THETA

'Theta' (uppercase 'Θ', lowercase 'θ' or 'ϑ') is the eighth letter of the Greek alphabet, derived from the Phoenician letter Teth. In the system of Greek numerals it has a value of 9. In Classical Greek θ represented an aspirated voiceless dental plosive (), but in Koiné and later dialects it became a voiceless dental fricative . In American English, the name of the letter is commonly pronounced . In Modern Greek and British English, the name is pronounced .
Letters such as the early Cyrillic letter ''fita'' () developed from θ.
In its archaic form, θ was written as:

★ a cross within a circle ( or )

★ and later, as a line or point within a circle ( or ).
According to Porphyry of Tyros, the Egyptians used an X within a circle as a symbol of the soul; having a value of nine, it was used as a symbol for Ennead. Johannes Lydus says that the Egyptians used a symbol for Kosmos in the form of theta, with a fiery circle representing the world, and a snake spanning the middle representing ''Agathos Daimon'' (literally: ''good spirit'').^[1]
The Egyptians also used the symbol of a point within a circle (, the ''sun disc'') to represent the sun, which might be a possible origin of its use as the Sun's astrological glyph. It is worthwhile to note that (''theta'') has the same numerical value in isopsephy as Ηλιος (''Helios''): 318.
In classical Athens, it was used as an abbreviation for the Greek θάνατος (''thanatos'', "death") and as it vaguely resembles a human skull, theta was used as a warning symbol of death, in the same way that skull and crossbones are used in modern times. It survives on potsherds used by Athenians when voting for the death penalty.^[1]

Contents

Symbol

Use in Options Investing

Use in Popular Sociology

Uses as names

Notes

References

Symbol

The lower-case letter θ is used as a symbol for:

★ A plane angle in geometry.

★ The voiceless dental fricative in the International Phonetic Alphabet, such as in the words ''thick'' or ''thin'' (but not as in ''the'', which is the voiced dental fricative).

★ The Potential temperature in meteorology.

★ The score of a test taker in item response theory.

★ Theta Type Replication - a type of bacterial DNA replication specific to circular chromosomes

★ Theta has also gained a new significance, in the Northeastern region of the United States, as a symbol for affection, in a similar capacity to the "heart" symbol .
The upper-case letter Θ is used as a symbol for:

★ Dimensionless temperature in transport phenomena.

★ Big O notation. Denoting an asymptotically tight bound in analysis of algorithms.

★ Θ (set theory), a certain ordinal number.

★ Representing pentaquarks, exotic baryons in particle physics.

★ Earth Day.

★ Brainwave Frequency (Beta, Alpha, Theta, Delta) ranging from 4-8 Hz

Use in Options Investing

★ Theta is known as an option Greek measuring the rate of time decay on a daily basis. One can look at this as an ice cube melting in your hand. A Theta of -.05 means that the option is losing a nickel of time value each day. Other option Greeks include Delta, Vega, Rho and Gamma. (See The Greeks)

Use in Popular Sociology

★ Theta is used colloqially to refer to the quotient of a person's appearance versus time. Similar to the Options investing as a description of the effect of time on price, Theta in this sense describes the effect of time on appearance. For example, a 50-year old woman, who looks as if she were 40 years old, would have a Theta of (50/40=1.20). An excellent example is Vanna White, who appears approximately 10 years younger than her calendar age. Theta is a desirable quality; people generally are more attracted to a person with good theta than those who look their age.

Uses as names

★ Theta Sigma is one of the nicknames of the Doctor of the television series Doctor Who

★ Kappa Alpha Theta is a sorority whose members are designated "Thetas."

★ Theta is also the name of a melodic death metal band based in Plattsburgh, New York

Notes

To add in a document type Alt-0415 (MS Word 2003 SP2 tested only)
1. .
2. .

References

★ .