SciTech

Lecture attendance reflects popularity of string theory

There are few geeks who don?t know Brian Greene. Through his books The Elegant Universe and The Fabric of the Cosmos and a recent NOVA special, the Columbia professor has succeeded in making string theory, a mathematically complex hypothesis describing the universe?s smallest particles, not only accessible but popular.
Greene spoke about string theory last Monday to an enthusiastic audience as part of the Drue Heinz lecture series at Carnegie Music Hall. In the audience were more than 80 physics students from the CMU physics department, which sponsored their admission tickets. The turnout is reflective of the popular appeal string theory has achieved, especially among physics enthusiasts.
To many of these students, the possibility of contributing to string theory seems unattainable. After all, Brian Greene was a child prodigy, able to multiply 30-digit numbers at the age of five, and was being privately tutored in math by a professor at 12.
There are already several professors on campus dabbling in string theory, including CMU physics professor Richard Holman, who described Greene as ?the King of Cool.?
The study of string theory is not limited to those with PhDs. This semester, professor Ira Rothstein inaugurated an undergraduate course titled ?Introductory String Theory.? Rothstein said, ?I heard from a friend of mine at MIT that they were offering the class for their undergrads, so I figured, if their students can handle it, then so can ours.? Although initially enrollment was quite high, Rothstein said, ?many of the [students] found it overwhelming?; about half have dropped out since the class began.
?I wanted to make the class real string theory, not a watered-down version of it. I?m very proud of the students who have persevered. They are very enthusiastic,? said Rothstein.
Asked if the class would be offered again, Rothstein responded, ?That depends upon whether the department has the manpower for it.?
String theory is the cutting edge of theoretical physics, and breaking into the field is very difficult. One of Rothstein?s students, senior physics major Peter Battaglino, hopes to pursue string theory in graduate school and is aware of the challenges.
?The only way I can survive the competition is to be obsessed with the subject. I know that it?s going to be frustrating at times, and ridiculously difficult all the time, and the only way that I?ll be able to cut it is to be 100 percent devoted,? said Battaglino.
Rothstein said of Greene, ?He has done some important work in string theory. But I think it?s fair to say that he?s really not a leader in the field.? Nevertheless, professor Greene does seem to have a unique ability to explain the theory. Battaglino, who also attended Greene?s lecture, said, ?I was amazed at how clearly he managed to convey the cutting-edge content of his field.?
Greene defined string theory as an attempt to answer one of the great questions in science: What is the most fundamental component of matter? Greene said that in the widely-accepted Standard Model, quarks and electrons are the most fundamental particles of the universe. In contrast, string theory states that the most fundamental ?things? are strings: tiny vibrating filaments of energy. Greene explained that just as different vibrations of a violin string create different musical notes, different vibrations of an energy string produce different particles. Every piece of matter in the universe ? every atom and every molecule ? is composed of identical strings that are simply vibrating at different frequencies. This is string theory in a nutshell, and remarkably, it resolves many conflicts within physics, such as the incompatibility between quantum mechanics and general relativity.
In spite of the hype surrounding the theory, Greene admitted, ?string theory is unproven.? But he remains optimistic that experiments will someday offer proof. For example, string theory predicts that colliding gravitons lose some energy, which escapes to one of a number of parallel universes. The opportunity to test this prediction may come when the Large Hadron Collider, a groundbreaking experimental particle physics facility located near Geneva, Switzerland, comes online. If the measurable energy of colliding gravitons is smaller than predicted under the Standard Model by the amount string theory predicts, this would be a confirmation of the theory.
String theory could lead to profound revelations about the character and composition of the universe. Of course, the concept that everything is made of vibrating strings of energy has no shortage of skeptics and lacks experimental confirmation, but string theory?s intrinsic mathematical elegance has convinced many scientists that string theorists are on to something.