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

According to the researchers, the new method delivers redshift estimates with precision comparable to spectroscopic measurements, but without requiring spectra.

From Science Daily • Jun. 29, 2026

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

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

When used in conjunction with ground-based instruments, they’ll be able to convert redshift into length to infer the distances to each galaxy.

From New York Times • Jul. 1, 2023