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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Waves

Frequency

Number of cycles per unit time.

SI unit

hertz (Hz)

Dimension: [ T−1 ][\,T^{-1}\,]

Other units

  • hertz (Hz)
  • megahertz (MHz)×1.00e+6

Order of magnitude

How values of frequency span the physical world (in Hz, log scale).

Audible (low)
2.00 × 101 Hz
FM radio
108 Hz
Visible light
5.00 × 1014 Hz
Gamma rays
1020 Hz
Lower limit10-7 HzUpper limit1022 Hz

Appears in 4 equations

Wave Speed Relation
v=fλv = f \lambda
Frequency and Period
f=1Tf = \dfrac{1}{T}
Planck–Einstein Relation
E=hfE = h f
Photoelectric Effect
Ek=hf−ϕE_k = h f - \phi

Associated scientists

Max PlanckAlbert EinsteinRobert Millikan