Convert Mile (mi) to A.U. of Length (a.u.) instantly.
About these units
Mile (mi)
The mile, equal to 5,280 feet, is a legacy of a long history of measurement stretching back to Roman times. Its ancestor, the Roman "mille passus" (thousand paces), established a rough distance of 1,480 meters, which evolved through medieval and early modern Europe into various regional miles. The English statute mile was standardized in 1593 and survives today in the United States, the United Kingdom (for roadways), and a few other territories. Despite being a non-metric unit, the mile remains deeply embedded in cultural and infrastructural systems. Road networks in the US are laid out with mile markers; athletic events include the famed "one-mile run"; and many people intuitively judge driving distances in miles. Aviation and international travel sometimes reference statute miles, though nautical miles dominate in navigation. Its long history and familiarity keep the mile relevant even in a metric world.
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.