A physicist uses two mathematical models, P and Q, to predict how the mean separation between selected distant galaxies and the average density of the Universe change over the same period.
| Model | Earlier mean separation / 1022 m10^{22}\ \mathrm{m}1022 m | Later mean separation / 1022 m10^{22}\ \mathrm{m}1022 m | Earlier average density / 10−27 kg/m310^{-27}\ \mathrm{kg/m^3}10−27 kg/m3 | Later average density / 10−27 kg/m310^{-27}\ \mathrm{kg/m^3}10−27 kg/m3 |
|---|---|---|---|---|
| P | 3.0 | 6.0 | 6.4 | 0.8 |
| Q | 3.0 | 6.0 | 6.4 | 6.4 |
Explain how the data can be used to identify which model represents the Big Bang theory and which represents the Steady State theory.
94 exam-style questions on Edexcel GCSE Physics 7.2 The Universe and red-shift, covering 7.2.1 Big Bang and Steady State theories, 7.2.2 Evidence for the Big Bang, 7.2.3 The Doppler effect and red-shift, 7.2.4 Red-shift as evidence for an expanding Universe, and 7.2.5 The CMB and the accepted model. Each one has a worked solution and a mark scheme showing where the marks go.