Steradian
The steradian (symbol: sr) or square radian is the SI unit of solid angle. It is used in three-dimensional geometry, and is analogous to the radian which quantifies planar angles. The name is derived from the Greek stereos for "solid" and the Latin radius for "ray, beam".
The steradian, like the radian, is a dimensionless unit, essentially because a solid angle is the ratio between the area subtended and the square of its distance from the vertex: both the numerator and denominator of this ratio have dimension length squared (i.e. L2/L2 = 1, dimensionless). It is useful, however, to distinguish between dimensionless quantities of a different nature, so the symbol "sr" is used to indicate a solid angle. For example, radiant intensity can be measured in watts per steradian (W·sr−1). The steradian was formerly an SI supplementary unit, but this category was abolished in 1995 and the steradian is now considered an SI derived unit.
Definition
A steradian can be defined as the solid angle subtended at the center of a unit sphere by a unit area on its surface. For a general sphere of radius r, any portion of its surface with area A = r2 subtends one steradian.
Square (algebra)
In mathematics, a square is the result of multiplying a number by itself. The verb "to square" is used to denote this operation. Squaring is the same as raising to the power 2, and is denoted by a superscript 2; for instance, the square of 3 may be written as 32, which is the number 9. In some cases when superscripts are not available, as for instance in programming languages or plain text files, the notations x^2 or x**2 may be used in place of x2.
The adjective which corresponds to squaring is quadratic.
The square of an integer may also be called a square number or a perfect square. In algebra, the operation of squaring is often generalized to polynomials, other expressions, or values in systems of mathematical values other than the numbers. For instance, the square of the linear polynomial x + 1 is the quadratic polynomial x2 + 2x + 1.
One of the important properties of squaring, for numbers as well as in many other mathematical systems, is that (for all numbers x), the square of x is the same as the square of its additive inverse −x. That is, the square function satisfies the identity x2 = (−x)2. This can also be expressed by saying that the squaring function is an even function.
22squared
22squared is the 4th largest independent advertising agency in the United States. Its headquarters are located in Atlanta, Georgia with a second office in Tampa, Florida. The agency has several long-standing Fortune 500 clients as well as a collection of travel, retail, casual dining and financial services clients.
History
The original agency (Tucker Wayne) was founded in Atlanta in 1922 and has operated under several names during its lifetime. In 1996, Tucker Wayne merged with The West Group of Tampa, FL and formed WestWayne. Then in the summer of 2007, the agency rebranded as 22squared. Though the agency has operated under several names over its 90-year history, it has always been independent, with continuous operation under current senior management ownership. The agency is independent and privately held.
Clients
Jim'll Paint It
Jim'll Paint It is an internet blog featured on Tumblr and other social networking sites, started on 21 February 2013 by James Murray. The blog consists of mostly humorous and surreal artwork painted by Murray using only Microsoft Paint, by request from Tumblr users. Murray has produced over 100 paintings since 2013. The first piece featured dinosaurs painting people in an art class. The title is an allusion to the BBC TV series Jim'll Fix It.
James Murray
James Murray is a speed painter from Bristol, England. The only tools he uses for his works are Paint XP and an optical mouse. In October 2014, Murray published a book on his works, with 17 paintings made especially for the book. In February 2015, he began a new blog called 30squared.
See also
References
Further reading
James Murray, Electric Dreams: The Collected Works of Jim'll Paint It (2014)
External links
Radian
The radian is the standard unit of angular measure, used in many areas of mathematics. An angle's measurement in radians is numerically equal to the length of a corresponding arc of a unit circle; one radian is just under 57.3 degrees (when the arc length is equal to the radius). The unit was formerly an SI supplementary unit, but this category was abolished in 1995 and the radian is now considered an SI derived unit.
Separately, the SI unit of solid angle measurement is the steradian.
The radian is represented by the symbol rad (Unicode-encoded as U+33AD ㎭ ). An alternative symbol is c, the superscript letter c, for "circular measure", or the letter r, but both of those symbols are infrequently used as it can be easily mistaken for a degree symbol (°) or a radius (r). So for example, a value of 1.2 radians could be written as 1.2 rad, 1.2 r, 1.2rad, or 1.2c.
Definition
Radian describes the plane angle subtended by a circular arc as the length of the arc divided by the radius of the arc. One radian is the angle subtended at the center of a circle by an arc that is equal in length to the radius of the circle. More generally, the magnitude in radians of such a subtended angle is equal to the ratio of the arc length to the radius of the circle; that is, θ = s /r, where θ is the subtended angle in radians, s is arc length, and r is radius. Conversely, the length of the enclosed arc is equal to the radius multiplied by the magnitude of the angle in radians; that is, s = rθ.
Radian (Morituri)
Radian (Louis Armanetti) is a fictional character, a superhero in the Marvel Universe, member of the Strikeforce: Morituri. The character was created by Peter B. Gillis and Brent Anderson.
Publication history
Radian (Louis Armanetti) was created by writer Peter B. Gillis and artist Brent Anderson and debuted in Strikeforce: Morituri #1 (December 1986). The codename "Radian" was introduced in issue #2. Radian remained in the regular cast of the book until his death in Strikeforce: Morituri #15.
Fictional character biography
Virtually nothing is known of Louis Armanetti's life, prior to his decision to join the Strikeforce: Morituri. A jokester and quick to mask his insecurities and fears behind jokes, in 2073, Armanetti volunteered for the Morituri process, a revolutionary scientific progress which gifts ordinary people with superhuman abilities. Armanetti was found genetically compatible for the process, one of only a handful among thousands of applicants. However, the recipients gained their powers at a terrible price: a fatal flaw in the process which ensures their death within a year of receiving it. The objective of this process was the formation of a team of superpowered beings which could be utilized as Earth's combatants in Earth's ongoing war against the savage alien race known as the Horde.
Radian (disambiguation)
Radian may refer to:
It may also refer to a number of species:
See also
Podcasts:
