My students came early for an advanced class today, and probably because of the rain, they stayed rather than drop off their bags and come back in time for the class.
Using some small foam dice as balls and some bags as bases, a game of baseball got going. Even though the foam dice aren’t heavy or hard, the mere action of swinging my umbrella caused it to bend. When I tried to bend it the other way, I ended up making a 90 degree bend in the shaft of the umbrella. Some other students tried using their umbrellas as well and similarly bent the main shaft.
Now our umbrellas are difficult to collapse. Now I know I need to get the "Unbreakable Umbrella." I’d expect that will not bend from the simple action of swinging the umbrella like a stick through the air.