 And you can listen to Radio Lab Saturdays at 2 p.m. and Sundays at 7 p.m. on NPR. This is American Life from Ira Glass. Each week on our show, of course, we choose a theme, bring you different kinds of stories on that theme. Today's show, Amusement Parks. It's July. It's hot. We wanted to go someplace fun here on the radio. We've arrived at Act 2 of our program, Act 2, Great Adventures.