This book does not question existing observations and the associated math. However, it does challenge the very limited and incorrect conceptual theories taught in current 2nd semester introductory physics. Bohr model explanations in the past have been successfully applied to explain chemistry, biology, DC power, and electronics. This book applies the same tools to explain AC power, and different aspects of electromagnetics and astrophysics. Educational physics books discredit the Bohr model but stop short of developing alternative understanding that would advance education and science in general.