Quote Originally Posted by Nessus View Post
Who cares about Earth when you're on that ship though
If it hasn't destroyed itself, and technological progress continued at its usual rate, you'd likely be aiming your ship at a planet that is still going to be of interest to future Earth and with the time dilation and your leaving much earlier than ships sent after you, you could be, technologically, culturally and perhaps even biologically, decades to millenia behind whatever human or human-species offshoots you might find there. Although that would be one giant mind-fuck.

Quote Originally Posted by Khendraja'aro View Post
I dare say that even for such a "tiny" trip as 20 lightyears, we'd still need a Generation ship. Reaching .5 c is a fantasy value as the ship would simply lack the reaction mass to reach this velocity. And you also have to consider the time spent decelerating.
I was merely using that value to show that developing Axe body spray and talking pens wasn't what was holding us back from being able to launch a starship to Gliese anytime soon, and I did factor in deceleration, hence the "at least" after the 40 years.

I forgot to factor in time dilation for the rest of it though, and don't know that off the top of my head...