Warped Passages - Lisa Randall [168]
Raman Sundrum, who was then a postdoctoral fellow at Boston University, had also decided to remain in Boston that summer. I had often met Raman at conferences or when we visited each other’s institutions, and we had even briefly overlapped as postdoctoral fellows at Harvard. Since Raman had already thought about extra dimensions, I decided that it could be useful to discuss my ideas and questions with him.
Raman is an interesting character. Whereas most physicists in the early stages of their career work on relatively safe problems—questions of general interest in which they are likely to make progress—Raman insisted on focusing on whatever he considered most important, even when it was an extremely difficult problem or diverged considerably from other people’s interests. Despite his obvious talent, his idiosyncratic approach had kept him from a faculty job and brought him to his third postdoctoral position. But at that time, Raman was thinking about extra dimensions and branes; his interests and those of the rest of the physics community had begun to converge.
Our collaboration began at MIT’s branch of Toscanini’s (now sadly closed), an ice cream shop in the MIT student center that served great ice cream and very good coffee. Toscanini’s was the ideal venue for discussing ideas without constraints or interruptions, as well as indulging in the delicious research stimulants that were available there.
From those early days, chatting over coffee, our research evolved and jelled as the summer progressed. By August it had reached the point where we needed bigger and bigger blackboards to hold all the details we were discussing. Since the blackboard in my office at MIT, where I was then a professor, was rather small, we would wander the “infinite corridor” (the very long hallway that runs the length of MIT’s main building) searching for empty classrooms.
The particular research problem we focused on was the application of sequestering to supersymmetry breaking. The idea was to sequester particles responsible for supersymmetry breaking from the Standard Model particles and thereby prevent unwanted interactions between them (see Figure 73). We chose the word “sequester” to distinguish models in which particles are separated on different branes from the so-called “hidden sector” models of supersymmetry breaking that were fashionable at the time. In hidden sector models, supersymmetry-breaking particles interacted feebly with Standard Model particles, but weren’t actually hidden (despite the name), and therefore could interact in ways that are not acceptable in the real world.
Figure 73. In this model for supersymmetry breaking, there are two branes. Standard Model particles are on one brane, and particles that break supersymmetry are sequestered on the other. The two branes each have three spatial dimensions and are separated in a fifth spacetime dimension, which is the fourth dimension of space.
In the beginning I was very enthusiastic about our ideas and Raman was skeptical, although our roles alternated over time. But with one enthusiast and one skeptic, we quickly covered a lot of ground and got to the heart of the physics we were thinking about. Sometimes we even dismissed ideas too quickly, but usually one or the other of us maintained a point of view long enough to make progress.
Francis Bacon, who along with Galileo is considered one of the founders of the modern scientific method, described the difficulty of making progress while nonetheless retaining the skepticism necessary to ensure the correctness of your results.* How can you take an idea seriously enough to delve into its consequences, while simultaneously suspecting that it might be incorrect? Given enough time, a single person can fluctuate between these