If a human were to wear a jetpack and could fly at the speed of sound, what would he feel? Would he feel the sound waves piling up on his head? What would he hear? Inside supersonic aircraft he would hear nothing, and anyone outside would hear the pressure wave, but, what if his head is the point where the sound waves pile up? What if he had a really strong helmet so that he would not be killed? What would his body feel? Would he feel the sound waves build up on his body? Assume he has a suit that he can't be killed.