Dark energy is the largest component of the universe, about 74% of the mass and energy that exists. Hard to imagine, isn't it? If you want to understand it better, the person to talk to is Steve Kuhlmann, physicist at Argonne National Laboratory. He'll be at Nichols Library on Tuesday, May 13 at 7 p.m. to talk about the Big Bang and dark energy. This adult program will meet in the Community Room.