Redshifts

Part of speech: noun

Definitions

1. The phenomenon where light or other electromagnetic radiation from an object is shifted to longer wavelengths due to the object moving away
2. A measurement that indicates an increase in wavelength of light as a galaxy or celestial body recedes from an observer, indicative of the universe's expansion
3. The occurrence of spectral lines moving toward the red end of the spectrum, often used in astronomy to infer speed and distance of astronomical objects

Etymology: "Redshifts" is simply the plural of "redshift," a noun that combines "red," the colour at the long-wavelength end of the visible spectrum, with "shift," a change in position or value. The compound describes what happens to light from a receding object: its wavelengths stretch, pushing the light toward the red end of the spectrum. Each plural form refers to one such measured shift, so astronomers can speak of comparing several redshifts across a survey of galaxies. The word is a plain English compound with no older foreign source, and its parts are both everyday words doing a technical job. "Red" supplies the direction of the change, and "shift" supplies the idea of a displacement. Because the shift is toward longer wavelengths, the same logic applies to the opposite case, which astronomers call a blueshift.

Synonyms: shifts, displacements, changes, movements, variations