Re: DEVS! Ocho buyer here. Please turn BS into a real game.k
Posted: 08 Jun 2012, 15:31
Nick Amin wrote:
> A mirror is an object that reflects light or sound in a way that preserves much of
> its original quality prior to its contact with the mirror. Some mirrors also filter
> out some wavelengths, while preserving other wavelengths in the reflection. This is
> different from other light-reflecting objects that do not preserve much of the
> original wave signal other than color and diffuse reflected light. The most familiar
> type of mirror is the plane mirror, which has a flat surface. Curved mirrors are also
> used, to produce magnified or diminished images or focus light or simply distort the
> reflected image.
>
> Mirrors are commonly used for personal grooming or admiring oneself (in which case
> the archaic term looking-glass is sometimes still used), decoration, and
> architecture. Mirrors are also used in scientific apparatus such as telescopes and
> lasers, cameras, and industrial machinery. Most mirrors are designed for visible
> light; however, mirrors designed for other types of waves or other wavelengths of
> electromagnetic radiation are also used, especially in non-optical instruments.
>
> Contents [hide]
> 1 History
> 2 Manufacturing
> 3 Types of glass mirror
> 4 Effects
> 4.1 Shape of a mirror's surface
> 4.2 Mirror image
> 5 Applications
> 5.1 Safety and easier viewing
> 5.2 Two-way versus one-way mirrors and windows
> 5.3 Signalling
> 5.4 Technology
> 5.4.1 Televisions and projectors
> 5.4.2 Instruments
> 5.4.2.1 Face-to-face mirrors
> 5.4.3 Military applications
> 5.4.4 Seasonal lighting
> 5.5 Leisure
> 5.5.1 Art
> 5.5.1.1 Paintings
> 5.5.1.2 Other artistic mediums
> 5.5.2 Decoration
> 5.5.3 Entertainment
> 5.5.4 Film and television
> 5.5.5 Literature
> 6 Mirrors and psychology
> 7 Mirrors and superstition
> 8 Mirrors and animals
> 9 Unusual kinds of mirrors
> 10 See also
> 11 Notes
> 12 References
> 13 Bibliography
> 14 External links
> [edit]History
>
>
>
> Seated woman holding a mirror.Ancient Greek Attic red-figure lekythos, ca. 470–460
> BC, National Archaeological Museum, Athens
>
>
> A sculpture of a lady looking into a mirror, India
> The first mirrors used by people were most likely pools of dark, still water, or
> water collected in a primitive vessel of some sort. The earliest manufactured mirrors
> were pieces of polished stone such as obsidian, a naturally occurring volcanic glass.
> Examples of obsidian mirrors found in Anatolia (modern-day Turkey) have been dated to
> around 6000 BC. Polished stone mirrors from Central and South America date from
> around 2000 BC onwards.[1] Mirrors of polished copper were crafted in Mesopotamia
> from 4000 BC,[1] and in ancient Egypt from around 3000 BC.[2] In China, bronze
> mirrors were manufactured from around 2000 BC,[3] some of the earliest bronze and
> copper examples being produced by the Qijia culture. Mirrors made of other metal
> mixtures (alloys) such as copper and tin speculum metal may have also been produced
> in China and India.[4] Mirrors of speculum metal or any precious metal were hard to
> produce and were only owned by the wealthy.[5]
>
> Metal-coated glass mirrors are said to have been invented in Sidon (modern-day
> Lebanon) in the first century AD,[6] and glass mirrors backed with gold leaf are
> mentioned by the Roman author Pliny in his Natural History, written in about 77
> AD.[7] The Romans also developed a technique for creating crude mirrors by coating
> blown glass with molten lead.[8]
>
> Parabolic mirrors were described and studied in classical antiquity by the
> mathematician Diocles in his work On Burning Mirrors.[9] Ptolemy conducted a number
> of experiments with curved polished iron mirrors,[10] and discussed plane, convex
> spherical, and concave spherical mirrors in his Optics.[11] Parabolic mirrors were
> also described by the physicist Ibn Sahl in the 10th century,[12] and Ibn al-Haytham
> discussed concave and convex mirrors in both cylindrical and spherical
> geometries,[13] carried out a number of experiments with mirrors, and solved the
> problem of finding the point on a convex mirror at which a ray coming from one point
> is reflected to another point.[14] By the 11th century, clear glass mirrors were
> being produced in Moorish Spain.[15][verification needed]
>
> In China, people began making mirrors with the use of silver-mercury amalgams as
> early as 500 AD.[16] Some time during the early Renaissance, European manufacturers
> perfected a superior method of coating glass with a tin-mercury amalgam. The exact
> date and location of the discovery is unknown, but in the 16th century, Venice, a
> city famed for its glass-making expertise, became a centre of mirror production using
> this new technique. Glass mirrors from this period were extremely expensive
> luxuries.[17] The Saint-Gobain factory, founded by royal initiative in France, was an
> important manufacturer, and Bohemian and German glass, often rather cheaper, was also
> important.
>
> The invention of the silvered-glass mirror is credited to German chemist Justus von
> Liebig in 1835.[18] His process involved the deposition of a thin layer of metallic
> silver onto glass through the chemical reduction of silver nitrate. This silvering
> process was adapted for mass manufacturing and led to the greater availability of
> affordable mirrors. Nowadays, mirrors are often produced by the vacuum deposition of
> aluminium (or sometimes silver) directly onto the glass substrate.
>
> [edit]Manufacturing
>
> Mirrors are manufactured by applying a reflective coating to a suitable substrate.
> The most common substrate is glass, due to its transparency, ease of fabrication,
> rigidity, hardness, and ability to take a smooth finish. The reflective coating is
> typically applied to the back surface of the glass, so that the reflecting side of
> the coating is protected from corrosion and accidental damage by the glass on one
> side and the coating itself and optional paint for further protection on the other.
>
> In classical antiquity, mirrors were made of solid metal (bronze, later silver) and
> were too expensive for widespread use by common people; they were also prone to
> corrosion. Due to the low reflectivity of polished metal, these mirrors also gave a
> darker image than modern ones, making them unsuitable for indoor use with the
> artificial lighting of the time (candles or lanterns).[citation needed]
>
> The method of making mirrors out of plate glass was invented by 16th-century Venetian
> glassmakers on the island of Murano, who covered the back of the glass with mercury,
> obtaining near-perfect and undistorted reflection. For over one hundred years,
> Venetian mirrors installed in richly decorated frames served as luxury decorations
> for palaces throughout Europe, but the secret of the mercury process eventually
> arrived in London and Paris during the 17th century, due to industrial espionage.
> French workshops succeeded in large scale industrialization of the process,
> eventually making mirrors affordable to the masses, although mercury's toxicity
> remained a problem[citation needed].
>
> In modern times, the mirror substrate is shaped, polished and cleaned, and is then
> coated. Glass mirrors are most often coated with non-toxic silver[19] or aluminium,
> implemented by a series of coatings:[citation needed]
>
> Tin(II) chloride
> Silver
> Chemical activator[disambiguation needed ]
> Copper
> Paint
> The tin(II) chloride is applied because silver will not bond with the glass. The
> activator causes the tin/silver to harden. Copper is added for long-term
> durability.[20] The paint protects the coating on the back of the mirror from
> scratches and other accidental damage.[citation needed]
>
> In some applications, generally those that are cost-sensitive or that require great
> durability, mirrors are made from a single, bulk material such as polished
> metal.[citation needed] For technical applications such as laser mirrors, the
> reflective coating is typically applied by vacuum deposition on the front surface of
> the substrate. This eliminates double reflections (a weak reflection from the surface
> of the glass, and a stronger one from the reflecting metal) and reduces absorption of
> light by the mirror. Technical mirrors may use a silver, aluminium, or gold coating
> (the latter typically for infrared mirrors), and achieve reflectivities of 90–95%
> when new. A protective transparent overcoat may be applied to prevent oxidation of
> the reflective layer. Applications requiring higher reflectivity or greater
> durability, where wide bandwidth is not essential, use dielectric coatings, which can
> achieve reflectivities as high as 99.999% over a narrow range of
> wavelengths.[citation needed]
>
> [edit]Types of glass mirror
>
>
>
> 18th century vermeil mirror in the Musée des Arts décoratifs, Strasbourg
> There are many types of glass mirrors, each representing a different manufacturing
> process and reflection type.
>
> An aluminium glass mirror is made of a float glass manufactured using vacuum coating,
> i.e. aluminium powder is evaporated (or "sputtered") onto the exposed
> surface of the glass in a vacuum chamber and then coated with two or more layers of
> waterproof protective paint.
>
> A low aluminium glass mirror is manufactured by coating silver and two layers of
> protective paint on the back surface of glass. A low aluminium glass mirror is very
> clear, light transmissive, smooth, and reflects accurate natural colors. This type of
> glass is widely used for framing presentations and exhibitions in which a precise
> color representation of the artwork is truly essential or when the background color
> of the frame is predominantly white.[citation needed]
>
> A safety glass mirror is made by sticking a special protective film on the back
> surface of a silver glass mirror, which prevents injuries in case the mirror is
> broken. This kind of mirror is used for furniture, doors, glass walls, commercial
> shelves, or public areas.[citation needed]
>
> A silkscreen printed glass mirror is produced using inorganic color ink that prints
> patterns through a special screen onto glass. Various colors, patterns, and glass
> shapes are available. Such a glass mirror is durable and more moisture resistant than
> ordinary printed glass and can serve for over 20 years. This type of glass is widely
> used for decorative purposes (e.g., on mirrors, table tops, doors, windows, kitchen
> chop boards, etc.).[citation needed]
>
> A silver glass mirror is an ordinary mirror, coated on its back surface with silver,
> which produces images by reflection. This kind of glass mirror is produced by coating
> a silver, copper film and two or more layers of waterproof paint on the back surface
> of float glass, which perfectly resists acid and moisture. A silver glass mirror
> provides clear and actual images, is quite durable, and is widely used for furniture,
> bathroom and other decorative purposes.[citation needed]
>
> Decorative glass mirrors are usually handcrafted. A variety of shades, shapes and
> glass thickness are often available.[citation needed]
>
> [edit]Effects
>
> See also: Mirror image and Specular reflection
> [edit]Shape of a mirror's surface
> A beam of light reflects off a mirror at an angle of reflection equal to its angle of
> incidence (if the size of a mirror is much larger than the wavelength of light). That
> is, if the beam of light is shining on a mirror's surface at a ° angle vertically,
> then it reflects from the point of incidence at a ° angle from vertically in the
> opposite direction. This law mathematically follows from the interference of a plane
> wave on a flat boundary (of much larger size than the wavelength).
>
> In a plane mirror, a parallel beam of light changes its direction as a whole, while
> still remaining parallel; the images formed by a plane mirror are virtual images, of
> the same size as the original object (see mirror image).
> In a concave mirror, parallel beams of light become a convergent beam, whose rays
> intersect in the focus of the mirror. Also known as converging mirror
> In a convex mirror, parallel beams become divergent, with the rays appearing to
> diverge from a common point of intersection "behind" the mirror.
> Spherical concave and convex mirrors do not focus parallel rays to a single point due
> to spherical aberration. However, the ideal of focusing to a point is a commonly-used
> approximation. Parabolic reflectors resolve this, allowing incoming parallel rays
> (for example, light from a distant star) to be focused to a small spot; almost an
> ideal point. Parabolic reflectors are not suitable for imaging nearby objects because
> the light rays are not parallel.
> [edit]Mirror image
> If one looks in a mirror, one's image reverses (e.g., if one raises one's right hand,
> his left hand will appear to go up in the mirror). However, a mirror does not
> "swap" left and right, any more than it swaps top and bottom. A mirror
> reverses the forward/backward axis, and we define left and right relative to front
> and back. Flipping front/back and left/right is equivalent to a rotation of 180
> degrees about the vertical axis (in the same way that text which is back-to-front and
> upside-down simply looks like it has been rotated 180 degrees on the page).
> Therefore, looking at an image of oneself with the front/back axis flipped is the
> same as looking at an image with the left/right axis flipped and the whole figure
> rotated 180 degrees about the vertical axis, which is exactly what one sees when
> standing in front of a mirror.
>
> [edit]Applications
>
>
>
> Reflections in a spherical convex mirror. The photographer is seen at top right.
>
>
> A mirror on a racing car.
> [edit]Safety and easier viewing
> Convex mirrors
> Convex mirrors provide a wider field of view than flat mirrors, and are often used on
> vehicles, especially large trucks, to minimize blind spots. They are sometimes placed
> at road junctions, and corners of sites such as parking lots to allow people to see
> around corners to avoid crashing into other vehicles or shopping carts. They are also
> sometimes used as part of security systems, so that a single video camera can show
> more than one angle at a time.[citation needed]
> Mouth mirrors or "dental mirrors"
> Mouth mirrors or "dental mirrors" are used by dentists to allow indirect
> vision and lighting within the mouth. Their reflective surfaces may be either flat or
> curved. Mouth mirrors are also commonly used by mechanics to allow vision in tight
> spaces and around corners in equipment.
> Rear-view mirrors
> Rear-view mirrors are widely used in and on vehicles (such as automobiles, or
> bicycles), to allow drivers to see other vehicles coming up behind them. Some
> motorcycle helmets have a built-in so-called MROS (Multiple Reflective Optic System):
> a set of reflective surfaces inside the helmet that together function as a rear-view
> mirror.[21] On rear-view sunglasses, the left end of the left glass and the right end
> of the right glass work as mirrors.
> [edit]Two-way versus one-way mirrors and windows
> Main article: Two-way mirror
> Two-way mirrors
> A two-way mirror is a sheet of glass coated with a layer of metal only a few dozen
> atoms thick, which reflects some percentage of the light incident on it and transmits
> the remainder to the other side.
> One-way mirrors
> One-way mirrors work by overwhelming dim transmitted light with bright reflected
> light. A true one-way mirror that actually allows light to be transmitted in one
> direction only without requiring external energy is not possible as it violates the
> second law of thermodynamics: if one placed a cold object on the transmitting side
> and a hot one on the blocked side, radiant energy would be transferred from the cold
> to the hot object.
> One-way windows
> One-way windows can be made to work with polarized light in the laboratory without
> violating the second law. This is an apparent paradox that stumped some great
> physicists, although it does not allow a practical one-way mirror for use in the real
> world.[22][23] Optical isolators are one-way devices that are commonly used with
> lasers.
> [edit]Signalling
> Main article: Heliograph
> With the sun as light source, a mirror can be used to signal by variations in the
> orientation of the mirror. The signal can be used over long distances, possibly up to
> 60 kilometres on a clear day. This technique was used by Native American tribes and
> numerous militaries to transmit information between distant outposts.
>
> Mirrors can also be used for rescue to attract the attention of search and rescue
> helicopters. Specialized signalling mirrors are available and are often included in
> military survival kits.
>
> [edit]Technology
> [edit]Televisions and projectors
> Microscopic mirrors are a core element of many of the largest high-definition
> televisions and video projectors. A common technology of this type is Texas
> Instruments' DLP. A DLP chip is a postage stamp-sized microchip whose surface is an
> array of millions of microscopic mirrors. The picture is created as the individual
> mirrors move to either reflect light toward the projection surface (pixel on), or
> toward a light absorbing surface (pixel off).
>
> Other projection technologies involving mirrors include LCoS. Like a DLP chip, LCoS
> is a microchip of similar size, but rather than millions of individual mirrors, there
> is a single mirror that is actively shielded by a liquid crystal matrix with up to
> millions of pixels. The picture is formed as light is either reflected toward the
> projection surface (pixel on), or absorbed by the activated LCD pixels (pixel off).
> LCoS-based televisions and projectors often use 3 chips, one for each primary color.
>
> Large mirrors are used in rear projection televisions. Light (for example from a DLP
> as mentioned above) is "folded" by one or more mirrors so that the
> television set is compact.
>
> [edit]Instruments
> See also: Mirror support cell
>
>
> E-ELT mirror segments under test.
> Telescopes and other precision instruments use front silvered or first surface
> mirrors, where the reflecting surface is placed on the front (or first) surface of
> the glass (this eliminates reflection from glass surface ordinary back mirrors have).
> Some of them use silver, but most are aluminium, which is more reflective at short
> wavelengths than silver. All of these coatings are easily damaged and require special
> handling. They reflect 90% to 95% of the incident light when new. The coatings are
> typically applied by vacuum deposition. A protective overcoat is usually applied
> before the mirror is removed from the vacuum, because the coating otherwise begins to
> corrode as soon as it is exposed to oxygen and humidity in the air. Front silvered
> mirrors have to be resurfaced occasionally to keep their quality. There are optical
> mirrors such as mangin mirrors that are second surface mirrors (reflective coating on
> the rear surface) as part of their optical designs, usually to correct optical
> aberrations.[24]
>
> The reflectivity of the mirror coating can be measured using a reflectometer and for
> a particular metal it will be different for different wavelengths of light. This is
> exploited in some optical work to make cold mirrors and hot mirrors. A cold mirror is
> made by using a transparent substrate and choosing a coating material that is more
> reflective to visible light and more transmissive to infrared light. A hot mirror is
> the opposite, the coating preferentially reflects infrared. Mirror surfaces are
> sometimes given thin film overcoatings both to retard degradation of the surface and
> to increase their reflectivity in parts of the spectrum where they will be used. For
> instance, aluminum mirrors are commonly coated with silicon dioxide or magnesium
> fluoride. The reflectivity as a function of wavelength depends on both the thickness
> of the coating and on how it is applied.
>
>
>
> A dielectric coated mirror used in a dye laser. The mirror is over 99% reflective at
> 550 nanometers, (yellow), but will allow most other colors to pass through.
>
>
> A dielectric mirror used in lasers
> For scientific optical work, dielectric mirrors are often used. These are glass (or
> sometimes other material) substrates on which one or more layers of dielectric
> material are deposited, to form an optical coating. By careful choice of the type and
> thickness of the dielectric layers, the range of wavelengths and amount of light
> reflected from the mirror can be specified. The best mirrors of this type can reflect
> >99.999% of the light (in a narrow range of wavelengths) which is incident on the
> mirror. Such mirrors are often used in lasers.
>
> In astronomy, adaptive optics is a technique to measure variable image distortions
> and adapt a deformable mirror accordingly on a timescale of milliseconds, to
> compensate for the distortions.
>
> Although most mirrors are designed to reflect visible light, surfaces reflecting
> other forms of electromagnetic radiation are also called "mirrors". The
> mirrors for other ranges of electromagnetic waves are used in optics and astronomy.
> Mirrors for radio waves (sometimes known as reflectors) are important elements of
> radio telescopes.
>
> [edit]Face-to-face mirrors
> Two or more mirrors placed exactly face to face can give an infinite regress of
> reflections. Some devices use this to generate multiple reflections:
>
> Fabry–Pérot interferometer
> Laser (which contains an optical cavity)
> 3D Kaleidoscope to concentrate light[25]
> momentum-enhanced solar sail
> [edit]Military applications
> It has been said that Archimedes used a large array of mirrors to burn Roman ships
> during an attack on Syracuse. This has never been proven or disproved; however, it
> has been put to the test. Recently, on a popular Discovery Channel show, MythBusters,
> a team from MIT tried to recreate the famous "Archimedes Death Ray". They
> were successful at starting a fire on a ship at 75 feet away; however, previous
> attempts to light the boat on fire using only the bronze mirrors available in
> Archimedes' time were unsuccessful, and the time taken to ignite the craft would have
> made its use impractical, resulting in the MythBusters team deeming the myth
> "busted". It was however found that the mirrors made it very difficult for
> the passengers of the targeted boat to see, likely helping to cause their defeat,
> which may have been the origin of the myth. (See solar power tower for a practical
> use of this technique.)
>
> [edit]Seasonal lighting
>
>
> A multi-facet mirror in the Kibble Palace conservatory, Glasgow, Scotland
> Due to its location in a steep-sided valley, the Italian town of Viganella gets no
> direct sunlight for seven weeks each winter. In 2006 a €100,000 computer-controlled
> mirror, 8×5 m, was installed to reflect sunlight into the town's piazza. In early
> 2007 the similarly situated village of Bondo, Switzerland, was considering applying
> this solution as well.[26][27] Mirrors can be used to produce enhanced lighting
> effects in greenhouses or conservatories.
>
> [edit]Leisure
> [edit]Art
> [edit]Paintings
>
>
> Titian's Venus with a mirror
> Painters depicting someone gazing into a mirror often also show the person's
> reflection. This is a kind of abstraction—in most cases the angle of view is such
> that the person's reflection should not be visible. Similarly, in movies and still
> photography an actor or actress is often shown obstensibly looking at him- or herself
> in the mirror, and yet the reflection faces the camera. In reality, the actor or
> actress sees only the camera and its operator in this case, not their own
> reflection.[citation needed]
>
> The mirror is the central device in some of the greatest of European
> paintings:[citation needed]
>
> Édouard Manet's A Bar at the Folies-Bergère
> Titian's Venus with a Mirror
> Jan Van Eyck's Arnolfini Portrait
> Pablo Picasso's Girl before a Mirror (1932)
> Diego Velázquez's Las Meninas, wherein the viewer is both the watcher (of a
> self-portrait in progress) and the watched, and the many adaptations of that painting
> in various media
> Veronese's Venus with a Mirror
> Mirrors have been used by artists to create works and hone their craft:
>
> Filippo Brunelleschi discovered linear perspective with the help of the
> mirror.[citation needed]
> Leonardo da Vinci called the mirror the "master of painters". He
> recommended, "When you wish to see whether your whole picture accords with what
> you have portrayed from nature take a mirror and reflect the actual object in it.
> Compare what is reflected with your painting and carefully consider whether both
> likenesses of the subject correspond, particularly in regard to the
> mirror."[citation needed]
> Many self-portraits are made possible through the use of mirrors:
> Without a mirror, the great self-portraits by Dürer, Frida Kahlo, Rembrandt, and Van
> Gogh could not have been painted.[citation needed]
> M. C. Escher used special shapes of mirrors in order to achieve a much more complete
> view of his surroundings than by direct observation in Hand with Reflecting Sphere
> (also known as Self-Portrait in Spherical Mirror).
> Mirrors are sometimes necessary to fully appreciate art work:
>
> István Orosz's anamorphic works are images distorted such that they only become
> clearly visible when reflected in a suitably shaped and positioned mirror.[citation
> needed]
> [edit]Other artistic mediums
> Some other contemporary artists use mirrors as the material of art:
>
> A Chinese magic mirror is an art in which the face of the bronze mirror projects the
> same image that was cast on its back. This is due to minute curvatures on its
> front.[28]
> Paintings on mirror surfaces (such as silkscreen printed glass mirrors)
> Sculptures comprised entirely or in part of mirrors
> Infinity Also Hurts is a mirror, glass and silicone sculpture by artist, Seth Wulsin
> Sky Mirror is a public sculpture by artist, Anish Kapoor
> Special mirror installations
> Follow Me mirror labyrinth by artist, Jeppe Hein (see also, Entertainment: Mirror
> mazes, below)
> Mirror Neon Cube by artist, Jeppe Hein
> [edit]Decoration
>
>
> Chimneypiece and overmantel mirror, c. 1750 V&A Museum no. 738:1 to 3–1897
> Mirrors are frequently used in interior decoration and as ornaments:
>
> Mirrors, typically large and unframed, are frequently used in interior decoration to
> create an illusion of space and amplify the apparent size of a room.[citation needed]
> They come also framed in a variety of forms, such as the pier glass and the
> overmantle mirror.
> Mirrors are used also in some schools of feng shui, an ancient Chinese practice of
> placement and arrangement of space, to achieve harmony with the environment.
> The softness of old mirrors is sometimes replicated by contemporary artisans for use
> in interior design. These reproduction antiqued mirrors are works of art and can
> bring color and texture to an otherwise hard, cold reflective surface. It is an
> artistic process that has been attempted by many and perfected by few.[citation
> needed]
> A decorative reflecting sphere of thin metal-coated glass, working as a reducing
> wide-angle mirror, is sold as a Christmas ornament called a bauble.
> [edit]Entertainment
> Illuminated rotating disco balls covered with small mirrors are used to cast moving
> spots of light around a dance floor.
> The hall of mirrors, commonly found in amusement parks, is an attraction in which a
> number of distorting mirrors are used to produce unusual reflections of the visitor.
> Mirrors are employed in kaleidoscopes, personal entertainment devices invented in
> Scotland by Sir David Brewster.
> Mirrors are often used in magic to create an illusion. One effect is called Pepper's
> ghost.
> Mirror mazes, often found in amusement parks as well, contain large numbers of
> mirrors and sheets of glass. The idea is to navigate the disorientating array without
> bumping into the walls. Mirrors in attractions like this are often made of plexiglass
> as to assure that they do not break.[citation needed]
> [edit]Film and television
> Candyman is a horror movie about mirrors
> Mirrors is a horror movie about mirrors
> Poltergeist III features mirrors as a major theme
> The 10th Kingdom miniseries requires the use of a magic mirror for the characters to
> change setting between modern day New York City (the 10th Kingdom), and the Nine
> Kingdoms of fairy tale, primarily the 4th Kingdom from Snow White.
> [edit]Literature
>
>
> An illustration from page 30 of Mjallhvít (Snow White) an 1852 Icelandic translation
> of the Grimm-version fairytale
>
>
> Taijitu within a frame of trigrams and a demon warding mirror. These charms are
> believed to frighten away evil spirits and to protect the dwelling from bad luck
> Mirrors play a powerful role in cultural literature.
>
> The Holy Bible passage, 1 Corinthians 13:12: "Through a Glass Darkly"
> references a dim mirror image or poor mirror reflection
> The magical objects employed in the Harry Potter series include:mirrors: the Mirror
> of Erised and two-way mirrors
> In Alfred, Lord Tennyson's famous poem "The Lady of Shalott", the titular
> character possesses a mirror that enables her to look out on the people of Camelot,
> as she is under a curse that prevents her from seeing Camelot directly.
> Narcissus of Greek mythology wastes away while gazing, self-admiringly, at his
> reflection in water
> In Oscar Wilde's novel, The Picture of Dorian Gray, a portrait serves as a magical
> mirror that reflects the true visage of the perpetually youthful protagonist, as well
> as the effect on his soul of each sinful act[29][30]
> In the European fairy tale, Snow White, the evil queen asks, "Mirror, mirror, on
> the wall... who's the fairest of them all?"
> Lewis Carroll's Through the Looking-Glass is one of the best-loved uses of mirrors in
> literature. The text itself utilizes a narrative that mirrors that of its
> predecessor, Alice's Adventures in Wonderland.[citation needed]
> Under "Appendix: Variant Planes & Cosmologies" of the Dungeons &
> Dragons Manual Of The Planes, is The Plane of Mirrors (page 204).[31] It describes
> the Plane of Mirrors as a space existing behind reflective surfaces, and experienced
> by visitors as a long corridor. The greatest danger to visitors upon entering the
> plane is the instant creation of a mirror-self with the opposite alignment of the
> original visitor.
> [edit]Mirrors and psychology
>
> Spectrophobia is the fear of mirrors.
>
> [edit]Mirrors and superstition
>
> There are many legends and superstitions surrounding mirrors. Mirrors are said to be
> a reflection of the soul, and they were often used in traditional witchcraft as tools
> for scrying or performing other spells. It is also said that mirrors cannot lie. They
> can show only the truth, so it is a bad omen to see something in a mirror which
> should not be there. Also there is a European legend that a newborn child should not
> see a mirror until its first birthday as its soul is still developing. If the child
> sees its reflection it is said that it will die.
>
> It is a common superstition that someone who breaks a mirror will receive seven years
> of bad luck.[32] The reason for this belief is that the mirror is believed to reflect
> part of the soul. Therefore, breaking a mirror will break part of the soul. However,
> the soul is said to regenerate every seven years, thus coming back unbroken.[citation
> needed] To prevent a broken mirror from reflecting a broken soul during the
> seven-year interim, one of many rituals must be performed. Two alternatives include
> grinding the broken mirror to dust (perhaps the easiest approach)[33] or burying the
> mirror.[citation needed] It is also said that tapping the broken mirror on a
> gravestone seven times will allow the soul to heal. However, if the mirror is both
> touched to the gravestone and buried, the bad luck will remain. The only course of
> action for one in this position is to dig up the mirror and grind it to dust. This
> dust must be sprinkled around the same gravestone on which the mirror was initially
> tapped.[citation needed]
>
> There is a Buddhist belief that negative spirits will enter houses through the door
> if they have triangular-shaped roofs. Hanging a small circular mirror in front of the
> door will prevent the bad spirits from entering.[citation needed]
>
> In days past, it was customary in the southern United States to cover the mirrors in
> a house where the wake of a deceased person was being held. It was believed that the
> person's soul would become trapped in a mirror if it was left uncovered. This
> practice is still followed in other countries (e.g., Romania), extending to
> everything that could reflect the deceased person's face (such as TVs and
> appliances). Another explanation given is that the devil will appear in the
> reflection of the dead. Mirrors falling from walls or otherwise breaking or cracking
> mysteriously were said to be haunted. A similar custom existed in Greece, in the
> belief that use of mirrors is a sign of vanity that does not become mourning. (Other
> Greek mourning customs include not playing music, not entertaining guests, and using
> no festive decorations, e.g. on Christmas, during the customary year-long mourning
> period).[citation needed]
>
> According to legend, a vampire has no reflection in mirrors because it is an undead
> creature and has already lost its soul.[citation needed]
>
> Another superstition claims it is bad luck to have two mirrors facing each
> other.[citation needed]
>
> A staple of childhood slumber parties is the game Bloody Mary, which involves
> chanting "Bloody Mary" three times in a darkened room while staring into a
> mirror. There are many versions of the game, but the general idea is that
> "Mary" will appear in the mirror and attempt to harm or kill the person who
> has summoned her. Thanks to a series of popular horror movies based on a supernatural
> killer who haunted mirrors, the phrase "Candyman" may be substituted for
> Mary.[citation needed]
>
> [edit]Mirrors and animals
>
>
>
> The Asian elephant can recognize its own reflection in a mirror
>
>
> 4.5-metre (15 ft) high acoustic mirror near Kilnsea Grange, East Yorkshire, UK
> Main article: Mirror Test
> Only a few animal species have been shown to have the ability to recognize themselves
> in a mirror, most of them mammals. Experiments have found that the following animals
> are able to pass the mirror test:
>
> Humans
> Bonobos
> Common chimpanzees
> Orangutans
> Gorillas
> Dolphins
> Orcas
> Asian elephants
> European Magpies
> [edit]Unusual kinds of mirrors
>
> Other types of reflecting device are also called "mirrors".
>
> Acoustic mirrors are passive devices used to reflect and perhaps to focus sound
> waves. Acoustic mirrors were used for selective detection of sound waves, especially
> during World War II. They were used for detection of enemy aircraft prior to the
> development of radar. Acoustic mirrors are used for remote probing of the atmosphere;
> they can be used to form a narrow diffraction-limited beam.[34] They can also be used
> for underwater imaging.
> Active mirrors are mirrors that amplify the light they reflect. They are used to make
> disk lasers.[35] The amplification is typically over a narrow range of wavelengths,
> and requires an external source of power.
> Atomic mirrors are devices which reflect matter waves. Usually, atomic mirrors work
> at grazing incidence. Such mirrors can be used for atomic interferometry and atomic
> holography. It has been proposed that they can be used for non-destructive imaging
> systems with nanometer resolution.[36]
> Cold mirrors are dielectric mirrors that reflect the entire visible light spectrum,
> while efficiently transmitting infrared wavelengths. These are the converse of hot
> mirrors.
> Corner reflectors use three flat mirrors to reflect light back towards its source.
> They are used for emergency location, and even laser ranging to the Moon.
> Hot mirrors reflect infrared light while allowing visible light to pass. These can be
> used to separate useful light from unneeded infrared to reduce heating of components
> in an optical device. They can also be used as dichroic beamsplitters. (Hot mirrors
> are the converse of cold mirrors.)
> Metallic reflectors are used to reflect infrared light (such as in space heaters or
> microwaves).
> Non-reversing mirrors are mirrors that provide a non-reversed image of their
> subjects.
> X-ray mirrors produce specular reflection of X-rays. All known types work only at
> angles near grazing incidence, and only a small fraction of the rays are
> reflected.[37] See also X-ray optics.
> [edit]See also
>
> Anamorphosis
> Aranmula kannadi
> Bronze mirror
> Chirality (mathematics)
> Cold mirror and Hot mirror
> Curved mirror
> Deformable mirror
> Dielectric mirror
> Digital micromirror device
> Distorting mirror
> Home decor
> Honeycomb mirror
> List of telescope parts and construction
> Mirror armour (an oriental partial plate armour from polished metal mirrors)
> Mirror Mirror: a history of the human love affair with reflection (book)
> Mirror writing
> Mirrors in Mesoamerican culture
> Perfect mirror
> Periscope
> Rear-view mirror
> Reflectivity
> Silvering
> TLV mirror — An ancient type of Chinese mirror from the Han Dynasty.
> Two-way mirror (Also known as one-way mirror)
> Venus effect
DAFUQ!!i just read this and i didn't understand a thing,:yaoming:
> A mirror is an object that reflects light or sound in a way that preserves much of
> its original quality prior to its contact with the mirror. Some mirrors also filter
> out some wavelengths, while preserving other wavelengths in the reflection. This is
> different from other light-reflecting objects that do not preserve much of the
> original wave signal other than color and diffuse reflected light. The most familiar
> type of mirror is the plane mirror, which has a flat surface. Curved mirrors are also
> used, to produce magnified or diminished images or focus light or simply distort the
> reflected image.
>
> Mirrors are commonly used for personal grooming or admiring oneself (in which case
> the archaic term looking-glass is sometimes still used), decoration, and
> architecture. Mirrors are also used in scientific apparatus such as telescopes and
> lasers, cameras, and industrial machinery. Most mirrors are designed for visible
> light; however, mirrors designed for other types of waves or other wavelengths of
> electromagnetic radiation are also used, especially in non-optical instruments.
>
> Contents [hide]
> 1 History
> 2 Manufacturing
> 3 Types of glass mirror
> 4 Effects
> 4.1 Shape of a mirror's surface
> 4.2 Mirror image
> 5 Applications
> 5.1 Safety and easier viewing
> 5.2 Two-way versus one-way mirrors and windows
> 5.3 Signalling
> 5.4 Technology
> 5.4.1 Televisions and projectors
> 5.4.2 Instruments
> 5.4.2.1 Face-to-face mirrors
> 5.4.3 Military applications
> 5.4.4 Seasonal lighting
> 5.5 Leisure
> 5.5.1 Art
> 5.5.1.1 Paintings
> 5.5.1.2 Other artistic mediums
> 5.5.2 Decoration
> 5.5.3 Entertainment
> 5.5.4 Film and television
> 5.5.5 Literature
> 6 Mirrors and psychology
> 7 Mirrors and superstition
> 8 Mirrors and animals
> 9 Unusual kinds of mirrors
> 10 See also
> 11 Notes
> 12 References
> 13 Bibliography
> 14 External links
> [edit]History
>
>
>
> Seated woman holding a mirror.Ancient Greek Attic red-figure lekythos, ca. 470–460
> BC, National Archaeological Museum, Athens
>
>
> A sculpture of a lady looking into a mirror, India
> The first mirrors used by people were most likely pools of dark, still water, or
> water collected in a primitive vessel of some sort. The earliest manufactured mirrors
> were pieces of polished stone such as obsidian, a naturally occurring volcanic glass.
> Examples of obsidian mirrors found in Anatolia (modern-day Turkey) have been dated to
> around 6000 BC. Polished stone mirrors from Central and South America date from
> around 2000 BC onwards.[1] Mirrors of polished copper were crafted in Mesopotamia
> from 4000 BC,[1] and in ancient Egypt from around 3000 BC.[2] In China, bronze
> mirrors were manufactured from around 2000 BC,[3] some of the earliest bronze and
> copper examples being produced by the Qijia culture. Mirrors made of other metal
> mixtures (alloys) such as copper and tin speculum metal may have also been produced
> in China and India.[4] Mirrors of speculum metal or any precious metal were hard to
> produce and were only owned by the wealthy.[5]
>
> Metal-coated glass mirrors are said to have been invented in Sidon (modern-day
> Lebanon) in the first century AD,[6] and glass mirrors backed with gold leaf are
> mentioned by the Roman author Pliny in his Natural History, written in about 77
> AD.[7] The Romans also developed a technique for creating crude mirrors by coating
> blown glass with molten lead.[8]
>
> Parabolic mirrors were described and studied in classical antiquity by the
> mathematician Diocles in his work On Burning Mirrors.[9] Ptolemy conducted a number
> of experiments with curved polished iron mirrors,[10] and discussed plane, convex
> spherical, and concave spherical mirrors in his Optics.[11] Parabolic mirrors were
> also described by the physicist Ibn Sahl in the 10th century,[12] and Ibn al-Haytham
> discussed concave and convex mirrors in both cylindrical and spherical
> geometries,[13] carried out a number of experiments with mirrors, and solved the
> problem of finding the point on a convex mirror at which a ray coming from one point
> is reflected to another point.[14] By the 11th century, clear glass mirrors were
> being produced in Moorish Spain.[15][verification needed]
>
> In China, people began making mirrors with the use of silver-mercury amalgams as
> early as 500 AD.[16] Some time during the early Renaissance, European manufacturers
> perfected a superior method of coating glass with a tin-mercury amalgam. The exact
> date and location of the discovery is unknown, but in the 16th century, Venice, a
> city famed for its glass-making expertise, became a centre of mirror production using
> this new technique. Glass mirrors from this period were extremely expensive
> luxuries.[17] The Saint-Gobain factory, founded by royal initiative in France, was an
> important manufacturer, and Bohemian and German glass, often rather cheaper, was also
> important.
>
> The invention of the silvered-glass mirror is credited to German chemist Justus von
> Liebig in 1835.[18] His process involved the deposition of a thin layer of metallic
> silver onto glass through the chemical reduction of silver nitrate. This silvering
> process was adapted for mass manufacturing and led to the greater availability of
> affordable mirrors. Nowadays, mirrors are often produced by the vacuum deposition of
> aluminium (or sometimes silver) directly onto the glass substrate.
>
> [edit]Manufacturing
>
> Mirrors are manufactured by applying a reflective coating to a suitable substrate.
> The most common substrate is glass, due to its transparency, ease of fabrication,
> rigidity, hardness, and ability to take a smooth finish. The reflective coating is
> typically applied to the back surface of the glass, so that the reflecting side of
> the coating is protected from corrosion and accidental damage by the glass on one
> side and the coating itself and optional paint for further protection on the other.
>
> In classical antiquity, mirrors were made of solid metal (bronze, later silver) and
> were too expensive for widespread use by common people; they were also prone to
> corrosion. Due to the low reflectivity of polished metal, these mirrors also gave a
> darker image than modern ones, making them unsuitable for indoor use with the
> artificial lighting of the time (candles or lanterns).[citation needed]
>
> The method of making mirrors out of plate glass was invented by 16th-century Venetian
> glassmakers on the island of Murano, who covered the back of the glass with mercury,
> obtaining near-perfect and undistorted reflection. For over one hundred years,
> Venetian mirrors installed in richly decorated frames served as luxury decorations
> for palaces throughout Europe, but the secret of the mercury process eventually
> arrived in London and Paris during the 17th century, due to industrial espionage.
> French workshops succeeded in large scale industrialization of the process,
> eventually making mirrors affordable to the masses, although mercury's toxicity
> remained a problem[citation needed].
>
> In modern times, the mirror substrate is shaped, polished and cleaned, and is then
> coated. Glass mirrors are most often coated with non-toxic silver[19] or aluminium,
> implemented by a series of coatings:[citation needed]
>
> Tin(II) chloride
> Silver
> Chemical activator[disambiguation needed ]
> Copper
> Paint
> The tin(II) chloride is applied because silver will not bond with the glass. The
> activator causes the tin/silver to harden. Copper is added for long-term
> durability.[20] The paint protects the coating on the back of the mirror from
> scratches and other accidental damage.[citation needed]
>
> In some applications, generally those that are cost-sensitive or that require great
> durability, mirrors are made from a single, bulk material such as polished
> metal.[citation needed] For technical applications such as laser mirrors, the
> reflective coating is typically applied by vacuum deposition on the front surface of
> the substrate. This eliminates double reflections (a weak reflection from the surface
> of the glass, and a stronger one from the reflecting metal) and reduces absorption of
> light by the mirror. Technical mirrors may use a silver, aluminium, or gold coating
> (the latter typically for infrared mirrors), and achieve reflectivities of 90–95%
> when new. A protective transparent overcoat may be applied to prevent oxidation of
> the reflective layer. Applications requiring higher reflectivity or greater
> durability, where wide bandwidth is not essential, use dielectric coatings, which can
> achieve reflectivities as high as 99.999% over a narrow range of
> wavelengths.[citation needed]
>
> [edit]Types of glass mirror
>
>
>
> 18th century vermeil mirror in the Musée des Arts décoratifs, Strasbourg
> There are many types of glass mirrors, each representing a different manufacturing
> process and reflection type.
>
> An aluminium glass mirror is made of a float glass manufactured using vacuum coating,
> i.e. aluminium powder is evaporated (or "sputtered") onto the exposed
> surface of the glass in a vacuum chamber and then coated with two or more layers of
> waterproof protective paint.
>
> A low aluminium glass mirror is manufactured by coating silver and two layers of
> protective paint on the back surface of glass. A low aluminium glass mirror is very
> clear, light transmissive, smooth, and reflects accurate natural colors. This type of
> glass is widely used for framing presentations and exhibitions in which a precise
> color representation of the artwork is truly essential or when the background color
> of the frame is predominantly white.[citation needed]
>
> A safety glass mirror is made by sticking a special protective film on the back
> surface of a silver glass mirror, which prevents injuries in case the mirror is
> broken. This kind of mirror is used for furniture, doors, glass walls, commercial
> shelves, or public areas.[citation needed]
>
> A silkscreen printed glass mirror is produced using inorganic color ink that prints
> patterns through a special screen onto glass. Various colors, patterns, and glass
> shapes are available. Such a glass mirror is durable and more moisture resistant than
> ordinary printed glass and can serve for over 20 years. This type of glass is widely
> used for decorative purposes (e.g., on mirrors, table tops, doors, windows, kitchen
> chop boards, etc.).[citation needed]
>
> A silver glass mirror is an ordinary mirror, coated on its back surface with silver,
> which produces images by reflection. This kind of glass mirror is produced by coating
> a silver, copper film and two or more layers of waterproof paint on the back surface
> of float glass, which perfectly resists acid and moisture. A silver glass mirror
> provides clear and actual images, is quite durable, and is widely used for furniture,
> bathroom and other decorative purposes.[citation needed]
>
> Decorative glass mirrors are usually handcrafted. A variety of shades, shapes and
> glass thickness are often available.[citation needed]
>
> [edit]Effects
>
> See also: Mirror image and Specular reflection
> [edit]Shape of a mirror's surface
> A beam of light reflects off a mirror at an angle of reflection equal to its angle of
> incidence (if the size of a mirror is much larger than the wavelength of light). That
> is, if the beam of light is shining on a mirror's surface at a ° angle vertically,
> then it reflects from the point of incidence at a ° angle from vertically in the
> opposite direction. This law mathematically follows from the interference of a plane
> wave on a flat boundary (of much larger size than the wavelength).
>
> In a plane mirror, a parallel beam of light changes its direction as a whole, while
> still remaining parallel; the images formed by a plane mirror are virtual images, of
> the same size as the original object (see mirror image).
> In a concave mirror, parallel beams of light become a convergent beam, whose rays
> intersect in the focus of the mirror. Also known as converging mirror
> In a convex mirror, parallel beams become divergent, with the rays appearing to
> diverge from a common point of intersection "behind" the mirror.
> Spherical concave and convex mirrors do not focus parallel rays to a single point due
> to spherical aberration. However, the ideal of focusing to a point is a commonly-used
> approximation. Parabolic reflectors resolve this, allowing incoming parallel rays
> (for example, light from a distant star) to be focused to a small spot; almost an
> ideal point. Parabolic reflectors are not suitable for imaging nearby objects because
> the light rays are not parallel.
> [edit]Mirror image
> If one looks in a mirror, one's image reverses (e.g., if one raises one's right hand,
> his left hand will appear to go up in the mirror). However, a mirror does not
> "swap" left and right, any more than it swaps top and bottom. A mirror
> reverses the forward/backward axis, and we define left and right relative to front
> and back. Flipping front/back and left/right is equivalent to a rotation of 180
> degrees about the vertical axis (in the same way that text which is back-to-front and
> upside-down simply looks like it has been rotated 180 degrees on the page).
> Therefore, looking at an image of oneself with the front/back axis flipped is the
> same as looking at an image with the left/right axis flipped and the whole figure
> rotated 180 degrees about the vertical axis, which is exactly what one sees when
> standing in front of a mirror.
>
> [edit]Applications
>
>
>
> Reflections in a spherical convex mirror. The photographer is seen at top right.
>
>
> A mirror on a racing car.
> [edit]Safety and easier viewing
> Convex mirrors
> Convex mirrors provide a wider field of view than flat mirrors, and are often used on
> vehicles, especially large trucks, to minimize blind spots. They are sometimes placed
> at road junctions, and corners of sites such as parking lots to allow people to see
> around corners to avoid crashing into other vehicles or shopping carts. They are also
> sometimes used as part of security systems, so that a single video camera can show
> more than one angle at a time.[citation needed]
> Mouth mirrors or "dental mirrors"
> Mouth mirrors or "dental mirrors" are used by dentists to allow indirect
> vision and lighting within the mouth. Their reflective surfaces may be either flat or
> curved. Mouth mirrors are also commonly used by mechanics to allow vision in tight
> spaces and around corners in equipment.
> Rear-view mirrors
> Rear-view mirrors are widely used in and on vehicles (such as automobiles, or
> bicycles), to allow drivers to see other vehicles coming up behind them. Some
> motorcycle helmets have a built-in so-called MROS (Multiple Reflective Optic System):
> a set of reflective surfaces inside the helmet that together function as a rear-view
> mirror.[21] On rear-view sunglasses, the left end of the left glass and the right end
> of the right glass work as mirrors.
> [edit]Two-way versus one-way mirrors and windows
> Main article: Two-way mirror
> Two-way mirrors
> A two-way mirror is a sheet of glass coated with a layer of metal only a few dozen
> atoms thick, which reflects some percentage of the light incident on it and transmits
> the remainder to the other side.
> One-way mirrors
> One-way mirrors work by overwhelming dim transmitted light with bright reflected
> light. A true one-way mirror that actually allows light to be transmitted in one
> direction only without requiring external energy is not possible as it violates the
> second law of thermodynamics: if one placed a cold object on the transmitting side
> and a hot one on the blocked side, radiant energy would be transferred from the cold
> to the hot object.
> One-way windows
> One-way windows can be made to work with polarized light in the laboratory without
> violating the second law. This is an apparent paradox that stumped some great
> physicists, although it does not allow a practical one-way mirror for use in the real
> world.[22][23] Optical isolators are one-way devices that are commonly used with
> lasers.
> [edit]Signalling
> Main article: Heliograph
> With the sun as light source, a mirror can be used to signal by variations in the
> orientation of the mirror. The signal can be used over long distances, possibly up to
> 60 kilometres on a clear day. This technique was used by Native American tribes and
> numerous militaries to transmit information between distant outposts.
>
> Mirrors can also be used for rescue to attract the attention of search and rescue
> helicopters. Specialized signalling mirrors are available and are often included in
> military survival kits.
>
> [edit]Technology
> [edit]Televisions and projectors
> Microscopic mirrors are a core element of many of the largest high-definition
> televisions and video projectors. A common technology of this type is Texas
> Instruments' DLP. A DLP chip is a postage stamp-sized microchip whose surface is an
> array of millions of microscopic mirrors. The picture is created as the individual
> mirrors move to either reflect light toward the projection surface (pixel on), or
> toward a light absorbing surface (pixel off).
>
> Other projection technologies involving mirrors include LCoS. Like a DLP chip, LCoS
> is a microchip of similar size, but rather than millions of individual mirrors, there
> is a single mirror that is actively shielded by a liquid crystal matrix with up to
> millions of pixels. The picture is formed as light is either reflected toward the
> projection surface (pixel on), or absorbed by the activated LCD pixels (pixel off).
> LCoS-based televisions and projectors often use 3 chips, one for each primary color.
>
> Large mirrors are used in rear projection televisions. Light (for example from a DLP
> as mentioned above) is "folded" by one or more mirrors so that the
> television set is compact.
>
> [edit]Instruments
> See also: Mirror support cell
>
>
> E-ELT mirror segments under test.
> Telescopes and other precision instruments use front silvered or first surface
> mirrors, where the reflecting surface is placed on the front (or first) surface of
> the glass (this eliminates reflection from glass surface ordinary back mirrors have).
> Some of them use silver, but most are aluminium, which is more reflective at short
> wavelengths than silver. All of these coatings are easily damaged and require special
> handling. They reflect 90% to 95% of the incident light when new. The coatings are
> typically applied by vacuum deposition. A protective overcoat is usually applied
> before the mirror is removed from the vacuum, because the coating otherwise begins to
> corrode as soon as it is exposed to oxygen and humidity in the air. Front silvered
> mirrors have to be resurfaced occasionally to keep their quality. There are optical
> mirrors such as mangin mirrors that are second surface mirrors (reflective coating on
> the rear surface) as part of their optical designs, usually to correct optical
> aberrations.[24]
>
> The reflectivity of the mirror coating can be measured using a reflectometer and for
> a particular metal it will be different for different wavelengths of light. This is
> exploited in some optical work to make cold mirrors and hot mirrors. A cold mirror is
> made by using a transparent substrate and choosing a coating material that is more
> reflective to visible light and more transmissive to infrared light. A hot mirror is
> the opposite, the coating preferentially reflects infrared. Mirror surfaces are
> sometimes given thin film overcoatings both to retard degradation of the surface and
> to increase their reflectivity in parts of the spectrum where they will be used. For
> instance, aluminum mirrors are commonly coated with silicon dioxide or magnesium
> fluoride. The reflectivity as a function of wavelength depends on both the thickness
> of the coating and on how it is applied.
>
>
>
> A dielectric coated mirror used in a dye laser. The mirror is over 99% reflective at
> 550 nanometers, (yellow), but will allow most other colors to pass through.
>
>
> A dielectric mirror used in lasers
> For scientific optical work, dielectric mirrors are often used. These are glass (or
> sometimes other material) substrates on which one or more layers of dielectric
> material are deposited, to form an optical coating. By careful choice of the type and
> thickness of the dielectric layers, the range of wavelengths and amount of light
> reflected from the mirror can be specified. The best mirrors of this type can reflect
> >99.999% of the light (in a narrow range of wavelengths) which is incident on the
> mirror. Such mirrors are often used in lasers.
>
> In astronomy, adaptive optics is a technique to measure variable image distortions
> and adapt a deformable mirror accordingly on a timescale of milliseconds, to
> compensate for the distortions.
>
> Although most mirrors are designed to reflect visible light, surfaces reflecting
> other forms of electromagnetic radiation are also called "mirrors". The
> mirrors for other ranges of electromagnetic waves are used in optics and astronomy.
> Mirrors for radio waves (sometimes known as reflectors) are important elements of
> radio telescopes.
>
> [edit]Face-to-face mirrors
> Two or more mirrors placed exactly face to face can give an infinite regress of
> reflections. Some devices use this to generate multiple reflections:
>
> Fabry–Pérot interferometer
> Laser (which contains an optical cavity)
> 3D Kaleidoscope to concentrate light[25]
> momentum-enhanced solar sail
> [edit]Military applications
> It has been said that Archimedes used a large array of mirrors to burn Roman ships
> during an attack on Syracuse. This has never been proven or disproved; however, it
> has been put to the test. Recently, on a popular Discovery Channel show, MythBusters,
> a team from MIT tried to recreate the famous "Archimedes Death Ray". They
> were successful at starting a fire on a ship at 75 feet away; however, previous
> attempts to light the boat on fire using only the bronze mirrors available in
> Archimedes' time were unsuccessful, and the time taken to ignite the craft would have
> made its use impractical, resulting in the MythBusters team deeming the myth
> "busted". It was however found that the mirrors made it very difficult for
> the passengers of the targeted boat to see, likely helping to cause their defeat,
> which may have been the origin of the myth. (See solar power tower for a practical
> use of this technique.)
>
> [edit]Seasonal lighting
>
>
> A multi-facet mirror in the Kibble Palace conservatory, Glasgow, Scotland
> Due to its location in a steep-sided valley, the Italian town of Viganella gets no
> direct sunlight for seven weeks each winter. In 2006 a €100,000 computer-controlled
> mirror, 8×5 m, was installed to reflect sunlight into the town's piazza. In early
> 2007 the similarly situated village of Bondo, Switzerland, was considering applying
> this solution as well.[26][27] Mirrors can be used to produce enhanced lighting
> effects in greenhouses or conservatories.
>
> [edit]Leisure
> [edit]Art
> [edit]Paintings
>
>
> Titian's Venus with a mirror
> Painters depicting someone gazing into a mirror often also show the person's
> reflection. This is a kind of abstraction—in most cases the angle of view is such
> that the person's reflection should not be visible. Similarly, in movies and still
> photography an actor or actress is often shown obstensibly looking at him- or herself
> in the mirror, and yet the reflection faces the camera. In reality, the actor or
> actress sees only the camera and its operator in this case, not their own
> reflection.[citation needed]
>
> The mirror is the central device in some of the greatest of European
> paintings:[citation needed]
>
> Édouard Manet's A Bar at the Folies-Bergère
> Titian's Venus with a Mirror
> Jan Van Eyck's Arnolfini Portrait
> Pablo Picasso's Girl before a Mirror (1932)
> Diego Velázquez's Las Meninas, wherein the viewer is both the watcher (of a
> self-portrait in progress) and the watched, and the many adaptations of that painting
> in various media
> Veronese's Venus with a Mirror
> Mirrors have been used by artists to create works and hone their craft:
>
> Filippo Brunelleschi discovered linear perspective with the help of the
> mirror.[citation needed]
> Leonardo da Vinci called the mirror the "master of painters". He
> recommended, "When you wish to see whether your whole picture accords with what
> you have portrayed from nature take a mirror and reflect the actual object in it.
> Compare what is reflected with your painting and carefully consider whether both
> likenesses of the subject correspond, particularly in regard to the
> mirror."[citation needed]
> Many self-portraits are made possible through the use of mirrors:
> Without a mirror, the great self-portraits by Dürer, Frida Kahlo, Rembrandt, and Van
> Gogh could not have been painted.[citation needed]
> M. C. Escher used special shapes of mirrors in order to achieve a much more complete
> view of his surroundings than by direct observation in Hand with Reflecting Sphere
> (also known as Self-Portrait in Spherical Mirror).
> Mirrors are sometimes necessary to fully appreciate art work:
>
> István Orosz's anamorphic works are images distorted such that they only become
> clearly visible when reflected in a suitably shaped and positioned mirror.[citation
> needed]
> [edit]Other artistic mediums
> Some other contemporary artists use mirrors as the material of art:
>
> A Chinese magic mirror is an art in which the face of the bronze mirror projects the
> same image that was cast on its back. This is due to minute curvatures on its
> front.[28]
> Paintings on mirror surfaces (such as silkscreen printed glass mirrors)
> Sculptures comprised entirely or in part of mirrors
> Infinity Also Hurts is a mirror, glass and silicone sculpture by artist, Seth Wulsin
> Sky Mirror is a public sculpture by artist, Anish Kapoor
> Special mirror installations
> Follow Me mirror labyrinth by artist, Jeppe Hein (see also, Entertainment: Mirror
> mazes, below)
> Mirror Neon Cube by artist, Jeppe Hein
> [edit]Decoration
>
>
> Chimneypiece and overmantel mirror, c. 1750 V&A Museum no. 738:1 to 3–1897
> Mirrors are frequently used in interior decoration and as ornaments:
>
> Mirrors, typically large and unframed, are frequently used in interior decoration to
> create an illusion of space and amplify the apparent size of a room.[citation needed]
> They come also framed in a variety of forms, such as the pier glass and the
> overmantle mirror.
> Mirrors are used also in some schools of feng shui, an ancient Chinese practice of
> placement and arrangement of space, to achieve harmony with the environment.
> The softness of old mirrors is sometimes replicated by contemporary artisans for use
> in interior design. These reproduction antiqued mirrors are works of art and can
> bring color and texture to an otherwise hard, cold reflective surface. It is an
> artistic process that has been attempted by many and perfected by few.[citation
> needed]
> A decorative reflecting sphere of thin metal-coated glass, working as a reducing
> wide-angle mirror, is sold as a Christmas ornament called a bauble.
> [edit]Entertainment
> Illuminated rotating disco balls covered with small mirrors are used to cast moving
> spots of light around a dance floor.
> The hall of mirrors, commonly found in amusement parks, is an attraction in which a
> number of distorting mirrors are used to produce unusual reflections of the visitor.
> Mirrors are employed in kaleidoscopes, personal entertainment devices invented in
> Scotland by Sir David Brewster.
> Mirrors are often used in magic to create an illusion. One effect is called Pepper's
> ghost.
> Mirror mazes, often found in amusement parks as well, contain large numbers of
> mirrors and sheets of glass. The idea is to navigate the disorientating array without
> bumping into the walls. Mirrors in attractions like this are often made of plexiglass
> as to assure that they do not break.[citation needed]
> [edit]Film and television
> Candyman is a horror movie about mirrors
> Mirrors is a horror movie about mirrors
> Poltergeist III features mirrors as a major theme
> The 10th Kingdom miniseries requires the use of a magic mirror for the characters to
> change setting between modern day New York City (the 10th Kingdom), and the Nine
> Kingdoms of fairy tale, primarily the 4th Kingdom from Snow White.
> [edit]Literature
>
>
> An illustration from page 30 of Mjallhvít (Snow White) an 1852 Icelandic translation
> of the Grimm-version fairytale
>
>
> Taijitu within a frame of trigrams and a demon warding mirror. These charms are
> believed to frighten away evil spirits and to protect the dwelling from bad luck
> Mirrors play a powerful role in cultural literature.
>
> The Holy Bible passage, 1 Corinthians 13:12: "Through a Glass Darkly"
> references a dim mirror image or poor mirror reflection
> The magical objects employed in the Harry Potter series include:mirrors: the Mirror
> of Erised and two-way mirrors
> In Alfred, Lord Tennyson's famous poem "The Lady of Shalott", the titular
> character possesses a mirror that enables her to look out on the people of Camelot,
> as she is under a curse that prevents her from seeing Camelot directly.
> Narcissus of Greek mythology wastes away while gazing, self-admiringly, at his
> reflection in water
> In Oscar Wilde's novel, The Picture of Dorian Gray, a portrait serves as a magical
> mirror that reflects the true visage of the perpetually youthful protagonist, as well
> as the effect on his soul of each sinful act[29][30]
> In the European fairy tale, Snow White, the evil queen asks, "Mirror, mirror, on
> the wall... who's the fairest of them all?"
> Lewis Carroll's Through the Looking-Glass is one of the best-loved uses of mirrors in
> literature. The text itself utilizes a narrative that mirrors that of its
> predecessor, Alice's Adventures in Wonderland.[citation needed]
> Under "Appendix: Variant Planes & Cosmologies" of the Dungeons &
> Dragons Manual Of The Planes, is The Plane of Mirrors (page 204).[31] It describes
> the Plane of Mirrors as a space existing behind reflective surfaces, and experienced
> by visitors as a long corridor. The greatest danger to visitors upon entering the
> plane is the instant creation of a mirror-self with the opposite alignment of the
> original visitor.
> [edit]Mirrors and psychology
>
> Spectrophobia is the fear of mirrors.
>
> [edit]Mirrors and superstition
>
> There are many legends and superstitions surrounding mirrors. Mirrors are said to be
> a reflection of the soul, and they were often used in traditional witchcraft as tools
> for scrying or performing other spells. It is also said that mirrors cannot lie. They
> can show only the truth, so it is a bad omen to see something in a mirror which
> should not be there. Also there is a European legend that a newborn child should not
> see a mirror until its first birthday as its soul is still developing. If the child
> sees its reflection it is said that it will die.
>
> It is a common superstition that someone who breaks a mirror will receive seven years
> of bad luck.[32] The reason for this belief is that the mirror is believed to reflect
> part of the soul. Therefore, breaking a mirror will break part of the soul. However,
> the soul is said to regenerate every seven years, thus coming back unbroken.[citation
> needed] To prevent a broken mirror from reflecting a broken soul during the
> seven-year interim, one of many rituals must be performed. Two alternatives include
> grinding the broken mirror to dust (perhaps the easiest approach)[33] or burying the
> mirror.[citation needed] It is also said that tapping the broken mirror on a
> gravestone seven times will allow the soul to heal. However, if the mirror is both
> touched to the gravestone and buried, the bad luck will remain. The only course of
> action for one in this position is to dig up the mirror and grind it to dust. This
> dust must be sprinkled around the same gravestone on which the mirror was initially
> tapped.[citation needed]
>
> There is a Buddhist belief that negative spirits will enter houses through the door
> if they have triangular-shaped roofs. Hanging a small circular mirror in front of the
> door will prevent the bad spirits from entering.[citation needed]
>
> In days past, it was customary in the southern United States to cover the mirrors in
> a house where the wake of a deceased person was being held. It was believed that the
> person's soul would become trapped in a mirror if it was left uncovered. This
> practice is still followed in other countries (e.g., Romania), extending to
> everything that could reflect the deceased person's face (such as TVs and
> appliances). Another explanation given is that the devil will appear in the
> reflection of the dead. Mirrors falling from walls or otherwise breaking or cracking
> mysteriously were said to be haunted. A similar custom existed in Greece, in the
> belief that use of mirrors is a sign of vanity that does not become mourning. (Other
> Greek mourning customs include not playing music, not entertaining guests, and using
> no festive decorations, e.g. on Christmas, during the customary year-long mourning
> period).[citation needed]
>
> According to legend, a vampire has no reflection in mirrors because it is an undead
> creature and has already lost its soul.[citation needed]
>
> Another superstition claims it is bad luck to have two mirrors facing each
> other.[citation needed]
>
> A staple of childhood slumber parties is the game Bloody Mary, which involves
> chanting "Bloody Mary" three times in a darkened room while staring into a
> mirror. There are many versions of the game, but the general idea is that
> "Mary" will appear in the mirror and attempt to harm or kill the person who
> has summoned her. Thanks to a series of popular horror movies based on a supernatural
> killer who haunted mirrors, the phrase "Candyman" may be substituted for
> Mary.[citation needed]
>
> [edit]Mirrors and animals
>
>
>
> The Asian elephant can recognize its own reflection in a mirror
>
>
> 4.5-metre (15 ft) high acoustic mirror near Kilnsea Grange, East Yorkshire, UK
> Main article: Mirror Test
> Only a few animal species have been shown to have the ability to recognize themselves
> in a mirror, most of them mammals. Experiments have found that the following animals
> are able to pass the mirror test:
>
> Humans
> Bonobos
> Common chimpanzees
> Orangutans
> Gorillas
> Dolphins
> Orcas
> Asian elephants
> European Magpies
> [edit]Unusual kinds of mirrors
>
> Other types of reflecting device are also called "mirrors".
>
> Acoustic mirrors are passive devices used to reflect and perhaps to focus sound
> waves. Acoustic mirrors were used for selective detection of sound waves, especially
> during World War II. They were used for detection of enemy aircraft prior to the
> development of radar. Acoustic mirrors are used for remote probing of the atmosphere;
> they can be used to form a narrow diffraction-limited beam.[34] They can also be used
> for underwater imaging.
> Active mirrors are mirrors that amplify the light they reflect. They are used to make
> disk lasers.[35] The amplification is typically over a narrow range of wavelengths,
> and requires an external source of power.
> Atomic mirrors are devices which reflect matter waves. Usually, atomic mirrors work
> at grazing incidence. Such mirrors can be used for atomic interferometry and atomic
> holography. It has been proposed that they can be used for non-destructive imaging
> systems with nanometer resolution.[36]
> Cold mirrors are dielectric mirrors that reflect the entire visible light spectrum,
> while efficiently transmitting infrared wavelengths. These are the converse of hot
> mirrors.
> Corner reflectors use three flat mirrors to reflect light back towards its source.
> They are used for emergency location, and even laser ranging to the Moon.
> Hot mirrors reflect infrared light while allowing visible light to pass. These can be
> used to separate useful light from unneeded infrared to reduce heating of components
> in an optical device. They can also be used as dichroic beamsplitters. (Hot mirrors
> are the converse of cold mirrors.)
> Metallic reflectors are used to reflect infrared light (such as in space heaters or
> microwaves).
> Non-reversing mirrors are mirrors that provide a non-reversed image of their
> subjects.
> X-ray mirrors produce specular reflection of X-rays. All known types work only at
> angles near grazing incidence, and only a small fraction of the rays are
> reflected.[37] See also X-ray optics.
> [edit]See also
>
> Anamorphosis
> Aranmula kannadi
> Bronze mirror
> Chirality (mathematics)
> Cold mirror and Hot mirror
> Curved mirror
> Deformable mirror
> Dielectric mirror
> Digital micromirror device
> Distorting mirror
> Home decor
> Honeycomb mirror
> List of telescope parts and construction
> Mirror armour (an oriental partial plate armour from polished metal mirrors)
> Mirror Mirror: a history of the human love affair with reflection (book)
> Mirror writing
> Mirrors in Mesoamerican culture
> Perfect mirror
> Periscope
> Rear-view mirror
> Reflectivity
> Silvering
> TLV mirror — An ancient type of Chinese mirror from the Han Dynasty.
> Two-way mirror (Also known as one-way mirror)
> Venus effect
DAFUQ!!i just read this and i didn't understand a thing,:yaoming: