COSMIC MICROWAVE BACKGROUND (CMB) RADIATION
2 marks · EasyExplain how the cosmic microwave background (CMB) radiation supports the Big Bang theory. Give two points in your answer.
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Show answer
Must show: States CMB is afterglow of Big Bang or result of a hot, dense origin, Explains that CMB is detected in all directions / CMB is microwaves and matches theoretical prediction
Common mistakes: Only mentions microwaves, without connection to origin or prediction
Show mark scheme and worked solution
Marking points
B1 · 1 mark · Explains that CMB is the afterglow or evidence that the universe started with a hot, dense event (the Big Bang).
B2 · 1 mark · States that CMB is detected in all directions / its nature matches predictions made by the Big Bang theory.
Worked solution
1. The CMB is the leftover radiation from the early universe, supporting the idea that the universe started with a big explosion (the Big Bang). 2. The CMB is detected as microwaves everywhere in the universe and matches what scientists predicted the afterglow from the Big Bang would be.