Zeno's Paradox: Achilles and the Tortoise
Zeno of Elea (circa 450 BC) is credited with creating several famous paradoxes, but by far the best known is the paradox of the tortoise and Achilles. A fleet-of-foot Achilles is unable to catch a plodding tortoise which has been given a head start, since during the time it takes Achilles to catch up to a given position, the tortoise has moved forward some distance. But this is obviously fallacious since Achilles will clearly pass the tortoise!
attempts — visualizes Achilles' successive attempts to catch up with the tortoise. You can see distances traveled by each participant after a fixed number of attempts.
time — shows a graph of the distance traveled by each participant as a function of time.
race — lets you see Achilles and the tortoise race!