The scientists who said they recorded particles traveling faster than light in September—and then confirmed their own findings last week—have it wrong, international scientists in Italy say. The ICARUS project, based in the same laboratory as the OPERA experiment, argued that if the particles had traveled faster than light, much of their energy would have been lost.
ICARUS scientists ran tests of their own and found that the neutrino beam sent from CERN had an energy spectrum appropriate for speed-of-light travel—and no faster, Reuters reports. A CERN scientist called the paper "definitive" and wrote that it explains that "the difference between the speed of neutrinos and the speed of light cannot be as large as that seen by OPERA, and is certainly smaller than that by three orders of magnitude, and compatible with zero." More debate is sure to follow as other scientists ready experiments of their own at Fermilab near Chicago and Japan's KEK lab. (Read more CERN stories.)