Redshift
A phenomenon in which light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum, usually due to the object moving away from the observer.
Cosmological redshift is a key piece of evidence for the expanding universe, as light from distant galaxies is stretched to longer (redder) wavelengths as space itself expands. Gravitational redshift also occurs when light escapes a strong gravitational field.
Word relationships
- Blueshift: A decrease in wavelength (shift to the blue end of the spectrum), indicating an object is moving towards the observer.
Word family
- redshifted (adjective): Having undergone redshift.
Collocations
- cosmological redshift
- gravitational redshift
- high redshift
- redshift measurement
Example sentences
- "The observed redshift of light from distant galaxies provides strong evidence that the universe is expanding." Explaining cosmic expansion.
- "By measuring the redshift of a star's spectrum, astronomers can determine its velocity relative to Earth." Referring to a scientific measurement.
Memory hook
Light 'SHIFTS' to the 'RED' end of the spectrum when things move away. Light Shifts Red
When not to use
Do not use 'redshift' to describe a color change in general or a shift towards red for non-scientific reasons. It's a specific term related to the Doppler effect and cosmic expansion.
Fun facts
- The discovery of redshift by Edwin Hubble in the 1920s was a cornerstone of the Big Bang theory.
- The higher the redshift of a galaxy, the faster it is moving away from us, and the further back in time we are observing it.
Related words
Explore more words
electromagnetic, black hole, Relativity, photon, wavelength, telescope
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