Barleycorn
A barleycorn is an old English unit of length, traditionally based on the length of a grain of barley. It is defined as exactly 1/3 of an inch or approximately 8.47 millimeters.
Historically, the barleycorn was used for measuring small lengths and was also the basis for the inch, which was originally considered to be three barleycorns long. It played a role in various traditional measurements, including shoe sizing in English-speaking countries, where shoe sizes were sometimes expressed in barleycorn units.
Although obsolete as a formal unit, the barleycorn remains culturally significant, especially in shoe sizing systems.
Summary:
1 barleycorn = 1/3 inch ≈ 8.47 mm
Based on the length of a grain of barley
Used historically in small measurements and shoe sizing
Mostly of historical and cultural interest today
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.
No conversions available for length.