For flying successfully, a pilot needs to understand the sky. This book is a guide for Balloonists, RC Modelers, Parachutists, Hang Glider, Paraglider and Sailplane Pilots.In the closing decades of the twentieth century, a fortunate coincidence of timing and technology has allowed our species-designed for life on the surface of planet earth-to enter the atmosphere and cavort among the clouds. Flying for fun has come into its own as a reasonable and legitimate pastime. But inhabiting the realm of the sky requires a certain amount of understanding. The air is an ever-changing environment and we must know its ways and wiles in order to fly safely and become excellent pilots.