A study at Manchester Metropolitan University involving dropping 100 slices under laboratory conditions established that toast typically lands on the floor butter-side-down as a result of the manner in which it is typically dropped from a table, and the aerodynamic drag caused by the air pockets within the bread. The toast is typically butter-side-up when dropped. As it falls, it rotates; given the typical speed of rotation and the typical height of a table, a slice of toast that began butter-side-up on the table will land butter-side-down on the floor in 81% of cases.[20]