Illustration: Alan Stonebraker

Figure 1: (Top) Dizzy Dean throws curveballs made of ordinary unentangled single baseballs (photons) at a target, and his probability of hitting the bull’s eye improves only as $1/N$, where $N=4$ is the number of balls thrown. (Bottom) Here Dean throws a single quantum ball composed of $N=2$ photons in a spatially entangled N00N state, and with a little postprocessing carried out by a computer at the target, the chances of hitting the bull’s eye now scales like $1/N$.