Foot
A foot (plural: feet) is a unit of length commonly used in the United States, the United Kingdom, and some other countries. One foot equals 12 inches or about 0.3048 meters. Feet are often used to measure height, room dimensions, and short distances. For example, a person might be 5 feet 8 inches tall. The abbreviation for foot is "ft". Although many countries use the metric system, feet remain popular in daily life and construction in countries using the imperial system.
X-unit
The X-unit (symbol: xu) is a very small unit of length used primarily to measure wavelengths of X-rays and gamma rays. It was introduced in the early 20th century for precision measurements in X-ray crystallography.
1 X-unit ≈ 0.1 picometers (pm) or 10⁻¹³ meters
It allows scientists to express extremely small wavelengths typical of X-rays, which are on the order of atomic spacing
The exact definition has varied historically, but the unit remains useful for comparing wavelengths in X-ray spectroscopy and crystallography
Though largely replaced by the picometer or ångström in modern usage, the X-unit played a crucial role in early developments of atomic-scale measurement.
No conversions available for length.