Georgia Southern University will host Dr. Steven Chu, a Nobel Prize Winner in physics and former U.S. energy secretary, as the keynote speaker for No Impact Week at 7 p.m. Tuesday at the Performing Arts Center, 847 Plant Drive. Chu will offer insight on the nation's energy future and how advances in science are the key to solving the most confounding global issues in his speech titled "Renewing Our Independence through Renewable Energy: Challenges and Opportunities." The event is part of Georgia Southern's No Impact Week, a weeklong challenge in which participants commit to gradually reducing their impact on the planet.