“Long before the idea of scanning specimens with a small spot of light produced confocal light microscopy, the idea of using a small spot of electrons to scan surfaces had been around for as long as electron microscopy itself. A surface demarcates the boundary of a solid, and is the site of interaction with the surrounding environment, from a ball bearing to a living cell. In the mechanical world, adhesion, friction, wear, and corrosion are all dependent upon surface properties. The smooth surface of a ball bearing is crucial in the reduction of friction, but its efficiency may well be compromised by wear or corrosion.”