February 1, 2009

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Fermi's Paradox & Other Scientific Conceits UPDATED

As a rational, non-God-fearing atheist who doesn't believe in ghosts, fairies and the Loch Ness Monster, people are quite surprised to learn that I still entertain the possibility that Earth has been (or is being) visited by extraterrestrial intelligences.

Surely, they chuckle, if I don't believe in all this other superstitious and supernatural bunk, then I must be immune to the notion of Little Green Men, also?

It's true that I've made a deliberate decision to keep my distance from UFO groups, and I've had heated debates over email with some noted UFOlogists, like Stanton T Friedman, who insists he can prove beyond doubt that "they" are here. He kindly posted a big brown envelope stuffed with cuttings and photocopied official-looking reports by "serious scientists" that he claims all adds up to an open and shut case that flying saucers are real. I do disagree with that conclusion. I think there's something decidedly unscientific about it all, and I remain unconvinced by the evidence.

But, I see equally woolly-minded arguments and evidence from the opposing side of so-called "skeptics" (who, I agree with Stanton on this, are anything but - they are dogmatically debunkers, and just as prone to ignoring evidence and twisting arguments as some of the more "out there" UFO nuts). Let's be honest, it's such a tricky subject that very, very few respectable scientists will touch it. Frankly, scientists get a bit doolally when the topic comes up. Take Fermi's Paradox, for example; aliens can't exist, because if they did, they'd be here. We'd see them, or signs of their presence. The fact that we see no signs means that they don't exist.

Oh, flying saucers? Well, they're not real, obviously. How do we know that? Because extraterrestrials couldn't and wouldn't visit us. Space is too vast, and anyway, why would they bother? Besides, they probably don't exist: Fermi proved that with his paradox.

This adds up to a circular argument that's every bit as irrational as Stanton T Friedman's? They can't exist, otherwise we'd see them. And when we see them, we must be mistaken because they can't get here, and probably don't exist anyway.

The reality is that there's nothing in our current understanding that rules out the possibility that other more advanced technological civilisations may have evolved in other solar systems, or that they may have sent intelligent interstellar probes - or even themselves - to visit our own solar system and Earth itself. Indeed, a space-faring civilisation could have colonised the entire Milky Way galaxy in a few hundred thousand years travelling at modest fractions of the speed of light, and such a civilisation may well have perfected computing to a level that would make things like highly intelligent self-replicating Von Neumann probes a reality. To us, such sophisticated machines might even appear to be biological.

For all we know, the outer reaches of our own solar system could be populated by trillions of such intelligent machines, living very happily off the truly enormous material resources that exist out there. And who knows, maybe they send in the odd scout to take a look around our own planet from time to time. After all, we have one type of material that might be very rare and very hard to synthesise from the raw inert chemistry of the Oort cloud or Kuiper belt - life. Living matter is extraordinary stuff, as materials go. I mean, you might think that superfluids or superheated plasmas display some unusual properties, but it's truly staggering what carbon, hydrogen and oxygen can do if you combine them with a few heavy elements and simmer for, oh, a few hundred million years.

Yes, I think life is one very good reason why they might be here. Everything else - water, metals, polymers, fuel (assuming their fuel doesn't come from water) - exists in abundance in the icy outer reaches of our solar system. But cats and dogs and chickens and sea monkeys and mice and men - you need to come in much closer to the Sun to get your hands on that sort of stuff.

Anyway, speculation aside, what I'm saying is that there's no reason to believe that they're not here, or that they've never been here in the past. It's by no means proven, but as far as I'm concerned it's not far-fetched enough for us to snigger and chortle like schoolchildren in a sex education class, and thus dismiss the whole notion out of hand.

And as for the apparant radio silence and the failure of SETI up to now, which has prompted many to refer back to Fermi's famous paradox: I'm imagining tribal elders sitting on the shore, staring out to sea looking for the tell-tale smoke signals of other "advanced tribes" and, never seeing any, concluding that they must be alone in the world.

UPDATE: This morning a reader emailed me and asked:

"'Anyway, speculation aside, what I'm saying is that there's no reason to believe that they're not here, or that they've never been here in the past.' I assume you apply the exact same reasoning to your belief in a God? And yet you come up with a dfferent conclusion?"

Actually, there is every reason to not believe in existence of God. Specifically, I can't point to a single scientifically verified instance of the existence of such a supernatural being. Can you? There are zero data points for God.

Intelligent, space-faring civilisations, on the other hand - I have one data point that proves beyond any reasonable doubt that such a thing is physically possible, namely us. Gather that, together with the accumulating data points about other potentially life-bearing planetary systems, the accumulating data points about complex biological building blocks being detected in many regions of outer space and our ever-widening appreciation of the extreme conditions in which life seems to flourish, and I think we have a building case for the possible existence of more advanced civilisations.

That intelligent, educated people sneer at the possibility of occasional visits from more advanced civilisations, while they throw themselves open to the notion of a supernatural, all-powerful God - well that is one of life's great mysteries.

Posted 12 years, 3 months ago on February 1, 2009