Solid materials get all the production credit. Don’t get us wrong, we depend on their strength and firmness for bridges, bones, and bento boxes. But liquids do us a solid, too. Their free-flowing properties drive the Earth’s magnetic field, inspire a new generation of smart electronics, and make biology possible. But the weird thing is, they elude clear definition. Is tar a liquid or a solid? What about peanut butter? In this episode: A romp through a cascade of liquids with a materials scientist who is both admiring and confounded by their properties; how Earth’s molten iron core is making the magnetic north pole high-tail it to Siberia; blood as your body’s information superhighway; and how a spittlebug can convert 200 times its body weight in urine into a cozy, bubble fortress. Guests: Mark Miodownik – Professor of Materials and Society, University College, London, and author of “Liquid rules: The Delightful and Dangerous Substances that Flow Through Our Lives” Arnaud Chulliat – Geophysicist, University of Colorado and Institut de physique du globe du Paris Philip Matthews – Comparative physiologist at the University of British Columbia Rose George – Journalist and author of “Nine Pints: A Journey Through the Money, Medicine, and Mysteries of Blood” originally aired April 8, 2019 Big Picture Science is part of the Airwave Media podcast network. Please contact sales@advertisecast.com to inquire about advertising on Big Picture Science. You can get early access to ad-free versions of every episode by joining us on Patreon. Thanks for your support!   Learn more about your ad choices. Visit megaphone.fm/adchoices