Overview: In this episode of SciTech Now, we visit one community in Central Florida that is working to better cohabitate with the area’s black bear population; Hari Sreenivasan sits down with climate scientist Richard Somerville to discuss the Doomsday Clock; we do “Show and Tell” with two tortoises, Hermes and Mud; Hari Sreenivasan speaks with Dr. Michael Lipton about the risks associated with head injuries and we take a closer look at the Theremin, a unique instrument that uses bioelectric magnetic fields to create sound.