Five Billion Years of Solitude Read Online Free PDF Page B

Union succeeded in harnessing the far more powerful process of thermonuclear fusion, squeezing the destructive force of hundreds of Nagasakis into individual bombs. The resulting arsenals of thermonuclear weapons were more than adequate to extinguish hundreds of millions of lives in a single nuclear exchange. Those who survived such a nuclear holocaust would face a severely damaged planetary biosphere and a world plunged into a new Dark Age. Less than a year after the Green Bank proceedings, the Cuban missile crisis would bring the world to the brink ofthermonuclear war, and as time marched on, more and more nations successfully weaponized the power of the atom. Humans had developed a global society, radio telescopes, and interplanetary rockets at roughly the same time as weapons of mass destruction.
    If it could happen here, Morrison gloomily suggested, it could happen anywhere. Perhaps all societies would proceed on similar trajectories, becoming visible to the wider cosmos at roughly the same moment they gained an ability to destroy themselves. In fact, he went on, running the numbers in his steel-trap mind, if the average civilization endured only a decade before passing into oblivion, at any time there would most likely be only one communicative planetary system throughout the galaxy. We would have already met the Milky Way’s only culture, for it would be us. One of the most compelling reasons to search for evidence of extraterrestrial civilizations, Morrison thought, would be to learn whether our own had a prayer of surviving its current technological adolescence. Maybe a message from the stars could provide some inoculation against humanity’s self-destructive tendencies.
    Sagan attempted to counter the doomsaying, noting that we could not rule out some technological civilizations achieving global stability and prosperity either before or even after developing weapons of mass destruction. They might master their planetary environment, and move on to exploit resources in the rest of their planetary system. He thought that such a society, flush with power and wisdom, would have a fighting chance to prevent or withstand nearly any natural calamity. It could, in theory, persist for geological timescales of hundreds of millions or even billions of years, potentially lasting as long as its host star continued to shine. And if, somehow, that civilization managed to escape its dying sun and colonize other planetary systems . . . well, perhaps then it would endure practically forever. Of all the attendees, Sagan was by far the most optimistic that technological civilizations could solve not only their many planetary problems, but also the manifold difficulties associated with interstellar travel. Somewhere out there, if not in our galaxy then in at least one of countless others, immortals passed their unendingdays amid the stars. Sagan thought we might yet be included in their number.
    After the participants had discussed and debated L to the point of exhaustion, Drake stood up and announced that they had reached a consensus. The lifetimes of technological civilizations, he said, were likely to be either relatively short, lasting at most perhaps a thousand years, or very long, extending to one hundred million years and beyond. If indeed longevity was the most crucial consideration of the Drake equation, that implied there were somewhere between one thousand and one hundred million technological civilizations in the Milky Way. A thousand planetary civilizations translated to one per every hundred million stars in our galaxy. If the number was that low, we’d be hard-pressed to ever find anyone to talk to, as our nearest neighboring civilization would most likely be many thousands of light-years away. Conversely, if a hundred million civilizations existed, they would occupy one out of every thousand stars, in which case we might expect to have heard from them already. Drake’s best guess in 1961 walked the line between