M is for messy is Martin Gardner's review of The Trouble With Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next; a book authored by Lee Smolin. It begins:
For more than thirty years, string theory has been what Murray Gell-Mann called “the only game in town.” By this he meant that it was the only good candidate for a TOE, or Theory of Everything. Not only does it claim to unify relativity and quantum mechanics, it also explains the existence of all fundamental particles. Instead of being “pointlike,” they are modeled by filaments of energy so tiny that there is no known way to observe them or even to prove they are real.
The review goes on to point out that from a skeptical few which included Richard Feynman and Sheldon Glashow skepticism increased and then surged. The review outlines some of the difficulties with the theory. There is this paragraph whose implications go well beyond physics and even science itself:
In a chapter on sociology, Smolin introduces the concept of “groupthink”—the tendency of groups to share an ideology. This creates a cultlike atmosphere in which those who disagree with the ideology are considered ignoramuses or fools. Most physicists tied up in the string mania, Smolin believes, have become groupthinkers, blind to the possibility that they have squandered time and energy on bizarre speculations that are leading nowhere.
It is human nature to become attached to what we have invested our time and energy. There is also this:
Woit has only harsh things to say about the recent acceptance of an anthropic principle by several leading string theorists, notably Weinberg and David Susskind. Susskind has even written a popular book about it—The Cosmic Landscape: String Theory and the Illusion of Intelligent Design. The notion that there could be millions of other universes, each with its own Calabi-Yau structure—or what amount to the same thing, with its own basic state of what physicists like to call the “vacuum”—is not one that appeals to Witten. “I’d be happy if it is not right,” Woit quotes from a 2004 lecture, “but there are serious arguments for it, and I don’t have any serious argument against it.”
An entertaining read for non-physicists.