nanometer

• 10^-9 meters
• 10 angstroms
• 0.001 micrometers

The term was first introduced in 1951 and replaced the term millimicron.

Nanometers are most useful for measuring the wavelengths of light (the visible spectrum is between 400 and 700 nanometers), the size of the smallest microbes (200 to 300 nanometers with some potentially as small as 20 nanometers) that have been found, the size of features on an integrated circuit (130 nanometers by 2003) and the size of machines being designed for nanotechnology (less than 100 nanometers).

A nanometer is utterly, mindbogglingly small. A nanometer is to a small pebble as a pebble is to the earth's diameter.

Even 100 nanometers is incomprehensibly small: a human hair grows 100 nanometers in 10 seconds.