How can sand, blown by the wind, form such intricate and beautiful patterns as ripples and dunes? The answer is a surprising secret of self-organization. In this video, we travel to Great Sand Dunes National Park in Colorado to climb the largest sand dunes in North America and bring you the science of how wind and sand combine to create ordered landforms out of chaos. The science must flow.

is zero something even if it's nothing? Is nothing just an idea? And if nothing is the opposite of something, does it actually exist?