Baryon Acoustic Oscillations from SDSS III . ... Credit Copyright: Zosia Rostomian ( LBNL ), SDSS-III , BOSS Explanation: How large do things appear when far away? When peering across the universe, the answer can actually tell us about its average gravitational history and hence its composition . ... These density ripples are known as baryon acoustic oscillations (BAOs) and are expected to emerge from the early universe at a known size scale. ... NASA Official: Jay Norris. ...