Convert Femtometer (fm) to Famn (famn) instantly.
About these units
Femtometer (fm)
A femtometer, equal to 10⁻¹⁵ meters, is the scale at which the structure of atomic nuclei becomes measurable. Also known historically as a "fermi," this unit is used extensively in nuclear physics to describe the radii of protons, neutrons, and nuclei, which typically span 1–10 femtometers. At this scale, the strong nuclear force dominates interactions, and classical intuition breaks down almost entirely—quantum mechanics provides the only meaningful framework. The femtometer also plays a role in high-energy particle experiments, where the wavelengths of probing particles (like high-velocity electrons) may be expressed in femtometer increments. These small wavelengths allow researchers to resolve sub-nuclear structures. While invisible to any optical instrument, distances in the femtometer range can be inferred through scattering experiments, such as those performed in particle accelerators.
Famn (famn)
The famn, related to the English fathom, was a Scandinavian unit roughly equal to 1.78 meters. Like other fathoms, it originated as the distance between a person's outstretched arms, making it a natural measure for tasks performed at arm's length. Historically, the famn was used in maritime contexts, forestry, and measuring firewood. Sailors relied on it when describing water depth, rope lengths, and the dimensions of boats. On land, stacked firewood was often quantified in famnar, making the unit central to resource management in cold northern regions. Today, the famn has largely disappeared from practical use, but it continues to appear in maritime literature, folklore, and historical accounts. Its surviving references help illuminate the working methods and daily experiences of Nordic sailors, fishermen, and rural communities prior to metrication.