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Sine Wave A sine wave or sinusoid is a mathematical curve that describes a smooth periodic oscillation. A sine wave is a continuous wave. It is named after the function sine, of which it is the graph. It occurs often in pure and applied mathematics, as well as physics, engineering, signal processing and many other fields [...More...]  "Sine Wave" on: Wikipedia Yahoo 

Light Light Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is the visible spectrum that is visible to the human eye and is responsible for the sense of sight.[1] Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), or 4.00 × 10−7 to 7.00 × 10−7 m, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths).[2][3] This wavelength means a frequency range of roughly 430–750 terahertz (THz).Beam of sun light inside the cavity of Rocca ill'Abissu at Fondachelli Fantina, SicilyThe main source of light on Earth Earth is the Sun. Sunlight Sunlight provides the energy that green plants use to create sugars mostly in the form of starches, which release energy into the living things that digest them [...More...]  "Light" on: Wikipedia Yahoo 

Radian The radian (SI symbol rad) is the SI unit for measuring angles, and is the standard unit of angular measure used in many areas of mathematics. The length of an arc of a unit circle is numerically equal to the measurement in radians of the angle that it subtends; one radian is just under 57.3 degrees (expansion at A072097). 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.[1] Separately, the SI unit of solid angle measurement is the steradian. The radian is most commonly represented by the symbol rad.[2] An alternative symbol is c, the superscript letter c (for "circular measure"), the letter r, or a superscript R,[3] but these symbols are infrequently used as it can be easily mistaken for a degree symbol (°) or a radius (r) [...More...]  "Radian" on: Wikipedia Yahoo 

Timbre In music, timbre (/ˈtæmbər/ TAMbər, also known as tone color or tone quality from psychoacoustics) is the perceived sound quality of a musical note, sound or tone. Timbre Timbre distinguishes different types of sound production, such as choir voices and musical instruments, such as string instruments, wind instruments, and percussion instruments. It also enables listeners to distinguish different instruments in the same category (e.g. an oboe and a clarinet). The physical characteristics of sound that determine the perception of timbre include spectrum and envelope. Singers and instrumental musicians can change the timbre of the music they are singing/playing by using different singing or playing techniques [...More...]  "Timbre" on: Wikipedia Yahoo 

Harmonics A harmonic is any member of the harmonic series, a divergent infinite series. Its name derives from the concept of overtones, or harmonics in musical instruments: the wavelengths of the overtones of a vibrating string or a column of air (as with a tuba) are derived from the string's (or air column's) fundamental wavelength. Every term of the series (i.e., the higher harmonics) after the first is the "harmonic mean" of the neighboring terms. The phrase "harmonic mean" likewise derives from music. The term is employed in various disciplines, including music, physics, acoustics, electronic power transmission, radio technology, and other fields. It is typically applied to repeating signals, such as sinusoidal waves. A harmonic of such a wave is a wave with a frequency that is a positive integer multiple of the frequency of the original wave, known as the fundamental frequency. The original wave is also called the 1st harmonic, the following harmonics are known as higher harmonics [...More...]  "Harmonics" on: Wikipedia Yahoo 

Ear The ear is the organ of hearing and, in mammals, balance. In mammals, the ear is usually described as having three parts—the outer ear, middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. Since the outer ear is the only visible portion of the ear in most animals, the word "ear" often refers to the external part alone.[1] The middle ear includes the tympanic cavity and the three ossicles. The inner ear sits in the bony labyrinth, and contains structures which are key to several senses: the semicircular canals, which enable balance and eye tracking when moving; the utricle and saccule, which enable balance when stationary; and the cochlea, which enables hearing [...More...]  "Ear" on: Wikipedia Yahoo 

Head Start (positioning) In positioning, a 'head start" is a start in advance of the starting position of others in competition, or simply toward the finish line or desired outcome. Depending on the situation, a head start may be inherent, obtained by special privilege, earned through one's accomplishments, or granted mercifully by an opponent. While not guaranteeing success, a head start will increase such chances.Contents1 In sports1.1 In baseball2 In traffic 3 In achieving a goal 4 See also 5 ReferencesIn sports[edit] In competitive sports, such as a race, a head start refers to a start ahead of other competitors, allowing a shorter distance to the finish line. The idea of a head start may seem unfair [...More...]  "Head Start (positioning)" on: Wikipedia Yahoo 

Curve In mathematics, a curve (also called a curved line in older texts) is, generally speaking, an object similar to a line but that need not be straight. Thus, a curve is a generalization of a line, in that its curvature need not be zero.[a] Various disciplines within mathematics have given the term different meanings depending on the area of study, so the precise meaning depends on context. However, many of these meanings are special instances of the definition which follows. A curve is a topological space which is locally homeomorphic to a line. In everyday language, this means that a curve is a set of points which, near each of its points, looks like a line, up to a deformation. A simple example of a curve is the parabola, shown to the right [...More...]  "Curve" on: Wikipedia Yahoo 

Time Series A time series is a series of data points indexed (or listed or graphed) in time order. Most commonly, a time series is a sequence taken at successive equally spaced points in time. Thus it is a sequence of discretetime data. Examples of time series are heights of ocean tides, counts of sunspots, and the daily closing value of the Dow Jones Industrial Average. Time Time series are very frequently plotted via line charts. Time Time series are used in statistics, signal processing, pattern recognition, econometrics, mathematical finance, weather forecasting, earthquake prediction, electroencephalography, control engineering, astronomy, communications engineering, and largely in any domain of applied science and engineering which involves temporal measurements. Time Time series analysis comprises methods for analyzing time series data in order to extract meaningful statistics and other characteristics of the data [...More...]  "Time Series" on: Wikipedia Yahoo 

Standing Wave In physics, a standing wave – also known as a stationary wave – is a wave in which its peaks (or any other point on the wave) do not move spatially. The amplitude of the wave at a point in space may vary with time, but its phase remains constant. The locations at which the amplitude is minimum are called nodes, and the locations where the amplitude is maximum are called antinodes. Standing waves were first noticed by Michael Faraday Michael Faraday in 1831 [...More...]  "Standing Wave" on: Wikipedia Yahoo 

Dot Product In mathematics, the dot product or scalar product[note 1] is an algebraic operation that takes two equallength sequences of numbers (usually coordinate vectors) and returns a single number. In Euclidean geometry, the dot product of the Cartesian coordinates Cartesian coordinates of two vectors is widely used and often called inner product (or rarely projection product); see also inner product space. Algebraically, the dot product is the sum of the products of the corresponding entries of the two sequences of numbers. Geometrically, it is the product of the Euclidean magnitudes of the two vectors and the cosine of the angle between them. These definitions are equivalent when using Cartesian coordinates. In modern geometry, Euclidean spaces are often defined by using vector spaces [...More...]  "Dot Product" on: Wikipedia Yahoo 

Tension (physics) In physics, tension may be described as the pulling force transmitted axially by the means of a string, cable, chain, or similar onedimensional continuous object, or by each end of a rod, truss member, or similar threedimensional object; tension might also be described as the actionreaction pair of forces acting at each end of said elements. Tension could be the opposite of compression. At the atomic level, when atoms or molecules are pulled apart from each other and gain potential energy with a restoring force still existing, the restoring force might create what is also called tension. Each end of a string or rod under such tension could pull on the object it is attached to, in order to restore the string/rod to its relaxed length. In physics, tension, as a transmitted force, as an actionreaction pair of forces, or as a restoring force, may be a force and has the units of force measured in newtons (or sometimes poundsforce) [...More...]  "Tension (physics)" on: Wikipedia Yahoo 

Wave Number In the physical sciences, the wavenumber (also wave number or repetency[1]) is the spatial frequency of a wave, measured in cycles per unit distance or radians per unit distance. Whereas temporal frequency can be thought as the number of waves per unit time, wavenumber is the number of waves per unit distance. In multidimensional systems, the wavenumber is the magnitude of the wave vector. The space of wave vectors is called reciprocal space. Wave numbers and wave vectors play an essential role in optics and the physics of wave scattering, such as Xray diffraction, neutron diffraction, and elementary particle physics. For quantum mechanical waves, the wavenumber multiplied by Planck's constant is the canonical momentum. Wavenumber can be used to specify quantities other than spatial frequency [...More...]  "Wave Number" on: Wikipedia Yahoo 

Noise (acoustic) Noise Noise is unwanted sound judged to be unpleasant, loud or disruptive to hearing. From a physics standpoint, noise is indistinguishable from sound, as both are vibrations through a medium, such as air or water. The difference arises when the brain receives and perceives a sound.[1][2] In experimental sciences, noise can refer to any random fluctuations of data that hinders perception of an expected signal.[3][4] Acoustic noise is any sound in the acoustic domain, either deliberate (e.g., music or speech) or unintended. In contrast, noise in electronics may not be audible to the human ear and may require instruments for detection.[5] In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a hiss [...More...]  "Noise (acoustic)" on: Wikipedia Yahoo 

Harmonic Series (mathematics) In mathematics, the harmonic series is the divergent infinite series: ∑ n = 1 ∞ 1 n = 1 + 1 2 + 1 3 + 1 4 + 1 5 + ⋯ displaystyle sum _ n=1 ^ infty frac 1 n =1+ frac 1 2 + frac 1 3 + frac 1 4 + frac 1 5 +cdots Its name derives from the concept of overtones, or harmonics in music: the wavelengths of the overtones of a vibrating string are 1/2, 1/3, 1/4, etc., of the string's fundamental wavelength [...More...]  "Harmonic Series (mathematics)" on: Wikipedia Yahoo 

Angular Frequency In physics, angular frequency ω (also referred to by the terms angular speed, radial frequency, circular frequency, orbital frequency, radian frequency, and pulsatance) is a scalar measure of rotation rate. It refers to the angular displacement per unit time (e.g., in rotation) or the rate of change of the phase of a sinusoidal waveform (e.g., in oscillations and waves), or as the rate of change of the argument of the sine function. Angular frequency (or angular speed) is the magnitude of the vector quantity angular velocity [...More...]  "Angular Frequency" on: Wikipedia Yahoo 