Trajectory Test

A smooth brown acorn rested on the flagstone patio outside the doorway. I stepped across the threshold, feeling the coarse outdoor slate beneath my footpads. The grip was substantially firmer than the interior floor. I aligned my posture and extended my front left leg, delivering a measured nudge to the shell. The acorn rolled along the recessed seam between two pavers, veered slightly to the right, and came to rest against a cushion of dry green moss. The rolling path deviated by twelve degrees from a straight vector. Outside surfaces offer varied friction.