The best thought experiments throw light into dark corners of the universe and also provide other scientists, philosophers, mathematicians and destitute PhD students a way to kill time while waiting for the bus.

Below is a classic thought experiment, pillaged from my book The Geeks' Guide to World Domination (Be Afraid, Beautiful People). I'll post a new thought experiment each day this week.

**Achilles and the Tortoise: Zeno’s Paradox**

Here’s a classic, pulled straight from the humanities course you took senior year in high school:

Achilles and a tortoise have a race. Achilles, being much the faster, allows the tortoise a 100-yard head start. They start. Of course, because Achilles allowed the turtle to start ahead of him, it takes time for Achilles to reach the tortoise’s starting point. However, the turtle is no longer there—it’s continued ahead and Achilles must again catch up. But, every time Achilles reaches a point the turtle has passed, the turtle has used the time to travel further ahead. Having always to catch up this distance, Achilles will never catch the tortoise!

Right?

And hey, it's been fun chatting thought experiments this week! Join me Monday morning and every Monday thereafter for grandtastic goodies from The Geeks' Guide to World Domination. Or if you like your geekery delivered fresh, consider subscribing to my rss feed or joining my Facebook Fan Page.