Oh that is truly amazing! I want to understand it but I'm going to accept it right now, on the general principle of acceptance over analysis. Plus I briefly looked into a scientific explanation, and not only did it not yield enlightenment, but like explanations for the evolution of the eye, it didn't really tell me what I wanted to know: what is the reason that so many chaotic forces combine to create something that functions with such tremendous beauty and power? Why not be messy and muddled? Wherefore the urge for order?
Enough. I'm often blown away by the fact that people negotiate sidewalk traffic.