On Life Beyond Earth
Published February 2017 in Bilkent News.
I’ve spoken at length before about the Earth, our unassuming blue home quietly revolving around the Sun. But as particular as it is in its delicate balance, it is still one among many worlds; what sets it apart to us is that it is our home, dour and self-contained, and that it has borne life out of water. It is probable that the Earth is not alone in the latter aspect either, and that the universe is teeming with strange beings; this is a delicious possibility, but one that must be carefully handled. One of the pastimes most intriguing to me is, I think, to try and handle it, to contemplate extraterrestrial life with my face tilted up into the cold; I sift through the night sky, picking out one crystalline star after another, trying to imagine what exquisite creatures might call them suns. If contemporary science is to be trusted, I still have billions of planets to consider – billions of potential worlds, thrumming with the wild pulse of life.
In my previous column I mentioned a theory about complex organic molecules that were formed out in the distant cosmos, carried by space debris to the early Earth as the harbingers of life. This theory, called panspermia, deals not with the question of how, but rather of where life first began; it implies that our planet is only one of many worlds in which the seeds of life have taken root. If the processes conducive to life are not unique to the Earth – if, say, all a planet needs to harbor it is to provide a specific environment – then, as in the good words of Sir William Huggins, “May it not be that, at least, the brighter stars are like our Sun, the upholding and energizing centres of systems of worlds, adapted to be the abode of living beings?”
It is not only the theory of panspermia that implies a much wider distribution of life in the cosmos. Until the 1970s science had linked life intimately to sunlight, but the discovery of organisms that live just as well in the shadows has broadened speculations on the nature of possible extraterrestrial habitats. The green sulfur bacteria of the deep ocean, for example, thrive by means of a photosynthetic process that uses geothermal light; their independence of the sun implies the existence of creatures in parts of the cosmos previously considered uninhabitable. But bacteria are notably not examples of intelligent life, and while the possible presence of life outside the Earth is on its own quite humbling to contemplate, it would be a very different matter to discover something more deeply alien – are there perhaps civilizations like ours, or civilizations that have surpassed ours, throughout the cosmos? This is really where the question gets darker, and begins to prod insistently at the sensitive recesses of human superiority. We’re so used to being the ultimate predator, haughty and untouchable, that it makes us deeply nervous to even consider the existence of something out there better than we are. Wouldn’t it challenge every hard-headed assumption we’ve made about our creation as sole proprietors of the universe – about our exceptional nature, about our having some wild luxury to divide within ourselves over our own flimsy conceptions of race, gender and politics – to know that we are definitely not alone? It would be like discovering once again in crushing disillusionment that no, the sun does not revolve around the Earth, and humankind is not the lone center of the universe. We are just as susceptible to extinction as all other species, many of which we ourselves have already eradicated in our profound delusions of grandeur. This is perhaps our true fear when we turn our wary eyes on the cosmos: that we’ll suffer the same fate we’ve dealt to others – that what we’re going to find won’t be alien at all, but instead deeply, devastatingly human. But this is not enough to justify a reluctance to listen to the universe. We can bury our heads in the sand all we like, but if there’s something out there, it’ll stay as it is, and if there isn’t, we’ll burn out alone. I think we owe it both to ourselves and to our origins to do our best to understand nature, in all its forms, throughout the cosmos. All we really have to work with at the moment are skeletal arguments, cradled partially by science and mathematics: astronomy reveals old suns in the vast darkness, and biology attempts to discover what their systems might shelter, building theories that mold themselves against the hard shell of probability. Some of these theories oppose the possibility of extraterrestrial intelligence: it might be that all technologically advanced civilizations are bound by evolution to destroy themselves or each other, or it might be that no such civilization can retain its organic form. There are also other theories that attempt to explain our apparent solitude; perhaps other civilizations do exist, but don’t want to contact us for reasons similar to ours. Perhaps they’re listening but not transmitting, or doing so in a manner that we cannot perceive. Perhaps they’re simply refraining from interfering with our development as a species, wondering what we’re going to do to ourselves. It’s a fair question; I wonder the same thing. The game of life is one we might lose, but if we survive, then things may become very interesting indeed. Maybe then we can really start looking beyond the Earth. Maybe we’re too daunted by the way we are to consider anything else just now.
Life is complex to us, already difficult to understand in forms we’re intimately in contact with. It’s even harder to regard the rest of the universe, to turn our attention skyward and comb through the eerie silence, wondering if it will always be so impenetrable. We look out into the cosmos because it is larger than we are, numinous as our gods and far more touchable; in the end we want to be part of something else, but it conflicts with our other primal desires. So it just happens that we set up observatories and refuse to fund them, tilt our heads to the sky but refuse to call out; so that all we end up doing is sticking to equations and philosophies, and arguing among ourselves over our possible isolation. Perhaps there will come a time when we know for certain what looms out there in the darkness. But until then, we’ll occupy ourselves with smaller things; staring out at the night perhaps, shoulders crooked with the cold, and wondering about life.