Unforgiving Gravity

Aristotle believed that gravity was evidence that all things tried to move to their proper place in the universe. The proper place for a dead leaf, it would seem, is on the ground; the table top is just a temporary way station in its journey.

Newton was less romantic. He argued that every particle in the universe is attracted to every other particle with a force directly proportional to the product of their masses. The dead leaf is attracted to the earth and the earth is attracted to the leaf. The leaf does the moving though; it's a case of size winning out.

Einstein tossed aside both Aristotle and Newton, and claimed that gravitation is a product of space-time being curved by the presence of mass. The fallen leaf, in other words, was traveling on a straight line through curved space toward the larger mass of the earth and the table got in the way.

All I know for certain is that dead things drop.