Cosmological concept · Cosmology
Cosmological Redshift
Cosmology & UniverseEstablished Science
Definition
The stretching of light to longer (redder) wavelengths as it travels through expanding space.
Scientific overview
As space expands, the wavelength of light travelling through it is stretched, shifting features in a galaxy's spectrum toward the red. The greater the redshift, the more the Universe has expanded since the light was emitted — making redshift the primary yardstick of cosmic distance and time.
Related topics
Knowledge connections
- Related toThe Expansion of the Universe
- Related toThe Expansion of the Universe
- Related toThe Hubble–Lemaître Law
- Related toThe Hubble–Lemaître Law
- Associated withRedshift & the Hubble–Lemaître Law
- Associated withPhotometric Redshifts
- Associated withRedshift Recession Velocity
Sources & references
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
- ESOEuropean Southern Observatory
Southern-hemisphere observatory data and imagery (VLT, ALMA partner).