Pale Blue Dot - Carl Sagan [139]
The prospects of such a time contrast provocatively with forecasts that the progress of science and technology is now near some asymptotic limit; that art, literature, and music are never to approach, much less exceed, the heights our species has, on occasion, already touched; and that political life on Earth is about to settle into some rock-stable liberal democratic world government, identified, after Hegel, as “the end of history.” Such an expansion into space also contrasts with a different but likewise discernible trend in recent times—toward authoritarianism, censorship, ethnic hatred, and a deep suspicion of curiosity and learning. Instead, I think that, after some debugging, the settlement of the Solar System presages an open-ended era of dazzling advances in science and technology; cultural flowering; and wide-ranging experiments, up there in the sky, in government and social organization. In more than one respect, exploring the Solar System and homesteading other worlds constitutes the beginning, much more than the end, of history.
IT’S IMPOSSIBLE, for us humans at least, to look into our future, certainly not centuries ahead. No one has ever done so with any consistency and detail. I certainly do not imagine that I can. I have, with some trepidation, gone as far as I have to this point in the book, because we are just recognizing the truly unprecedented challenges brought on by our technology. These challenges have, I think, occasional straightforward implications, some of which I’ve tried briefly to lay out. There are also less straightforward, much longer-term implications about which I’m even less confident. Nevertheless, I’d like to present them too for your consideration:
Even when our descendants are established on near-Earth asteroids and Mars and the moons of the outer Solar System and the Kuiper Comet Belt, it still won’t be entirely safe. In the long run, the Sun may generate stupendous X-ray and ultraviolet outbursts; the Solar System will enter one of the vast interstellar clouds lurking nearby and the planets will darken and cool; a shower of deadly comets will come roaring out of the Oort Cloud threatening civilizations on many adjacent worlds; we will recognize that a nearby star is about to become a supernova. In the really long run, the Sun—on its way to becoming a red giant star—will get bigger and brighter, the Earth will begin to lose its air and water to space, the soil will char, the oceans will evaporate and boil, the rocks will vaporize, and our planet may even be swallowed up into the interior of the Sun.
Far from being made for us, eventually the Solar System will become too dangerous for us. In the long run, putting all our eggs in a single stellar basket, no matter how reliable the Solar System has been lately, may be too risky. In the long run, as Tsiolkovsky and Goddard long ago recognized, we need to leave the Solar System.
If that’s true for us, you might very well ask, why isn’t it true for others? And if it is true for others, why aren’t they here? There are many possible answers, including the contention that they have come here—although the evidence for that is pitifully slim. Or there may be no one else out there, because they destroy themselves, with almost no exceptions, before they achieve interstellar flight; or because in a galaxy of 400 billion suns ours is the first technical civilization.
A more likely explanation, I think, issues from the simple fact that space is vast and the stars are far apart. Even if there were civilizations much older and more advanced than we—expanding out from their home worlds, reworking new worlds, and then continuing onward to other stars—they would be unlikely, according to calculations