If Sol goes - whether it be by dying or exploding, we better have done more than just colonized space. Being anywhere in this solar system will not be good enough. We will need to be at other stars. The nearest Sol-like star is Tau-Ceti, which is 12 light-years away. That might sound "close" in interstellar terms, but that's 70,388,352,000,000 miles - 70 Trillion miles.
So - what does it *really* take to reach the *closest* Sol-like star?
1) The ability to travel at a speed of at least half the speed of light. That will make the journey a *mere* 24 years - not counting the time it takes to reach 50% of the speed of light and then slow back down. Is this possible in a million years? I would like to think so.
2) The ability to live in space for the time of the transit. Again assuming 50% of c, it is a minimum of 24 years, most of that time in the vast gulf between the stars. We will have to take ALL of our life-sustaining environmentals with us - air, water, food, etc. The alternative is suspended animation. Neither of these seems possible to me - not based on the human form as we know it today.
OK, so what if we assume we are not restricted to the human form?
3) Moving beyond H. sapiens. Could we evolve into a form that could survive outside of Earth's protective embrace? A million years ago, H. Sapiens did not yet exist. Neither did H. neanderthal. H. erectus was at approximately the midpoint of its existence. So, yes, a million years is enough time for a significant amount of natural evolution - but even H. erectus is not a very large evolutionary change. He's still a mostly water-filled sack of protoplasm that breathes oxygen and expels carbon dioxide. That's level of change isn't going to provide us any significant ability to survive in space or on anywhere different than good old Earth.
Could we *create* the ability to change ourselves? In a million years could we engineer our DNA or our molecular architecture such that we could survive off Earth? Hmm - that's a tough one. I am thinking the issue is less about whether we *could*, and more about what would we change into? What would allow us to survive in space? What can survive in vacuum and at a temperature so close to absolute zero that's the difference doesn't matter? But, maybe we don't have to go that far. In Old Man's War, John Scalzi wrote about humans that were modified to survive war on alien worlds. The modifications included skin that could photosynthesize so you did not need food, smart blood that would instantly clot and repair tissues and the ability to transfer your mind from one body to another. Which leads me to the next idea...
4) Mind transference as a means of travel. Since the flesh is weak, leave it behind. If you can transfer a mind like a stream of digital data, then there is no reason to transport the body at a fraction of the speed of light. All you need to do is send your mind as a transmission to a body waiting for you on the other side of the transfer. Travel time is cut in half (12 years to Tau Ceti), and there would be no pesky body aging or life-support needed during the transfer. Time would not even pass for your consciousness while in transit. Of course, this requires an awful lot of infrastructure at the receiving end, so this is definitely putting the cart before the horse. *If* we can establish an interstellar civilization, then such miracles might come - but not before...
Edited by billybob_jcv - 4/13/15 at 6:37pm