 |
 |
|
|
|
|||
|
|||
 |
|||
Rewriting e = mc2
2004 Nobel Laureate offers new theories on mass and matter
By Jessica Ullian
|
|
MIT Professor and Nobel Laureate Frank Wilczek (left) lectured at the Metcalf Science Center on February 1. The audience included Lawrence Sulak, CAS physics chairman (right), and Sheldon Glashow, the Arthur G. B. Metcalf Professor of Physics and a 1979 Nobel laureate. Photo by Vernon Doucette |
|
|
|
A hundred years after the discovery of the theory of relativity, Nobel Laureate Frank Wilczek is reworking Einstein’s famous equation describing the relationship between mass and energy. Einstein wrote e = mc2, using mass as a tool to explain the properties of energy. But those seeking more information about the origins of mass, Wilczek said last week, would do well to look at the mathematical statement in a new way.
“As you’ll see, that’s the wrong equation,” Wilczek said. “Different formulations of the law can suggest different things.”
Wilczek, the Herman Feshbach Professor at MIT and one of three recipients of the 2004 Nobel Prize in Physics, gave the College of Arts and Sciences department of physics annual Dean S. Edmonds, Sr., lecture on February 1. The lecture, Wilczek’s first since traveling to Sweden to receive the prize in December, was part of the University’s annual gathering to “celebrate the fun of doing physics,” said Lawrence Sulak, the department chairman. The event honors the late U.S. patent attorney Dean S. Edmonds, who supported a number of inventors in the early 20th century, and established a foundation to “foster science, foster development, and foster innovation,” according to his son, Physics Professor Emeritus Dean S. Edmonds, Jr.
“If he’s up there looking down on the things we do today, he’s smiling,” said Edmonds.
In his talk, entitled The Origin of Mass, Wilczek explained that until Einstein created his special theory of relativity in 1905, mass was believed to be a finite concept. Einstein’s work revealed that there was more to be discovered about mass and its composition; Wilczek, by rewriting e = mc2, offered a new way of looking at the problem.
Rewriting the equation as m = e/c2, Wilczek suggested that energy is the source of mass, and that quarks and gluons, the smallest known components of the nucleus of an atom, generate the energy that is subsequently stabilized into protons and neutrons, the building blocks of atoms.
The explanation — which Wilczek termed “QCD Lite,” in reference to the theory of matter known as quantum chromodynamics — stemmed from the work that earned him a Nobel. Wilczek, David J. Gross of the University of California at Santa Barbara, and H. David Politzer of the California Institute of Technology won the award for their 1973 discovery of the force that binds quarks together to form an atomic nucleus. It explains why quarks can never be isolated from one another and provides insight into the strong force, one of the fundamental forces in nature, along with electromagnetism, gravity, and the weak force.
Their discovery, known as asymptotic freedom, shows that quarks are bound by a force that increases with distance. The further apart two quarks get, the stronger the binding forces are — making it impossible to observe a quark in isolation.
“What they did made it possible to create a theory of the strong interactions,” said Sheldon Glashow, a 1979 Nobel laureate in physics, a UNI professor, and the Arthur G. B. Metcalf Professor of Physics. Glashow’s research focuses on the weak forces, he said, making his and Wilczek’s work “complementary parts of the same story.”
During his talk at the Metcalf Science Center, Wilczek explained that asymptotic freedom enables the creation of mass. “If you put a quark in an empty space, it starts to generate quark and antiquark fields that grow with distance,” he said. The quark energy continues to build in a “runaway process,” but “Mother Nature’s way of solving that problem” is to produce, out of the vacuum, the quarks and antiquarks that stabilize it into equilibrium. “Empty space,” he said, “becomes a medium.”
The theory was deemed “fascinating” by several of the students, faculty, and guests in the audience, including physics major John Penwell (CAS’06). “The origin of mass is such a simple question, but at the same time no one has a definite answer to it,” he said. “It’s questions like that which are really at the heart of physics.”
Wilczek finished by discussing the future possibilities of Einstein’s equation and what they mean for scientific discovery. Removing mass as a tool of measurement in the equation and replacing it with energy, he said, improves “the symmetry and uniqueness of our equations.” Further permutations reveal, on a more basic level, the roles mass and energy play in everything — such as music, he said, in which mass is associated, “very literally and uniquely, with tones.”
“It may not appear to you that what I’ve presented to you is simple,” he concluded. “But in a higher sense, it’s as simple as could be.”
11
February 2005
Boston University
Office of University Relations