The Foundation for Theoretical Physics is pleased to offer Playing with Einstein: Reflections on E=mc2. This is a book for the intelligent reader who may not have a background in mathematics or physics, but who nevertheless is curious about the intellectual foundations of modern physics. After a brief historical introduction, each of the variables of Einsteins equation is carefully studied with a view to understanding it. Armed with intellectual tools provided from theoretical physics, the reader is enabled to make a thorough analysis of each variable. The meanings of energy, mass, and the speed of light are thus reflected upon in the context of the spontaneous decomposition of fissile materials. In addition to clarifying the variables in Einsteins equation, the analysis reveals alternate explanations for fission. In Einsteins equation the idea of energy is found either misleading or meaningless. The idea of mass is found ambiguous and misleading. The speed of light as specified in Einsteins equation is found meaningless. While acceptable as a definition, as an equation Einsteins equation is judged invalid. Inasmuch as Einsteins equation forms the basis of modern physics, these reflections challenge modern physicists to reexamine their discipline. The Foundation for Theoretical Physics is dedicated to supporting a science of physics free of contradictions.