Imagine a much simpler mechanism, a long crystalline pole, effectively incompressible. When you push one one end of the pole the whole thing moves. Now imagine there is a button at the other end of the pole that is operated when you push on the pole, i.e. you push on one end and simultaneously the button is operated at the other end. If this pole is 300km long how long will it take for the information to push the button be propagated from one end of the pole to the other since the button is effectively pushed at the time time that you input the energy to push it at the opposite end?