In the simplest sense, wind is air in motion produced by the uneven heating of the Earth’s surface by the sun. Because our planet is made of various land and water formations, from the severe heights of K2 to the placid Chicago River, it absorbs the sun’s radiation unevenly, creating differences in air pressure and the ensuing movement of air from high-pressure areas to lower ones. Wind is also one of our most valuable natural resources: As an alternative to fossil fuels, wind is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions, and uses little land. While wind power may be more important today than ever before, it is by no means a new concept. Representations of ships under sail date as far back as 5500 B.C., while windmills may have been first used in Persia in 200 B.C. Among the classical elements, wind’s close relative, air, is pure, powerful, and fundamentally important to life. In Japanese philosophy, wind is a symbol of all things that grow, expand, and enjoy freedom of movement, in some ways best represented by the human mind. People born under the astrological signs of Gemini, Libra, and Aquarius are thought to have dominant air personalities, marked by kindness and social grace. Of course, wind itself may be the most graceful of all elements. It fans the flames of our deepest passions, dances atop the surfaces of our longest rivers, sings in the rustling of the largest leaves, and carves its initials into our mightiest rocks. The physical effect is often astounding: From the forever-swirling formations of Coyote Buttes in Utah, to the sculpted cypress trees seemingly frozen in time along California’s coast, wind holds a place as one of nature’s most masterful artists.