A network of 1,400 ground-based particle detectors and two dozen telescopes has located the possible origin of the highest-energy cosmic rays. Traveling at near light speed, these rays—most likely protons—pack 10<sup>20</sup> electron volts, 100 million times the energy produced by the largest particle accelerators and roughly equivalent to that of a fast-pitch baseball. The source appears to be nearby active galactic nuclei: bright galactic cores probably powered by supermassive black holes. Scientists say they would never have guessed that black holes might have such powers if not for high-energy cosmic rays. —JR Minkel


The fatty acids in human milk may boost IQ. Breast-fed infants with at least one copy of a common variant of the gene FADS2 had IQ scores that were six to seven points higher than those of nonnursed kids with similar genetics. But breast-feeding did not appear to affect those children (10 percent of the study population) with only a less common version of FADS2. The gene variants may affect the conversion of dietary precursors to long-chain polyunsaturated fatty acids, which aggregate in the brain after birth. Alternatively, the fatty acids may act on the gene itself, causing it to affect the metabolic processing of the acids. —Nikhil Swaminathan


For robots to be accepted as human peers (as Bender is on Futurama), it might just take a light touch. Scientists introduced a classroom of toddlers—who naturally had no preconceived notions regarding droids—to a two-foot-tall humanoid robot, QRIO, which giggled when its head was touched. Over time, the children bonded with QRIO, touching it as they did other humans. After five months, the children treated QRIO as a near equal, even covering it with a blanket and telling it “night night” when its batteries ran out. But when the robot was reprogrammed just to dance, the toddlers lost interest. The findings appear in the November 13 Proceedings of the National Academy of Sciences USA. —Charles Q.Choi