Mirror
Encyclopedia
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
or sound
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
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
Plane mirror
A plane mirror is a mirror with a plane reflective surface.For light rays striking a plane mirror, the angle of reflection equals the angle of incidence...
, which has a flat surface. Curved mirror
Curved mirror
A curved mirror is a mirror with a curved reflective surface, which may be either convex or concave . Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices...
s are also used, to produce magnified
Magnification
Magnification is the process of enlarging something only in appearance, not in physical size. This enlargement is quantified by a calculated number also called "magnification"...
or diminished images or focus light or simply distort the reflected image.
Mirrors are commonly used for personal grooming
Personal grooming
Personal grooming is the art of cleaning, grooming, and maintaining parts of the body. It is a species-typical behavior that is controlled by neural circuits in the brain.- In humans :...
or admiring oneself (in which case the archaic term
Archaism
In language, an archaism is the use of a form of speech or writing that is no longer current. This can either be done deliberately or as part of a specific jargon or formula...
looking-glass is sometimes still used), decoration, and architecture. Mirrors are also used in scientific apparatus such as telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
s and laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
s, camera
Camera
A camera is a device that records and stores images. These images may be still photographs or moving images such as videos or movies. The term camera comes from the camera obscura , an early mechanism for projecting images...
s, and industrial machinery. Most mirrors are designed for visible light; however, mirrors designed for other types of waves or other wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
s of electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
are also used, especially in non-optical instruments.
History
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 obsidianObsidian
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock.It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth...
, a naturally occurring volcanic glass
Volcanic glass
Volcanic glass is the amorphous product of rapidly cooling magma. Like all types of glass, it is a state of matter intermediate between the close-packed, highly ordered array of a crystal and the highly disordered array of gas...
. Examples of obsidian mirrors found in Anatolia
Anatolia
Anatolia is a geographic and historical term denoting the westernmost protrusion of Asia, comprising the majority of the Republic of Turkey...
(modern-day Turkey) have been dated to around 6000 BC. Polished stone mirrors from Central and South America date from around 2000 BC onwards. Mirrors of polished copper were crafted in Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
from 4000 BC, and in ancient Egypt from around 3000 BC. In China, bronze mirrors were manufactured from around 2000 BC, some of the earliest bronze and copper examples being produced by the Qijia culture
Qijia culture
The Qijia culture was an early Bronze Age culture distributed around the upper Yellow River region of western Gansu and eastern Qinghai, China, it is regarded as one of the earliest bronze cultures. Johan Gunnar Andersson discovered the initial site at Qijiaping in 1923...
. Mirrors made of other metal mixtures (alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s) such as copper and tin speculum metal
Speculum metal
Speculum metal is a mixture of around two-thirds copper and one-third tin making a white brittle alloy that can be polished to make a highly reflective surface. It is used primarily to make different kinds of mirrors including early reflecting telescope optical mirrors...
may have also been produced in China and India. Mirrors of speculum metal or any precious metal were hard to produce and were only owned by the wealthy.
Metal-coated glass mirrors are said to have been invented in Sidon
Sidon
Sidon or Saïda is the third-largest city in Lebanon. It is located in the South Governorate of Lebanon, on the Mediterranean coast, about 40 km north of Tyre and 40 km south of the capital Beirut. In Genesis, Sidon is the son of Canaan the grandson of Noah...
(modern-day Lebanon) in the first century AD, and glass mirrors backed with gold leaf
Gold leaf
right|thumb|250px|[[Burnishing]] gold leaf with an [[agate]] stone tool, during the water gilding processGold leaf is gold that has been hammered into extremely thin sheets and is often used for gilding. Gold leaf is available in a wide variety of karats and shades...
are mentioned by the Roman author Pliny
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
in his Natural History, written in about 77 AD. The Romans also developed a technique for creating crude mirrors by coating blown glass with molten lead.
Parabolic mirrors were described and studied in classical antiquity
Classical antiquity
Classical antiquity is a broad term for a long period of cultural history centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome, collectively known as the Greco-Roman world...
by the mathematician Diocles
Diocles (mathematician)
Diocles was a Greek mathematician and geometer.- Life and work :Although little is known about the life of Diocles, it is known that he was a contemporary of Apollonius and that he flourished sometime around the end of the 3rd century BC and the beginning of the 2nd century BC.Diocles is thought...
in his work On Burning Mirrors. Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
conducted a number of experiments with curved polished iron mirrors, and discussed plane, convex spherical, and concave spherical mirrors in his Optics. Parabolic mirrors were also described by the physicist Ibn Sahl
Ibn Sahl
This article is about the physicist. For the physician, see Ali ibn Sahl Rabban al-Tabari. For the poet, see Ibn Sahl of Sevilla.Ibn Sahl was a Muslim Persian mathematician, physicist and optics engineer of the Islamic Golden Age associated with the Abbasid court of Baghdad...
in the 10th century, and Ibn al-Haytham discussed concave and convex mirrors
Curved mirror
A curved mirror is a mirror with a curved reflective surface, which may be either convex or concave . Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices...
in both cylindrical
Cylinder (geometry)
A cylinder is one of the most basic curvilinear geometric shapes, the surface formed by the points at a fixed distance from a given line segment, the axis of the cylinder. The solid enclosed by this surface and by two planes perpendicular to the axis is also called a cylinder...
and spherical geometries
Spherical geometry
Spherical geometry is the geometry of the two-dimensional surface of a sphere. It is an example of a geometry which is not Euclidean. Two practical applications of the principles of spherical geometry are to navigation and astronomy....
, 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. By the 11th century, clear glass mirrors were being produced in Moorish Spain
Al-Andalus
Al-Andalus was the Arabic name given to a nation and territorial region also commonly referred to as Moorish Iberia. The name describes parts of the Iberian Peninsula and Septimania governed by Muslims , at various times in the period between 711 and 1492, although the territorial boundaries...
.
In China, people began making mirrors with the use of silver-mercury amalgams
Amalgam (chemistry)
An amalgam is a substance formed by the reaction of mercury with another metal. Almost all metals can form amalgams with mercury, notable exceptions being iron and platinum. Silver-mercury amalgams are important in dentistry, and gold-mercury amalgam is used in the extraction of gold from ore.The...
as early as 500 AD. Some time during the early Renaissance
Renaissance
The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...
, 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
Venice
Venice is a city in northern Italy which is renowned for the beauty of its setting, its architecture and its artworks. It is the capital of the Veneto region...
, 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. The Saint-Gobain
Saint-Gobain
Saint-Gobain S.A. is a French multinational corporation, founded in 1665 in Paris and headquartered on the outskirts of Paris at La Défense and in Courbevoie. Originally a mirror manufacturer, it now also produces a variety of construction and high-performance materials.The company has its head...
factory, founded by royal initiative in France, was an important manufacturer, and Bohemia
Bohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
n and German glass, often rather cheaper, was also important.
The invention of the silvered-glass
Silvering
Silvering is the chemical process of coating glass with a reflective substance. When glass mirrors first gained widespread usage in Europe during the 16th century, most were made of an amalgam of tin and mercury, but by the 19th century mirrors were commonly made through a process by which silver...
mirror is credited to German chemist Justus von Liebig
Justus von Liebig
Justus von Liebig was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. As a professor, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the...
in 1835. His process involved the deposition of a thin layer of metallic silver onto glass through the chemical reduction of silver nitrate
Silver nitrate
Silver nitrate is an inorganic compound with chemical formula . This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides...
. 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
Vacuum deposition
Vacuum deposition is a family of processes used to deposit layers atom-by-atom or molecule-by-molecule at sub-atmospheric pressure on a solid surface. The layers may be as thin as one atom to millimeters thick . There may be multiple layers of different materials...
of aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
(or sometimes silver) directly onto the glass substrate.
Manufacturing
Mirrors are manufactured by applying a reflective coatingSilvering
Silvering is the chemical process of coating glass with a reflective substance. When glass mirrors first gained widespread usage in Europe during the 16th century, most were made of an amalgam of tin and mercury, but by the 19th century mirrors were commonly made through a process by which silver...
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; they were also prone to corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
. 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 (candle
Candle
A candle is a solid block or cylinder of wax with an embedded wick, which is lit to provide light, and sometimes heat.Today, most candles are made from paraffin. Candles can also be made from beeswax, soy, other plant waxes, and tallow...
s or lantern
Lantern
A lantern is a portable lighting device or mounted light fixture used to illuminate broad areas. Lanterns may also be used for signaling, as 'torches', or as general light sources outdoors . Low light level varieties are used for decoration. The term "lantern" is also used more generically to...
s).
The method of making mirrors out of plate glass
Flat glass
Flat glass, sheet glass, or plate glass is a type of glass, initially produced in plane form, commonly used for windows, glass doors, transparent walls, and windshields. For modern architectural and automotive applications, the flat glass is sometimes bent after production of the plane sheet...
was invented by 16th-century Venetian glassmakers on the island of Murano
Murano
Murano is a series of islands linked by bridges in the Venetian Lagoon, northern Italy. It lies about 1.5 km north of Venice and measures about across with a population of just over 5,000 . It is famous for its glass making, particularly lampworking...
, who covered the back of the glass with mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
, 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
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
remained a problem.
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
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
or aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
, implemented by a series of coatings:
- Tin(II) chlorideTin(II) chlorideTin chloride is a white crystalline solid with the formula 2. It forms a stable dihydrate, but aqueous solutions tend to undergo hydrolysis, particularly if hot. SnCl2 is widely used as a reducing agent , and in electrolytic baths for tin-plating...
- SilverSilverSilver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
- Chemical activatorActivatorActivator may mean:* Activator , a DNA-binding protein that regulates one or more genes by increasing the rate of transcription* Activator , a type of effector that increases the rate of enzyme mediated reactions...
- CopperCopperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
- PaintPaintPaint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
The tin(II) chloride
Tin(II) chloride
Tin chloride is a white crystalline solid with the formula 2. It forms a stable dihydrate, but aqueous solutions tend to undergo hydrolysis, particularly if hot. SnCl2 is widely used as a reducing agent , and in electrolytic baths for tin-plating...
is applied because silver will not bond with the glass. The activator causes the tin/silver to harden. Copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
is added for long-term durability. The paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
protects the coating on the back of the mirror from scratches and other accidental damage.
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. For technical applications such as laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
mirrors, the reflective coating is typically applied by vacuum deposition
Vacuum deposition
Vacuum deposition is a family of processes used to deposit layers atom-by-atom or molecule-by-molecule at sub-atmospheric pressure on a solid surface. The layers may be as thin as one atom to millimeters thick . There may be multiple layers of different materials...
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
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
coating (the latter typically for infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
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
Dielectric mirror
A dielectric mirror is a type of a mirror composed of multiple thin layers of dielectric material, typically deposited on a substrate of glass or some other optical material. By careful choice of the type and thickness of the dielectric layers, one can design an optical coating with specified...
, which can achieve reflectivities as high as 99.999% over a narrow range of wavelengths.
Types of glass mirror
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
Float glass
Float glass is a sheet of glass made by floating molten glass on a bed of molten metal, typically tin, although lead and various low melting point alloys were used in the past. This method gives the sheet uniform thickness and very flat surfaces. Modern windows are made from float glass...
manufactured using vacuum coating, i.e. aluminium is spread over the glass in the 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.
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.
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 board
Cutting board
A cutting board is a durable board on which to place material for cutting. Common is the kitchen cutting board used in preparing food; other types exist for cutting raw materials such as leather or plastic....
s, etc.).
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.
Decorative glass mirrors are usually handcrafted. A variety of shades, shapes and glass thickness are often available.
Shape of a mirror's surface
A beam of light reflects off a mirror at an angle of reflection equal to its angle of incidenceAngle of incidence
Angle of incidence is a measure of deviation of something from "straight on", for example:* in the approach of a ray to a surface, or* the angle at which the wing or horizontal tail of an airplane is installed on the fuselage, measured relative to the axis of the fuselage.-Optics:In geometric...
(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 wavePlane wave
In the physics of wave propagation, a plane wave is a constant-frequency wave whose wavefronts are infinite parallel planes of constant peak-to-peak amplitude normal to the phase velocity vector....
on a flat boundary (of much larger size than the wavelength).
- In a plane mirror, a parallelParallel (geometry)Parallelism is a term in geometry and in everyday life that refers to a property in Euclidean space of two or more lines or planes, or a combination of these. The assumed existence and properties of parallel lines are the basis of Euclid's parallel postulate. Two lines in a plane that do not...
beam of light changes its direction as a whole, while still remaining parallel; the images formed by a plane mirror are virtual imageVirtual imageIn optics, a virtual image is an image in which the outgoing rays from a point on the object always diverge. It will appear to converge in or behind the optical device . A simple example is a flat mirror where the image of oneself is perceived at twice the distance from oneself to the mirror...
s, of the same size as the original object (see mirror imageMirror imageA mirror image is a reflected duplication of an object that appears identical but reversed. As an optical effect it results from reflection off of substances such as a mirror or water. It is also a concept in geometry and can be used as a conceptualization process for 3-D structures...
). - In a concave mirror, parallel beams of light become a convergent beam, whose rays intersect in the focusFocus (optics)In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...
of the mirror. - In a convex mirror, parallel beams become divergent, with the raysRay (optics)In optics, a ray is an idealized narrow beam of light. Rays are used to model the propagation of light through an optical system, by dividing the real light field up into discrete rays that can be computationally propagated through the system by the techniques of ray tracing. This allows even very...
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 aberrationSpherical aberrationthumb|right|Spherical aberration. A perfect lens focuses all incoming rays to a point on the [[Optical axis|optic axis]]. A real lens with spherical surfaces suffers from spherical aberration: it focuses rays more tightly if they enter it far from the optic axis than if they enter closer to the...
. However, the ideal of focusing to a point is a commonly-used approximation. Parabolic reflectorParabolic reflectorA parabolic reflector is a reflective device used to collect or project energy such as light, sound, or radio waves. Its shape is that of a circular paraboloid, that is, the surface generated by a parabola revolving around its axis...
s 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.
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.Applications
Safety and easier viewing
Convex mirrors- Convex mirrors provide a wider field of viewField of viewThe field of view is the extent of the observable world that is seen at any given moment....
than flat mirrors, and are often used on vehicles, especially large trucks, to minimize blind spotsBlind spot (automobile)A blind spot in a vehicle is an area around the vehicle that cannot be directly observed by the driver while at the controls, under existing circumstances...
. They are sometimes placed at road junctions, and corners of sites such as parking lotParking lotA parking lot , also known as car lot, is a cleared area that is intended for parking vehicles. Usually, the term refers to a dedicated area that has been provided with a durable or semi-durable surface....
s to allow people to see around corners to avoid crashing into other vehicles or shopping cartShopping cartA shopping cart is a cart supplied by a shop, especially supermarkets, for use by customers inside the shop for transport of merchandise to the check-out counter during shopping...
s. They are also sometimes used as part of security systems, so that a single video cameraVideo cameraA video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in...
can show more than one angleAngleIn geometry, an angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle.Angles are usually presumed to be in a Euclidean plane with the circle taken for standard with regard to direction. In fact, an angle is frequently viewed as a measure of an circular arc...
at a time.
Mouth mirror
Mouth mirror
A mouth mirror or dentist's mirror is an instrument used in dentistry. The head of the mirror is usually round, and the most common sizes used are the No. 4 and No. 5. A No. 2 is sometimes used when a smaller mirror is needed, such as when working on back teeth with a dental dam in place. The...
s or "dental mirrors"
- Mouth mirrors or "dental mirrors" are used by dentistDentistA dentist, also known as a 'dental surgeon', is a doctor that specializes in the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity. The dentist's supporting team aides in providing oral health services...
s 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 engineerEngineerAn engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...
s to allow vision in tight spaces and around corners in equipment.
Rear-view mirror
Rear-view mirror
A rear-view mirror is a mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's backlight ....
s
- Rear-view mirrors are widely used in and on vehicleVehicleA vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
s (such as automobileAutomobileAn automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
s, or bicycles), to allow drivers to see other vehicles coming up behind them. Some motorcycle helmetMotorcycle helmetA motorcycle helmet is a type of protective headgear used by motorcycle riders. The primary goal of a motorcycle helmet is motorcycle safety - to protect the rider's head during impact, thus preventing or reducing head injury or saving the rider's life...
s 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.http://www.reevu.fr On rear-view sunglassesSunglassesSunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that...
, the left end of the left glass and the right end of the right glass work as mirrors.
Two-way versus one-way mirrors and windows
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 thermodynamicsSecond law of thermodynamicsThe second law of thermodynamics is an expression of the tendency that over time, differences in temperature, pressure, and chemical potential equilibrate in an isolated physical system. From the state of thermodynamic equilibrium, the law deduced the principle of the increase of entropy and...
: 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. Optical isolators are one-way devices that are commonly used with lasers.
Signalling
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 kilometreKilometre
The kilometre is a unit of length in the metric system, equal to one thousand metres and is therefore exactly equal to the distance travelled by light in free space in of a second...
s on a clear day. This technique was used by Native American
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
tribes and numerous militaries
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...
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.
Televisions and projectors
Microscopic mirrors are a core element of many of the largest high-definition televisions and video projectorVideo projector
A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...
s. A common technology of this type is Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
' 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
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
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
Liquid crystal
Liquid crystals are a state of matter that have properties between those of a conventional liquid and those of a solid crystal. For instance, an LC may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of LC phases, which can be...
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.
Instruments
TelescopeTelescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
s and other precision instruments use front silvered or first surface mirrors
First surface mirrors
A first surface mirror or front surface mirror is a mirror with the reflective surface being above a backing, as opposed to the conventional, second surface mirror with the reflective surface behind a transparent substrate such as glass or acrylic.They are made for applications requiring a strict...
, 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
Vacuum deposition
Vacuum deposition is a family of processes used to deposit layers atom-by-atom or molecule-by-molecule at sub-atmospheric pressure on a solid surface. The layers may be as thin as one atom to millimeters thick . There may be multiple layers of different materials...
.
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 mirror
Mangin mirror
In optics, a Mangin mirror is a negative meniscus lens with the reflective surface on the rear side of the glass forming a curved mirror that reflects light without spherical aberration...
s that are second surface mirrors (reflective coating on the rear surface) as part of their optical designs, usually to correct optical aberrations.
The reflectivity of the mirror coating can be measured using a reflectometer
Reflectometer
Some scientific instruments commonly designated Reflectometer are:*Vector Network Analyser *Spectrophotometer: in optics, an instrument for measuring the reflectivity or reflectance of reflecting surfaces*Optical time domain 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 mirror
Cold mirror
A cold mirror is a specialized dielectric mirror, a dichroic filter, that reflects the entire visible light spectrum while very efficiently transmitting infrared wavelengths. Similar to hot mirrors, cold mirrors can be designed for an incidence angle ranging between zero and 45 degrees, and are...
s and hot mirror
Hot mirror
A hot mirror is a specialized dielectric mirror, a dichroic filter, often employed to protect optical systems by reflecting infrared light back into a light source, while allowing visible light to pass...
s. 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
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
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.
For scientific optical
Optics
Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
work, dielectric mirror
Dielectric mirror
A dielectric mirror is a type of a mirror composed of multiple thin layers of dielectric material, typically deposited on a substrate of glass or some other optical material. By careful choice of the type and thickness of the dielectric layers, one can design an optical coating with specified...
s 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
Adaptive optics
Adaptive optics is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems to reduce the...
is a technique to measure variable image distortions and adapt a deformable mirror
Deformable mirror
Deformable mirror represents the most convenient tool for wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in adaptive optics...
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
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
. Mirrors for radio waves (sometimes known as reflectors) are important elements of radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
s.
Face-to-face mirrors
Two or more mirrors placed exactly face to face can give an infinite regress
Infinite regress
An infinite regress in a series of propositions arises if the truth of proposition P1 requires the support of proposition P2, the truth of proposition P2 requires the support of proposition P3, .....
of reflections. Some devices use this to generate multiple reflections:
- Fabry–Pérot interferometer
- LaserLaserA laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
(which contains an optical cavityOptical cavityAn optical cavity or optical resonator is an arrangement of mirrors that forms a standing wave cavity resonator for light waves. Optical cavities are a major component of lasers, surrounding the gain medium and providing feedback of the laser light. They are also used in optical parametric...
) - 3D KaleidoscopeKaleidoscopeA kaleidoscope is a circle of mirrors containing loose, colored objects such as beads or pebbles and bits of glass. As the viewer looks into one end, light entering the other end creates a colorful pattern, due to the reflection off the mirrors...
to concentrate light - momentum-enhanced solar sailSolar sailSolar sails are a form of spacecraft propulsion using the radiation pressure of light from a star or laser to push enormous ultra-thin mirrors to high speeds....
Military applications
It has been said that ArchimedesArchimedes
Archimedes of Syracuse was a Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and an...
used a large array of mirrors to burn Roman
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
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
Discovery Channel
Discovery Channel is an American satellite and cable specialty channel , founded by John Hendricks and distributed by Discovery Communications. It is a publicly traded company run by CEO David Zaslav...
show, MythBusters
MythBusters
MythBusters is a science entertainment TV program created and produced by Beyond Television Productions for the Discovery Channel. The series is screened by numerous international broadcasters, including Discovery Channel Australia, Discovery Channel Latin America, Discovery Channel Canada, Quest...
, 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
Solar power tower
The solar power tower is a type of solar furnace using a tower to receive the focused sunlight. It uses an array of flat, movable mirrors to focus the sun's rays upon a collector tower...
for a practical use of this technique.)
Seasonal lighting
Viganella
thumb|ViganellaViganella is a comune in the Province of Verbano-Cusio-Ossola in the Italian region Piedmont, located about 120 km northeast of Turin and about 30 km northwest of Verbania...
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
Bondo, Switzerland
Bondo is a former municipality in the district of Maloja in the Swiss canton of Graubünden. It's now part of the municipality of Bregaglia.-Geography:...
, was considering applying this solution as well. Mirrors can be used to produce enhanced lighting effects in greenhouses or conservatories.
Paintings
.jpg)
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
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.
The mirror is the central device in some of the greatest of European paintings:
- Édouard ManetÉdouard ManetÉdouard Manet was a French painter. One of the first 19th-century artists to approach modern-life subjects, he was a pivotal figure in the transition from Realism to Impressionism....
's A Bar at the Folies-BergèreA Bar at the Folies-BergèreA Bar at the Folies-Bergère , painted and exhibited at the Paris Salon in 1882, was the last major work by French painter Édouard Manet. It depicts a scene in the Folies Bergère nightclub in Paris... - TitianTitianTiziano Vecelli or Tiziano Vecellio Tiziano Vecelli or Tiziano Vecellio Tiziano Vecelli or Tiziano Vecellio (c. 1488/1490 – 27 August 1576 better known as Titian was an Italian painter, the most important member of the 16th-century Venetian school. He was born in Pieve di Cadore, near...
's Venus with a MirrorVenus effectThe Venus effect is a phenomenon in the psychology of perception, named after various paintings of Venus gazing into a mirror, such as Diego Velázquez's Rokeby Venus, Titian's Venus with a mirror, and Veronese's Venus with a mirror... - Jan Van EyckJan van EyckJan van Eyck was a Flemish painter active in Bruges and considered one of the best Northern European painters of the 15th century....
's Arnolfini PortraitArnolfini portraitThe Arnolfini Portrait is an oil painting on oak panel dated 1434 by the Early Netherlandish painter Jan van Eyck. It is also known as The Arnolfini Wedding, The Arnolfini Marriage, The Arnolfini Double Portrait or the Portrait of Giovanni Arnolfini and his Wife, among other titles... - Pablo PicassoPablo PicassoPablo Diego José Francisco de Paula Juan Nepomuceno María de los Remedios Cipriano de la Santísima Trinidad Ruiz y Picasso known as Pablo Ruiz Picasso was a Spanish expatriate painter, sculptor, printmaker, ceramicist, and stage designer, one of the greatest and most influential artists of the...
's Girl before a Mirror (1932) - Diego VelázquezDiego VelázquezDiego Rodríguez de Silva y Velázquez was a Spanish painter who was the leading artist in the court of King Philip IV. He was an individualistic artist of the contemporary Baroque period, important as a portrait artist...
's Las MeninasLas MeninasLas Meninas is a 1656 painting by Diego Velázquez, the leading artist of the Spanish Golden Age, in the Museo del Prado in Madrid. The work's complex and enigmatic composition raises questions about reality and illusion, and creates an uncertain relationship between the viewer and the figures...
, 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 - VeronesePaolo VeronesePaolo Veronese was an Italian painter of the Renaissance in Venice, famous for paintings such as The Wedding at Cana and The Feast in the House of Levi...
's Venus with a Mirror
Mirrors have been used by artists to create works and hone their craft:
- Filippo BrunelleschiFilippo BrunelleschiFilippo Brunelleschi was one of the foremost architects and engineers of the Italian Renaissance. He is perhaps most famous for inventing linear perspective and designing the dome of the Florence Cathedral, but his accomplishments also included bronze artwork, architecture , mathematics,...
discovered linear perspective with the help of the mirror. - Leonardo da VinciLeonardo da VinciLeonardo di ser Piero da Vinci was an Italian Renaissance polymath: painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist and writer whose genius, perhaps more than that of any other figure, epitomized the Renaissance...
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." - Many self-portraits are made possible through the use of mirrors:
- Without a mirror, the great self-portraits by Dürer, Frida KahloFrida KahloFrida Kahlo de Rivera was a Mexican painter, born in Coyoacán, and perhaps best known for her self-portraits....
, Rembrandt, and Van Gogh could not have been painted. - M. C. EscherM. C. EscherMaurits Cornelis Escher , usually referred to as M. C. Escher , was a Dutch graphic artist. He is known for his often mathematically inspired woodcuts, lithographs, and mezzotints...
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).
- Without a mirror, the great self-portraits by Dürer, Frida Kahlo
Mirrors are sometimes necessary to fully appreciate art work:
- István OroszIstván OroszIstván Orosz Hungarian painter, printmaker, graphic designer and animated film director, is known for his mathematically inspired works, impossible objects, optical illusions, double-meaning images and anamorphoses. The geometric art of István Orosz, with forced perspectives and optical...
's anamorphicAnamorphosisAnamorphosis or anamorphism may refer to any of the following:*Anamorphosis, in art, the representation of an object as seen, for instance, altered by reflection in a mirror...
works are images distorted such that they only become clearly visible when reflected in a suitably shaped and positioned mirror.
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 casted on its back. This is due to minute curvatures on its front.
- 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 siliconeSiliconeSilicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications , cookware, and insulation....
sculpture by artist, Seth WulsinSeth WulsinSeth Wulsin is an artist working primarily with space and light through large-scale, site-specific, ephemeral sculpture and drawing.... - Sky MirrorSky Mirroris a public sculpture by artist Anish Kapoor. Commissioned by the Nottingham Playhouse from the artist, it is installed outside the theatre in Wellington Circus, Nottingham, England. Sky Mirror is a six-metre-wide concave dish of polished stainless steel weighing ten tonnes and angled up towards...
is a public sculpturePublic artThe term public art properly refers to works of art in any media that have been planned and executed with the specific intention of being sited or staged in the physical public domain, usually outside and accessible to all...
by artist, Anish KapoorAnish KapoorAnish Kapoor CBE RA is a British sculptor of Indian birth. Born in Mumbai , Kapoor has lived and worked in London since the early 1970s when he moved to study art, first at the Hornsey College of Art and later at the Chelsea School of Art and Design.He represented Britain in the XLIV Venice...
- Infinity Also Hurts is a mirror, glass and silicone
- Special mirror installations
- Follow Me mirror labyrinth by artist, Jeppe HeinJeppe HeinJeppe Hein is an artist based in Berlin and Copenhagen. Hein is widely known for his production of experiential and interactive artworks that can be positioned at the junction where art, architecture, and technical inventions intersect...
(see also, Entertainment: Mirror mazes, below) - Mirror Neon Cube by artist, Jeppe HeinJeppe HeinJeppe Hein is an artist based in Berlin and Copenhagen. Hein is widely known for his production of experiential and interactive artworks that can be positioned at the junction where art, architecture, and technical inventions intersect...
- Follow Me mirror labyrinth by artist, Jeppe Hein
Decoration
- 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. They come also framed in a variety of forms, such as the pier glassPier glassA pier glass is a mirror which is placed on a pier, i.e. a wall between two windows supporting an upper structure. It is therefore generally of a long and tall shape to fit the space. It may be as a hanging mirror or as mirrored glass affixed flush to the pier, in which case it is sometimes of...
and the overmantle mirror. - Mirrors are used also in some schools of feng shuiFeng shuiFeng shui ' is a Chinese system of geomancy believed to use the laws of both Heaven and Earth to help one improve life by receiving positive qi. The original designation for the discipline is Kan Yu ....
, an ancient ChineseCulture of ChinaChinese culture is one of the world's oldest and most complex. The area in which the culture is dominant covers a large geographical region in eastern Asia with customs and traditions varying greatly between towns, cities and provinces...
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.
- A decorative reflecting sphereSphereA sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point...
of thin metal-coated glass, working as a reducing wide-angle mirror, is sold as a Christmas ornamentChristmas ornamentChristmas ornaments are decorations that are used to festoon a Christmas tree.Ornaments take many different forms, from a simple round ball to highly artistic designs...
called a bauble.
Entertainment
- Illuminated rotating disco ballDisco ballA disco ball is a roughly spherical object that reflects light directed at it in many directions, producing a complex display...
s covered with small mirrors are used to cast moving spots of light around a dance floor. - The hall of mirrorsHouse of mirrorsA house of mirrors or hall of mirrors is a traditional attraction at funfairs and amusement parks. The basic concept behind a house of mirrors is to be a maze-like puzzle. In addition to the maze, participants are also given mirrors as obstacles, and glass panes to parts of the maze they cannot...
, commonly found in amusement parkAmusement parkthumb|Cinderella Castle in [[Magic Kingdom]], [[Disney World]]Amusement and theme parks are terms for a group of entertainment attractions and rides and other events in a location for the enjoyment of large numbers of people...
s, is an attraction in which a number of distorted mirrors are used to produce unusual reflections of the visitor. - Mirrors are employed in kaleidoscopeKaleidoscopeA kaleidoscope is a circle of mirrors containing loose, colored objects such as beads or pebbles and bits of glass. As the viewer looks into one end, light entering the other end creates a colorful pattern, due to the reflection off the mirrors...
s, personal entertainment devices invented in ScotlandScotlandScotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
by Sir David BrewsterDavid BrewsterSir David Brewster KH PRSE FRS FSA FSSA MICE was a Scottish physicist, mathematician, astronomer, inventor, writer and university principal.-Early life:...
. - Mirrors are often used in magicMagic (illusion)Magic is a performing art that entertains audiences by staging tricks or creating illusions of seemingly impossible or supernatural feats using natural means...
to create an illusionIllusionAn illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation. While illusions distort reality, they are generally shared by most people....
. One effect is called Pepper's ghostPepper's ghostPepper's ghost is an illusionary technique used in theatre and in some magic tricks. Using a plate glass and special lighting techniques, it can make objects seem to appear or disappear, transparent, or make one object seem to morph into another...
. - Mirror mazeMazeA maze is a tour puzzle in the form of a complex branching passage through which the solver must find a route. In everyday speech, both maze and labyrinth denote a complex and confusing series of pathways, but technically the maze is distinguished from the labyrinth, as the labyrinth has a single...
s, often found in amusement parkAmusement parkthumb|Cinderella Castle in [[Magic Kingdom]], [[Disney World]]Amusement and theme parks are terms for a group of entertainment attractions and rides and other events in a location for the enjoyment of large numbers of people...
s 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.
Film and television
- CandymanCandyman (film)Candyman is a 1992 horror film starring Virginia Madsen, Tony Todd and Xander Berkeley. It was directed by Bernard Rose and is based on the short story "The Forbidden" by Clive Barker, though the film's scenario is switched from England to Chicago. The film was scored by Philip Glass. The film was...
is a horror movie about mirrors - MirrorsMirrors (film)Mirrors is a 2008 horror film directed by Alexandre Aja, and stars Kiefer Sutherland. The film was first titled Into the Mirror, but the name was later changed to Mirrors...
is a horror movie about mirrors - Poltergeist IIIPoltergeist IIIPoltergeist III is a 1988 American horror film. It is the third and final film of the Poltergeist film series...
features mirrors as a major theme
Literature
Mirrors play a powerful role in cultural literature.- The Holy BibleBibleThe Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...
passage, 1 Corinthians 13:12: "Through a Glass Darkly" references a dim mirror image or poor mirror reflection - The magical objectsMagical objects in Harry PotterThe following is a list of magical objects used in Harry Potter. These objects exist for the use of the characters in the series by J. K. Rowling.-Enchanted coins:...
employed in the Harry PotterHarry PotterHarry Potter is a series of seven fantasy novels written by the British author J. K. Rowling. The books chronicle the adventures of the adolescent wizard Harry Potter and his best friends Ron Weasley and Hermione Granger, all of whom are students at Hogwarts School of Witchcraft and Wizardry...
series include:mirrors: the Mirror of Erised and two-way mirrors - NarcissusNarcissus (mythology)Narcissus or Narkissos , possibly derived from ναρκη meaning "sleep, numbness," in Greek mythology was a hunter from the territory of Thespiae in Boeotia who was renowned for his beauty. He was exceptionally proud, in that he disdained those who loved him...
of Greek mythologyGreek mythologyGreek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
wastes away while gazing, self-admiringly, at his reflection in water - In Oscar WildeOscar WildeOscar Fingal O'Flahertie Wills Wilde was an Irish writer and poet. After writing in different forms throughout the 1880s, he became one of London's most popular playwrights in the early 1890s...
's novel, The Picture of Dorian GrayThe Picture of Dorian GrayThe Picture of Dorian Gray is the only published novel by Oscar Wilde, appearing as the lead story in Lippincott's Monthly Magazine on 20 June 1890, printed as the July 1890 issue of this magazine...
, a portraitPortraitthumb|250px|right|Portrait of [[Thomas Jefferson]] by [[Rembrandt Peale]], 1805. [[New-York Historical Society]].A portrait is a painting, photograph, sculpture, or other artistic representation of a person, in which the face and its expression is predominant. The intent is to display the likeness,...
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 - In the European fairy taleFairy taleA fairy tale is a type of short story that typically features such folkloric characters, such as fairies, goblins, elves, trolls, dwarves, giants or gnomes, and usually magic or enchantments. However, only a small number of the stories refer to fairies...
, Snow WhiteSnow White"Snow White" is a fairy tale known from many countries in Europe, the best known version being the German one collected by the Brothers Grimm...
, the evil queen asks, "Mirror, mirror, on the wall... who's the fairest of them all?" - Lewis CarrollLewis CarrollCharles Lutwidge Dodgson , better known by the pseudonym Lewis Carroll , was an English author, mathematician, logician, Anglican deacon and photographer. His most famous writings are Alice's Adventures in Wonderland and its sequel Through the Looking-Glass, as well as the poems "The Hunting of the...
's Through the Looking-GlassThrough the Looking-GlassThrough the Looking-Glass, and What Alice Found There is a work of literature by Lewis Carroll . It is the sequel to Alice's Adventures in Wonderland...
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 WonderlandAlice's Adventures in WonderlandAlice's Adventures in Wonderland is an 1865 novel written by English author Charles Lutwidge Dodgson under the pseudonym Lewis Carroll. It tells of a girl named Alice who falls down a rabbit hole into a fantasy world populated by peculiar, anthropomorphic creatures...
.
Mirrors and superstition
There are many legendLegend
A legend is a narrative of human actions that are perceived both by teller and listeners to take place within human history and to possess certain qualities that give the tale verisimilitude...
s and superstition
Superstition
Superstition is a belief in supernatural causality: that one event leads to the cause of another without any process in the physical world linking the two events....
s surrounding mirrors. Mirrors are said to be a reflection of the soul, and they were often used in traditional witchcraft
Witchcraft
Witchcraft, in historical, anthropological, religious, and mythological contexts, is the alleged use of supernatural or magical powers. A witch is a practitioner of witchcraft...
as tools for scrying
Scrying
Scrying is a magic practice that involves seeing things psychically in a medium, usually for purposes of obtaining spiritual visions and less often for purposes of divination or fortune-telling. The most common media used are reflective, translucent, or luminescent substances such as crystals,...
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 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. 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
Regeneration (theology)
Regeneration, while sometimes perceived to be a step in the Ordo salutis , is generally understood in Christian theology to be the objective work of God in a believer's life. Spiritually, it means that God brings Christians to new life from a previous state of subjection to the decay of death...
every seven years, thus coming back unbroken. To prevent a broken mirror from reflecting a broken soul during the seven-year interim
Interim
Interim is an album by British rock band The Fall, compiled from live and studio material and released in 2004. It features the first officially released versions of "Clasp Hands", "Blindness" and "What About Us?" — all of which were later included on the band's next studio album Fall Heads Roll —...
, one of many rituals must be performed. Two alternatives include grinding the broken mirror to dust (perhaps the easiest approach) or burying the mirror. 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.
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.
In days past, it was customary in the southern United States to cover the mirrors in a house where the wake
Wake (ceremony)
A wake is a ceremony associated with death. Traditionally, a wake takes place in the house of the deceased, with the body present; however, modern wakes are often performed at a funeral home. In the United States and Canada it is synonymous with a viewing...
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
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
), 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
Vanity
In conventional parlance, vanity is the excessive belief in one's own abilities or attractiveness to others. Prior to the 14th century it did not have such narcissistic undertones, and merely meant futility. The related term vainglory is now often seen as an archaic synonym for vanity, but...
that does not become mourning
Mourning
Mourning is, in the simplest sense, synonymous with grief over the death of someone. The word is also used to describe a cultural complex of behaviours in which the bereaved participate or are expected to participate...
. (Other Greek mourning customs include not playing music, not entertaining guests, and using no festive decorations, e.g. on Christmas
Christmas
Christmas or Christmas Day is an annual holiday generally celebrated on December 25 by billions of people around the world. It is a Christian feast that commemorates the birth of Jesus Christ, liturgically closing the Advent season and initiating the season of Christmastide, which lasts twelve days...
, during the customary year-long mourning period).
According to legend, a vampire
Vampire
Vampires are mythological or folkloric beings who subsist by feeding on the life essence of living creatures, regardless of whether they are undead or a living person...
has no reflection in mirrors because it is an undead
Undead
Undead is a collective name for fictional, mythological, or legendary beings that are deceased and yet behave as if alive. Undead may be incorporeal, such as ghosts, or corporeal, such as vampires and zombies...
creature and has already lost its soul.
Another superstition claims it is bad luck to have two mirrors facing each other.
A staple of childhood slumber parties
Slumber Party
Slumber Party is an indie rock band from Detroit, Michigan. In 2000, 2 years after the band's formation, they signed to Kill Rock Stars.-Albums:*Slumber Party - Kill Rock Stars *Psychedelicate -Kill Rock Stars...
is the game Bloody Mary
Bloody Mary (folklore)
Bloody Mary is a ghost or witch featured in English folklore. She is said to appear in a mirror when her name is called three times or sometimes more while in a dark room, depending upon the version of the story, often as part of a game or dare.-Overview:...
, 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
Candyman (film)
Candyman is a 1992 horror film starring Virginia Madsen, Tony Todd and Xander Berkeley. It was directed by Bernard Rose and is based on the short story "The Forbidden" by Clive Barker, though the film's scenario is switched from England to Chicago. The film was scored by Philip Glass. The film was...
" may be substituted for Mary.
Mirrors and animals
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Mirror test
The mirror test is a measure of self-awareness, as animals either possess or lack the ability to recognize themselves in a mirror.The test was developed by Gordon Gallup Jr. in 1970, based in part on observations made by Charles Darwin. While visiting a zoo, Darwin held a mirror up to an orangutan...
:
- Asian elephantAsian ElephantThe Asian or Asiatic elephant is the only living species of the genus Elephas and distributed in Southeast Asia from India in the west to Borneo in the east. Three subspecies are recognized — Elephas maximus maximus from Sri Lanka, the Indian elephant or E. m. indicus from mainland Asia, and E. m....
s - BonoboBonoboThe bonobo , Pan paniscus, previously called the pygmy chimpanzee and less often, the dwarf or gracile chimpanzee, is a great ape and one of the two species making up the genus Pan. The other species in genus Pan is Pan troglodytes, or the common chimpanzee...
s - Common chimpanzeeCommon ChimpanzeeThe common chimpanzee , also known as the robust chimpanzee, is a great ape. Colloquially, the common chimpanzee is often called the chimpanzee , though technically this term refers to both species in the genus Pan: the common chimpanzee and the closely related bonobo, formerly called the pygmy...
s - DolphinDolphinDolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
s - European MagpieEuropean MagpieThe European Magpie, Eurasian Magpie, or Common Magpie, , is a resident breeding bird throughout Europe, much of Asia and northwest Africa. It is one of several birds in the crow family named as magpies, and belongs to the Holarctic radiation of "monochrome" magpies...
s - MagpieMagpieMagpies are passerine birds of the crow family, Corvidae.In Europe, "magpie" is often used by English speakers as a synonym for the European Magpie, as there are no other magpies in Europe outside Iberia...
s - OrangutanOrangutanOrangutans are the only exclusively Asian genus of extant great ape. The largest living arboreal animals, they have proportionally longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping...
s
Unusual kinds of mirrors
Other types of reflecting device are also called "mirrors".- Acoustic mirrorAcoustic mirrorAn acoustic mirror is a passive device used to reflect and perhaps to focus sound waves.- Overview :Prior to World War II and the invention of radar, acoustic mirrors were built as early warning devices around the coasts of Great Britain, with the aim of detecting airborne invasions...
s 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 radarRadarRadar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
. Acoustic mirrors are used for remote probing of the atmosphere; they can be used to form a narrow diffraction-limited beam. They can also be used for underwater imaging.
- Active mirrors are mirrors that amplifyAmplifierGenerally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
the light they reflect. They are used to make disk laserDisk laserA disk laser or active mirror is a type of solid-state laser characterized by a heat sink and laser output that are realized on opposite sides of a thin layer of active gain medium...
s. The amplification is typically over a narrow range of wavelengthWavelengthIn physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
s, 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 interferometryInterferometryInterferometry refers to a family of techniques in which electromagnetic waves are superimposed in order to extract information about the waves. An instrument used to interfere waves is called an interferometer. Interferometry is an important investigative technique in the fields of astronomy,...
and atomic holographyHolographyHolography is a technique that allows the light scattered from an object to be recorded and later reconstructed so that when an imaging system is placed in the reconstructed beam, an image of the object will be seen even when the object is no longer present...
. It has been proposed that they can be used for non-destructive imaging systems with nanometer resolution.
- Cold mirrorCold mirrorA cold mirror is a specialized dielectric mirror, a dichroic filter, that reflects the entire visible light spectrum while very efficiently transmitting infrared wavelengths. Similar to hot mirrors, cold mirrors can be designed for an incidence angle ranging between zero and 45 degrees, and are...
s are dielectricDielectricA dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
mirrors that reflect the entire visible light spectrum, while efficiently transmitting infraredInfraredInfrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
wavelengths. These are the converse of hot mirrors.
- Corner reflectorCorner reflectorA corner reflector is a retroreflector consisting of three mutually perpendicular, intersecting flat surfaces, which reflects waves back directly towards the source, but shifted . Unlike a simple mirror, they work for a relatively wide-angle field of view. The three intersecting surfaces often have...
s use three flat mirrors to reflect light back towards its source. They are used for emergency location, and even laser ranging to the MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
.
- Hot mirrorHot mirrorA hot mirror is a specialized dielectric mirror, a dichroic filter, often employed to protect optical systems by reflecting infrared light back into a light source, while allowing visible light to pass...
s 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 microwavesMicrowaveMicrowaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
).
- Non-reversing mirrorNon-reversing mirrorA Non-reversing mirror is a mirror that presents its subject as it would be seen from the mirror. It is possible to make a non-reversing mirror by connecting two regular mirrors at their edges at a 90 degree angle. If you position the join so that it is vertical and look into the angle, you will...
s are mirrors that provide a non-reversed image of their subjects.
- X-ray mirrors produce specular reflection of X-rayX-rayX-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s. All known types work only at angles near grazing incidence, and only a small fraction of the rays are reflected. See also X-ray opticsX-ray opticsX-ray optics is the branch of optics which manipulates X-rays instead of visible light. While lenses for visible light are made of transparent materials that can have a refractive index substantially larger than 1, for X-rays the index of refraction is slightly smaller than unity. The principal...
.
See also
- AnamorphosisAnamorphosisAnamorphosis or anamorphism may refer to any of the following:*Anamorphosis, in art, the representation of an object as seen, for instance, altered by reflection in a mirror...
- Aranmula kannadiAranmula kannadiAn Aranmula kannadi or Aranmula metal mirror is a special type of mirror produced at Aranmula, a village in the state of Kerala in India. Composed of a special metal alloy, instead of glass, the Aranmula kannadi is a front surface reflection mirror, which eliminates secondary reflections and...
- Bronze mirrorBronze mirrorBronze mirrors preceded the glass mirrors of today. This type of mirror has been found by archaeologists among elite assemblages from various cultures, from Etruscan Italy to China.-History:-Egypt:...
- Chirality (mathematics)Chirality (mathematics)In geometry, a figure is chiral if it is not identical to its mirror image, or, more precisely, if it cannot be mapped to its mirror image by rotations and translations alone. For example, a right shoe is different from a left shoe, and clockwise is different from counterclockwise.A chiral object...
- Cold mirrorCold mirrorA cold mirror is a specialized dielectric mirror, a dichroic filter, that reflects the entire visible light spectrum while very efficiently transmitting infrared wavelengths. Similar to hot mirrors, cold mirrors can be designed for an incidence angle ranging between zero and 45 degrees, and are...
and Hot mirrorHot mirrorA hot mirror is a specialized dielectric mirror, a dichroic filter, often employed to protect optical systems by reflecting infrared light back into a light source, while allowing visible light to pass... - Curved mirrorCurved mirrorA curved mirror is a mirror with a curved reflective surface, which may be either convex or concave . Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices...
- Deformable mirrorDeformable mirrorDeformable mirror represents the most convenient tool for wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in adaptive optics...
- Dielectric mirrorDielectric mirrorA dielectric mirror is a type of a mirror composed of multiple thin layers of dielectric material, typically deposited on a substrate of glass or some other optical material. By careful choice of the type and thickness of the dielectric layers, one can design an optical coating with specified...
- Digital micromirror deviceDigital micromirror deviceA digital micromirror device, or DMD, is an optical semiconductor that is the core of DLP projection technology, and was invented by Dr. Larry Hornbeck and Dr. William E. "Ed" Nelson of Texas Instruments in 1987....
- Home decor
- Honeycomb mirrorHoneycomb mirrorA honeycomb mirror is a large mirror usually used as the primary mirror in astronomical reflecting telescopes whose face is supported by a ribbed structure that resembles a honeycomb. The design provides sufficient rigidity for ultra-high precision optics while reducing the weight of the mirror...
- List of telescope parts and construction
- Mirror armourMirror armourMirror armour , sometimes referred to as disc armour or Chahar-Ainé , was a type of armour used in Asia and...
(an oriental partial plate armour from polished metal mirrors) - Mirror Mirror: a history of the human love affair with reflectionMirror Mirror: a history of the human love affair with reflectionMirror Mirror: A history of the human love affair with reflection is a 2003 nonfiction book written by American investigative journalist Mark Pendergrast. It was widely reviewed.ISBN: 0-465-05470-6 -Synopsis:...
(book) - Mirror writingMirror writingMirror writing is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the mirror image of normal writing: it appears normal when it is reflected in a mirror. It is sometimes used as an extremely primitive form of cipher...
- Perfect mirrorPerfect mirrorA perfect mirror is a theoretical mirror that reflects light perfectly, and doesn't transmit or absorb it.Domestic mirrors are not perfect mirrors as they absorb a significant portion of the light which falls on them....
- PeriscopePeriscopeA periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle....
- Rear-view mirrorRear-view mirrorA rear-view mirror is a mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's backlight ....
- ReflectivityReflectivityIn optics and photometry, reflectivity is the fraction of incident radiation reflected by a surface. In general it must be treated as a directional property that is a function of the reflected direction, the incident direction, and the incident wavelength...
- SilveringSilveringSilvering is the chemical process of coating glass with a reflective substance. When glass mirrors first gained widespread usage in Europe during the 16th century, most were made of an amalgam of tin and mercury, but by the 19th century mirrors were commonly made through a process by which silver...
- TLV mirrorTLV mirrorA TLV mirror is a type of bronze mirror that was popular during the Han Dynasty in China. They are called TLV mirrors because symbols resembling the letters T, L, and V are engraved into them...
— An ancient type of Chinese mirror from the Han DynastyHan DynastyThe Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...
. - Two-way mirrorTwo-way mirrorA one-way mirror, also known as a two-way mirror, one-way glass, or two-way glass is a mirror which is partially reflective and partially transparent...
(Also known as one-way mirrorTwo-way mirrorA one-way mirror, also known as a two-way mirror, one-way glass, or two-way glass is a mirror which is partially reflective and partially transparent...
) - Venus effectVenus effectThe Venus effect is a phenomenon in the psychology of perception, named after various paintings of Venus gazing into a mirror, such as Diego Velázquez's Rokeby Venus, Titian's Venus with a mirror, and Veronese's Venus with a mirror...