When Galaxies Were Born

Princeton University Press £25  HB

Professor Ellis’s long career has taken him from an astronomy undergraduate at University College London in the 1960s full circle to being professor of astrophysics at the same institution today. As a dedicated observational astronomer, he has worked at or overseen many of the world’s great telescopes and observatories, from the 200-inch Hale reflector at Mount Palomar in San Diego, California, the Anglo-Australian Telescope at Siding Spring in New South Wales, and the Isaac Newton Telescope in the Canary Islands, to the giant 10-metre Keck telescopes on Hawaii, and many more. In his marvellous new book, he uses his time with these instruments as a backbone to tell the story of his life’s work: the search for light from the first stars and galaxies formed in the aftermath of the Big Bang.

Subtitled The Quest for Cosmic Dawn, the book is a combination of historical account, autobiography and scientific explication, blended together to take us on a whirlwind tour of the advances made in astronomy since the mid-20th century. These have allowed Ellis and colleagues to identify individual galaxies – and characterise entire populations – at ever-greater distances, taking advantage of the ‘cosmic time machine’ effect imposed by the limited speed of light to look further back in time. Ellis’s explanations of complex scientific and technological challenges faced along the journey are an exemplar of how to bring approachability and clarity to potentially tricky subjects, but it is the fascinating incidental details that really grab the attention. Offering a rare insight into how professional astronomy actually ‘gets done’, they elevate this to must-read status for anyone interested in the ways of modern science. ★★★★★

Giles Sparrow is an author and popular science communicator