Time travel is not possible

If it is, we will have been visited by time travelers.

Feel free to disagree and/or flame!

Didn't even bother I see.  Well the reson this problem seems impossible to solve is because it is.  TIME is a Concept, Speed is a Concept, Distance is a Concept.  Don't belive me rephase that problem anyway you want it will still be impossible.  Argueing about time travel is silly when there is no time to travel in.