I haven’t talked physics in a long time, so now’s as good a time as any.
The video below is a demonstration of sonic booms. It is really nice, and shows some condensation clouds created by planes nearing the speed of sound. Folks of seen this before.
One additional neat thing: the video shows that as light enters the pressure wave, and refracts, one can see an effect similar in many ways to a desert mirage … except that it will move away from the aircraft along with the wave. It is at the end of the video, and I thought it was pretty cool!