"Did you have fun with your robot buddy?"
--Homer Simpson to Lisa Simpson, on Stephen Hawking's departure
"How can the human race survive the next hundred years?" Stephen Hawking wants to know. So much so that he posted the question on line, in quest of enlightenment from the Netizen masses and their collective wisdom.
At the heart of Hawking's quest is a profound pessimism, and a tremendous ignorance of history. "Before the 1940s, the main threat to our survival came from collisions with asteroids," he writes. He is thinking of nuclear weapons, and their collective capacity to render the Earth virtually sterile, just as a bad encounter with, say, 200-km-diameter asteroid could do.
The nuclear threat is substantial, but let's be realistic: it's only one self-inflicted way, among numerous natural ways, for our species to meet its end. Admittedly, it would be regrettable if we should become the architects our demise, but we shall be just as dead if famine, disease, natural climate change, or geological catastrophe spirits us all away.
Hawking frets also about man-made global warming, and the possibility that we will "pass a tipping point at which the temperature rise becomes self sustaining."
Now, it's absolutely certain that the Earth's temperature has been rising of late, and it's absolutely certain that human activity is contributing to that rise. The problem is, no one knows the portion of global warming that our incontinent release of carbon into the atmosphere represents. The true figure is somewhere between "hardly any of it" and "nearly all of it."1
Again, it would be unfortunate if we were to die as a species by our own hand. But climate change happens, and the human race has already survived a natural, and quite radical, one: it's called the Ice Age. Our ancestors were here before it; no doubt millions perished during it; and yet we are here after it.
No doubt it cost us collectively. It's entirely possible that, during the Ice Age, there were advanced civilizations in the coastal regions of all the continents that have been lost - swallowed by the rising seas and buried under yards of silt - whose remains, invisible to us, lie but a few miles off shore in scores of locations around the globe.
Of course, it's entirely possible that there were no such civilizations. But if there were, the wisdom that we lost might never be recovered; and yet, here we all are. We certainly lost a lot of people: some genetic studies suggest that the human population might have fallen to merely tens of thousands at the worst point of the Ice Age, poised to eliminate itself with a few bad decisions (a point Hawking imagines to have arrived only in the 1940's); and yet, here we all are.
"There are other dangers, such as the accidental or intentional release of a genetically engineered virus," Hawking says. Note the presumption that a genetically engineered pathogen would be more deadly than the Black Death, the Spanish flu, or HIV. Mankind has seen its deadly pandemics, and yet, mysteriously, we continue to draw breath.
When Europeans arrived in the Americas, they landed in a world with few deadly communicable pathogens, perhaps owing to the savages' queer habit of not sleeping with their livestock, as their more advanced conquerors had been doing for millennia. In any event, tens of millions perished. Meanwhile, back in Europe, the Black Death returned numerous times, threatening what had become, and what remains, the world's most advanced civilization. And yet, here we all are.
As for geological catastrophes, there is a caldera in the islands of Santorini from a volcano that erupted in the Bronze Age, and may well have caused a flood that destroyed the Minoans - then the world's most advanced civilization - and spawned the legends of Atlantis and the great flood described in Genesis. And there is a caldera in North America - called the Yellowstone - from a volcano so massive that, when it blows, it will make the worst nuclear war we can mount today look like a garden party. And it looks as much like blowing tomorrow as in half a million years.
And yet we manage to go on.