An enigma, an unsolvable mystery yet there they lie, unseen movement, taking their course. There have been many suggestions why or how.
My mind, empirical, tells me to find why but, for a moment, I pause and think more of fantasy or symbolism. They move because they are a metaphor for our lives. They have direction, seemingly random, yet they journey along their course until one day their journey ends.
The empirical mind returns.
Movement is an action of wind, ice, water and slippery clay. I take one small step along my course through life, a metaphor for their journey.