Sonic boom research. Coloured schlieren image showing the shock waves around a T-38 jet aircraft flying at Mach 1.1 (1.1 times the speed of sound). The shock (compression) waves appear as red and green diagonal lines. The main shock waves come from the nose and tail of the aircraft, with smaller shock waves from the engine inlets and the wings. Behind the aircraft is a wake (yellow) caused by the exhaust of the jet engines. The image was made using a special camera which allows schlieren photography of shock waves from real aircraft to be performed for the first time. This is of particular benefit to scientists researching the propagation of sonic 'booms'.