redshift: meaning, definition, pronunciation and examples
C2Technical/Scientific, occasionally used in popular science contexts.
Quick answer
What does “redshift” mean?
The displacement of light or other electromagnetic radiation towards longer wavelengths, observed when an object moves away from the observer.
Audio
Pronunciation
Definition
Meaning and Definition
The displacement of light or other electromagnetic radiation towards longer wavelengths, observed when an object moves away from the observer.
In physics and astronomy, a measurable increase in wavelength (a shift towards the red end of the spectrum) used to calculate the velocity and distance of celestial objects moving away from Earth. Informally, it can symbolise distance, retreat, or cosmic expansion.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling is consistent. Pronunciation of the /r/ and vowel in 'red' may vary slightly between rhotic (AmE) and non-rhotic (BrE) accents.
Connotations
Identical technical connotations. In popular science, it carries the same awe-inspiring connotation of cosmic expansion.
Frequency
Equally low-frequency in general language but standard and equally frequent in astrophysics contexts in both regions.
Grammar
How to Use “redshift” in a Sentence
The redshift of [celestial object] is [value].[Celestial object] exhibits/showed a redshift.Astronomers measured the redshift.Vocabulary
Collocations
Examples
Examples of “redshift” in a Sentence
adjective
British English
- redshift measurement
- redshift data
American English
- redshift survey
- redshift galaxy
Usage
Meaning in Context
Business
Not used, except possibly in the name of a company or product (e.g., Amazon Redshift).
Academic
Core term in astrophysics, cosmology, and physics. Used in research papers, lectures, and textbooks to discuss the expansion of the universe and galactic motion.
Everyday
Virtually never used. Might be encountered in popular science documentaries or articles.
Technical
The primary domain. Precisely defined phenomenon critical for calculating distances and velocities in astronomy.
Vocabulary
Synonyms of “redshift”
Strong
Neutral
Vocabulary
Antonyms of “redshift”
Watch out
Common Mistakes When Using “redshift”
- Using 'redshift' as a verb (e.g., 'The galaxy redshifts'). It is a noun.
- Confusing 'redshift' with 'red shift' (the standard form is the closed compound).
- Using it to describe any red colour in the sky.
FAQ
Frequently Asked Questions
Redshift for light is analogous to the Doppler effect for sound. It is often called the 'Doppler redshift' when caused by relative motion. However, 'cosmological redshift' is due to the expansion of space itself, not motion through space.
No, in standard technical and general English, 'redshift' is exclusively a noun. Scientists say 'light is redshifted' (using the adjective) or 'exhibits a redshift'.
The opposite is 'blueshift', where light is shifted to shorter wavelengths, indicating an object is moving towards the observer.
Edwin Hubble's observation that distant galaxies show redshift proportional to their distance provided the first direct evidence for the expansion of the universe, forming the basis of modern cosmology and the Big Bang theory.
The displacement of light or other electromagnetic radiation towards longer wavelengths, observed when an object moves away from the observer.
Redshift is usually technical/scientific, occasionally used in popular science contexts. in register.
Redshift: in British English it is pronounced /ˈrɛdʃɪft/, and in American English it is pronounced /ˈrɛdʃɪft/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think of a siren moving away from you – the sound's pitch drops (gets lower). Similarly, light moving away stretches to longer, redder wavelengths: RED-SHIFT.
Conceptual Metaphor
THE EXPANDING UNIVERSE IS A STRETCHING FABRIC (redshift as the 'stretch marks' on light).
Practice
Quiz
What does a 'redshift' observation most directly indicate about a celestial object?