Convert Russian Archin (archin) to A.U. of Length (a.u.) 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 Today, the archin appears in historical documents, literature, and museum records.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.
A.U. of Length (a.u.)
The atomic unit of length, also known as the Bohr radius unit in atomic units, is approximately 5.29177 × 10⁻¹¹ meters. It is defined as the radius of the lowest-energy orbital of the hydrogen atom, providing a natural scale for describing atomic and quantum mechanical systems. Atomic units were devised to simplify equations in quantum chemistry and atomic physics by normalizing fundamental constants such as electron charge, Planck's constant, and electron mass to 1. In this system, many equations become dimensionless and far easier to manipulate mathematically. The atomic unit of length is essential in molecular orbital calculations, quantum simulations, and the study of electron behavior in atoms and molecules. Its use reflects an approach to physics in which units are chosen to match the natural scales of the systems being studied.