Sonic boom faster than the speed of sound, thus creating a sonic boom. The whip is probably the first human invention to break the sound barrier. A bullwhip tapers down from the handle section to the cracker. The cracker has much less mass than the handle section. When the whip is sharply swung, the energy is transferred down the length of the tapering whip. Goriely and McMillen showed that the physical explanation is complex, involving the way that a loop travels down a tapered filament under tension. Sonic boom A sonic boom is the sound associated with the shock waves created whenever
Swept wing air in front of the aircraft begins to compress. This creates a force known as wave drag. This wave drag increases steeply until the whole aircraft is supersonic and then reduces. However, shock waves can form on some parts of an aircraft at a speed where the aircraft is moving at less than M=1.0 because the "local" speed of sound is determined by air temperature. A rapid drop in air density caused by aircraft contours will reduce the local air temperature and will correspondingly cause a drop in the local speed of sound that can cause shock waves to form.