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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c

Fundamental Constants

Speed of Light

Speed of electromagnetic radiation in vacuum; appears in relativity and E = mc².

SI unit

metre per second (m/s)

Dimension: $[\,L T^{-1}\,]$

Other units

metre per second (m/s)

Defined value

Fixed constant from the A-level data sheets.

3.00 × 10⁸ m/s

A-level value (vacuum)

Appears in 1 equation

Mass–Energy Equivalence

E = m c^2

Associated scientists

Albert Einstein