Order the Greek Alphabet, Part 2 Quiz

Nu, the 13th letter in the Greek alphabet, is derived from the Phoenician letter nun. In Latin, it arose the letter "N", though its lowercase symbol looks like the Roman "v".

In statistics, it represents degrees of freedom. In physics, it represents any of three kinds of neutrinos in particle physics.

Xi, the 14th letter of the Greek alphabet, was derived from the Phoenician letter samekh. It has no Roman/Latin equivalent, since the letter chi was chosen to represent the "ks" sound. It was adopted into the Cyrillic alphabet as the letter ksi.

It is used to represent the Riemann Xi function in analytic number theory.

Omicron, the 15th letter of the Greek alphabet, is derived from the Phoenician letter ayin.

Its use as a mathematical symbol is avoided, since it is indistiguishable from the Arabic numeral zero ("0").

The UN's World Health Organization used the Greek alphabet to label the variants of SARS-COV-2, the COVID-19 virus. COVID-19 Omicron was assigned to variant of concern B.1.1.259. Many people unfamiliar with the Greek alphabet pronounced omicron as "omnicron", and used the prefix "omni-" in many references to the variant.

Pi, the 16th letter of the Greek alphabet, is derived from the Phoenician letter pe. The Latin "P" arose from pi.

The uppercase Pi is used in mathematics to indicate multiplication of a sequence of common factors, much as capital Sigma is used to indicate summation of a sequence.

Lowercase pi is most commonly known as the symbol representing the constant ratio of a circle's circumference to its diameter. This value is often built into modern electronic calculators up to the 9th decimal place, or the nearest billionth (3.141592654). In 2024, a US computer storage company calculated pi to 105 trillion digits. This took 75 days to complete and used up 1 million gigabytes of data.

Pi was used for this ratio because the Greek word περίμετρος means "perimeter"; the perimeter of a circle is also known as its circumference.

Rho, the 17th letter of the Greek alphabet, is derived from the Phoenician letter res. Even though its symbols are Ρ and ρ, it's actually the forebearer of the Roman "R".

In physics, rho is used to represent various densities: mass, air, or charge. It's also a type of subatomic particle, the rho mesons.

In mathematics, its used as the length coordinate in polar, spherical, and cylindrical coordinate systems. For example, a polar equation that graphs as a four-leaf rose is: ρ = cos(2θ).

Sigma, the 18th letter of the Greek alphabet, is derived from the Phoenician letter shin. The Latin "S" derives from sigma.

Sigma has two lower-case forms: σ is used at the beginning and middle of words, and ς at the end of words (final form). An example of this is the name Odysseus, which in Greek is Ὀδυσσεύς.

Upper-case sigma is used in mathematics as a summation symbol, expressing the sum of similar terms in a sequence.

In statistics, lower case sigma represents the standard deviation of a population; sigma-squared represents the variance.

Tau, the 19th letter of the Greek alphabet, is derived from the Phoenician letter taw. It gave rise to the Roman "T".

Some mathematicians use tau as the ratio of a circle's circumference to its radius, equivalent to 2π or 6.283185307 decimal. They use this because it's the circumference of a unit circle. Also, when transforming trigonometric functions to a different period, the factor 2π is often used. But if dividing by 2π and neglecting grouping parentheses, the calculation is not done correctly by computers/calculators. So using a single symbol helps avoid this problem.

In physics, tau is sometimes used as a time variable, if the modern "t" has already been used for temperature.

Upsilon, the 20th letter of the Greek alphabet, is derived from the Phoenician letter waw. In the Latin alphabet, four letters have arisen from Upsilon: "U", "Y", "V", and "W".

In statistics, it is sometimes used to represent degrees of freedom.

Phi, the 21st letter in the Greek alphabet, represent the Romanization "ph" or "f". The Cyrillic letter ef arose from phi.

In mathematics, the golden ratio is represented with lowercase phi. ((1+ √5)/2) = 1.618033988. It's reciprocal is 1 less that itself; that is, 1/ϕ = ϕ - 1.

In trigonometry, phi is often used as a secondary angle after theta.

Chi, the 22nd letter of the Greek alphabet, is the forebearer of the Latin letter "X".

Chi was the origin of using the modern letter to represent Christ, as in "Xmas". This is because chi is the first letter of Χριστός, the Greek translation of "Christ".

In statistics, the term chi-squared has various uses: chi-squared distribution, chi-squared test, and chi-squared target models.

Psi, the 23rd letter of the Greek alphabet, has an uncertain origin. The Cyrillic letter, also called psi, arose from the Greek letter.

Psi is used in physics to represent wave functions in quantum mechanics.

In mathematics, psi represents the reciprocal Fibonacci constant and the super-golden ratio.

In astronomy, it's the symbol for the planet Neptune. This assignment comes from the sea god Neptune, who carries a trident similar in shape to the letter psi.

In Biblical studies, it serves as an abbreviation for the book of Psalms.

Omega, the 24th letter and last letter of the Greek alphabet, simply means "Great O", as opposed to omicron which means "little o". The lowercase omega, ω, looks like the modern "w", but is unrelated.

As the last letter, omega is used to denote the last of a set of things. Its also used in the idiom "alpha and omega", meaning from beginning to end, or everything.

In electronics, capital omega, Ω, represents the SI unit of electrical resistance, the Ohm, named after German physicist Georg Ohm.

Lowercase omega is used in trigonometry to represent angular velocity; i.e., how fast something is spinning. Its most common use in the trigonometric equation:
v = r∙ω which equates linear velocity (the linear speed of an object on a rotating body) as the product of the rotating body's radius times the angular velocity. The ω must be in units of radians per unit of time.

In "Star Trek" lore, an omega molecule is a highly unstable molecule and the most powerful substance known to exist. The Borg knew it as Particle 010. The molecule could be synthesized with sufficient amounts of boronite ore. However, proper containment methods did not exist to prevent the violent destabilization of the molecule, which destroyed subspace and rendered warp travel impossible. The explosion of one molecule could destroy all subspace within several light years.