Saturday, December 29, 2007

Looking back, Part IV

If--as is beginning to seem frighteningly less likely every year--humanity is still around a thousand years from now, what do you suppose their history books will have in them about our times? Does anyone suppose that they will pay any more attention to our wars and famines and political crises than we do to King Aethelred's wars with the Danes, or the eruption of Mount Merapi? (What were those? Well, that's my point.)

One thing will be what we did about global warming, which I discussed the other day. But I suspect that another will be our exploration of the solar system. The average person's reaction to Mars data is an excellent example of how quickly we adapt: what was jaw-dropping only a very short time ago now rarely makes the news at all, much less a lead story. Most people have heard of Titan, but how many could tell you what Enceladus is?

surface of marsYet we have images coming in daily of the surface of Mars that are as detailed as what you would see standing there.
More to the point, as the images continue to come in, the probability that Mars once supported life--and may even now have at least some sort of active microbial life--goes ever up.

surface of TitanSo do the possibilities that perhaps Titan and Enceladus (as Casey Stengel once famously said, "You could look it up") might host life. Moreover, all these possibilities are of the conservative "life as we know it" form: the possibilities for more exotic yet scientifically plausible forms (biochemistry different from terrestrial sorts) expand considerably the range.

It is also true that the continuing discoveries of planets around other suns greatly raises the possibility--now, to many, probability--that a sufficiency of Earth-like specimens will be found such that the probability of life there will be high. But the crux for contemporary humankind is that it is in our astronomical backyard that we may well find the first definitive proof that life is not unique to Earth. True, we have a ways to go before anyone could expect that proof even if life does exist elsewhere in our solar system. But this year is remarkable and may well be memorable as the time when the tide turned, and cautious skepticism in the scientific community turned to cautious optimism.

The impact of definite knowledge that life is not unique to Earth is hard to estimate. The conventional wisdom is that it would cause massive upheavals and be a watershed in the history of humankind; me, I doubt it. The ability of human beings to turn the sensational to the boring in no time flat is astonishing. I suspect that the discovery would be a nine-days' wonder and little more, at least outside the scientific community. The idea that religions would crumble sorely underestimates the durability of established religions, and their ability to either co-opt or disregard almost anything; think how many Americans (it's 48% if you were wondering) still do not believe in--not doubt but disbelieve--simple evolution. Some microbes on Mars are going to mean nothing.

Whether we will discover even the traces of prior life, much less actual living organisms, somewhere within the solar system is still a bit iffy, however much hopes have risen. But with the extra-solar planetary spottings coming in, it would take a true ostrich to deny the probability that somewhere out there is life, and, given size of the numbers, almost certainly intelligent life (though exactly what that term might signify for extraterrestrial life forms is itself dicey).

Many still wait hopefully for Project SETI to cough up some promising result. The problem with it and analogous searches is its inherent assumption that we have a reasonable handle on how extraterrestrials might signal over interstellar distances; but our deductions on that point are necessarily grounded in our current best understandings of physics. It might be well to remember that less than a hundred years ago, it was suggested in all seriousness that we arrange geometric patterns of bright lights (even large bonfires) to tell the presumed aliens that we are here. What seems "obvious" today may look just as silly another hundred years down the road.

But, to round out, I do think that if there are literate humans in a thousand years, our era will be remembered (to the extent it is at all) for our breaking out in search of life beyond our own world; and 2007 may well be seen as the year attitudes began to change.

Those interested in following up will find satisfactory starting points at the Wikipedia articles listed below:

Drake equation
Extraterrestrial life
Communication with Extraterrestrial Intelligence
Darwin mission

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