Kilograms—which have long been defined as the weight of the International Prototype kilogram—a cylinder stored in France—might not actually weigh kilograms anymore. There are 40 exact replicas of the IPK that have been sent all over the world to standardize weight for trade and science, but these things have been gaining weight at different paces, and the sort of people who freak out about stuff like this are really freaking out about this. Peter Cumpson, professor of Micro Electro Mechanical Systems at Newcastle University, says, "Mass is such a fundamental unit that even this very small change is significant and the impact of a slight variation on a global scale is absolutely huge." He went on to say that "there are cases of international trade in high-value materials—or waste—where every last microgram must be accounted for." Which is as close as a brainiac will come to just running around his lab, pulling his hair out ...