The Edge of the Sky: All You Need to Know about the All-There-Is

  • Roberto Trotta
Basic Books: 2014. 978-0465044719 | ISBN: 978-0-4650-4471-9

When we think of cosmology, we might think of some of its most complex scientific theories, such as inflation or the general theory of relativity. Or we might consider its astounding discoveries, such as the twinned mysteries of dark matter and dark energy, which together comprise 96% of the contents of the Universe. We may then have the unsettling idea that the remaining 4% (including the stuff of which humanity is made) is insignificant in the grand scheme of things — a thought all the more remarkable when we consider the extent to which the bits of recycled stars known as humans understand cosmology.

The Antennae galaxies. Credit: Hubble Heritage/ESA/NASA

The extraordinary story of the Universe and our journey to understand it is not an easy one to tell to the general public. But because it is the story that binds us all together, it is important to tell it in myriad ways to reach as many people as possible. The Edge of the Sky is an inventive, enjoyable and thought-provoking contribution to that effort.

Inspired by 'Up Goer Five' — an instalment of the webcomic xkcd, by former NASA roboticist Randall Munroe — theoretical cosmologist Roberto Trotta uses fewer than 90 pages to take the reader through a strange, yet sometimes compelling, exercise. He translates our current understanding of cosmology into the 1,000 most popular words in English (or as the book would say, “the ten hundred most-used words in our tongue”). Effectively, this approach demanded the invention of a new language through renaming of common objects: aeroplanes, for instance, become flying cars. It is as if we are reading a book by an observer on a different planet. Paradoxically, this simplicity of language encourages us to think outside the familiar.

So we follow a “student-person” (scientist) through one night of observation using a “Big-Seer” (telescope), and her reflections on the series of “Why? questions” (science) that have led her, and humanity, to the point of understanding as much as we do about the “All-There-Is” (Universe). We move from early (Western) cosmology that the “old people” believed in, centred on “Crazy Stars” (planets), to the discoveries of planets outside the Solar System and today's search for new “Home-Worlds”. We then follow a fairly conventional path with the usual suspects, including the “student-people” Mr Hubble, Mr Einstein and Mrs Rubin, as Trotta brings us through discoveries from the expansion of the Universe to Big Bang nucleosynthesis — all using a total of just 707 different words (and 42 names).

This linguistic constriction left me wondering about the intended readership. At times, the exercise feels like just that, yielding pained oversimplifications that give the impression of inaccuracy, such as “tired light” for redshift. We begin to wonder whether Trotta embarked on the project merely as an intellectual puzzle, proving to himself that he could write a satisfactory explanation of cosmology with an arbitrary constraint on vocabulary. (There are faint echoes here, for instance, of the French writer and filmmaker Georges Perec's experimental 1969 novel La Disparition, which excludes the letter e.)

In reading this book, do the cosmologically uninitiated really gain a clearer understanding of the workings of the Universe, and could they then explain this to someone else using ordinary terminology? Probably not. But, as with a well-told folk tale, perhaps some of the passion and poetry of this ultimate quest will be conveyed, inspiring a new student-person to ask the right Why? questions. This would be no small success.