Physics Ontology

One map of physics, three ways in. Drill down on any quantity to see its units, the equations it lives in, and how its values span the universe.

QuantitiesAreas & EquationsTimeline
← Back to all quantities
SS
Quantum

Action

Integral of energy over time; quantised in units of ℏ.

SI unit

joule second (J·s)

Dimension: [ ML2T−1 ][\,M L^2 T^{-1}\,]

Other units

  • joule second (J·s)

Order of magnitude

How values of action span the physical world (in J·s, log scale).

Planck constant
6.63 × 10-34 J·s
Pendulum swing
100 J·s
Lower limit10-34 J·sUpper limit101 J·s