Number 274 (Story #1), June 7, 1996 by Phillip F. Schewe and Ben Stein A NEW MEASUREMENT OF COSMIC DEUTERIUM . By looking for signs of deuterium in very distant gas clouds, backlit by an even more distant quasar (at a redshift of 3.7), astronomers at UC San Diego have determined that the ratio of primordial deuterium to hydrogen is 2.3 x 10**-5, a factor of 10 less than measurements reported by other groups in 1994. Primordial in this case refers to the abundances relatively early after the big bang as opposed to more recent eras by which time much deuterium will have been consumed by fusion burning in stars. The new lower D/H estimates imply that the overall early baryon (protons and neutrons) density was actually higher than previously thought, although still far less than would be required for the universe to eventually close back on itself. (David Tytler et al., Nature, 16 May 1996.)