From what I think, any physical value has at most 3 parts - 1)Orientation - Or more explicitly, the angle that it makes with axis of the Cartesian coordinate system. Transforming will not change this value. 2) Position - This is the translational stuff...exactly from which point to which point. 3)Direction, after defining orientation and position, the line drawn (representing the physical value) should also have a direction at which it points. Since the orientation and position has been defined, there are only 2 values for this. I don't think the position is specific, but however, if I'm right then what does a scalar and vector define?