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.
Ell
An ell is a historical unit of length that was commonly used in medieval Europe, especially for measuring textiles and cloth. Its length varied by region but was typically about 45 inches (approximately 1.143 meters).
The ell originated from the length of the arm or forearm and was often used by tailors and merchants to measure fabric. Different countries had their own versions—for example, the English ell was about 45 inches, while the Scottish ell was longer, around 37 inches.
Although obsolete today, the ell played an important role in trade and clothing production before standardized measurements became widespread.
Summary:
1 ell ≈ 45 inches (1.143 meters)
Used mainly for measuring cloth and textiles
Length varied by region and country
The ell is now largely of historical interest but reflects the origins of many modern measurement systems.
No conversions available for length.