The POINT of a alcubierre drive is to move at FTL speeds but regardless, if one could build one, then the "rocket" would have to have the ability distort Space time in front of it and we have no idea how to produce such a distortion of space-time without enormous amounts of mass, and so we can't actually build this alcubierre rocket. Nope, I pointed out that those inside the Alcubierre rocket were at rest with respect to locally flat space so there are no time dilation effects. So for them, if you are travelling (as you again just suggested, at subluminal speeds) then if you were travelling 100s of light years in distance then 100s of years would also pass for the crew. Which makes it totally impossible to go between other Galaxies since the nearest is 2.5 million LY away. http://www.npl.washington.edu/av/altvw81.html Yes, but YOUR claim is still absurd: Mercury travels at ~50 km/s, so even doubling the speed is only 100 km/s, FAR FAR FAR lower than 300,000 km/s Sure planets could go faster, but nowhere near half the speed of light.