This is a question that has bothered me for quite some time but I don't have a clue where to start in researching it.
Let's say we have a string which is arbitrarily long, light enough to not take much effort to pull but rigid enough that it would not break or stretch. If I now stand at one end of the string and pull on it, does the other end move instantaneously? If so, could we use such a method to send a message faster than light? I'm not referring to the speed of the rope itself, but to the time between pulling one end and the other end moving accordingly.
My knowledge of FTL messaging/travel (basically gen-ed physics and the movie Interstellar) tells me the answer is no, and there's a whole lot more going on at the atomic level, but I don't know exactly what forces are at play.