Nova: What is the strongest material in the world? Is it iron? Are Kevlar and carbon nanotubes the way of the future, or will the powerful properties discovered in natural spider silk one day replace steel? NOVA begins the ambitious four-hour program with a quest for the world’s strongest stuff. Host David Pogue helps viewers understand what defines strength, examining everything from mollusks to a toucan’s beak and testing the world’s strongest materials. Pogue travels from the deck of a U.S. naval aircraft carrier to a demolition derby to the country’s top research labs to check in with the experts who are re-engineering what nature has given us to create the next generation of strong “stuff.”