N. McClure-Griffiths, S. Stanimirovic, and D. Rybarczyk. (2023)cite arxiv:2307.08464Comment: Manuscript (48 pages, 11 figures) accepted to Annual Reviews of Astronomy and Astrophysics for publication in Volume 61. This is the authors' own version. The final version, and associated supplementary material, will become available from: https://doi.org/10.1146/annurev-astro-052920-104851.
B. Tinsley. (2022)cite arxiv:2203.02041Comment: This paper has been transcribed from a hard copy of Beatrice M. Tinsley's original manuscript into a digital file prepared by Michael J. Greener, a PhD student at the University of Nottingham. If you notice any errors or problems with this transcribed paper, please email Michael at either michael.greener@nottingham.ac.uk or mickgreener@protonmail.com. This version 2 includes a clearer Figure 6.