Convert A.U. of Length (a.u.) to Centiinch (cin) instantly.
About these units
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.
Centiinch (cin)
A centiinch is 1/100 of an inch, making it a small but straightforward derivative of the imperial system. Although seldom used today, it historically appeared in precision engineering, machining, and scientific instruments that relied on extremely fine calibrations before widespread adoption of decimal-based units like millimeters. Because the inch was long established in many English-speaking industries, dividing it into 100 equal parts provided a convenient decimal alternative to the more cumbersome 1/8 or 1/16 subdivisions found in carpentry and early tooling. The centiinch never gained strong traction, particularly once the metric system became dominant for precision work. However, it remains an interesting footnote in the evolution of measurement, illustrating attempts to reconcile the decimal preference with traditional imperial standards.