A research team compares two computer models of an expanding region of the Universe.
The average density of matter is calculated using
average density=amount of mattervolume\text{average density}=\dfrac{\text{amount of matter}}{\text{volume}}average density=volumeamount of matter
| Snapshot | Volume / m3\mathrm{m^3}m3 | Model P: amount of matter / kg\mathrm{kg}kg | Model P: average density / kg/m3\mathrm{kg/m^3}kg/m3 | Model Q: amount of matter / kg\mathrm{kg}kg | Model Q: average density / kg/m3\mathrm{kg/m^3}kg/m3 |
|---|---|---|---|---|---|
| 1 | 2.0×10682.0\times10^{68}2.0×1068 | 1.2×10421.2\times10^{42}1.2×1042 | 6.0×10−276.0\times10^{-27}6.0×10−27 | 1.2×10421.2\times10^{42}1.2×1042 | 6.0×10−276.0\times10^{-27}6.0×10−27 |
| 2 | 6.0×10686.0\times10^{68}6.0×1068 | 1.2×10421.2\times10^{42}1.2×1042 | 6.0×10−276.0\times10^{-27}6.0×10−27 |
Complete the table by calculating the two missing values.
Explain which computer model represents the Big Bang theory and which represents the Steady State theory.
The team compares the models with a weak microwave signal of almost the same intensity detected from every direction in space.
Explain which model this observation supports more strongly.
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.