For better and for worse, these are heady times in cosmology. Over the past two decades, astronomers have pinned down the age of the universe quite precisely (13.72 billion years), confirmed its geometry as perfectly flat through exquisite maps of the Big Bang's faint afterglow, and found that its expansion is speeding up rather than slowing down. Three researchers shared the physics Nobel Prize for the latter discovery just last month.
Yet, embarrassingly, cosmologists have also come to realize that everything we see – the myriad celestial bodies that our telescopes reveal – constitutes a tiny sliver of what makes up the cosmic pie. Mysterious "dark matter," undetected except through its gravitational tug on galaxies, count for much more. The rest, a whopping 73 per cent, is in the even more bizarre form of "dark energy," the dominance of which dictates a dismal long-term future for the universe.
In A Universe From Nothing, Lawrence Krauss, celebrated physicist, speaker and author, tackles all that plus a whole lot else. In fewer than 200 pages, he delivers a spirited, fast-paced romp through modern cosmology and its strong underpinnings in astronomical observations and particle physics theory.
Other popular science books have covered many of the same topics, but Krauss's slim volume is bolder in its premise and more ambitious in its scope than most. He makes a persuasive case that the ultimate question of cosmic origin – how something, namely the universe, could arise from nothing – belongs in the realm of science rather than theology or philosophy. What's more, he goes on to argue, our current understanding makes it quite plausible that the universe indeed emerged from quantum nothingness, thus dispensing with any need for divine intervention. There is free lunch after all.
The book traces its own beginnings to a lecture that Krauss delivered in 2009. The video of the lecture has netted nearly a million views online, becoming something of a YouTube hit (though not compared to a clip of a piano playing cat, with 23 million views). So it is not surprising that the book at times has the tone of a lecture: You can almost hear the author's gleeful voice and picture a wry smile. Some sentences run long: I counted one at 107 words. Exclamation marks are sprinkled liberally. There are delightful historical anecdotes and humorous commentary. My favourite story is about the amateur astronomer who persuaded Einstein to publish "the results of a little calculation" on how gravity could act as a lens, the basis of techniques now used by researchers to weigh distant galaxy clusters and to find planets around other stars.
The author does not shy away from tackling complex physical concepts, and often finds clever ways to illustrate them. Even if you don't feel fully conversant with eternal inflation (of the cosmological, not economic, variety) or false vacuum energy by the end, you will almost certainly be rewarded with interesting insights, and a sense of awe, if you persist. Krauss explains how scientists know what they claim to know, for example, laying out the multiple, compelling lines of evidence for a hot Big Bang. He is careful to delineate what is well supported by experiments or observations and what is at the more speculative end of the scientific discussion.
A Universe From Nothing is not always an easy read – unless you are a science buff familiar with some of the lingo and the ideas – but it is surely a very rewarding one to plow through. The many fans of Krauss will devour it, and rejoice. Others, picking up a cosmology book for the first time, perhaps after watching Big Bang Theory or curious about what's new in astronomy, would find it demanding, but also mind-blowing. Those who feel the need to invoke a supernatural cause for the origin of the universe may – should? – find it disturbing.
Ray Jayawardhana is Canada Research Chair in observational astrophysics at the University of Toronto, and author of Strange New Worlds: The Search for Alien Planets and Life Beyond Our Solar System.