Breaking The Sound Barrier

In aerodynamics, the sound barrier usually refers to the point at which an aircraft moves from transonic to supersonic speed. The term came into use during World War II when a number aircraft started to encounter the effects compressibility, a collection several unrelated aerodynamic effects. By the 1950s, new aircraft designs started to routinely "break" the sound barrier.
Some common whips such as the bullwhip or sparewhip are able to move faster than sound: the tip the whip breaks the sound barrier and causes a sharp crack—literally a sonic boom. Firearms since the 19th century have generally had a supersonic muzzle velocity.
The sound barrier may have been first breached in nature some 150 million years ago. Some paleobiologists report that, based on computer models their biomechanical capabilities, certain long-tailed dinosaurs such as apatosaurus and diplodocus may have possessed the ability to flick their tails at supersonic velocities, possibly used to generate an intimidating booming sound. This finding is theoretical and disputed by others in the field.