Regarding the above posts regarding the tractor / stump and the weight on the end of the rope there is a fatal flaw that can be corrected by further explanation.
Tractor / tree stump: If the tractor drives in a circle and is held in that path by a rope tied to the stump, then the tractor will travel in ever decreasing circles unless there is some provision to keep the tractor rotating in relation to the center of the stump. That provision being a shaft that either can rotate with the tractor or, a metal eye braided into the rope with the eye rotating about the shaft.
Weight at the end of a rope: This condition is similar to the above tractor example in that when the shaft starts to rotate the weight will be drawn to the shaft as the rope winds around the shaft. There is no means to transmit the movement of the shaft to the weight through the rope and keeping the rope taut. Once the rope is wound around the shaft there is no way to get the weight to move outward as to do so it would have to move faster than the shaft.
I realize there are explanations that can account for these anomalies but when you speak about anything using analogies then someone will find fault or possibly not understand when the only thing they know is that rotorblades are made to spin because they are attached to the rotorhead.