My favorite demonstration of this effect is this moment of Queen during Live Aid at Wembley Stadium: https://youtu.be/TkFHYODzRTs?t=1094 https://youtu.be/TkFHY

My favorite demonstration of this effect is this moment of Queen during Live Aid at Wembley Stadium: https://youtu.be/TkFHYODzRTs?t=1094 https://youtu.be/TkFHYODzRTs?t=1094 Everyone in the audience is clapping in time with the beat, _as it reaches them_, and you can see the speed of sound as the beat propagates out through the crowd. I often use this to illustrate yet another reason that CPUs went multi-core: When propagation across the chip takes longer than your clock speed, you have to reduce the distances somehow. A bunch of small stages in the same acreage would have a much easier time each clapping "together enough".