Fluoridating the universe.

Fluoridating the universe

The abundance of fluorine in the universe has puzzled scientists because there is no plausible way so much could be created in the elemental "nursery" at the center of stars. Two astrophysicists now suggest that the usually noninterfering neutrino might have a hand in arranging things.

The burst of neutrinos recorded during the initial explosion of supernova 1987 A demonstrated that such supernovas produce prodigious quantities of neutrinos. Although neutrinos are so weakly interactive they can be ejected into space fro the center of a star and leave no mark of their passage, the intense flashof neutrinos during a supernova may create fluorine out of the nuclei of its neighbor on the periodic table, neon, say Stanford Woosley of the Universityof California at Santa Cruz and Wick Haxton of the University of Washington in Seattle in the July 7 NATURE.

According to their theory, a very small fraction of the neutrinos produced by the supernova excite some of the dying star's neon-20 nuclei, which then take a step down the periodic table by ejecting a proton to create fluorine-19. The process would produce just the ratio of neon-20 to fluorine-19 that we see today, and "could account for the fluorine in our galaxy (and in our toothpaste)," say the researchers.