I'm sure along with discovering this, it also gave you an explanation for the science of sweeping which is also super neat and to the casual observer, not a well understood part of the game. At the micro level, the abrasive texture of the brooms is melting pebble (not entirely, just temporarily along the sweeping path) and affecting distance, deceleration, curl.

Sorry, kinda nerding out over seeing a curling article on HN.