But would we really want to become like Eloi and have no need to think or provide for ourselves? Would we prefer to have learned the laws of mechanics from ET rather than Galileo and Newton? If ET really came "to serve man”, would we actually be better off? Would life be worth living?
The universe has existed for 13.7 billion years. One percent of one percent of that is 1.37 million years. I suspect it is rather unlikely that two intelligent species reached our technological level together in the galaxy within a time span less than that. We are probably either well ahead of whichever species (if any) is in second place, or well behind any other that might be in first place. And if there are tens of thousands of such species, as some SETI promoters suggest, at least one of them at one time in its history could easily have had a leader who led a campaign of galactic cleansing. It only had to be done once for our species to be exterminated. I submit that if any species became technological before us, they would have wiped out our ancestors as vermin long ago, and we would not be holding this discussion.
So I would be worried and not pleased if SETI were successful in finding ETI. Yet since our ancestors were not destroyed by extraterrestrials long ago, that sets asides my fears and leads me to the happy conclusion that technological ETs never have existed.
You might enjoy the collection of papers in a book that speaks to both sides of the question:
Extraterrestrials: Where Are They?
Click this link for more info on the book:
http://www.amazon.com/exec/obidos/ASIN/0521443350/crastro-20
Another good one that's more recent is:
If the Universe Is Teeming with Aliens... Where Is Everybody? Fifty Solutions to Fermi's Paradox and the Problem of Extraterrestrial Life
Here's the link to its info:
http://www.amazon.com/exec/obidos/ASIN/0387955011/crastro-20
