I don't think this is true, we have many renewable resources, like water, fruits, vegetables. plants, etc. The only reason we would need to leave is if the Earth was exploding or if a meteor we couldn't stop was heading our direction. Over population can be considered an obstacle but we can easily control population if it gets to be out of hand.
But that's exactly what I'm talking about. All it takes is one meteor, one bioweapon "accident," one gamma ray burst, one rogue planet/black hole.
At any given time we only watch something like 3% of the sky, less than the size of the sky than if you held a dime out at arm's reach against it.
Since we've begun to keep track of meteors/asteroids/comets, there have been several times where objects have passed so close to Earth that they were between the distance of Earth and Luna. The scary part? Most of the time we didn't know about them until they'd already passed or with only a few days to spare; far too little time to conduct an Earth-saving operation. One would think that these close calls would be a wakeup call to the nations of Earth but no; just because we've been lucky so far most leaders never spend even a day in office considering how we could initiate a program that could potentially save Earth from an impact.
A gamma ray burst would end life as we know it -- in fact it's hypothesized that some of the mass extinction events in Earth's past were from a gamma ray burst. They're thought to occur when a star goes supernova and extremely powerful gamma rays are shot from the polar ends of the star. Yes, the odds are low that any individual stars' poles are pointing straight at us but there are 400 billion stars in this galaxy.
In fact, there is at least one known star system -- called WR 104, a binary star system -- that indeed has its poles pointed nearly directly at earth. Do we know when it will go nova and blast its gamma rays right at us? Our best guess is in hundreds of thousands of years, but we really don't know. It could really be at any time, and then the only thing between us and extinction is the 8,000 light years of distance between us. But guess what? As far as we know, it could have already gone nova 7,999 years ago and the invisible, deadly gamma ray burst could be reaching us next year!
I'm not a doomsday theorist, I'm just saying that the universe is a dangerous place for a planet. Consider Mars, which used to be Earth-like until some sort of catastrophe stripped it of its atmosphere and turned it into a barren wasteland... or Venus, which had an out-of-control greenhouse gas event that's turned the surface so inhospitable that even
lead melts. There are things which could literally happen at any time -- tonight, tomorrow, next year, in 10 years -- that we would never know is coming until it's too late.
We shouldn't panic about it, but we should be preparing for the absolute worst by putting our eggs in more than one basket. At the very least we have a few billion years before Sol enters its red giant stage, at which Earth will become absolutely inhospitable to life. Before that even happens, the Andromeda galaxy (which is on a collision course with our smaller Milky Way galaxy) will collide with our galactic neighborhood -- though the odds are low that Sol or its system of planets will be disturbed during this event (galaxies are mostly empty space) it's still an alarming threat that needs to be prepared for. We may laugh and say "Oh let them worry about it in a few billion years," but no one will be laughing when something rears its ugly head and it's too late to do anything about it.
crimsonlung said:
Why is it so important to preserve humanity? Once you leave this Earth, you wont be part of it again. So why do you care what happens to the planet once you die?
Because I cherish being alive... I cherish that I was born at all to experience this life, with all its good and bad. Out of all the "potential people" that were never able to be (all the trillions of sperms and eggs which never met), somehow against phenomenal odds
I was given the opportunity to experience... well, anything at all. Of all the never-have-beens, I and the other 6 billion people alive right now have against all odds been given the incredible gift to experience being alive.
That's a gift we give to the next generation, and the generation after that. That is, to me, why we should try to leave this world a better place than when we entered it in any way that we can -- in our own way. Part of that gift includes securing the possibility of a future at all for more humans to experience this incredible thing we call life and the universe. In my opinion it should be a top priority to give a future to future humans; I take the philosophy that we are all caretakers for the next caretakers who are caretakers for the next ones.
