Convert Femtometer (fm) to Arpent (arpent) 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.
Arpent (arpent)
The arpent is a French unit of length and area, historically used in France and French colonial territories like Louisiana and Canada. As a length, it was roughly 58.47 meters, while as an area unit it varied regionally but was commonly used for agricultural plots. The arpent was central to land measurement, urban planning, and agriculture, particularly in colonies where standard French units were imposed. It helped define plots for farming, taxation, and property distribution, often in combination with other traditional French units such as the perche. Although largely replaced by metric units, the arpent remains significant for historians, geographers, and legal scholars interpreting colonial-era land documents and property records.