Physics A-Level
Cosmic microwave background
What Cosmic microwave background means in Physics A-Level, as defined for OCR.
Definition of Cosmic microwave background
Check what you remember
Read the wording for your board, then hide it and explain Cosmic microwave background in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: OCR
Radiation released at recombination, when electrons and nuclei combined into neutral atoms so radiation could travel freely, now cooled to about 2.7 K.
Topics that use Cosmic microwave background
- Cosmology (OCR A-Level)
Related terms
- Age of the universe
- Astronomical distance units
- Baseline
- Big Bang nucleosynthesis
- Big Bang theory
- Cosmic microwave background radiation
- Cosmological redshift
- Dark matter and its gravitational evidence
Using Cosmic microwave background in the exam
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