Special bonus of the week! A video inspired by the mathematician, Steve Strogatz. At the age of thirteen, Steve was astonished to find that pendulums and water fountains had a strange relationship that had previously been completely hidden from him.

Chris had a crush on Lisa. But how to woo her? He met her on a park bench in Chicago, handed her a stack of CD's, and sent her off on an extremely specific mission. Did it work? Find out on this week's podcast.

Two short pieces on sperm that hint at the new ideas and amazing stories we came across once we started following the trail of this wriggly little cell.

Remember the first time you ever saw an ant hill? That parade of black insects pouring in and out of a small sand mound...most of us stopped, looked, and then moved on to other parts of the playground. E. O. Wilson is the kid who never took his eyes off the mound.

We play some never-released tape from the vault, and reveal a bit about what techniques we used to try and make it sing.

Jad and cellist Zoe Keating discuss the physics (if not metaphysics) of looping sound, and how to use a 17th century instrument to make avant-garde electronic music.

Robert and Brian Greene discuss what's beyond the horizon of our universe, what you might wear in infinite universes with finite pairs of designer shoes, and why the Universe and swiss cheese have more in common than you think.

Robert Krulwich's commencement speech at California Institute of Technology gets at the heart of what we do here at Radiolab. It's a treat to hear his passion. We enjoyed it. And we thought you might too.

This week, a piece from one of our favorite radio-makers, Jonathan Mitchell. 'City X' is a history of the modern shopping mall through perspectives of people living in a real, yet unnamed, city.

First, we asked you to tell us what song gets stuck in your head. Then, we asked you how you got it out. Finally, we made a podcast. Thank you to everyone who called in, shared their secret techniques, and sang without shame.

An excerpt from Wordless Music on WNYC, a 4-part music program hosted by Jad, exploring the boundaries between classical and pop music. Jad waxes googly-eyed fan when he gets to talk about one of his favorite bands, Stars of the Lid.

Jad presents a piece by one of his favorite producers: Ben Rubin. This audio portrait, called 'Open Outcry,' visits the trading floor of the New York Mercantile Exchange, with its hundreds of traders shouting unintelligible phonic abbreviations and numbers back and forth.

Ever wonder how Jad and Robert met? They tell their tale on stage at Oberlin College, and talk about how they started tinkering around with tape to come up with the Radiolab you know today.