A gigantic, previously unknown set of galaxies has been found in the distant universe, shedding light on the underlying skeleton of the cosmos. "Matter is not distributed uniformly in the universe," said Masayuki Tanaka, an astronomer with the European Southern Observatory (ESO) who helped discover the galactic assemblage. "In our cosmic vicinity, stars form in galaxies and galaxies usually form groups and clusters of galaxies." But those collections of matter are just small potatoes compared to larger structures long-theorized to exist. "The most widely accepted cosmological theories predict that matter also clumps on a larger scale in the so-called 'cosmic...