nu

Nu is the thirteenth letter of the Greek alphabet, written uppercase Ν and lowercase ν. It follows mu and precedes xi, and in Greek it represents the consonant n. In the system of Greek numerals, nu has the value 50. The name nu is transliterated as “nu” in English; the letter is part of the broader Greek script used in science, mathematics, and literature.

The letter’s origin traces back to the Phoenician alphabet, where the corresponding sign denoted a consonant sound similar to n. Over time, nu became a standard symbol in Greek and, by extension, in many fields of study that adopt Greek letters for variables and constants.

In science and mathematics, ν (nu) is a versatile symbol. It commonly denotes frequency, such as the frequency of a wave or photon. In particle physics, ν stands for the neutrino. In statistics, the degrees of freedom are often labeled by ν. In fluid dynamics, kinematic viscosity is represented by ν (with SI units of m^2/s). In solid mechanics and materials science, Poisson’s ratio is frequently denoted by ν as well.

In astronomy, Greek letters including ν are used in star designations within a constellation (for example, ν Lyrae). The letter also appears in various specialized notations across disciplines, reflecting its long-standing role as a general-purpose symbol.

In typography, the lowercase nu ν resembles a Latin lowercase v, which can lead to occasional confusion in mixed-script texts. Overall, nu serves as a compact, widely recognized symbol with diverse applications in science, mathematics, and beyond.