A research group from the Technion-Israel Institute of Technology reports in Nature an unprecedented achievement in electron microscopy: the direct measurement of “dark points” within light waves. By doing so, the researchers were able to confirm a prediction from the 1970s that the speed of these points exceeds the speed of light.

The “dark points” measured by the group are essentially tiny “holes” in the wave structure. Known as vortices, the holes are a common phenomenon in nature: We encounter them in ocean waves, in air currents, and even in coffee when we stir it or pour it into the sink. As early as the 1970s, a surprising theoretical prediction was proposed: Vortices may move faster than the wave in which they are formed. As strange as it sounds—imagine a vortex in a river overtaking the flow of water in which it exists—the phenomenon is real. Until now, this was based on theory. The research team’s achievement has now confirmed it experimentally.