Light does not usually surprise people. It travels, it reflects, it bends. In labs, researchers can twist it into more exotic forms, but that has often required special surfaces, unusual materials, or intense focusing with powerful optics. This time, the surprise came from free space itself. Scientists at the University of East Anglia, working with colleagues in South Africa, report that light can develop a kind of handedness as it moves through empty space, without mirrors, materials, or special lenses shaping it along the way. The work, published in Light: Science & Applications, points to a new way of controlling light by using its internal geometry. That matters because handedness, also called chirality, sits at the center of chemistry and biology. Many molecules, including some used in medicines, come in left- and right-handed forms that can look nearly identical while behaving very differently in the body. Schematic of the experimental setup depicting (a) the generation and (b) detection components. (c) Experimentally recorded polarization intensities for H, V, D, A, R and L for 3 separate …