The 'onion questions' in physics

Most questions in physics and astronomy are like onions. They may seem smooth and uncomplicated on the surface, but inside, many layers of subsidiary questions await anyone with the patience and talent to strip them away. "What are gamma-ray bursts?" is definitely an onion-type question, and Joshua Bloom's book of the same title does a thorough job of unpeeling it. As Bloom writes in the preface, at one level the answer is simple: gamma-ray bursts (GRBs) are "unannounced flashes of high-energy light detected from seemingly random places on the sky". But this bald explanation does not even begin to address the origins of these events, nor what Bloom, an astronomer at the University of California, Berkeley, calls the "engine" behind their creation. What astrophysical processes could possibly compress so much energy – as much, in fact, as the Sun will release in its entire lifetime – into just a few seconds? And then there is the most intriguing question of all, which Bloom addresses in the book's final chapter: what can GRBs tell us about the universe as a whole? These are still very active topics of research, and it is a pleasant surprise to find them discussed in a book aimed at a semi-popular audience. What are Gamma-ray Bursts? is, in fact, the second in a promising new series from Princeton University Press on the "frontiers of physics". Like its 2010 predecessor, Abraham Loeb's How Did the First Stars and Galaxies Form?, it seems best suited for readers who want a "big picture" of a field before embarking on in-depth study. Although the book contains numerous equations, as well as graphs taken from research papers on GRBs, it is written in an accessible style. Moreover, unlike a journal article, it is possible for a newcomer to read it without constantly referring to earlier work for basic definitions and background. There are a few niggles, including a proliferation of acronyms, but on the whole, Bloom (and Princeton) deserves kudos for filling this gap.

  • 2011 Princeton University Press £19.95/$27.95pb 280pp

Written wonders of the universe

The BBC's two critically acclaimed Wonders series saw millions tuning in each week to watch physicist Brian Cox deliver mountain-top lectures on the magnificence of the cosmos. But for some, particularly sticklers for traditional media, these programmes placed so much focus on the spectacle of nature that the wonder of scientific facts too often came second place to the special effects (and to Cox's radiant haircut). If you are among them, then Seven Wonders of the Universe (That You Probably Took for Granted) by C Renée James offers a pleasant alternative to Cox and his crew. The book's fly-by tour of the cosmos, with its seven stop-offs that include "gravity", "stuff" and "time", does not contain a single photograph. Instead, James, an astronomer at Texas' Sam Houston State University who regularly contributes essays to popular-science magazines, opts for old-fashioned prose, interspersed with the occasional sketchy cartoon. James defends this concept in her preface, pointing out that with so many stunning pictures of the heavens freely available from websites such as NASA's, it feels a bit arbitrary to pick a crop for a published book. It is an excellent point, and James' witty, lucid writing style brings humanness and a sense of perspective to a subject where technicolour blockbusters can leave viewers numbed. In James' cosmic journey, everything in nature is assigned a personality, from antiparticles being the evil twins of matter to the hailing of Jupiter as the solar system's king. Particularly enjoyable is the chapter on light, in which the Sun is painted in varying portraits, including "happy visible" and "creepy ultraviolet", to convey the idea that astronomers study different types of light to learn about different processes in the universe. At times, James overcooks the jokes, and the frequent references to American culture can sometimes leave foreign readers feeling on the outside of the joke. But on the whole, this geeky comedy is an effective strategy for taking the wonder of astrophysics and grounding it firmly in everyday life.

  • 2010 Johns Hopkins University Press £13.00/$25.00pb 256pp