# The universe began with the Big Bang. Describe the evidence that supports the Big Bang theory and explain what this evidence tells us about the early universe.

> Eduqas A-Level Physics — 4.3 Orbits and the wider universe · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. Cosmic Microwave Background (CMB) radiation is detected coming from all directions in space
2. CMB radiation is the remnant heat/energy from the Big Bang (or: left over from the very hot early universe)
3. Light from distant galaxies is redshifted (wavelength of light is increased/stretched)
4. Redshift shows that galaxies are moving away from us / the universe is expanding
5. If the universe is expanding now, it must have started from a single point / all matter was once concentrated in one place (Big Bang)

## Key terms

- [Big Bang](https://www.gradenine.co.uk/glossary/big-bang)

## Related

- [Revision notes for Eduqas A-Level Physics](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/the-universe-began-with-the-big-6310f6ac) · Published by Druglandscape Ltd.