Fermi
A fermi is a unit of length used in nuclear physics to measure extremely small distances, such as the size of atomic nuclei. It is equal to 1 femtometer (fm), which is 10⁻¹⁵ meters.
The unit is named after the Italian physicist Enrico Fermi, known for his work in nuclear physics.
Key facts:
1 fermi = 1 femtometer = 10⁻¹⁵ meters
Used to measure nuclear dimensions and particle sizes
Essential in the study of nuclear and particle physics
The fermi is vital for describing distances at the subatomic scale, much smaller than atoms and molecules.
Chain
A chain is a unit of length traditionally used in land surveying. The most common version is the Gunter’s chain, which equals 66 feet or 22 yards, approximately 20.1168 meters.
The chain was introduced by English clergyman Edmund Gunter in the 17th century to simplify land measurement. One chain consists of 100 links, each 0.66 feet long. It became a standard unit in British and American land surveying and was instrumental in defining land areas, especially in the U.S. Public Land Survey System.
Key Conversions:
1 chain = 66 feet
1 chain = 22 yards
1 chain ≈ 20.1168 meters
10 chains = 1 furlong
80 chains = 1 mile
Though now largely replaced by metric units and modern surveying tools, the chain still appears in older land deeds, maps, and rural property descriptions.
No conversions available for length.