“Electrical resistance is a simple concept: Rather like friction slowing down an object rolling on a surface, resistance slows the flow of electrons through a conductive material. But two physicists have now found that electrons can sometimes cooperate to turn resistance on its head, producing vortices and backward flow of electric current. The prediction of “negative resistance” is just one of a set of counterintuitive and bizarre fluid-like effects encountered under certain exotic circumstances, involving systems of strongly interacting particles in a sheet of graphene, a two-dimensional form of carbon. The findings are described in a paper appearing today in the journal Nature Physics, by MIT professor of physics Leonid Levitov and Gregory Falkovich, a professor at Israel’s Weizmann Institute of Science.”