At the University of Vienna, physicist Jani Kotakoski and his team have resolved a long-standing mystery in materials science: the shape of atomic-scale holes in hexagonal boron nitride is not fixed by physics alone, but is negotiated between physical force and chemical atmosphere. By introducing oxygen during electron beam irradiation, researchers discovered they could steer pore geometry from circular to triangular — a distinction that, at the scale of individual atoms, determines how a material interacts with the world passing through it. This quiet mastery over atomic architecture opens a