Hubble finds most of visible light in the Universe

A closer look at the Hubble Space Telescope's most detailed image, the Hubble Deep Field, reveals that the faint galaxies seen by Hubble could account for most of the visible light in the cosmos. "We appear close to completing a 'light census' of the universe,'' reports Michael S. Vogeley of the Princeton University Observatory. "The extraordinary smoothness of the background sky suggests that most of the visible light in the universe hails from galaxies that Hubble can detect.''