The single most articulate and passionate advocate of citizen action to remedy the nuclear and environmental crises, and Nobel Peace Prize nominee, Dr. Helen Caldicott will speak in the Main Theater of the Tilden Arts Center at Cape Cod Community College on Wednesday April 4th at 7 p.m. She has devoted the last 38 years to an international campaign to educate the public about the medical hazards of the nuclear age and the necessary changes in human behavior to stop environmental destruction. Named by the Smithsonian as one of the most influential women of the 20th Century, Caldicott comes as questions are raised over the relicensing of the Pilgrim Nuclear Power Plant in Plymouth.