Why do balloons pop around an adhered point when subjected to movement (pulling rubbing etc.)?
First create an adhered point by cleaning all the talc/cornstarch from a balloon, inflating it, and rubbing it against itself with a lot of force. Or by making a lock-twist. Or tie a knot in the nozzle and roll the ever-tightening knot towards the nozzle. If you press your clean palm against a clean table, press down and then try to slide, you will get a jerky, stop-and-go motion called “stick-slip motion” or “stiction” (sticking-friction). If you look very carefully at the adhered point on the balloon when subjected to movement, you will get the same thing – the rubber welds to itself (sticks) and then tears (as it slides) because of the low shear and tensile strength of the latex. You can actually see the tearing debris accumulate when you do this (wear goggles!) Once this mechanism tears a hole in the balloon, the shape of the hole, stress in the wall of the balloon, toughness, and thickness of the latex all come into play in determining how the balloon responds. This kind of thing
