NASA reveals secret supersonic airplane that quiets the sonic boom to a thump

For decades, aerospace engineers have attempted to design supersonic jets that could achieve incredible speeds without rattling windows and angering residents of inhabited areas below the planes’ flight paths.

Did they? Because my understanding is the we mostly stopped bothering putting resources into civilian supersonic flight, and the military didn’t care about sonic booms. Then, when we finally started applying modern tools to the problem, innovation happened at roughly the rate you’d expect for any major advance in aviation.