(Physics only) Explain why the Big Bang theory is currently the only theory that can explain cosmic microwave background radiation.

(Physics only) Explain why the Big Bang theory is currently the only theory that can explain cosmic microwave background radiation.. Within Red-shift, this learning objective sits inside Red-shift and evidence for an expanding universe for AQA Physics 8463. Focus on using ideas such as physics only, Big Bang theory, cosmic microwave background radiation accurately in your explanation. A strong response should define the core idea, describe the relevant physical process, and connect it back to the question wording instead of giving a vague definition. When revising, students should aim to explain the subject clearly, include precise physics vocabulary, and show how the idea links to the wider topic rather than listing isolated facts.