The theoretical physics and particle physics communities in many of the major physics departments, especially in the United States, lean heavily toward string theory as the preferred approach to a quantum gravity theory. In fact, the growing need for diverse approaches is maintained even by some string theorists, who realize the importance of including conflicting viewpoints.
In a debate between Brian Greene and Lee Smolin on National Public Radio, Greene acknowledged the need to work on areas other than string theory, pointing out that some of his own graduate students are working on other approaches to solving problems of quantum gravity.
Lisa Randall — whose own work has often been influenced by string theory — describes how, during the first superstring revolution, Harvard physicists remained more closely tied to the particle physics tradition, and to experimental results, while Princeton researchers devoted themselves largely to the purely theoretical enterprise of string theory.
In the end, every particle theorist at Princeton worked on string theory, which she identifies as a mistake — and one that continues to this day.
These stances indicate that if a “string theory cult” does exist, then Brian Greene and Lisa Randall have apparently not been inducted into it. Still, the fact is that theoretical physics departments at several major universities are now dominated by string theory supporters, and some feel that other approaches are inherently marginalized by that.
This criticism is one of the fairest, because science, like any other field of endeavor, needs criticism. Psychologists have shown that the phenomenon of “groupthink” takes hold in situations where the only people who are allowed a seat at the table are those who think alike.
If you want to have a robust intellectual exchange — something that’s at the heart of physics and other sciences — it’s important that you include people who will challenge your viewpoints and not just agree with them.
Some criticisms of Smolin’s book have indicated that he wants some sort of handout for himself and his buddies who aren’t able to cut it in the normal grant application process. (In the other direction, Smolin and Woit have implied that similar economic interests are at the heart of the support for string theory.)
But if the institutes that determine how funding is allocated are dominated by people who believe that string theory is the only viable theory, then these alternate approaches won’t get funded. Add to that the citation issues described earlier in this chapter, which possibly make string theory look more successful than it actually is, and there’s room for valid criticism of how funding is allocated in physics.
Still, hope for these alternatives isn’t lost. As popular as string theory is, it’s likely that most theoretical physicists want to find answers more than they want to be proved right. Physicists will gravitate (so to speak) toward the theories that provide them the best opportunity to discover a fundamental truth about the universe.
So long as these non-string theorists continue doing solid work in these other areas, then they have the hope of drawing recruits from the younger generation. Eventually, if string theorists don’t find some way to make string theory succeed, it will lose its dominant position.