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
zz
Relativity

Redshift

Fractional increase in wavelength of light from a receding astronomical source.

SI unit

dimensionless (—)

Dimension: [ 1 ][\,1\,]

Other units

  • dimensionless (—)

Order of magnitude

How values of redshift span the physical world (in —, log scale).

Nearby galaxy
10-2 —
Distant quasar
6.00 × 100 —
Lower limit0 —Upper limit101 —

Appears in 1 equation

Redshift
z=Δλλ≈vcz = \dfrac{\Delta\lambda}{\lambda} \approx \dfrac{v}{c}