Why does it have to be relative to earth? I though teleporting means that you move from point A to B Instantly, without actually traveling the distance between them!,(reply>), @Nulono You're right, in that the most sensible reference frame is the smallest one which includes both your origin and your destination.,(reply>), +Nillie I always assumed teleportation would either be relative to your starting position or your chosen destination.,(reply>), I guess you are right. I thought the teleportation would happen at the same time as I have chosen the location. :/,(reply>), @Gairos The transportation bit is instantaneous, but in most works of fiction it takes a tiny amount of time from you make the decision to when you actually teleport. (Even the time it takes to spin around once, like when Apparating in the <i>Harry Potter</i> universe, is enough to cause you to miss your target.)<br>Therefore, you either need to use the Earth as your inertial reference frame (simple) or calculate where your destination will be at the exact moment of teleporting, and being even a fraction of a second off schedule will cause you to end up way off target.,(reply>), But because teleportation is instant you wouldn't have to worry about that. the exact moment you pick a spot you will be transferred there, right?