Also during the Pacific/UC Santa Barbara baseball game a high pop foul ball was hit to the first-base bleachers. It reached the apex of its tall arc and came down onto the vinyl shade covering of one of the VIP “suites.” The coverings are slanted similarly to a roof on a house, so everyone assumed that the ball would simply roll off and fall to the ground. But it surprised us all when it came down with a dull thud and stayed in the spot where it landed, with nary a slide, bounce or roll. It was as if the covering was made of adhesive tape or coated in glue.
There is the engineering term of critical angle of repose. It refers to the maximum angle that granular material can be deposited in a conical pile before it starts sloughing off. Different materials have different angles due to how much friction they generate. That particular baseball wasn’t magically defying gravity but must have had a pretty high coefficient of friction and steep angle of repose.