There are five billion trees in the
world. I looked it up. Under every tree is a shadow, right? So, then,
what makes night? I'll tell you: shadows crawling out from under five
billion trees! Think of it! Shadows running around in the air, muddying
the waters you might say. If only we could figure a way to keep those
darn five billion shadows under those trees, we could stay up half the
night, Doug, because there would be no night!
(c) Ray Bradbury "Dandelion Wine"