Frogs' Pants

An 18th century scientist fitted a pair of tailor-made briefs on a male frog to determine the animal’s contribution to reproduction. Find out what was learned, and what other odd-ball theories scientists tested to answer the question of where babies come from. Also, why the 1970s Viking experiments designed to see if there’s life on Mars couldn’t give us a conclusive answer. And, a tour of the world’s barren places.