Led by Vera Rubin
About this course
The closing module of the Edexcel GCSE Astronomy course is the spec's cosmology unit — the synthesising chapter in which everything from the Earth–Moon–Sun system in M3 to the galactic-scale structures of M15 are placed in their universal context. The student moves from the redshift observation through Hubble's law, the evidence for the Big Bang (quasars, the cosmic microwave background, the Hubble Deep Field), the significance of CMB fluctuations as measured by WMAP and Planck, the existence and inferred properties of dark matter and dark energy, and the possible long-term fates of the universe.
It is led by Vera Rubin, whose galaxy rotation curves established that visible matter accounts for only a small fraction of the gravitating mass of a galaxy, and that the rest — dark matter — must be present in a halo extending far beyond the visible disc. Her contribution is foundational to the modern cosmological model.
The student leaves the course able to apply Hubble's law and the redshift formula, describe the principal evidence for the Big Bang, account for the significance of CMB fluctuations, describe dark matter and dark energy as inferred components of the cosmic energy budget, and outline the principal scenarios for the long-term fate of the universe.
Led by Vera Rubin
The question
Why are galaxies receding from us, what does Hubble's law say about the age and size of the universe, what are the three principal lines of evidence for the Big Bang, what do CMB fluctuations tell us about the structure and composition of the universe, what is dark matter and dark energy, and how will the universe end? The spec covers redshift, Hubble's law and the cosmological parameters derived from H₀, the discrimination between Big Bang and Steady State theories, the major Big Bang evidence (quasars, CMB, Hubble Deep Field), the WMAP and Planck CMB measurements, dark matter and dark energy, and the possible fates of the universe.
Outcome
the student can apply the redshift formula and Hubble's law, estimate the age and size of the universe, describe the principal evidence for the Big Bang, explain the significance of CMB fluctuations, describe dark matter and dark energy as inferred components, and outline the principal scenarios for the long-term fate of the universe. *(Edexcel 1AS0 Paper 2 — Topic 16, spec points 16.1–16.13)*
Sub-units