What else do we have available?
The evidence against things like FTL travel are backed up by scientific theory
The theory of relativity dictates the joining of space and time as a single entity.
It would require infinite energy to accelerate an object past the speed of light which alone should indicate to all but the very stubborn that it would be virtually impossible for any life form to leave its local area.
Traveling faster than light would also break down the bonds in atoms, the proton would loose its electrons and you and the very ship you were trying to travel in would disintegrate into nothingness..
It's mental that people think this is anything but a pipe dream but I suppose if you've already made your mind up that aliens are here then you're not going to let science get in the way of that