Review- a brief history of time

A Brief History of Time by Stephen Hawking

My rating: 5 of 5 stars


There were parts of this book that I did not understand- perhaps as one would expect, otherwise, I would myself be a theoretical physicist. However, I did learn a great deal from it, and it's definitely a book that I'll re-read at some point, which is absolutely what one would want from a science book written for a general audience.

Hawking sets the scene for the findings of modern science by discussing previous models of cosmology, such as the ancient idea that the earth is the centre of the universe, and that the sun revolves around the earth. He then gives a potted history of the central ideas underpinning modern physics, most of which concern gravitational forces and how they influence matter both on the large scale- celestial bodies- and on the tiny scale- atoms.

For the most part, Hawking is a good writer, and many of the chapters highlight his wonder at the scale and majesty of the universe, in addition to his sense of fun. He plainly enjoyed a silly anecdote and a witty turn of phrase. This means that although some of the ideas expressed are hard to understand for a lay reader, the book never feels imposing.

At a few points, the figurative language used seemed a little uneven. For example, Hawking suggests that the universe might be like the earth, in that it possesses neither a beginning or an end; one can travel around the earth without ever 'falling off'. It's possible that only the analogy is faulty here rather than the idea (as I'm not qualified to assess the idea), but I found this very confusing, as the earth has a boundary. If one flies up, one eventually leaves the earth behind. I suspect Hawking doesn't mean to imply that one could leave the universe by going the fourth dimensional equivalent of 'up'.

Also, a few of the ideas were expressed only in passing and could have been unpacked a little more. For example, Hawking at one point suggests that the universe would have been infinitely dense and have no size before the big bang. Although elsewhere, he says that the rules of causality did not apply prior to the big bang, that sentence indicated that something that can be labelled 'the universe' could at one point be said to contain no properties. Perhaps this is just being greedy in a book so packed with ideas, but I'd have liked to know what that meant.

I was much less convinced by the passages where Hawking comments on philosophy and the philosophical implications of his work. For example, at one point, he states that the uncertainty principle has great implications for philosophy that philosophers have not worked through because of their ignorance of physics. On the description given in the book, the uncertainty principle limits the ability of an observer to establish causality because measuring matter changes the properties of matter. This clearly undermines scientific determinism- the ability to predict everything if one knew the properties of all matter in the universe, but not necessarily determinism per se. It may be the case that determinism is true, but that finite beings cannot learn enough to establish universal causality in practice. As is often the case, a person with brilliant knowledge in one subject can overreach when discussing another.

However, despite the difficulties I've outlined, this is a book that I would recommend without question to any general reader. It is well written, compelling, even thrilling, which is not a description one often applies to work of theoretical physics.



View all my reviews