/r/Damnthatsinteresting: Damn, that's interesting! - The most interesting place on reddit - February 3, 2022 - 15:33
/r/shockwaveporn: Shock Wave Porn - A subreddit dedicated to shockwaves Definition: "region of abrupt change of pressure and density moving as a wave front at or above the velocity of sound, caused by an intense explosion or supersonic flow over a body" - February 3, 2022 - 15:33