Michael Slobodien, a nuclear physicist who is an expert in occupational and public radiological health and safety and was a first responder to the Three Mile Island nuclear reactor accident in 1979, recently visited the Epstein School to lead a science lesson for Stephanie Lampert’s pre-kindergarten class, which includes Natan Slobodien Rodriguez, his grandson. Using soda cans filled to various levels with water, Slobodien demonstrated how you can balance a can on its edge by finding its center of gravity. He also showed how to balance a plate on a stick with the same center-of-gravity trick and explained that the same basic principles are used by a tightrope walker.