Convert Finger (Cloth) (finger) to Bohr Radius (a₀) instantly.
About these units
Finger (Cloth) (finger)
The cloth finger is a small measurement used in tailoring and weaving, typically about 2.1 cm (0.83 inches). It allowed precise adjustments when cutting and aligning fabric patterns. Merchants and craftsmen relied on the finger as a convenient subdivision of larger units like spans and ells. Its use highlights the practical application of body-based measurements in the textile industry. While no longer standard, the cloth finger provides a window into historical garment production and the role of human-scale units in everyday work.
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.