Imagine an astronomer working in a galaxy very far from the Earth. The astronomer considers what the Big Bang theory and the Steady State theory each predict.
Which would the astronomer expect according to both theories?
Most other distant galaxies are moving away from the astronomer's galaxy.
The Universe has the same average density at every stage of its history.
Radiation from the hot early Universe reaches the astronomer from all directions.
The total amount of matter increases while the Universe becomes less dense.
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.