Convert Aln (aln) to Femtometer (fm) instantly.
About these units
Aln (aln)
The aln was a traditional Swedish unit of length equal to roughly 59.4 cm, though its exact value varied slightly by region and period. It belongs to the broader family of "ell" measurements used across Europe, originally based on the length of a human forearm. The aln played a crucial role in Swedish commerce, especially in the textile industry, where cloth was measured by stretching it along standardized rods or boards marked in aln lengths. Because such goods were often woven locally and traded regionally, the aln helped regulate and unify commercial practices before the adoption of the metric system. Although obsolete today, the aln survives in historical texts, architectural references, and Scandinavian museum records. Understanding the aln helps scholars interpret pre-modern construction records, land measurements, and traditional clothing industries, revealing a great deal about everyday life in early Sweden.
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.