in their moving frame of reference i think you can see but the problem all as a political straight line it looks exactly the same as the day before when doctor whom did the experiment with the car etc if we were moving along in this frame of reference and we couldn't see the surroundings then we wouldn't be able to tell by this experiment that we were moving at a constant velocity as a matter of fact we wouldn't be able to tell by any experiment that we were moving at a constant velocity i'm gonna do the experiment once more and this time i'm not going to stand here behind the ball at the fall so that you won't have any fixed repertoire