Hello. Some years ago I came across an animated illustration of relativity, housed in what seems to be a classic use of a bouncing light within a spaceship. (Similar to that found in http://galileoandeinstein.physics.virginia.edu/lectures/srelwhat.html.) My education in physics is limited to one general physic course in college, so I'm not even up to novice level in this field. But after thinking on this (in my own limited way), two questions have haunted me that I am hoping someone can kindly explain to me. One, the mental experiment is build upon the premise that besides light's own trajectory (at c) perpendicular to the path of the spaceship (SS), light is also traveling along within SS at the latter's velocity -- as if it is inerially bound to the vehicle. Before even attempting to deal with questions of whether this forces light to travel at faster than C (mathematically, the SqRt of c2 + Vss2), I am first curious as to what is the basis for believing that the light beam will be "pulled" along within the trajectory of SS? My assumption is that light is not inertially bound to SS, and thus once "started" that beam of light would travel in a straight line totally independent of SS's movement, non-movement, or change in movement. What am I missing? Can someone point me to experimental (or other) evidence that ties light to the movement of a material vehicle? Second, I'm having trouble grasping the differences in distances (and thus, the warping of time/space to allow for light speed constancy) that this experiment is supposed to illustrate. According to what I've read, within the same fraction of a second the light beam travels different distances relative to the onboard and outside observers (arguably necessitating a warp in time/space to allow light to remain a constant speed as it travels these different distances). I do follow the explanation of difference in distance..., but I'm not seeing how that really describes the situation. Using a four-dimensional coordinate system (i.e., the spacial X, Y and Z axises within SS (or whatever coordinate system that light is bound to), plus a fourth dimension of where those axises are at T(1) and T(2) (Time 1 and Time 2) as the coordinate system (SS?) itself travels through space, it looks like the distances are identical for both observers -- in fact, for all observers wherever they may be. If that is right, then it seems to me to remove the necessity for time/space warp, at least within the illustration. Please understand, I'm not approaching this as a challenge to Einstein or his theory. It's just that I'm hoping that someone more knowledgeable in this area can kindly explain what I'm missing. Thanks.