Charles posted this interesting Question on a Super Hero crossing the Mach 1 Speed. Visitors are requested to respond with your ideas.
“I’m working on a novel with a “superhero” protagonist. The guy puts on his spandex, and takes off across state, say.
OK, as he speeds up, can he tell when he approaches and passes Mach one? I mean, do you think such a character would feel vibrations as he nears the speed of sound, and can slow so he doesn’t boom people below? I read where a condensation cloud appears around jets as they pass Mach 1.”
Answer: When an object crosses the speed of sound (Mach 1) boom is heard if he is traveling through air or another medium. No boom will be heard in vacuum no matter how fast he is traveling. (Sound requires a medium for propagation as it is a mechanical wave). When you write a novel, you can just assume special abilities and capabilities to the super hero. (That is why he is super)