TWO PARADOXES BY ZENO

From GAMES Magazine

November/December, 1979

 

1. Achilles sees a tortoise in the distance moving slowly ahead and sets out to catch up with it. But when he reaches point A, where the tortoise was when first seen, the tortoise will have moved to point B. When Achilles reaches point B, the tortoise will have gone on to point C. Therefore, however many times this process is repeated, the tortoise will always be that much ahead of Achilles, and he can never catch up.

2. Motion does not exist. Consider an arrow in flight. At each instant of flight, the arrow occupies a space equal to itself at rest. But anything occupying a space equal to itself at rest is at rest. Therefore the arrow is at rest.