New NIST Nano-ruler Sets Some Very Small Marks

ScienceDaily: "NIST has issued a new ruler, and even for an organization that routinely deals in superlatives, it sets some records. Designed to be the most accurate commercially available 'meter stick' for the nano world, the new measuring tool boasts uncertainties below a femtometer. That's 0.000 000 000 000 001 meter, or roughly the size of a neutron."