Assume there is a long rod or a string connecting two points separated by a distance of several light years. It will take light several years to travel, but by a simple pull or push of the string or rod we can transmit date in binary format, what do you think?
No, that's not true. The time it takes for the rod to move will be much slower than if you send a light pulse from one end of the rod to the other. The rod moves because all its atoms move in a certain direction. The speed in which the atoms move and signal for the others to move is much slower than the speed of light. It is counter-intuitive because most rods we are dealing with are SHORT.