The mirror crack'd: Why physics is lopsided

时间:2019-03-15 14:17:01166网络整理admin

By Frank Close The alternative to symmetry is intriguing (Image: Simon Danaher) Forget symmetry, it’s asymmetry that could be the key to life, the universe and almost everything SYMMETRY is deeply satisfying. It has harmony and balance – it feels right. But while physicists use it as a guide in building theories, nature is more often lopsided than manifestly symmetric. Asymmetries are often far more informative. Trying to understand why a particular asymmetry exists can reveal clues about the profound nature of reality. That’s exactly what Peter Higgs and François Englert were doing 50 years ago when they came up with what’s now known as the Higgs mechanism, which imparts mass to fundamental particles. In October last year, their efforts were rewarded when they shared the Nobel prize in physics. Sometimes symmetry itself springs from asymmetry. We are made of atoms, which are held together by the attraction of opposite electrical charges. The simplest atom, hydrogen, consists of a single negative electron and a positive proton. These electrical charges counterbalance so precisely within matter that they cancel out one another, leaving gravity as the dominant long-range force outside. This is a case where perfect balance is crucial. Yet the way it is achieved is utterly lopsided. The electron, as far as we know, is a fundamental particle whereas the proton is not: it is made of three quarks. If the electron carries a charge of value -1,