Convert Bohr Radius (a₀) to Ken (ken) instantly.
About these units
Bohr Radius (a₀)
The Bohr radius, equal to approximately 5.29177 × 10⁻¹¹ meters, is the most probable distance between the electron and nucleus in the ground state of hydrogen according to the Bohr model. While modern quantum mechanics has evolved far beyond the Bohr model, the radius remains a remarkably accurate approximation for average atomic dimensions. The Bohr radius acts as a natural "yardstick" for the size of atoms and is frequently used in atomic physics and quantum chemistry. Many atomic properties — orbital sizes, electron probability distributions, and energy levels — are conveniently expressed in multiples of the Bohr radius. Because it reflects fundamental constants, including Planck's constant and the electron charge, the Bohr radius also appears in theoretical analyses of physical systems and helps unify atomic physics concepts across different contexts.
Ken (ken)
The ken is a traditional Japanese unit of length, typically about 1.8 meters, though historically it ranged from 1.6 to 1.9 meters depending on the era and region. The ken is deeply tied to traditional Japanese architecture, especially temple and shrine construction. In classic building design, the ken measured the spacing between pillars in wooden structures. Because Japanese architecture emphasizes modularity and harmonious proportions, the ken allowed builders to create spaces that were both structurally efficient and aesthetically consistent. Many tatami room layouts are also derived from ken-based proportions. Beyond architecture, the ken carried symbolic importance in religious and cultural contexts. Temples were often laid out using ken multiples, reinforcing a sense of order, symmetry, and sacred geometry. Even though modern Japan uses the metric system, the ken persists in the restoration and preservation of historical buildings.