Hold your hands out in front of you, and no matter how you rotate them, it’s impossible to superimpose one over the other. Our hands are a perfect example of chirality — a geometric configuration by which an object cannot be superimposed onto its mirror image. Chirality is everywhere in nature, from our hands to the arrangement of our internal organs to the spiral structure of DNA. Chiral molecules and materials have been the key to many drug therapies, optical devices, and functional metamaterials. Scientists have until now assumed that…