The search for extraterrestial life involves one of the most profound philosophical, theological, and biological questions that humanity has ever wrestled with: Are We Alone. Recently, I have been disappointed by the frequency with which I see reputable scientists answer that question in the negative with certitude approaching conviction. (although I was encouraged to see the June00 (or was it July...) issue of Scientific American with a series of articles explaining why, in fact, we may be alone) The excellent program Universe 2001, which aired on TLC in Septerber '99, quoted a scientist comparing the number of stars in the universe to the number of grains of sand on Earth: "Imagine that one of these grains, our grain, is blue. What are the odds that there would be no other blue sand grains anywhere?" {correct answer: we have no idea}. Dr. Robert "The Case For Mars" Zubrin makes a similar error in his fascinating new book Entering Space (which I highly recommend): "...there are probably 5 million active technological civilizations in the galaxy right now...". Virtually everyone remotely involved in science, including myself, would love to receive proof positive that we are not alone - whether it's an alien artifact, radio message, or actual visit. It would be the biggest news ever. It would fire our thinking and our imaginations for centuries to come, and forever alter our view of ourselves. It would be a tremendous priviledge to be alive in such a time. (er.... um... that is, if they didn't kill us all!) But desire of a particular outcome should not stop us from looking at the data scientifically. The data - or more precisely, the lack of data, is simple: We have never detected any evidence that we're not alone. In 1950, Enrico Fermi posed his famous paradox at a Los Alamos meeting: "If there are aliens, where are they?" It's a valid question. In another couple thousand years, we will have sent manned expiditions to nearby stars. Once we sucessfully populate a handful of worlds in other star systems, it is hard to envision a scenario that could wipe out all humans. A million years later, we'll be all over this galaxy like a pestilence. A million years is an eyeblink in the lifetime of the Universe. If intelligent life is common in our galaxy, they would have spread throughout the galaxy already - unless we're the first/only technological civilization in the galaxy. (I'll save remarks directed at the UFO believers for a separate page) So - Are We Alone? Perhaps. Maybe. We really don't know, we don't have any data, except that the fact that we have no data is data in itself. Based on existing data, I think we can rule out the possibility that intelligent life is common. If it were common, it would be here, or failing that, we would have detected radio / microwave signals already. Intelligent life is therefore either rare or unique. As fascinating as it would be to know that it is rare but not unique, we don't know. Wishful thinking is just that - wishful. To date, all that can be said is that existing data is both consistent and congruent with the thesis that We Are Alone. I think we should adopt that hypothesis, and expend considerable effort in attempting to prove it wrong. |