A nanometer (nm) is a unit of length in the metric system, equal to one billionth of a meter (1 x 10-9 m). Many have probably heard of it before: it is often associated with nanotechnology and the creation or study of very small things. A nanometer is clearly smaller than a meter, but you may be wondering, how small? Or, what types of professions or real products operate at this nanoscopic scale? Or, how does it compare to other metric length measurements?

Metric measurements are all based on the meter. Look at any ruler or tape measure and you will see numbered markings for meters, centimeters, and millimeters. With a mechanical pencil and a steady hand, it is not difficult to draw lines that are one millimeter apart. Now imagine trying to fit a million parallel lines into the space of one millimeter, that is, a nanometer. Creating those lines would definitely require specialized equipment, since:

Without the aid of aids (such as magnifying glasses or microscopes), a normal human eye (that is, normal vision) can see individual objects with a diameter of about two hundredths of a millimeter, which is equal to 20 micrometers.

To give the 20 micrometer size some context, see if you can identify a single cotton/acrylic fiber sticking out of a sweater (holding it up to a light source helps tremendously) or floating in the air as dust. Or sift some fine sand into the palm of your hand to find the tiniest, barely noticeable grains. If that’s a bit tricky, try looking at human hairs, which range from 18 micrometers (very fine) to 180 micrometers (very coarse) in diameter.