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The analogy from my physics class long ago was we each hold one end of a broomstick, if I shove the stick, you'll feel the stick move at a delay consistent with the speed of sound (speed of sound in wood, different than air...) yet the stick actually moves physically a good deal slower than the speed of sound when it transmits the force that moves at the speed of sound. If I whack the broomstick you'll feel it vastly sooner than I can hand the entire stick to you. Speed of sound in wood is hundreds of miles per hour, but I can't physically move a wood broomstick faster than several dozen miles per hour.

Bulk material moves slower than forces move... usually. The physics of shock waves and supersonic stuff is interesting.




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