>>13912269Nice bait. The movement propagates at the speed of sound *in the medium*. The speed c = sqrt(E / rho), where E is the Youngs modulus and rho is the desnity. E = sigma / epsilon, where sigma is stress and epsilon is strain.
Obviously if your material has zero density or your ratio of stress to strain is infinite your speed is infinite, but such a material is not physically possible.
