Is seeing believing?: Atomic-scale imaging of surface structures using scanning tunnelling microscopy

Scanning tunnelling microscopy produces beautiful atomic resolution images of surfaces which appear to show atomic positions in a very direct fashion. However, the technique is intrinsically a probe of spatial variations in electronic structure, so interpreting such images correctly is sometimes far from trivial. A brief survey is presented of some of the known effects and their physical origins, and of the progress being made in theoretical modelling which has helped to understand many of these phenomena and to provide far more reliable image interpretation.