Quick action by astronomers leads to new insights on mysterious gamma-ray bursts

Scientists “arriving quickly on the scene” of an October 4 gamma-ray burst have announced that their rapid accumulation of data has provided new insights about this exotic astrophysical phenomenon. The researchers have seen, for the first time, ongoing energizing of the burst afterglow for more than half an hour after the initial explosion. The findings support the “collapsar” model, in which the core of a star 15 times more massive than the sun collapses into a black hole. The black hole’s spin, or magnetic fields, may be acting like a slingshot, flinging material into the surrounding debris.

Gravity test confines string theory

Researchers have conducted the most sensitive search to date for gravitational-strength forces between masses separated by only twice the diameter of a human hair, but they have observed no new forces. The results rule out a substantial portion of parameter space for new forces with a range between one-tenth and one-hundredth of a millimeter, where theoretical physicists using string theory have proposed that “moduli forces” might be detected, according to the researchers.

Surfactant curtails nanotube clumping in water, removing barrier to applications

Scientists have long touted carbon nanotubes as a futuristic means of delivering drugs, fortifying brittle materials and conducting current in miniaturized circuits. But attempts to introduce actual nanotubes into these roles have often been stopped in their tracks by the slender filaments’ stubborn and unhelpful tendency to clump together in solution. Now scientists at the University of Pennsylvania have found that a readily available chemical, a surfactant called sodium dodecylbenzene sulfonate (NaDDBS), disperses nanotubes in water with remarkable efficiency. The discovery, described in a paper published this month in the journal Nanoletters, represents an important step towards wider applications of nanotubes.

Beer, yeast offer new insight into evolution

Researchers studying yeast reproductive habits have for the first time observed a rapid method for the creation of new species, shedding light on the way organisms evolve. “Most models of speciation require gradual change over a very long period of time, and geographic or ecological isolation for a new species to arise,” says University of Houston biologist Michael Travisano. “Our study suggests that mating two separate species to produce hybrids can result in a new species readily and relatively quickly, at least in yeast, but possibly in other organisms as well.”