Aerodynamics, from Greek ἀήρ aer (air) + δυναμική itself from δύναμις dynamis (force ; specially, miraculous power), is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a solid object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with the difference being that gas dynamics applies to all gases.
Founded as Società anonima Carrozzeria Pinin Farina in 1930 by automobile designer and builder Battista "Pinin" Farina, Pininfarina has been employed by a wide variety of high-end automobile manufacturers, including Ferrari, Maserati, Rolls-Royce, Cadillac, Jaguar, Volvo, Alfa Romeo, Honda, Fiat, Proton, Peugeot and Lancia. It also has designed trams in France, Switzerland and Greece, high-speed trains in Holland, and trolleys in the USA. Since the 1980s Pininfarina has been consulted on industrial and interior design.
Pininfarina was run by Battista's son Sergio Pininfarina until 2001, then his grandson Andrea Pininfarina until his death in 2008. Andrea's younger brother Paolo Pininfarina was appointed as successor.