Take an average size orange and wrap it tightly in plastic food wrap. If the Earth were the size of the orange, the atmosphere that sustains almost all known life would be the thickness of the plastic wrap. The oceans have great streams moving through them. England and Europe, for instance, aren't as cold as Labrador, which is at the same latitude, because the Gulf Stream warms them. There are also great streams of air running around the Earth. Here at 32,000 feet, a thunderhead crown has drifted into a minor air stream and, like the butcher who backed into his meat slicer, is getting a little behind in its work.