Breaking The Sound Barrier

Don't know how many of you have seen photos of aircraft "breaking the sound barrier" but it is a strange phenomenon, and interesting how it clings to the aircraft until you can increase your speed to go thru that zone. These pictures do a good job of showing how the "barrier" flows around the plane, although it does not show how the front of the aircraft, typically the nose, or on some fighters, the engine nacelle, hits the front of the "barrier", then slowly leaves the aircraft, and when it does, there is a large "boom", known as "breaking the sound barrier", which some of you have obviously heard.  The Boom happens because the plane catches up to and passes the sound it already has produced. At that point there is a collision between the vibrating air (sound) it has produced and the current sound it is making. Faster than this point, the plane arrives to strike before the warning of it's sound does.

This phenomenon only happens at the instant an aircraft breaks the sound barrier.

And it literally appears like the aircraft goes through a wall.

I hope you find these pictures as fascinating as I do.