when horns are blown in opposite directions (as sound revolves around the world and finally collides...)

shadow...

"for years i've been trying to pick up my shadow on a sunny day, to put it in my pocket for a rainy day. i remember to do this now and then. it's been difficult. and to tell the truth, i've never succeeded. the shadow changes as i bend over, and i can't quite compress it to fit into my jeans."

allan kaprow, 1997