Three researchers who have contributed greatly to physicists’ understanding of the Standard Model of particle physics won the Nobel Prize in Physics. The Royal Swedish Academy of Sciences awarded Yoichiro Nambu of the Enrico Fermi Institute at the University of Chicago half the prize. Makoto Kobayashi of the High Energy Accelerator Research Organization in Tsukuba, Japan, and Toshihide Maskawa of the Yukawa Institute for Theoretical Physics at Kyoto University, Japan, each won one-quarter of the prize.
Nambu’s research touched on how the laws of nature can spontaneously break symmetry on the subatomic level. What do we mean by symmetry? The best way I’ve seen to explain this concept is to imagine a pencil standing on a table by its pointy end. The object is symmetrical from every direction. However, when the pencil falls, that symmetry is lost. The pencil has decided on one direction.
Kobayashi’s and Maskawa’s research focused on broken symmetry that’s been around since immediately after the Big Bang. They helped to explain why the laws of physics are different for matter and antimatter. The forces and particles in the universe appear symmetrical on a larger scale, but they cannot be. Antimatter and matter cannot be symmetrical, or else you and I wouldn’t be here (when matter meets antimatter, they annihilate, leaving only radiation). Somehow, matter must have won out. How? Well, hopefully the Large Hadron Collider (LHC) at CERN, when it starts up again in the spring, will provide answers to why the universe favored matter over antimatter.
Kobayashi and Maskawa also predicted three families of quarks — only two families were known at the time. Each quark family consists of two types of quarks. Since their prediction, scientists have experimentally discovered all six quarks. The top quark was the most recently proved; physicists discovered it in 1994.
I’ll leave the details of symmetry and how it fits into the Standard Model of particle physics to the physics experts (the Ph.D.s). Refer to the Nobel Prize in Physics web site for a great explanation.
One thing that strikes me is how different areas of physics are intertwined. Nambu’s, Kobayashi’s, and Maskawa‘s research focused on particle physics, but the Standard Model of particle physics is also a cornerstone of cosmology. And cosmology also draws on astronomy. You really can’t do astronomy/astrophysics without thinking about particle physics.