Two archived reports give measurements for different absorption lines in the light from two galaxies.
| Galaxy | Laboratory wavelength in nm | Observed wavelength in nm |
|---|---|---|
| M | 500 | 510 |
| N | 700 | 712 |
Astronomer 1 concludes that galaxy N is more distant than galaxy M.
Astronomer 2 concludes that galaxy M is more distant than galaxy N.
Using the data, which astronomer's conclusion is justified?
Include calculations in your answer.
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.