Magazine

Most of the universe is void. Of the rest, most is invisible. Yet it weaves a sprawling cosmic web, lit at its nodes by clusters of galaxies. The May/June edition of CERN Courier reports on how a faint radio glow between cluster pairs may set new constraints on dark-matter models, on the physics facilities that sustain the supply of radiopharmaceuticals, and on a technique for taming the systematics that limit the next generation of neutrino-oscillation experiments.