system
Given the following post, respond as if you're commenting on Reddit:
human
How does a sonic boom work?

I was asked this question by a child (11y) and didn't have a fitting answer. Thanks in advance!
gpt
If you make sound, the air compresses in peaks and relaxes in troughs while moving away from you at the speed of sound.
 
If you start moving almost at the speed of sound, you keep putting energy into the peaks, but the last peak has barely been able to move away because you're nearly keeping up with it. 
 
At the sound barrier, you just stack a ton of energy into the same peak over and over, resulting in a massive energy spike at the shock front.