Date:  2023-11-12

Article ID:  00980

Article 52890 explained how to construct models of scalar quantum fields in a mathematically straightforward way by treating space as a lattice. The free scalar field, whose equation of motion is linear, is a special case in which the energy eigenstates can all be determined explicitly. This article uses the free scalar field to highlight some basic points about the vacuum state, the state with the lowest energy.