April 2, 2004: Hour One: Leptin and the Brain / Cancer Stem Cells
April 2, 2004: Hour Two: Alternative Fuel Vehicles / Science of Lewis and Clark
April 9, 2004: Hour One: Science Policy / RFID / Kids and TV / Amazon
April 9, 2004: Hour Two: Rat Genome / Jonathan Weiner, 'His Brother's Keeper'
April 16, 2004: Hour One: Gravity Probe B / New Source Review
April 16, 2004: Hour Two: World's Fairs / 'Tooth and Claw' Play
April 23, 2004: Hour One: Peer Review Policy / Tree Height
April 23, 2004: Hour Two: New Science Museum / Smallpox Vaccine
April 30, 2004: Hour One: First Fire Use / Spyware
April 30, 2004: Hour Two: Stem Cells and Heart Repair / Margaret Atwood