The Greek letter **κ** (kappa) was derived from the ancient Phoenician letter 𐤊 (kāp) which meant “palm” (of a hand).

The lower-case **κ** is pretty much just a smaller version of the upper-case **Κ** and is virtually indistinguishable from the upper-case Roman **K** as well as the Cyrillic **К**/**к**. I prefer using the cursive **ϰ**.

The lower-case κ and/or cursive ϰ have quite a few uses in maths, engineering and sciences, for instance:

- in coordination chemistry: a symbol for denticity
- in geometry: kappa curve, or Gutschoven’s curve, a two-dimensional curve resembling the letter ϰ
- in electrical engineering: conductivity (the reciprocal of resistivity ρ)
- in fluid dynamics: the von Kármán constant
- in immunology: a type of the immunoglobulin light chain
- in mathematics and physics: the curvature
- in pharmacology: κ-opioid receptor (KOR)
- in statistics: Cohen’s kappa coefficient

## No comments:

## Post a Comment