DVS BSTrD said:
FTL IS Time Travel. Besides if someone fucked-up the past it's not like we'd notice.
This is the correct way of viewing it, + 1 Internetz for you good sir/madam[footnote]Delete as appropriate[/footnote]
Anyway a time machine would have to be able to travel through space with absolute accuracy too if it would be of any use. You see everything is in motion. There is no such thing as absolute rest. You probably think you are sitting still while reading this post, your not. You are in fact on a spinning ball of rock which is it's self spinning round the sun, that is spinning around the galaxy, which is moving within the local cluster, that is also moving in relation to the rest of the universe.
If you had a time machine and traveled just one year into the past you had better be able to breath vacuum because when you re-appeared you would be in the same place but the earth will have moved on in space[footnote]Even if you went back exactly one year you might expect that the earth would be in the same place as when you left, but remember the solar system, galaxy, and universe have also moved. So even though the earth would be in the exact same place in it's orbit around the sun, the rest of the universe has moved, taking the solar system with it [/footnote]
MasterOfHisOwnDomain said:
They're both pretty crap if you think long and hard about it. Time travel into the past would be insanely dangerous if your actions could influence what your present would turn out to be -- heck, even the sight of you appearing in a Time machine would properly completely and utterly change the course of history.
Well not really, it wold be impossible for you to fuck up the past. You see if you somehow changed something that altered the future then when you got back to the future the thing you changed would always have been that way. Also say you changed history to accidently and caused, some how, your mum and dad not to ever meet, you would never have been born. Meaning you could not go back to change anything.
And then FTL travel is also terrible. Sure you'd be able to travel places, but then you would return to a world that is totally changed through the fact that time operates differently when you're moving at greater speeds. So everyone you know would be long dead, and possibly the Earth itself could be destroyed.
Depends on the method of FTL.
Yeah sure that would happen if you accelerated all the way to c using something like a rocket or some other means of convectional propulsion. Though with this method we would still somehow need to get round the problem of mass increasing exponentially as an object approached c. This method would also need you to be able to generate stupid amounts of energy too.
However you can get round it by using a 'warp' drive, which warps space around the object. This would negate the time dilation by allowing the object to travel faster than the speed of light without actually braking c. This btw is currently in the very very early stages of research [http://www.zmescience.com/space/warp-drive-plausible-nasa-research-312031/]
So in closing FTL FTW!
D
