Convert Russian Archin (archin) to Femtometer (fm) instantly.
About these units
Russian Archin (archin)
The archin was a Russian unit of length equal to approximately 71.1 cm. Like many traditional European units, it was based on body proportions and was widely used in textile trade, tailoring, land measurement, and carpentry. Before Russia adopted the metric system in the early 20th century, the archin formed part of a larger system of customary units such as the sazhen and vershok. Merchants relied heavily on the archin when measuring cloth and other traded goods, making it central to the economic life of Imperial Russia. Today, the archin appears in historical documents, literature, and museum records. Understanding the archin is essential for historians studying Russian industrialization, daily commerce, and rural life before modernization efforts transformed the measurement landscape.
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.