A museum curator is preparing two panels about models of the Universe.
| Panel | Description |
|---|---|
| 1 | The Universe has a finite age. It began as a very small, extremely hot and dense region and has expanded and cooled. |
| 2 | The Universe has always existed. New matter is created continuously as the Universe expands, so its average density stays constant. |
The curator also checks archive records for three galaxies. The laboratory wavelength of the absorption line in the records is 656 nm656\ \mathrm{nm}656 nm.
| Galaxy | Distance in millions of light-years | Observed wavelength in nm\mathrm{nm}nm |
|---|---|---|
| P | 100 | 658 |
| Q | 500 | 666 |
| R | 1000 | 676 |
A further archive record describes faint microwave radiation of almost the same intensity arriving from every direction in space.
Name the theory represented by Panel 1 and the theory represented by Panel 2.
State the relationship between the distance of a galaxy and its red-shift shown by the archive records.
The curator must choose which panel will carry the label ‘currently accepted model’. Give the panel number and state why the microwave record supports the account on that panel.
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.