redshift

American  

[red-shift] / ˈrɛdˌʃɪft /

Or red shift

noun

Astronomy.

1. a shift toward longer wavelengths of the spectral lines emitted by a celestial object that is caused by the object moving away from the earth.

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redshift British  

/ ˈredˌʃɪft /

noun

1. Compare: blueshift.  a shift in the lines of the spectrum of an astronomical object towards a longer wavelength (the red end of an optical spectrum), relative to the wavelength of these lines in the terrestrial spectrum, usually as a result of the Doppler effect caused by the recession of the object

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Etymology

Origin of redshift

First recorded in 1920–25; red ¹ + shift

Compare meaning

How does redshift compare to similar and commonly confused words? Explore the most common comparisons:

• redshift vs. blueshift

Example Sentences

Astronomers call a shift to longer wavelengths a redshift.

From Salon • Feb. 14, 2025

This corresponds to a redshift of about 14, which is a measure of how much a galaxy's light is stretched by the expansion of the universe.

From Science Daily • May 30, 2024

The researcher analyzed data from recent papers on the distribution of galaxies at low redshifts and the angular size of the sound horizon in the literature at high redshift.

From Science Daily • Mar. 15, 2024

These objects were high in redshift, meaning they emitted light skewed toward the red side of the electromagnetic spectrum, which is a sign of old and distant objects.

From Scientific American • Jul. 20, 2023

Euclid also has a near-infrared spectrometer and photometer for measuring each galaxy’s redshift, or the wavelength-stretching effect that occurs in light arriving from the faraway cosmos.

From New York Times • Jul. 1, 2023