Cosmological redshift
What Cosmological redshift means in Physics A-Level, as defined for AQA, OCR.
Definitions of Cosmological redshift
Exam boards and our study guides word this term in slightly different ways. Learn the version your board uses.
Check what you remember
Read the wording for your board, then hide it and explain Cosmological redshift in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
Large redshifts indicate recession and therefore distance in an expanding Universe, and are used to infer quasar distances.
Expansion stretches the wavelength of light travelling through space, producing cosmological redshift.
As space stretches, photon wavelengths increase, so distant galaxies appear redshifted.
Topics that use Cosmological redshift
- Hubble's law (A-level only) (AQA A-Level)
- Quasars (A-level only) (AQA A-Level)
- Cosmology (OCR A-Level)
Related terms
- Hubble's law
- Age of the universe
- Big Bang nucleosynthesis
- red shift
- Accretion discs and black hole mass
- Active galactic nuclei
- Astronomical distance units
- Baseline
Using Cosmological redshift in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Physics questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge