Here's a bit of history and perhaps comedy for you. Ever heard of the SR-71 Blackbird? It was a spy airplane built in the sixties when we used to like real innovation. It could do Mach 3, three times the speed of sound.
The speed of sound is over 700 miles per hour, but it varies wildly based upon many atmospheric conditions. One day over L.A. a few planes asked LA Center for their ground speed. The date of which is classified apparently still since out of all the stories I've found about this, the exact date is never mentioned. Suffice it to say it was before GPS was widely implemented. Anyways, it was pretty funny apparently, but here's some stuff about it. An article:
SR-71 BLACKBIRD PILOT TELLS THE STORY BEHIND HIS FAMED GROUND SPEED CHECK
And here's one of many speeches by said pilot of thatg day:
