Students will learn how radiocarbon dating works to determine the ages of some very old materials. They will explore how it has changed our view of history and the controversy that has arisen from its use.   The program includes an activity using M&M's candy illustrating "half life", a concept critical in understanding how radiocarbon dating works. The lecture will end by showcasing LLNL's capacity to radiocarbon date objects at the Center for Accelerator Mass Spectrometry (CAMS). Students and teachers attending the SOS lecture will be given the opportunity to write a proposal (due March 1, 2001) to compete to get a radiocarbon date (FREE) for an object of their choice. This is the first presentation in this year's Science on Saturday lecture series. The series is co-hosted by LLNL's Science & Technology Education Program and Sigma Xi.