Are we stuck in our solar system?

Assume that FTL travel is impossible. Assume that the human race and its civilizations continue to exist for the next 500 years and that by that time, we can travel at half the speed of light and have created spaceships that are the size of cities and meant to go and never return, carrying a crew of thousands and everything they need toward the stars. In 8 years, the spaceship and crew can be at the nearest star. Assume that every year after that, another ship and crew departs. Within a century, humans could be at every star within 50 light years that has planets capable of supporting humans. Let each of the colonies at each of those stars have. Assume that each of the 100 colonies spends a century colonizing and using the resources of the new planets to create new colonies and that each sends out 100 colony ships of their own. Those 10000 "grandcolonies" can advance a few hundred light years more in another couple centuries. In about 300,000 years, humans can inhabit every inhabitable planet in the galaxy, all without developing any technology beyond that that we'll have in 500 years. By the end of the 300,000 years, there will be trillions of humans inhabiting millions of planets and the gene pool will be safe. No doubt, by then, colonists will have gone to the Milky Way satellite galaxies, and a few will have set off on a multimillion year trip toward the Andromeda galaxy.

Now, assume that rather than being stuck with the technology of 500 years from now, we learn to get to .999 of the speed of light or that we find that FTL is not impossible. Suddenly, the 300000 years can be down to a few thousand or even a few hundred.

Until FTL speed is proved possible and we produce the technology to go FTL, we are not going to run around the galaxy like James T. Kirk. All travel will be primarily one way and will take years and decades to do...It'll be like people sailing from Europe for the New World in the 1600's...making one way trips while hoping to build a new life.

The trick to colonizing the galaxy and ensuring that no 6 mile wide asteroid can wipe humanity from the memory of the planet is merely staying alive for the next half millennium. In the year 1500, ships sailed at speeds of less than 10 miles per hour, horse drawn carriages made 15 where there were good roads, riders on horses could do 40 miles and hour for about a mile before the horses tired. In 1500, there was no electricity, we didn't believe that the Earth moved around the Sun, diseases were all the work of demons and devils, life was fleeting and full of drudgery for most people. In 500 years, we've improved on all the technology and only 3/5 of the world still lives in drudgery. Hopefully, in another 500 years, technology will be as much advanced over today's as today's is over that of 1500. Hopefully, no one in that day will live a life of day to day subsistence, and looking outward to space colonies will not only be a reasonable thing, it will be a realizable idea.

For the forseeable future, yes. My (educated) guess, based on what I know of these things, is that somewhere in the next 100-200 years we'll likely send a probe to the nearest star, and maybe some other really close ones like Barnard's Star. That is, sometime within the next century we'll probably send the probe, and it'll take another century (or a large fraction of one) to get there. And that's just a probe. Colonizing an extrasolar planet would be an undertaking of much larger proportions, even if we can find a planet that's suitable for colonization.

Well, if you are to consider the course of human evolution throughout the whole of our species' future, it becomes a matter of motivation not ability. If the last 1500 years is any indication, humans can be expected to expand their environment in an effort to satisfy unlimited desires with limited resources. Significant advances in technology are a product of a need to survive or dominate rather than academic gain.

So while it can be said with certainty that this century will see the first extra-planetary human colonization, it can be assured that the technologies that will facilitate truly large scale human emigration will be a product of a major event. Good or bad, catastrophe or alliance, we will one day need more than our planet can provide.

By extrapolation one could apply the same formula to human expansion beyond the solar system, however if the motivation to colonize beyond our solar system truly arises, one can be sure that the human race will have changed greatly. I can't tell what is scarier, if we expand beyond the solar system out of a need to survive, or out of a desire to dominate.

So it would seem. The stars, even the closest ones, are many years away in our space craft. If we could travel near light speed, the trip would still take years - we would age more slowly, but not so for the people we left behind. A generations ship might get us out there, but we could never return home to those we left behind.

A breakthrough in physics is needed, or we need to be visited by an ET who knows ever so much more than we do. Current science says both are unlikely or impossible.

How do we identify a suitable destination in interstellar space (a life bearing planet is a must)? How do we power a spaceship at a high enough fraction of the speed of light (antimatter is not available as a fuel)? How to shield the blue shifted cosmic background radiation in the X-ray wavelength at near light speed (heavy lead shielding is not practical? These are just a few of the questions which need solutions before we even think about the political will, and depletion of Earth's resources, in order to make such a one way journey lasting several generations for a select few and their offspring possible; towards a very uncertain future, hundreds perhaps thousands of light years distant.

Not in the near future but let some millennia pas by and we will find a way (when there is a will there is a way). Einstein’s and general science portrait light as having a speed limit, wrong, such a limit is imposed by Dark Matter, ones we understand what it is and how it behaves we will break the limit and go like Capt. Kirk in the enterprise, (warp speed). We will colonize other solar systems and beyond.

Yes depressing isn't it? Oh an don't count on travelling at the speed of light. If we can achieve 1/10 th of the speed of light it would be a remarkable feat. So the 20 light year star would take us 200 years to get there.

I Say a higher to more moderate Solar flare even took out the Dinosaurs, and changing life on Planet Earth !

No. The faster you go the more your mass increases. If we even went 99.99% the speed of light our mass would be so great that gravity would just began to crush the ship and people in it.

Yes, we'll get there eventually. Also if we could get up to near light speeds, time would slow and we wouldn't notice as much time passing, e.g. we wouldn't age as much.