# The universe is thought to have begun with the Big Bang. Explain how observations of light from distant galaxies provide evidence that the universe is still expanding.

> Eduqas GCSE Physics — 2.1 Light, lenses and the universe · Explain · 4 marks

## Mark scheme (4 marks)

1. Light from distant galaxies is shifted towards the red end of the spectrum (red-shift)
2. Red-shift means the wavelength of light received is longer / frequency is lower than expected
3. This indicates that distant galaxies are moving away from us
4. The greater the red-shift, the faster / further away the galaxy is, showing the universe is expanding

## Key terms

- [universe](https://www.gradenine.co.uk/glossary/universe)
- [expanding](https://www.gradenine.co.uk/glossary/expanding)

## Related

- [Revision notes for Eduqas GCSE Physics](https://www.gradenine.co.uk/learn)
- [How to answer "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-is-thought-to-have-d4120e36) · Published by Druglandscape Ltd.