From first principles, I think the most we can say about any of those future goodies and gizmos we've been promised -- warp drives, longevity, colonies on Mars,

From first principles, I think the most we can say about any of those future goodies and gizmos we've been promised -- warp drives, longevity, colonies on Mars, asteroid mining -- is "we're not getting there anytime soon" (within 2-3 generations, say). Beyond that, everything about the unpredictable nature of science and innovations says: we just don't know. And any attempt to assert confidently otherwise is exactly what it seems -- just posturing.