Why was the “sound barrier” ever considered a barrier in the first place? What is it about the properties of air that made achieving supersonic flight such a heralded feat of aerospace
Speed of Sound in Physics
Two Sound Phenomena Explained: Sonic Boom and Acoustic Shadow – Flypaper
Sound barrier | Supersonic Flight, Mach Number & Shock Waves | Britannica
Acoustics: Definition,Meaning, Types of Acoustics and Questions