Once I finished Steven Weinberg’s book Dreams of a Final Theory, I figured I’d write a long-winding review about what I think the book is really about, and its merits and demerits. But there is a sentence in the seventh chapter – titled ‘Against Philosophy’ – which I think sums up all that the book essentially attempts to explain.
Nothing in the history of science is ever simple.
And Dreams of a Final Theory wants to make you understand why that is so. To Weinberg’s credit, he has done a good job – not a great one – with complexity as his subject. I say ‘not a great one’ because it has none of the elegance that Brian Greene’s The Elegant Universe did, and it laid out string theory from beginning to end. At the same time, it is still Weinberg, one of the towering figures of particle physics, at work, and he means to say, first, that there is no place for simplicity in his line of work and, second, even in all the terrible complexity, there is beauty.
The book, first published in 1992, is a discourse on the path to a ‘final theory’ – one theory to rule them all, so to speak – and the various theoretical, experimental, mathematical and philosophical challenges it presents. Weinberg is an erudite scientist and you can trust him to lay out almost all facets of all problems that he chooses to introduce in the book – and there are many of them. Also, I wouldn’t call the book technical, but at the same time it demands its fair share of intellectual engagement because the language tends to get (necessarily) intricate. And if you’re wondering: There are no equations.
In fact, I would be able to describe the experience of reading Dreams of a Final Theory using a paragraph from the book, and such internal symmetry is unmistakable throughout the book:
But why should the final theory describe anything like our world? The explanation might be found in what [Robert] Nozick has called the principle of fecundity. It states that the different logically acceptable universes all in some sense exist, each wit its own set of fundamental laws. The principle of fecundity is not itself explained by anything, but at least it has a certain pleasing self-consistency; as Nozick says, the principle of fecundity states ‘that all possibilities are realized, while it itself is one of those possibilities’.