Smoke and mirrors

WHEN Alice stepped through the looking-glass in Lewis Carroll's classic children's story, she found a world populated by talking chess pieces and bread-and-butterflies. The “standard model” of particle physics is hardly less strange. It says that there is indeed a looking-glass world, which is a near-perfect mirror image of this one. This week, physicists at the Stanford Linear Accelerator Centre (SLAC) in America and KEK, a high-energy physics laboratory in Japan, have unveiled the first results from experiments meant to test this theory. And, in doing so, they have come a step closer to finding out why the universe of people, planets and stars, rather than shadowy reflections of such things, exists at all.