THE DOPPLER EFFECT
3 marks · NormalDescribe two scientific arguments that support the Big Bang theory, other than red-shift.
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1. The cosmic microwave background radiation, which is observed uniformly from all directions and is thought to be the cooled remnant of the initial explosion. 2. The relative abundance of light elements such as hydrogen and helium in the universe, which matches predictions based on the Big Bang model.
Also accept: Uniform background radiation and element distribution
Common mistakes: Listing only one argument; Incorrectly describing red-shift
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Marking points
B1 · 1 mark · Identifies cosmic microwave background radiation as evidence.
B1 · 1 mark · Identifies light element abundance as evidence.
B1 · 1 mark · Explains or describes either point for the third mark (e.g., uniformity of background or prediction agreement for helium/hydrogen).
Worked solution
One argument is the existence of cosmic microwave background radiation, the faint, uniform afterglow of the Big Bang observed in all directions. A second argument is the observed abundance of light elements (like hydrogen and helium), which matches what is predicted if the universe started hot and dense as suggested by the Big Bang.