A symposium called Crossroads: The Future of Human Life in the Universe seems timely about now (the site has been down all morning but should be up soon). With the Kepler mission undergoing calibration and CoRoT actively searching for small extrasolar worlds, we’re probably within a few dozen months of the detection of an Earth-like world around another star (and maybe, by other methods, much closer). This is sometimes referred to as the ‘Holy Grail’ of planetary sciences, but as soon as we accomplish it, a new ‘Grail’ emerges: The discovery of life on these worlds. And then another: Finding intelligent life.
We can kick the Fermi Paradox around all day, and enjoyably so because it forces us to use our imaginations, but ultimately we hope to put together the hard data that will tell us which of our speculations is most accurate. I see that the Crossroads symposium, which will take place May 1-2 as part of the Cambridge Science Festival, will include Frank Drake’s re-examination of his famous Drake Equation, but will also question whether crisis points like exhaustion of our natural resources may be the kind of ‘filter’ that any intelligent species must overcome.
Chokepoints for Technological Cultures
That’s a good Fermi solution if you posit the emergence of a million technological civilizations in our galaxy, as Carl Sagan once did. Those of us who think intelligent life is rare see no real contradiction in our lack of observed neighbors, but where are all those highly adapted technological cultures otherwise? Thus the plausibility of the doomsday hypothesis: Getting through that phase when a society is capable of destroying itself may be too high a hurdle for most to overcome. There are other forms of cultural collapse, too, as our own experience with the fragmentation of Roman culture in the 5th Century and later makes clear.
Then again, maybe that ‘great silence’ is only a transient phenomenon. Yesterday I talked about Seth Shostak’s new book Confessions of an Alien Hunter, and because it’s germane to this discussion (and sitting right here on my desk), I’ll return to it. Shostak notes that ever more powerful computers are ramping up SETI’s powers to the point that by the year 2030, the Allen Telescope Array ought to be able to check for signals in the direction of a million or more star systems. He points to Sagan as well as Frank Drake’s estimate of 10,000 communicating civilizations in examining the implications:
That’s enough to offer success if Drake is correct. If Sagan’s right, a signal will be found sooner. In other words, either we will discover evidence for ET within the lifetime of the present generation or we’ve erred badly in our presumptions.
Moore’s inexorable law thus makes our generation possibly the first with a real chance to witness that detection. The pace of change in digital technology seems inexorable. By 2020, a desktop computer should have the computational capabilities of a human being. Will we have something — electromagnetic leakage, a beacon, a directed transmission — by then?
A Machine on the Line
Assuming we are indeed at that crossroads the symposium notes in its title, it’s also plausible to speculate that another key filter is the development of artificial intelligence. If we do go through a ‘singularity’ event and our intelligent equipment begins to evolve on the fly in directions we cannot imagine, it’s more than possible that any SETI signal we receive is going to come, as Shostak notes, from a machine. All of which has ramifications for where we look for a signal:
Serbian astronomer Milan Ćirković has suggested that the best location for cerebrating hardware would be the outer fringes of the galaxy. In those godforsaken neighborhoods, where temperatures are colder than dead penguins, energy-consuming machinery could run most efficiently. That’s basic thermodynamics. But while Ćirković’s argument has its appeal, the galactic boondocks might be too dull for big brains with semi-eternity on their hands. They might prefer to exchange thermal efficiency for the opportunity to be situated closer to the galaxy’s central regions, where there’s a lot more astronomical action.
But then, if we’re truly dealing with machines at this order of complexity, it’s clear that our ability to gauge their intentions is going to be minimal. A crossroads indeed looms ahead as we ponder all this, hoping to hear a signal from another star system, wondering whether Earth-like worlds are indeed as common as some have come to believe, and speculating on the survivability of a nuclear-tipped species like our own whose digital tools may one day be beyond our ability to control. All good reasons to check out this symposium, which will be available as a Webcast.