A review by davidr
The Trouble with Physics: The Rise of String Theory, the Fall of a Science and What Comes Next by Lee Smolin

5.0

It is well known now, that a very large cadre of talent in theoretical physics has been working on string theory. The theory solves a lot of problems in physics, and Lee theoretical physicist Lee Smolin has published a number of papers on the subject. The problem is that, the theory does not make any predictions that might allow it to be "falsifiable". So, according to my definition of a theory--a scientific idea that is supported by much observational evidence from a number of different approaches--string theory is not a theory at all. It is a hypothesis that has yet to be upheld by observational evidence. And, in the three decades preceding this book, Smolin writes that no fundamental discoveries had been made in physics--a sudden stoppage in progress that had been flowing since the early 1900's. And, when presented with this problem, string theorists are simply certain that their approach is correct; they are even willing to change the philosophical definition of what is science, by suggesting that science requires a new paradigm that does not require confirmation by observational evidence.

This book begins by reviewing the landscape of physics before the rise of string theory, and then goes into some detail about string theory itself. Then the book describes the successes and shortcomings of string theory, and the alternative theories/hypotheses that have been proposed.

But this book is as much about the sociology of physicists, as it is about science. To me, this is quite interesting, as Lee Smolin is not subtle in his discussion about the physics community. And, Smolin is quick to admit that he is as guilty as others, in his inability to make progress. He had been working in quantum gravity, and
"felt like the high school dropout invited to watch his sister graduate from Harvard with simultaneous degrees in medicine, neurobiology, and the history of dance in ancient India.

Now, this book was published in 2006, and I am told that the situation has changed somewhat since then, especially with the new discoveries being made by the LHC (Large Hadron Collider) at CERN. However, Smolin documents some very disturbing tendencies that are still alive in physics, and in science in general. Smolin asserts that these tendencies are very close to a phenomenon called "groupthink", where everyone in a community is pressured to think in the same way.

Smolin writes that there are two types of scientists; craftsmen and seers. The craftsmen are very clever and have excellent technical skills. They have a tendency to work on what Smolin calls "normal science", that is, to follow the fashionable trends. They generate incremental progress in science through hard work. The problem is that they are not going to produce a "revolution" in science. The "seers", on the other hand, are visionaries. They are willing to question the fundamental assumptions that underlie physics. They do not necessarily have strong technical skills, but they are visionaries, and are not willing to "follow the crowd".

It is ironic that the scientists who first developed string theory were themselves scientific pariahs for many years. They worked on the fringes of the physics community, and their ideas were not welcomed. They could not obtain academic positions. After more than a decade, their ideas started to get noticed, up to the point where string theory became mainstream. Now, it is the physicists who do not research in string theory who are the pariahs. And according to Joanne Hewett, "... the arrogance of some string theorists [is] astounding, even by physicists' standards. Some truly believe that all non-stringy theorists are inferior scientists. It's all over their letters of recommendation for each other ..."

Smolin writes that science needs both the craftsmen and the seers, but only the craftsmen can have normal careers in the present system. Only when young PhD's pursue research along the lines of the older generation, can they have a hope of advancing to a postdoc position, gain funding, and ultimately obtain a professor position. Today, that is how the system works.

Much of the physics that Smolin writes is over my head--it is difficult for someone not already steeped in theoretical physics to follow very closely. But I was fascinated by a discovery known as "Milgrom's law" in the 1980s. The discovery has to do with where the gravitational acceleration of galaxies breaks down--it breaks down at 1.2x10^-8 cm/sec^2, which is precisely c^2/R, where R is the scale of the curvature of the universe. Physicists invented the concept of "dark matter" to explain this break-down, so question is whether this match in acceleration is simply a coincidence, or a sign of something more fundamental at work.

Smolin is a distinguished researcher, and his descriptions of the science are authoritative. Some discussions I've had with physicists corroborate much of what Smolin writes about the sociology of string theorists. This is an important book, not only about academic physics, but about how all sciences are conducted.