In this video excerpt from NOVA: “Hunting the Elements,” New York Times technology columnist David Pogue explores how isotopes of carbon can be used to determine the age of once-living matter. Learn how variations in atomic structure form isotopes of an element and how the three natural isotopes of carbon differ from each other. Meet paleoclimatologist Scott Stine, who uses radiocarbon dating to study changes in climate. Find out what it means for an isotope to be radioactive and how the half-life of carbon-14 allows scientists to date organic materials.

This video is available in both English and Spanish audio, along with corresponding closed captions.