A parabolic reflector (also known as a parabolic dish or a parabolic mirror) is a reflective device, formed in the shape of a paraboloid of revolution. Parabolic reflectors can either collect or distribute energy such as light, sound, or radio waves. A mirror is a surface with good specular reflection that is smooth enough to form an image. ... In mathematics, a paraboloid is a quadric, a type of surface in three dimensions, described by the equation: (elliptic paraboloid), or (hyperbolic paraboloid). ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength. ... A schematic representation of hearing. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ...

The parabolic reflector functions due to the geometric properties of the paraboloid shape: if the angle of incidence to the inner surface of the collector equals the angle of reflection, then any incoming ray that is parallel to the axis of the dish will be reflected to a central point, or "focus". Because many types of energy can be reflected in this way, parabolic reflectors can be used to collect and concentrate energy entering the reflector at a particular angle. Similarly, energy radiating from the "focus" to the dish can be transmitted outward in a beam that is parallel to the axis of the dish. FOCUS is a software product of Information Builders Inc. ...

John Hadley introduced parabolic mirrors into practical astronomy in 1721 when he used one to build a reflecting telescope with very little spherical aberration. Before that, telescopes used spherical mirrors. The most common applications of the parabolic reflector are in satellite dishes, telescopes (including radio telescopes), parabolic microphones, and many lighting devices such as spotlights, car headlights, PAR Cans and LED housings. External link Biography from the School of Mathematics and Statistics at the University of St Andrews, Scotland Categories: Astronomers stubs | 1682 births | 1744 deaths | British astronomers | British inventors ... Radio telescopes are among many different tools used by astronomers Astronomy (Greek: αστρονομία = άστρον + νόμος, astronomia = astron + nomos, literally, law of the stars) is the science of celestial objects and phenomena that originate outside the Earths atmosphere, such as stars, planets, comets, auroras, galaxies, and the cosmic background radiation. ... Ritchey 24 reflecting telescope A reflecting telescope (reflector) is an optical telescope which uses a combination of curved and plane (flat) mirrors to reflect light and form an image, rather than lenses to refract or bend light to form an image. ... Focal plane Longitudinal sections In optics, spherical aberration is an image imperfection that occurs due to the increased refraction of light rays that occurs when rays strike a lens or mirror near its edge, in comparison with those that strike nearer the center. ... For other uses, see sphere (disambiguation). ... Special dish for up to 16 satellite positions (Ku-band) Satellite dish antenna for C-Band DTH redirects here. ... 50 cm refracting telescope at Nice Observatory. ... A parabolic microphone uses a parabolic reflector to collect and focus sound waves onto a microphone receiver, in much the same way that a parabolic antenna (e. ... Most of the industrialized world is lit by electric lights, which are used both at night and to provide additional light during the daytime. ... Spotlight can refer to: SpotLight - a diagnostic application developed by CaseBank Technologies Spotlight - a search technology integrated into the Mac OS X operating system The Spotlight a weekly US newspaper, now out of print In theatre, a spotlight is a particular type of stage lighting which can be used to... A SAAB headlight with combination projector/reflector optics A headlight or headlamp is a lamp, usually attached to the front of a vehicle such as a car, with the purpose of illuminating the road ahead during periods of low visibility, such as night or precipitation. ... Lighting instruments are used in stage lighting to illuminate theatrical productions, rock concerts and other performances taking place in a large auditorium or staduim. ...

Parabolic reflectors suffer from an aberration called coma. This is primarily of interest in telescopes because most other applications do not require sharp resolution off the axis of the parabola. To meet Wikipedias quality standards, this article or section may require cleanup. ... In optics (especially telescopes), the coma in an optical system refers to monochromatic aberration inherent to certain optical designs or due to imperfection in the lens or other components which results in off-axis point sources such as stars appearing distorted. ...

The Olympic Flame is lit using a parabolic reflector concentrating sunlight. The Olympic Flame at the Athens 2004 Summer Olympics The Olympic Flame, Olympic Fire, Olympic Torch, Olympic Light, Olympic Eye, and Olympic Sun is a symbol of the Olympic Games. ... Prism splitting light Sunlight in the broad sense is the total spectrum of electromagnetic radiation given off by the Sun. ...

Mirage bowl

Parabolic mirror wok with optical illusion

A mirage bowl or parabolic mirror wok is a toy consisting of two parabolic mirrors that are put together like a wok pan and a lid with a hole in it, gives the optical illusion that something is on the lid, but actually it is at the bottom of the pan below. Image File history File links Parabolische-spiegelwok-gezichtsbedrog. ... Image File history File links Parabolische-spiegelwok-gezichtsbedrog. ... An optical illusion characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. ... Cooking in a wok A wok on an electric stove The wok (Traditional Chinese: 鑊; Simplified Chinese: 镬; pinyin: ; Cantonese: wok6) is a versatile cooking utensil used especially in East Asia and Southeast Asia. ... An optical illusion characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. ...

See also

• Parabola
• Parabolic trough
• Paraboloid
• Spherical reflector
• Solar Death Ray

Wikisource has an original article from the 1911 Encyclopædia Britannica about: Parabola A parabola The parabola (from the Greek: παραβολή) is a conic section generated by the intersection of a right circular conical surface and a plane parallel to a generating straight line of that surface. ... A parabolic trough is a type of solar thermal collector. ... Paraboloid of revolution Hyperbolic paraboloid In mathematics, a paraboloid is a quadric, a type of surface in three dimensions, described by the equation: (elliptic paraboloid), or (hyperbolic paraboloid). ... A spherical reflector is a reflector shaped like a portion of a sphere, so that light (or other electromagnetic radiation such as radio waves) from a point-source located at the virtual centre point of the sphere will reflect off the mirrored surface and back through the centre point of... Solar Death Ray is a website about an array of mirrors focused on an area to burn anything there. ...

External links

• Java demonstration of a parabolic reflector
• Solar Energy Blog: See and discuss how concentrating solar energy is going to power our world in the not too distant future.