" in The Econo-
mist (Jan. 18, 1986), 25 St.James's St.,Lon-
don, SWA1A lHG, England.
Under normal circumstances, most people experience a four-dimensional world (three dimensions in space and one in time). Most students envision the building blocks of matter as little "bits," with electrons circling an atomic nucleus much as the Earth orbits the Sun.
Such notions will soon be considered obsolete. Contemporary physi- cists, like their forebears during the 1920s, are reinterpreting...