to follow up on the point above, how do you know that leaving earth is the only way to escape extinction? that's only what you can imagine given the technology

to follow up on the point above, how do you know that leaving earth is the only way to escape extinction? that's only what you can imagine given the technology available, just like someone living in 320 couldn't conceive of space travel. I agree that the ultimate purpose of any species is to continue to exist. I'm just skeptical because your definition of that is so related to modern science fiction