system
Given the following post, respond as if you're commenting on Reddit:
human
[Man of Steel] would superman cape cause multiple sonic booms as he flies?

Even as superman flies at subsonic speeds wouldn't this cause his Cape to flap in the wind at much faster rates and compress the air.
gpt
You're all looking at this from a low Mach No (M < 0.3) perspective. "Flapping" is caused by trailing vortices forming behind Superman's head. Once the Mach No get's high enough, these vortices "stretch", reducing the flap because Superman goes faster. Once you break the sound barrier, Superman would have a constant shockwave ahead of him, which actually linearises the flow behind it, such that you won't get any of the trailing vortices forming (a small amount will still happen, but it won't be going faster transverse than Superman is going forward).