Suppose we have a perfect lever, which has 0 quality, and perfect rigidity. It is long enough that can reach Proxima Centauri from the earth.
Someone push one side of lever from Proxima Centauri, immediately, the person from the earth will get the force. That means the force speed is infinity. With this way, information can be transferred via the lever immediately.
In real world, what the force speed will be for quality>0, and not perfect rigidity? Roughly, speed will be bigger for smaller quality lever, and speed will be bigger for high rigidity thing.
My question, is there any research on this area?