The speed of light in a vacuum has been known as both a universal constant and a hard speed limit for all matter in the universe ever since Albert Einstein published his special theory of relativity in 1905. Rules, however, are made to be broken. And an international team of physicists appears to have found just such a loophole: the only thing that goes faster than light, it turns out, is darkness.

More specifically, individual dark spots known as optical vortices, or phase singularities, do so. As a light wave travels through space, it oscillates and twists—at the center of that twist, the peaks and troughs of the light wave cancel each other out, creating dark spots that—under certain conditions—outrun the light wave itself. The research was conducted by Technion–Israel Institute of Technology physicist Ido Kaminer and his colleagues.

To make their discovery, the researchers constructed a unique microscope system that let them observe optical vortices in hexagonal boron nitride, a two-dimensional form of ceramic that can be used to convert light into quasiparticles that are a mixture of light and matter called polaritons. Polaritons move relatively sluggishly—around 100 times slower than the speed of light. With that speed, the team was able to observe how oppositely charged singularities approached each other and accelerated each other to superluminal, or faster-than-light, speeds before they were annihilated.