NPR reporter David Kestenbaum tells host Ira Glass about the time, when he was doing graduate work in physics, he and his other single friends decided to figure out the mathematical probability that they'd find girlfriends. They wanted to know what the chances were that there was more than one person in the world for them.

In the war on terror, the government is rounding up foreigners, checking their immigration status, and then, sometimes, deporting them. It won't give out their names.

We hear two stories of everyday life which are more easily understood if one knows some of the laws of physics, specifically the Mediocrity Principle and the Casimir Effect.