An astronomer measures the wavelength of the same spectral line in light from four galaxies. In a laboratory, this line has a wavelength of 500 nm.
| Distance of galaxy from Earth (million light years) | Wavelength measured from the galaxy (nm) |
|---|---|
| 100 | 504 |
| 200 | 507 |
| 300 | 511 |
| 500 | 518 |
Explain what the measurements show about the motion of the galaxies and how this evidence contributes to a model of the universe. Explain why that model could change as scientists make further observations.
79 exam-style questions on AQA GCSE Physics 8.2 Red-shift, covering 8.2 Red-shift. Each one has a worked solution and a mark scheme showing where the marks go.