Describing Nambu's early work, Laurie M. Brown of Northwestern University writes of its "exuberant sense of play." As his student, I enjoyed Nambu's sheer pleasure in ideas and his ready laugh (even if I did not always get the joke). In the belief that too much work is harmful, he urged me to attend baseball games and to read the exploits of V. I. Warshawski, the fictional Chicago sleuth.
In 1952 Nambu was invited to visit the Institute for Advanced Study. There he found many brilliant and aggressive young men. "Everyone seemed smarter than I. I could not accomplish what I wanted to and had a nervous breakdown," Nambu wrote to me decades later, trying to bring comfort during my own travails as a postdoctoral fellow. In 1957, after having moved to Chicago, he proposed a new particle and met with ridicule. ("In a pig's eye!" Richard Feynman shouted at the conference, Brown recalls. The omega was discovered the next year, in an accelerator.) Meanwhile Nambu had heard J. Robert Schrieffer describe the theory of superconductivity that he had just devised with John Bardeen and Leon N. Cooper. The talk disturbed Nambu: the superconducting fluid did not conserve the number of particles, violating an essential symmetry of nature. It took him two years to crack the puzzle.
Imagine a dog faced with two bowls of equally enticing food. Being identical, the bowls present a twofold symmetry. Yet the dog arbitrarily picks one bowl. Unable to accept that the symmetry is entirely lost, Nambu discovered that the dog, in effect, cannot make up her mind and constantly switches from one bowl to the other. By the laws of quantum physics, the oscillation comes to life as a new particle, a boson.
Nambu points out that others, such as Bardeen, Philip W. Anderson, then at Bell Laboratories, and Gerald Rickayzen, then at the University of Illinois, also saw that a superconductor should have such a particle. It was Nambu, however, who detailed the circumstances and significance of its birth and realized that the pion, as well, was born in like manner (by breaking the chiral, or leftright, symmetry of quarks). While he searched for more of its siblings in nature, Nambu circulated his findings in a preprint.
Jeffrey Goldstone, then a postdoctoral fellow at CERN, the European laboratory for particle physics, realized the import of this work and soon published a simpler derivation, noting that the result was general. Thereafter the new particle was dubbed the Goldstone boson. ("At the very least, it should be called the Nambu-Goldstone boson," Goldstone comments.) When Nambu finally published his calculations in 1960, his paper also showed how the initially massless particle mixes with a magnetic field in a superconductor to become heavy. Recognized by Anderson, Peter Higgs, then at the Institute for Advanced Study, and others as a general phenomenon, it later became the Higgs mechanism of the Standard Model of particle physics.
In the years that followed, Nambu studied the dynamics of quarks, suggesting they were held together by gluons carrying a color quantum number to and fro. "He did this in 1965, while the rest of us were floundering about," Gell-Mann says. (Nambu, however, believed the quarks to be observable and assigned them integer electrical charges, an error that Gell-Mann and others corrected.) In 1970, perusing a complex mathematical formula on particle interactions, Nambu saw that it described strings. In the 1980s his "string action" became the backbone of string theory.
"He has an amazing power of coming up with pictures," says Peter G. O. Freund, a colleague at Chicago. While working with Nambu, I noticed that he would look at a problem from several different, yet simultaneous, points of view. It was as if instead of one mind's eye he had at least two, giving him stereoscopic vision into physical systems. Where anyone else saw a flat expanse of meaningless dots, he could perceive vivid, three-dimensional forms leaping out.
See what we're tweeting about
1 Comments
Add CommentIn this article Yoichiro Nambu explains how the principle of symmetry may result to the creation of an exhange subatomic particle or force. The principle of symmetry thus blends the relativistic and the quantum platforms, as in both cases forces turn out to be but the effects of the alteration between equivalent possibilities or probabilities.
Reply | Report Abuse | Link to thisThere appears to be a homology between the principle of equality of the theory of relativity and the law of quantum entanglement. According to the equality principle an observer does not distinguish between two systems in a state of balance, such as between the weight of an object counteracted by the earths resistance, and an accelerating force in empty space counteracted by the inertia of the accelerated mass ( Relativity , by Albert Einstein, 1920).
Similarly, in quantum entanglement, an observer does not distinguish between the two frames of reference at either side of a mirror. As the observer always notices his mirror-image when looking through a mirror, he cannot assess whether he is seated in the real or the reflected world. Therefore the connection between symmetrical counterparts remains unbroken while jumping into or out of a mirror.
Yet with respect to the principle of indeterminacy relating does not necessarily imply acting. Because of the spontaneous symmetry breaking the definition of a frame of reference causes the alignment of the contents of that frame. But that does not reduce the uncertainty, as different observers can choose different frames and no one can hold the other is wrong.
Consequently the violation of the symmetry may be attributed not to the alteration of the intrinsic nature of an object itself, but rather to the altered properties of the relevant frame of reference: The inversion of the deflection of a reflected beta particle, with respect to the parity symmetry violation, may be due to the inversion of the properties of the intercepting magnetic field. The fact that the asymmetries do not cancel out, according to the charge-parity (CP) symmetry violation, further indicates that a frame of reference may behave as a multiple mirror.
The symmetric relation of matter and antimatter depends both on opposite mass-energy values and opposite time directions. Therefore the essential balance of the universe is unshaken by the phenomenal prevalence of matter or antimatter either by the apparent preference of a direction of the arrow of time, as such distinction is a fact (or an artifact) of the observation.