Imagine a vibrating rod in the water
If the rod had been vibrating
In one place we would have seen
Concentric circles centered on the same point
But since the source of the waves is moving
The wavelenght is shortened on one side
And the kenghted on the other.
This is known as the doppler effect

In the airplanes this effect
Is very cool in the speed of sound,
Also known as match one,
An explosion cuting the air

Sonic boom!
Crushing the glasses.
Sonic boom!
Cuting the air
Sonic boom!