Fundamental laws
Before we build atoms or stars, we need the rules that describe change: where events occur, how motion is described, what quantities are conserved and how physical systems influence one another.
Space and timeThey provide the arena and ordering of physical events. Relativity shows that measurements of space and time depend on motion and gravitation.
Motion and dynamicsPhysics connects the state of a system with how that state changes. Classical mechanics is an excellent approximation for many slow macroscopic processes.
Energy and momentumThese quantities organize dynamics and are linked to deep conservation laws.
SymmetryMany conservation laws are connected with symmetries of the physical description.
Quantum principlesAt microscopic scales, physical states and transitions obey quantum rules rather than classical trajectories alone.