I don't know how common knowledge this is, but you can feel the "boom" as the Concorde passes you westbound.
We were in an AA 767, As I was recording some video of it passing us overhead (like watching a contrail pass you on the ground), Other crew says "here comes the boom". I thought he was smoking something but in perfectly smooth air came a muffled slight boom. Not much, more like a slight slap one might get with an open hand on a car door, but still readily apparent in the smooth sunshine westbound on the tracks.
It seems somewhat strange for me growing up watching men walk on the moon, Mach 3 spyplanes and Mach 2 airliners, to end up where we are now. the world of aviation is starting to seem like the accounting field.
I'd better brush up on my Chinese so I can understand the next moon landing speech.