The slides show some of the calculations behind the astonishing
results David refers to. I find it most interesting to note
1) that long duration (and I mean REALLY long duration) trips in
space will both demand AND be limited to essentially constant
accelerations pretty darn close to g due to the requirements AND
limitations of human physiology.
2) that, as a result, in a Newtonian universe--in which
"speed is unlimited"--we would be limited by our own longevities
to exploring at most a minute fraction of our own galaxy.
3) but that, in a relativistic universe--which naively appears to
impose a "speed limit"--we could easily--and, more importantly,
*comfortably*--explore essentially the entire universe.