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.
Nautical Mile (UK)
The nautical mile (UK) is a unit of distance used primarily in maritime and aviation navigation in the United Kingdom. Traditionally, it was defined as 6,080 feet (about 1,853 meters), which is slightly longer than the modern international nautical mile of 1,852 meters. This UK definition was used before international standardization in 1929. Today, the international nautical mile is widely adopted, but the UK nautical mile historically played an important role in navigation and mapping.
No conversions available for length.