Has science lost its way? What is the nature of the universe, and more importantly, how do we go about discovering it? In the past 30 years, one theory to answer this question has dominated the physics community. String theory, while starting off as a fringe concept in science, has taken over the field. Virtually all work on theoretical physics now centers around it.
But is string theory deserving of all this attention? And even if ultimately found to be correct, is examining only one theory at a time the right way to approach science? Does science need competition to have progress? These questions are discussed in The Trouble with Physics by Lee Smolin.
The Trouble with Physics is split into four parts, each of which offers an excellent look into science through different prisms. Part I concentrates on the history of physics, and specifically the concept of unification, as well as the questions that string theory tries to answer. Unification is the idea that two disparate concepts in science are actually related somehow. Gravity and acceleration were unified by Einstein, electricity and magnetism were unified by Maxwell. Some attempts at unification have failed, such as the unification of light and sound using ether.
In fact, there have been just as many failed attempts at unification as there have been successful ones. As different theories were put forth, experiments would be devised in due course to test them. Over time, evidence would mount that would allow the scientific community to conclude whether the theory was valid or not, usually in the span of about 10 years. This idea repeats many times throughout the book, as string theory is examined, since there is no experimental evidence that string theory is correct, even after 30 years.
Part II looks specifically at the history of string theory. Here Smolin writes a fairly easy-to-read history, and tells the tale with great suspense. He goes to great lengths not to fault string theory at every turn in it's history. Quite the contrary, there are many times when reading the chapters in this part where you'll be convinced that string theory is right, only to find out later that something new was discovered to dash the hopes of scientists everywhere. As each new problem is discovered, some new idea is tacked on in what ends up being a desperate attempt to save the theory, until we're finally left with something that is nothing like an Elegant Universe.
This is far from a hatchet job on string theory though. Smolin spends considerable time describing what string theory does well at explaining, but at the same time explains why this is not enough to conclude that string theory is proven science as so many have.