noun

redshift

RED-shift

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Redshift (noun) means a stretching in the wavelength of light as it crosses space, shifting it towards the red end of the spectrum. Example: “Astronomers measured the redshift of the distant galaxy to work out how far away it was.”

noun

A stretching in the wavelength of light as it crosses space, shifting it towards the red end of the spectrum.

"Astronomers measured the redshift of the distant galaxy to work out how far away it was."

"A larger redshift generally points to a more distant object."

"The spectrograph recorded a small redshift in the star's light."

verb

To shift, or cause light to shift, towards the red end of the spectrum as it travels through space.

"Light from a receding galaxy redshifts as it crosses the expanding universe."

"Astronomers noted how strongly the quasar's light had redshifted."

How to use redshift

Learner’s notes

In plain EnglishRedshift is what happens when light stretches out and turns redder as its source moves away.

When to use it

Redshift is a specialist term from physics and astronomy, not used in everyday speech.

Memory tip

Picture light being stretched, like a wave pulled longer, and you'll remember why it shifts towards red.

Trace the full origin ↓

Common pairings

measure the redshift high redshift cosmological redshift redshift and blueshift

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C2 · Advanced serendipity Fortunate discoveries made entirely by accident.

Gen Z slang rizz Charm — the ability to attract a romantic interest.

B2 · Intermediate empathy The capacity to share another person’s feelings.

C1 · Advanced nonchalant Casually calm and relaxed; unconcerned.

Internet slang delulu Delusional — believing something against the odds.

Etymology nostalgia Greek nostos “return home” + algos “pain”.

C2 · Advanced serendipity Fortunate discoveries made entirely by accident.

Gen Z slang rizz Charm — the ability to attract a romantic interest.

B2 · Intermediate empathy The capacity to share another person’s feelings.

C1 · Advanced nonchalant Casually calm and relaxed; unconcerned.

Internet slang delulu Delusional — believing something against the odds.

Etymology nostalgia Greek nostos “return home” + algos “pain”.

Test yourself on “redshift” A quick quiz — meaning, synonyms & usage →

Fill the gap

Can you complete this real example?

Astronomers measured the _____ of the distant galaxy to work out how far away it was.

Etymology

Redshift is a straightforward English compound, formed by joining red and shift to describe light shifting towards the red end of the spectrum.

Origin: English

Antonyms

blueshift

Frequently asked questions

What is redshift in astronomy?

It is the stretching of light's wavelength as it travels through space, shifting the light towards the red end of the spectrum and pointing to a lower frequency.

What is the opposite of redshift?

Blueshift, where light's wavelength shortens instead, shifting it towards the blue end of the spectrum.

Is redshift related to the Doppler effect?

Redshift caused by a source moving away resembles the Doppler effect known from sound.

What is the meaning of redshift?

"redshift" (noun) means a stretching in the wavelength of light as it crosses space, shifting it towards the red end of the spectrum.