http://www.foxnews.com/scitech/2010/08/09/abandon-earth-face-extinction-warns-stephen-hawking/
I think everyone understands that eventually the human race on earth will perish if from nothing else than when our sun nova's out or goes cold...
The Sun is only halfway through its approximately billion-year lifespan, so there's little worry about that.
Though its output will surely vary over that time - over the next tens of thousands of years there will surely be more Global Warming and Global Cooling than we've seen in history, so those who live here then will have to adapt, or more likely modify things as needed (have mirrors that reflect more sunlight to Earth to compensate for cooling, or add shades to compensate for warming).
The biggest and most imminent danger appears to be ourselves and nuclear bombs. Somebody oughta outlaw those things...
This is not the first time Hawking has made a statement like this. The problem is, its too easy a statement to make. I have been reading stuff like this since the 50's. It's not new.
What would be new is if someone like Hawking come up with a propulsion system that would jump start space travel and exploration. In reality, the human race has only been venturing into near space for the last 50 years. But, because of cost, we are now stuck on how much farther we can go until someone somewhere comes up with a propulsion system that can jump start the next phase...
Any thoughts...
Yes - I agree with him. I've not been reading stuff like this since the '50's, only because I hadn't learned to read yet in the '50's.
It's not just how much farther we can go, it's how many people we can get into space using rockets. It's quite inefficient compared to proposed alternatives.
In the next few centuries, perhaps even decades, we can/will build things such as skyhooks which will let us take massive quantities of materials and people into Earth orbit cheaply (yes, even with the humongous cost of the skyhook itself amortized over what gets put into orbit). It may take more decades before those living in space become self-sustaining, but when they do there's at least a part of humanity that will be pretty much immune from problems on Earth such as plagues and Global Thermonuclear War (unless someone decides to nuke the space colony - many nuclear-warhead missiles could do that now).
Going to the stars would take many centuries - all the better to seriously start now on the design of generation ships and propulsion systems.
But I really have a problem (actually several) with this article.
In May Hawking said he believed humans could travel millions of years into the future and repopulate their devastated planet. If spaceships are built that can fly faster than the speed of light, a day on board would be equivalent to a year on Earth. That's because -- according to Einstein -- as objects accelerate through space, time slows down around them.
No, that (the sentence in bold) is bullshit. The ship would only have to go NEAR the speed of light, not go past it, to have this slowing effect - something that would take a hell of a lot of energy, but is well within physics as has been known since Einstein.
And did Hawking actually say we should ABANDON Earth? I suspect that was an interpretation by the writer. Earth is one of our baskets. Let's leave some people behind in case the rest of us get blown away in outer space.
I read too many science articles where the writer gets it wrong. You don't have to be a physics major to know these things, and it really irks me. With so many people like this, it's amazing anyone gets into space at all.
