| Good intuition Zeroca;
"A" and "C" are the predominant motions in nature when it comes to atomic structure and interactions. All the others tend to oppose natures bonding mechanisms. Both provide an interface of contact that produces a minimal relative motion between the objects "C" is by far the most common orientation in atomic structures and atomic particle pairs. It is the fundamental concept to what is referred to as "Up-spin" and "Down-spin" in thermodynamics and can produce negative values of temperature below "absolute zero". This is like treating the standing wave functions of matter as being "Angular Momentum" and thus the conservation of angular momentum seems to be maintained.
Another thing to think about is that velocity (linear motion) tends to cause the axes to align parallel to the direction of motion.
__________________ David |