In the world of particle physics, there is no such thing as nothing. Particles of matter, and their anti-matter counterparts, are forever flitting in and out of existence. Theorists have predicted that the presence of such transient visitors has little effect on everyday life. However, a group of experimental physicists has just shown this view to be mistaken. Atomic nuclei are bundles of protons and neutrons which, along with electrons, are the basis of matter. But protons and neutrons themselves are made of more fundamental particles called quarks. These quarks have fractional electrical charges and combine to give each particle its overall electric charge, whether positive in the case of protons or neutral in the case of neutrons. They also give each particle its magnetic properties.
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