Life, the universe, and everything. We know the answer (42), but have we learned to ask the question? In these two books, conveniently collected into one exceedingly well-produced volume, Stephen Hawking sets forth the fundamental thinking underlying modern cosmology. From this vantage point, he also probes some of those deeper questions which naturally follow from the empirical study.
The first of the selections is A Brief History of Time, Hawking’s bestselling primer on astrophysics. Though the title would suggest, well, a history book, the possible origins of the universe occupy only a portion of the discussion. Hawking first lays out the scientific developments which culminated in those theories, detailing the changes from Ptolemy’s geocentric model to Newtonian mechanics to the revolutionary discoveries made at the start of the 20th century. Of these latter two in particular are of great interest: Einstein’s general theory of relativity, which relates to the gravitational interactions of objects on an astronomical scale, and quantum mechanics, the formulas developed by Heisenberg and his colleagues at Copenhagen to explain the interactions of subatomic particles. Both theories completely overthrew the conventional wisdom which had preceded them, both agree to a high degree of accuracy with empirical observation – and both are mutually exclusive to the other. “These two theories are known to be inconsistent with each other,” Hawking writes, “they cannot both be correct.” He goes on to state that one of the main goals of contemporary physics is the search for a quantum theory of gravity that will resolve the inherent contradictions between the two.
With these tools of the trade, incomplete though they are, in hand, Hawking then does turn his attention to their implications on the origin and development of the universe. Much of the discussion centers around singularities – termination points on the space-time continuum at which infinite density results in infinite temperature, the cessation of time, and a complete breakdown of all known laws of science. Hawking handles two examples: localized instances of the phenomenon resulting from the collapse of large stars, termed “black holes,” and the postulated explosion by which the universe might have begun – the “Big Bang.” In treating this last, he is careful to point out that though our current understanding of the laws of physics might take us right up the moment of the Bang, they are rendered meaningless at the singularity itself and thus we cannot speak scientifically about what might have come “before” (if the notion of time would even still apply) or speculate as to possible causes. But Hawking also introduces another possibility, that there might be no beginning singularity at all. In this case, space-time could be viewed as a finite, unbounded expanse, like the surface of a ball but in four dimensions instead of three. Thus, the universe had no beginning, no moment of creation, and by implication, no creator. While difficult to imagine, the math apparently is plausible, and while Hawking doesn’t explicitly endorse this view, he does give it serious consideration.
In The Universe in a Nutshell, Hawking continues his discussion of advanced physics studies and their implications on the observable world. Having laid the foundations in the previous book, here he tackles a number of topics, from string theory to time travel, in chapters than can be read more or less independently. Collected as the two are here in one volume, Universe reads more like a set of extended appendices to Brief History, which probably aids comprehension as well as presentation. The information presented, though informative and interesting, doesn’t have the same impact as those fundamental principles handled in the former work. Nevertheless, the latter does provide a primer to several trendy topics as well as provide ammunition for a few good physics puns (braaaaaaaanes), and thus is worth at least a glance. The modular nature of the discussion makes skimming easy, if that happens to be one’s aim.
Hawking’s prose is consistent throughout both volumes, lucid and engaging and liberally sprinkled with humor. The narrative will move, mostly seamlessly, from scientific explication to philosophical speculation, but is never didactic in the first case and never dogmatic in the second. Though easy to read and follow (Brief History contains just one equation – guess which one), this conversational tone does have its drawbacks. Hawking’s work is an excellent introduction for the layman, but has less to offer the acolyte. Those who have studied physics at the university level will find the collection a good refresher, but not plumbing any uncharted waters. Another detriment stems from the lack of mathematical proofs: Hawking’s conclusions must of necessity be taken for granted. While most of the fundamental theories discussed are universally accepted, many of the conjectures the author makes are not, and without being able to consider the step-by-step reasoning the reader must simply take them on faith. I understand the reasoning here – the book is a primer, not a college text – but I did find myself wishing some of the sweeping claims were given more support.
That being said, both of those complaints can be rectified by further study, and Hawking does provide a long list of references. For what it is – an introduction to the problems and theories that shape modern physics – Hawking’s work succeeds admirably. I highly recommend that anyone wishing to tackle the subject start with this particular edition (ISBN 978-0-307-29122-6). Not only do you get two books in one, but the whole volume is filled with charts and diagrams that illustrate otherwise difficult-to-picture concepts. Whatever one’s worldview might be, the questions of the origin and design of the universe must be a central component, and the contributions of modern science to the discussion cannot be ignored. This volume is an excellent way to dive into that discussion.