Vacuum energy is underlying background energy that exists in space throughout the entire Universe. This behavior is codified in Heisenberg’s energy-time uncertainty principle. Why does the zero-point energy of the vacuum not cause a large cosmological constant? What cancels it out? There are still some deficiencies in the Standard Model of physics, such as the origin of mass, the strong CP problemneutrino massmatter-antimatter asymmetry, and the nature of dark matter and dark energy. Supernovae: What is the exact mechanism by which an implosion of a dying star becomes an explosion?