# Explain why the Steady State Theory is no longer accepted as a model for the origin of the universe.

> Edexcel A-Level Physics (9PH0) — 7.2 Capacitors · Explain · 5 marks

> Scientists have proposed different theories to explain the origin and evolution of the universe. The Big Bang Theory is currently the accepted model, but the Steady State Theory was once considered a competing explanation.

## Mark scheme (5 marks)

1. The Steady State Theory suggests the universe has always existed / the universe is the same at any time and any place / matter is continuously created as the universe expands
2. Cosmic microwave background radiation (CMBR) is detected in all directions / all around us
3. The Steady State Theory cannot explain / does not account for CMBR
4. Observations show that different types of stars / the universe looked different in the past / the universe has evolved over time
5. The Big Bang Theory accounts for all the experimental evidence (red-shift and CMBR), so it is the more accepted / better-supported model

## Key terms

- [Steady State Theory](https://www.gradenine.co.uk/glossary/steady-state-theory)

## Related

- [Revision notes for Edexcel A-Level Physics (9PH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-the-steady-state-theory-d2267fa3) · Published by Druglandscape Ltd.