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.

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uu
Fundamental Constants

Unified Atomic Mass Unit

Standard atomic mass unit; 1 u ≈ 931.5 MeV/c².

SI unit

atomic mass unit (u)

Dimension: [M][\,M\,]

Other units

  • atomic mass unit (u)

Defined value

Fixed constant from the A-level data sheets.

1.66 × 10-27 u

A-level value (kg)