Gamma

Gamma (upper case Γ, lower case γ) is the third letter of the Greek alphabet. It derives from the Phoenician Gimel Image:Phoenician gimel.png. In Modern Greek, it is pronounced [ɣ] or [ʝ], and in Ancient Greek, it was pronounced [ɡ]. In the system of Greek numerals it has a value of 3.

Letters that arose from Gamma are the Roman C and G and the Cyrillic letters Ge Г and Ghe Ґ.

Use in Science

Gamma is often used to denote a variable in mathematics and physics. In certain areas it has specific meaning.

Gamma characteristic power law, and gamma correction in photography, television and computer display systems. Gamma is the exponent in a power-law relationship between video or pixel values and the displayed brightness. In photography it is the slope of the curve of (density or log(opacity)) of the film image versus log(exposure) (the Hurter-Driffield curve), in the straight line region.
1 gamma is a unit of magnetic flux density, 1 gamma = 10⁻⁹ tesla or 1 nanotesla.
Gamma waves are a type of brain waves around 40 hertz.

The upper-case letter Γ is used as the symbol for:

The lower-case letter γ is used as the symbol for:

The Euler-Mascheroni constant in mathematics.
A risk management measure in mathematical finance.
The photon, seen as an elementary particle in physics.
Gamma rays in physics and astronomy.
The gamma factor in relativity theory and astronomy.
The adiabatic index of a gas in physics. Often the letter kappa κ is used.
The propagation constant of an electromagnetic wave (in electrical engineering and electromagnetic theory).
The third brightest (usually) star in a constellation. See Bayer designation.

In the game of Tetris, gamma is another name for the J tetromino.
E-102 Gamma is a fictional character in the Sonic the Hedgehog universe.
Gamma is a giant peace-keeping robot stolen by Dr. Wily which is the final boss of Capcom's Nintendo game Megaman 3.