Dear old Stephen Hawkins. Lovely man, brain the size of a planet, and gifted with the ability to explain complex ideas in simple terms. But he also demonstrates the ability for great minds to miss the bleeding obvious.
Space.com news : "Stephen Hawking Says Humanity Won't Survive Without Leaving Earth".
"Humans stuck on Earth are at risk from two kinds of catastrophes, Hawking said. First, the kind we bring on ourselves, such as possible devastating impacts from climate change, or nuclear or biological warfare.
A number of cosmic phenomena could spell our demise, too. An asteroid could slam into Earth, killing large swaths of the population and rendering the planet uninhabitable. Or a supernova or gamma-ray burst near our spot in the Milky Way could prove ruinous for life on Earth".
Second, asteroids. Yes there is a possibility of asteroid impacts. Here, the same considerations apply. At the moment we are on a path to auto-destruction. An asteroid might get us before our own idiocy does - but what difference would it make, apart from a couple of centuries maybe? If, however, we make the necessary cognitive shift and address the sustainability problem, then we should be able to extend the strategy to a small asteroid interception facility. It's not rocket science*. You just have to send an unmanned vehicle to the asteroid and give it a gentle nudge away from its impact route.
Stephen is also worried about aliens. He shouldn't. The chance of spatio-temporal co-existence is too small.
This all reminds us of James Lovelock, another genius who has an Achilles' heel in the matter of nuclear power.
In short, geniuses are geniuses, but geniuses are not infallible.
More Hawking on this blog.
This is interesting.
And although this post gets a lot of stick, I'm in good company:
*Ok, Ok, it is rocket science, but it is not that difficult.