Flight

Flight is the process of moving through the air. It occurs among many animals, notably birds, which employ true or powered flight through the use of wings and specially adapted bone and feather structures. Other animals and some plants can use gliding for flight with slightly less volition over direction and range of flight. Gliding relies upon a body or shape that offers resistance to the air and possibly using upwardly moving air thermals to maintain or increase height. The purposes of flight in nature include mobility, escape, ability to reproduce, and the search for food.

The human desire to achieve the freedom of flight inspired the imagination of many scholars and scientists over the centuries. Leonardo da Vinci sketched a flying machine reminiscent of modern ...