At first glance, it seems like a paper worthy of an Ig Nobel Prize. Roland Ennos, University of Manchester, has examined why fingernails, when nibbled or torn, tend to rip in a transverse direction, not longitudinally toward the nail bed.[1] Using 3 mm-long snippets of undergraduates' nails, he found that it took twice the energy (6kJm-2) to cut them lengthwise as crosswise (3kJm-2). "And that's a good thing," he says. "Otherwise, we would be in agony throughout our lives, because every tear would damage our nail bed, inflicting great pain and incurring infection."