cosmological redshift: meaning, definition, pronunciation and examples
Very LowAcademic / Technical / Scientific
Quick answer
What does “cosmological redshift” mean?
The shifting of light from distant galaxies towards longer (redder) wavelengths due to the expansion of the universe.
Audio
Pronunciation
Definition
Meaning and Definition
The shifting of light from distant galaxies towards longer (redder) wavelengths due to the expansion of the universe.
An observed phenomenon in astrophysics where the spectral lines of objects are displaced toward the red end of the spectrum; this is not due to the Doppler effect from relative motion but rather the stretching of space itself over cosmic distances as the universe expands, providing key evidence for the Big Bang theory.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or use. The concept and term are identical in both academic communities.
Connotations
Neutral, technical term in both varieties.
Frequency
Identically low and restricted to astrophysics/cosmology contexts in both varieties.
Grammar
How to Use “cosmological redshift” in a Sentence
The cosmological redshift [of a galaxy/quasar] is [a value/measured].Cosmological redshift [indicates/proves/suggests] [expansion/distance].Vocabulary
Collocations
Examples
Examples of “cosmological redshift” in a Sentence
verb
British English
- [No standard verb form] The light is cosmologically redshifted.
- Data must be corrected for redshift effects.
American English
- [No standard verb form] The light is cosmologically redshifted.
- We need to redshift-correct the data.
adverb
British English
- [No standard adverb form] The light shifted cosmologically.
American English
- [No standard adverb form] The light shifted cosmologically.
adjective
British English
- The cosmological-redshift data was crucial.
- They studied high-redshift galaxies.
American English
- The cosmological redshift data was crucial.
- They studied high-redshift galaxies.
Usage
Meaning in Context
Business
Virtually never used.
Academic
Core term in cosmology and astrophysics lectures, papers, and textbooks.
Everyday
Extremely rare, only in popular science discussions about the universe.
Technical
Essential term in astrophysical research, data analysis, and telescope observation reports.
Vocabulary
Synonyms of “cosmological redshift”
Strong
Neutral
Weak
Vocabulary
Antonyms of “cosmological redshift”
Watch out
Common Mistakes When Using “cosmological redshift”
- Confusing it with the Doppler redshift from a galaxy's peculiar motion.
- Using 'cosmological redshift' to describe the redshift from nearby moving objects.
- Pronouncing 'cosmological' with stress on 'cos' instead of the third syllable.
- Misspelling as 'cosmological red shift' or 'cosmological red-shift' (standard is solid or open compound).
FAQ
Frequently Asked Questions
No. While both cause redshift, the Doppler effect is due to motion through space. Cosmological redshift is caused by the expansion of space itself between the source and observer.
No, it is only significant over vast cosmological distances (millions to billions of light-years). For nearby objects, any observed redshift is dominated by their local motion (Doppler effect).
It is typically denoted by the lowercase letter 'z'. A higher z value indicates a greater redshift and a greater distance/look-back time.
The phenomenon was first observed by Vesto Slipher and later interpreted by Edwin Hubble in the 1920s as evidence for an expanding universe, building on earlier theoretical work.
The shifting of light from distant galaxies towards longer (redder) wavelengths due to the expansion of the universe.
Cosmological redshift is usually academic / technical / scientific in register.
Cosmological redshift: in British English it is pronounced /ˌkɒz.məˈlɒdʒ.ɪ.kəl ˈred.ʃɪft/, and in American English it is pronounced /ˌkɑːz.məˈlɑː.dʒɪ.kəl ˈred.ʃɪft/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “[None applicable for this technical term]”
Learning
Memory Aids
Mnemonic
Imagine the universe as expanding dough with raisins (galaxies). As the dough stretches, the light waves from the raisins also stretch, becoming longer and 'redder' — a COSMOLOGICAL REDshift.
Conceptual Metaphor
THE EXPANDING UNIVERSE IS A STRETCHING FABRIC (that stretches light waves).
Practice
Quiz
What does cosmological redshift primarily indicate?