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.
Reddish spots on the icy surface of Jupiter’s moon Europa may indicate pockets of warmer ice rising from below. This upwelling could provide an elevator ride to the surface for material in an ocean beneath the ice, say scientists studying data from NASA’s Galileo spacecraft.