Zeta

Zeta (UK: /ˈziːtə/, US: /ˈzeɪtə/) is the sixth letter of the Greek alphabet. It looks like a capital Ζ and a small ζ. In ancient times, people pronounced it as zē̂ta or zdɛ̌ːta, but today in Modern Greek, it is said as zíta (ˈzita).

In a special counting system called Greek numerals, zeta stands for the number 7. It came from an old letter called zayin used by the Phoenician people, whose symbol was 𐤆. Over time, zeta helped create other letters, like the Roman Z (Z) and the Cyrillic З (З).

Name

Unlike other Greek letters, zeta was given a new name, similar to beta, eta, and theta. The word "zeta" is the origin of "zed," which is the name for the Latin letter Z in Commonwealth English. In Swedish and many Romance languages like Italian and Spanish, the term "zeta" refers to both the Greek letter ζ and the Roman letter Z.

Main articles: Greek letters, Phoenician, beta, theta

Further information: Z, Swedish, Romance languages, Italian, Spanish

Uses

The letter ζ represents the voiced alveolar fricative sound in Modern Greek. Its pronunciation in ancient Greek before 400 BC is still debated among scholars. Some believe it was pronounced like "zd" (similar to the word "Mazda"), while others think it was an affricate sound like "dz" (similar to the tool called an adze).

Zeta has a numerical value of 7 in the Greek numeral system. In mathematics and science, the lowercase zeta is used for various concepts, such as the Riemann zeta function, the damping ratio in physics, and the effective nuclear charge on an electron.

Unicode

The Greek letter Zeta has several representations in Unicode, a system that helps computers use and display text from many different languages. For Zeta, there is a capital letter (Ζ) and a small letter (ζ). These are used in normal Greek text. There are also special forms used in mathematics and other scripts, like the Coptic and Old Permic alphabets, each with their own unique codes.