The light on the leaves brightens and fades in rhythm with the passing of clouds.

I could, with not too much effort, tell you the exact wavelengths of light or the amount of light or lack thereof needed to turn just these wavelengths. Then I could go on to trace the excitation of neurons from the retina through the visual cortex and into the idea of photons filtering sideways through early autumn changing leaves, the shadow layers not quite totally blocking the light falling on one leaf on the west side of the birch that sparkles out thereby.

It is a crazy wonderful thing to be human; part solo wolf, part herd cow, part body and part idea. Unlike wolves, our aloneness contributes to the herd just as that leaf is part of my tree experience and my tree is also the parade of thoughts around the tree, angstroms and earth's tilt and duality included.

There is no dichotomy in our duality. We are science plus spirit down to our bones just as surely as we are learned astronomers and swingers of birches, and each of us, wolf and cow alike, contribute to the splendor that is mankind: a birch tree set against snow covered mountains.