This has come to be called Fermi's Paradox. It isn't a paradox but it is a bloody good question. It is a much better question than, Is there life elsewhere in the universe? Better because "So what?" isn't one possible honest answer to Fermi's question. A lot of thinking has since gone into providing answers (or ducking the question) -- see Wikipedia for details. I think it is interesting how the mood of the times and the sensibilities of successive generations have affected the search for possible answers to Fermi's Pointed Question.
]]> Fermi was a nuclear physicist. He build the first self-sustaining atomic pile, a slow nuclear reaction that pulsed for fifty years in a lead-lined racquets court at Chicago University. He is one of the fathers of the atomic bomb and the generation that grew up with his progeny was so influenced by it that they used the flash and the fallout to provide their best answer. Which was that life elsewhere in the universe is not here on Earth because it invariably annihilates itself in total nuclear war. The theory goes that to harness the power of the atom is to make a species-wide commitment towards inevitable extinction. Professor Fermi, the answer is this: They are not Here because They wiped Themselves out.All well and good, if unsatisfying. The nuclear generation, cowering under beds and desks during the drills, wetting themselves in fear of intercontinental ballistic death, thought that intelligent life There must inevitably die in the atomizing flash or in the post-holocaust wreckage before it could get Here. Perhaps the survivors fall back into a dark age. Worse, perhaps They rise periodically to high civilization before foolishly reinventing their destruction time and again, stuck in a radioactive rut, joke's on them. They aren't Here because They're too busy either splitting atoms or splitting rocks. And, portentously, perhaps this may be our fate…
Bummer.
That was not the nuclear generation's only answer to Fermi's Pointed Question. Bleak and pessimistic as the times seemed to many, it got worse. Another answer could be that there is no life elsewhere. There is no They to be the subject of "Where are They?". Human beings are alone in the universe and are daft enough to be messing with nukes?! At least the purported absence of life leads to interesting questions like "Why not?"
Another, less depressing answer is that there is indeed intelligent life developing around other stars but that we are simply the leaders, the first to send radio signals to aliens too primitive to receive them. They are not Here because They can't be, yet. This smacks of human arrogance and, until we have evidence that we are special, we should assume we are ordinary. It's taken us 30,000 years to get from cave painting to Pioneer - with sixteen billion years and billions of solar systems, are we seriously entertaining the idea that we are first in this galaxy, let alone the universe?
As physics gets the hang of Einstein, another possibility occurs: that intelligence is scarce in the universe and the gaps are forever unbridgeable because the speed limits of physical laws keep us apart - They are not Here because They can't be, ever. This is hard to reconcile with the universe: it's a big universe but it's also been around for so very long that, even if They only travel at a fraction of the speed of light, They've had plenty time to get Here if they are even approximately in our neighbourhood. There's scarce and then there's really scarce. So scarce that their signals aren't here yet? Perhaps, say the pessimists, the gaps are so large that they require an advanced hyperdrive few species manage to develop and so They aren't Here…but watch the skies! Doubtful; it only has to happen once in the aforementioned big universe. Or an advanced hyperdrive requires six impossible things, in which case They aren't Here and you're wasting your time watching the skies.
Sheesh! Can somebody cheer us up? Well, nuclear technology begat the IT generation and a new and happier riposte to Fermi. Intelligent life, thought the first geeks as they stumbled one-eyed (the other eye looking into cyberspace) through drab RL (real life) -- intelligent life, they thought, if it skips by early armageddon, develops information technology to the point where They choose inner over outer space. Space exploration is costly and dangerous and sort of pointless. Instead, aliens from here to Stavromula Beta learn how to upload Themselves into alternative realities, never leaving home. Cyberspace is destiny and maximizing felicific calculus is what it is all about. Why fret and sweat in the real world when you can take the 'trode road to paradise? Why go out when there's all this great stuff on TV? Perhaps civilizations first surround their star with a shell of solar panels, hiding it from view and harvesting vast quantities of energy which they can use to power their silicon heavens, their backed-up jacked-up matrices. Then They disappear up their own input port, leaving mundane reality to spin mechanically onwards while They cavort for subjective eternities in heavens of Their own devising.
The IT revolution begat the genomics revolution as the technology gave us the capability to handle life's diversity. A billion bases and biopsies ordered as bits and bytes. The biotechnology generation took on the earlier responses to Fermi first then launched into the master himself. First, they repudiated the nuclear pessimists as overly concerned with their own destructive power. Hype to the contrary, the destruction of life on Earth can't be achieved with any likely extrapolation of today's arsenals; only civilization is a legitimate target and there's always the chrysalids in New Zealand or Kamandi in the midwest to carry the torch. Surely we can't all die, right? Cycles of rise and fall, upskill then fallout - and you are seriously suggesting that nobody gets out alive with a working transmitter and the will to pass on the bad news to the solar system next door? Give us a break!
Then they mocked the geeks. Overly optimistic, you see? Pessimism is not confined to the nuclear generation. No, said the biotechnology generation (repudiating its repudiation), advanced intelligence in the universe proceeds to the point that it discovers how to manipulate its own substrate, to tinker with itself. The approaching abyss is a biological hurdle, not a nuclear chasm. This goes for plasmatic organisms, sentient star hearts, superintelligent shades of the colour blue, whatever esoteric form life takes. A couple of billion years of evolution builds a system -- carbon- or plasma- or photon-based -- of staggering complexity, shored up and Rube-Goldberg'd together in ways that are all too easy to break with only a generation's practice. Aliens invent superbugs and megaviruses, diseases with 99.9% morbidity, agricultural monocultures that become single points of failure for
Now who's bumming us out?
Every technological revolution finds its own answer to Fermi. The cognitive scientists are up next. They're honing their answers right now, in the scientific and popular literatures: that there are snowcrash memes lurking around every creative corner, that Langford hacks for all sensory modes are inherent in mathematical representations discovered by all species, or that there are gestalt minds to build that, sans silicon, will take us to the rapturous heavens in our heads towards which the geeks were programming us. That last one might work and contains hidden hopes: They aren't Here because Their childhood ended (and everyone knows that grown-ups don't get out much).
Of course, it's never that simple. Nuclear didn't begat IT who begat biotech who begat cognitive and whatever is to come next. Disciplines overlapped and interacted and exchanged ideas and personnel, while there was a lot of other stuff going on too. But it seems that many fields of science offer a pessimistic answer to Fermi's Pointed Question. IT and its cognitive variant are unusual in the lack of bleakness in some of their answers, though they hardly fall short in the nihilism department. Particle physicists, on the other hand, worry in their unguarded moments that the next superduper supercollider will exceed some hitherto-unsuspected energy threshhold in the substructure of the universe, smashing not only the accelerated protons under study but also the surprisingly fragile (mem)brane keeping the universes apart, tearing open a hole in the universe and tipping the Earth into the fires between realities like dropping the pizza face-down as you open the oven door. Or some student working late at CERN will accidentally create a black hole that plunges to the centre of the Earth and spends a few years sucking the planet from under our feet. The counter-Fermian is obvious: They aren't Here because the universe ate Them.
Down the corridor, astronomers count the number of fast-moving city-sized rocks hurtling through space, or the oscillations of a solar system through the galactic plane into areas exposed to collosal blasts of interstellar dust or constellation-wide sheets of searing radiation, and conclude that They aren't Here because They are pounded or irradiated or suffocated by what is, on the scale of galaxies, merely a fluctuation in local weather conditions.
Across the courtyard in the shabbier buildings, the humanities are just as bad: students of human nature extrapolate from the colonial era and conclude that intelligent life proceeds to a point where it is sufficiently developed to come to the notice of the first species that got intelligent enough. This first-comer species, in recognition of the danger posed by upstarts, turns up beweaponed and hand-delivers the obliteration the universe has failed to provide. In this scenario, life is self-limiting. They aren't Here because either (a) They have been oppressed or (b) They are the intergalactic opressors who have yet to notice us. In which case, why are we beaming signals in all directions at light speed? Not so much "Hello universe" as "Come and get us". To Fermi we say: Actually, any minute now They will be Here and, er, shortly after that we won't be.
Fermi didn't have an answer either. Where the hell is he!?
And it also applies to time-travellers -- where are they?
]]>"The brain is not a Reality-Recorder. There is no perfect replica of reality inside our brains. The brain elides, confabulates, conflates, denies, suppresses, evades, confuses and distorts. It has its own agenda and can even work at cross-purposes with our conscious selves. Consciously, we may think that we see all and know all, but our brains may be "blind" to much of what is going on around us."
Errol Morris, blogging on perception
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