| Briefly explain the significance of any TWO of the following in the establishment of the Hot Big Bang theory as the best cosmological model: | |
| The main issue here is to ensure that you answer the question! What aspects of the topic in question support the Hot Big Bang model in preference to other models (especially, but not uniquely, the Steady State), and why? 2.5 marks represent 1/20 of the total paper, so nominally 6 minutes' work: we're looking for maybe half a page (depending on your handwriting!). | |
| the abundances of 2H and 4He; | [2.5] |
| Issues to cover: what's special about these particular isotopes? How does the Big Bang contribute to their abundances? Why doesn't this work for other models? | |
| radio source counts; | [2.5] |
| Issues to cover: what feature of radio source counts is relevant? How does it disfavour the Steady State? Why isn't it a problem for the Big Bang? | |
| the blackbody spectrum of the cosmic microwave background. | [2.5] |
| Issues to cover: how is the CMB generated in the Big Bang? Why does this produce a blackbody spectrum? Why doesn't this work for other models? |
(2005 Q2.)