Impossible assumes we know everything there is to know about, well, everything. There was a time when everything mad knew said that traveling faster than the speed of sound was impossible. These same geniuses said escape velocity was impossible. I'm sure before that people said powered flight was impossible. We know of theoretical particles that could travel faster than light if we could prove their existence, like tachyons, so can't we say that it's improbable, instead? If space, not our universe, is really infinite, which is the only logical conclusion I can come to, it seems to me our laws of physics would only apply to us, in our universe. They might not even apply here if we "did the math". Like remember when scientists said nothing was smaller than an atom, that it was impossible to have any particles smaller than that? How'd that work out? Every absolute in science seems to be broken at some point.
We are a VERY young species in the greater scheme of things and it always amazes me how humans now, in the year 2012 think they have it all figured out. These are the same folks who say the fact that since aliens haven't visited us, they can't exist, or don't have the technology to travel here. Which presumes they want to. Or that they're simply not as advanced. And then you see those UFO videos the Navy has. I'm not one for conspiracy theories, but objects traveling faster than the speed of sound with no sonic boom: explain that. Or any of the other alleged details. Like Mach speed to 0 and hovering in less than a second. Nothing on Earth we know of does that, so maybe they are here? I have no idea. I really don't care if they are, to be honest. I'm more interested in the physics.
I realize the amount of energy it takes to travel at light speed, but that's what we know of light speed. And of gravity. What if FTL doesn't utilize the same physics? What if you never need to go light speed to go to FTL speeds? What if in the future someone figures it out by tapping into dark matter or dark energy? If one or both exist everywhere in the universe, and, presumably, beyond, and you only need to tap into it, not actually "use it up" like a fuel, there's your energy source.
Or maybe man figures out how to cheat and uses a stable wormhole if they're ever proven to be real, or figures out how to create one (Event Horizon). I know 100% for a fact it wouldn't happen in our lifetimes, but how can anyone say 2 Billion years from now if man still exists they won't be able to travel faster than light to an absolute certainty? Maybe technology will be created to remove the mass of an object in space, I don't know, it seems to me if that were possible light speed would be easy at that point. Most of what we know about the physics of the universe are theories. Like with black holes, which violates the laws of physics if information is destroyed, but since we can't really test that theory, we just go with it.