![Enhanced aluminum coated first surface mirror on an optical flat](https://upload.wikimedia.org/wikipedia/commons/9/95/Enhanced_aluminum_coated_first_surface_mirror_on_an_optical_flat.JPG)
A mirror or looking glass is an object that
reflects an
image
An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensiona ...
. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the image in an equal yet opposite angle from which the light shines upon it. This allows the viewer to see themselves or objects behind them, or even objects that are at an angle from them but out of their field of view, such as around a corner. Natural mirrors have existed since prehistoric times, such as the surface of water, but people have been manufacturing mirrors out of a variety of materials for thousands of years, like stone, metals, and glass. In modern mirrors, metals like
silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
or
aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
are often used due to their high
reflectivity
The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the electronic ...
, applied as a thin coating on
glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...
because of its naturally smooth and very
hard
Hard may refer to:
* Hardness, resistance of physical materials to deformation or fracture
* Hard water, water with high mineral content
Arts and entertainment
* ''Hard'' (TV series), a French TV series
* Hard (band), a Hungarian hard rock supe ...
surface.
A mirror is a
wave
In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (res ...
reflector.
Light
Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...
consists of waves, and when light waves reflect from the flat surface of a mirror, those waves retain the same degree of curvature and
vergence
A vergence is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision.
When a creature with binocular vision looks at an object, the eyes must rotate around a vertical axis so that the proje ...
, in an equal yet opposite direction, as the original waves. This allows the waves to form an image when they are focused through a lens, just as if the waves had originated from the direction of the mirror. The light can also be pictured as
rays
Ray may refer to:
Fish
* Ray (fish), any cartilaginous fish of the superorder Batoidea
* Ray (fish fin anatomy), a bony or horny spine on a fin
Science and mathematics
* Ray (geometry), half of a line proceeding from an initial point
* Ray (gra ...
(imaginary lines radiating from the light source, that are always perpendicular to the waves). These rays are reflected at an equal yet opposite angle from which they strike the mirror (incident light). This property, called
specular reflection
Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface.
The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surf ...
, distinguishes a mirror from objects that
diffuse
Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...
light, breaking up the wave and scattering it in many directions (such as flat-white paint). Thus, a mirror can be any surface in which the texture or roughness of the surface is smaller (smoother) than the
wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...
of the waves.
When looking at a mirror, one will see a
mirror image
A mirror image (in a plane mirror) is a reflected duplication of an object that appears almost identical, but is reversed in the direction perpendicular to the mirror surface. As an optical effect it results from reflection off from substances ...
or reflected image of objects in the environment, formed by light emitted or scattered by them and reflected by the mirror towards one's eyes. This effect gives the illusion that those objects are behind the mirror, or (sometimes)
in front of it. When the surface is not flat, a mirror may behave like a reflecting
lens
A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...
. A
plane mirror
A plane mirror is a mirror with a flat (planar) reflective surface. For light rays striking a plane mirror, the angle of reflection equals the angle of incidence. The angle of the incidence is the angle between the incident ray and the surface n ...
yields a real-looking undistorted image, while a
curved mirror
A curved mirror is a mirror with a curved reflecting surface. The surface may be either ''convex'' (bulging outward) or ''concave'' (recessed inward). Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are ...
may distort, magnify, or reduce the image in various ways, while keeping the lines,
contrast,
sharpness
Sharpness ( ) is an English port in Gloucestershire, one of the most inland in Britain, and eighth largest in the South West. It is on the River Severn at , at a point where the tidal range, though less than at Avonmouth downstream ( typical sp ...
, colors, and other image properties intact.
A mirror is commonly used for inspecting oneself, such as during
personal grooming
Grooming (also called preening) is the art and practice of cleaning and maintaining parts of the body. It is a species-typical behavior.
In animals
Individual animals regularly clean themselves and put their fur, feathers or other skin cove ...
; hence the old-fashioned name "looking glass".
[ This use, which dates from prehistory,][ overlaps with uses in ]decoration
Decoration may refer to:
* Decorative arts
* A house painter and decorator's craft
* An act or object intended to increase the beauty of a person, room, etc.
* An award that is a token of recognition to the recipient intended for wearing
Other ...
and architecture
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing building ...
. Mirrors are also used to view other items that are not directly visible because of obstructions; examples include rear-view mirror
A rear-view mirror (or rearview mirror) is a flat mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's rear window (rear windshield).
In cars, the rear-view mirror is usually affixed to ...
s in vehicles, security mirrors in or around buildings, and dentist's mirrors. Mirrors are also used in optical and scientific apparatus such as telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...
s, laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
s, camera
A camera is an Optics, optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), ...
s, periscope
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.
In its simplest form, it consists of an outer case with ...
s, and industrial machinery.
According to superstitions
A superstition is any belief or practice considered by non-practitioners to be irrational or supernatural, attributed to fate or magic, perceived supernatural influence, or fear of that which is unknown. It is commonly applied to beliefs and ...
breaking a mirror is said to bring seven years of bad luck.
The terms "mirror" and "reflector" can be used for objects that reflect any other types of waves. An acoustic mirror
An acoustic mirror is a passive device used to reflect and focus (concentrate) sound waves. Parabolic acoustic mirrors are widely used in parabolic microphones to pick up sound from great distances, employed in surveillance and reporting of ...
reflects sound waves. Objects such as walls, ceilings, or natural rock-formations may produce echo
In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the list ...
s, and this tendency often becomes a problem in acoustical engineering
Acoustical engineering (also known as acoustic engineering) is the branch of engineering dealing with sound and vibration. It includes the application of acoustics, the science of sound and vibration, in technology. Acoustical engineers are typical ...
when designing houses, auditoriums, or recording studios. Acoustic mirrors may be used for applications such as parabolic microphone
A parabolic microphone is a microphone that uses a parabolic reflector to collect and focus sound waves onto a transducer, in much the same way that a parabolic antenna (e.g. satellite dish) does with radio waves. Though they lack high fidelity ...
s, atmospheric
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
studies, sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigation, navigate, measure distances (ranging), communicate with or detect o ...
, and seafloor mapping
Seafloor mapping (or seabed mapping), also called seafloor imaging (or seabed imaging), is the measurement, mapping, and imaging of water depth of the ocean (''seabed topography'') or another given body of water. Bathymetric measurements are ...
.[ An ]atomic mirror In physics, an atomic mirror is a device which reflects neutral atoms in the similar way as a conventional mirror reflects visible light. Atomic mirrors can be made of electric fields or magnetic fields, electromagnetic waves or just silicon wafer; ...
reflects matter waves
Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave ...
and can be used for atomic interferometry
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber opt ...
and atomic holography
Holography is a technique that enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating real three-dimensional images, but it also has a wide range of other applications. In principle, i ...
.
History
Prehistory
The first mirrors used by humans were most likely pools of dark, still water, or water collected in a primitive vessel of some sort. The requirements for making a good mirror are a surface with a very high degree of flatness (preferably but not necessarily with high reflectivity
The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the electronic ...
), and a surface roughness
Surface roughness, often shortened to roughness, is a component of surface finish (surface texture). It is quantified by the deviations in the direction of the normal vector of a real surface from its ideal form. If these deviations are large, ...
smaller than the wavelength of the light.
The earliest manufactured mirrors were pieces of polished stone such as obsidian
Obsidian () is a naturally occurring volcanic glass formed when lava extrusive rock, extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock.
Obsidian is produced from felsic lava, rich in the lighter elements s ...
, a naturally occurring volcanic glass
Volcanic glass is the amorphous (uncrystallized) product of rapidly cooling magma. Like all types of glass, it is a state of matter intermediate between the closely packed, highly ordered array of a crystal and the highly disordered array of liqu ...
.[ Examples of obsidian mirrors found in ]Anatolia
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
(modern-day Turkey) have been dated to around 6000 BCE.[ Mirrors of polished copper were crafted in ]Mesopotamia
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the F ...
from 4000 BCE,[ and in ancient Egypt from around 3000 BCE.][ Polished stone mirrors from Central and South America date from around 2000 BCE onwards.][
]
Bronze Age to Early Middle Ages
By the Bronze Age
The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second pri ...
most cultures were using mirrors made from polished discs of bronze
Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids such ...
, copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...
, silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
, or other metals.[ The people of ]Kerma
Kerma was the capital city of the Kerma culture, which was located in present-day Sudan at least 5,500 years ago. Kerma is one of the largest archaeological sites in ancient Nubia. It has produced decades of extensive excavations and research, in ...
in Nubia
Nubia () (Nobiin: Nobīn, ) is a region along the Nile river encompassing the area between the first cataract of the Nile (just south of Aswan in southern Egypt) and the confluence of the Blue and White Niles (in Khartoum in central Sudan), or ...
were skilled in the manufacturing of mirrors. Remains of their bronze kiln
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
s have been found within the temple of Kerma. In China, bronze mirror
Bronze mirrors preceded the glass mirrors of today. This type of mirror, sometimes termed a copper mirror, has been found by archaeology, archaeologists among elite assemblages from various cultures, from Etruscan art, Etruscan Italy to Japan. T ...
s were manufactured from around 2000 BC, some of the earliest bronze and copper examples being produced by the Qijia culture
The Qijia culture (2200 BC – 1600 BC) was an early Bronze Age culture distributed around the upper Yellow River region of Gansu (centered in Lanzhou) and eastern Qinghai, China. It is regarded as one of the earliest bronze cultures in China.
T ...
. Such metal mirrors remained the norm through to Greco-Roman
The Greco-Roman civilization (; also Greco-Roman culture; spelled Graeco-Roman in the Commonwealth), as understood by modern scholars and writers, includes the geographical regions and countries that culturally—and so historically—were di ...
Antiquity and throughout the Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...
in Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
.[ During the ]Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterr ...
silver mirrors were in wide use by servants.[
]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 was used historically to make different kinds of mirrors from personal grooming a ...
is a highly reflective alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...
of copper and tin
Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal.
Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...
that was used for mirrors until a couple of centuries ago. Such mirrors may have originated in China and India.[ Mirrors of speculum metal or any precious metal were hard to produce and were only owned by the wealthy.][
Common metal mirrors tarnished and required frequent polishing. Bronze mirrors had low reflectivity and poor ]color rendering
The color rendering of a light source refers to its ability to reveal the colors of various objects faithfully (i.e. to produce illuminant metamerism) in comparison with an ideal or natural light source. Light sources with good color rendering are ...
, and stone mirrors were much worse in this regard.[ These defects explain the ]New Testament
The New Testament grc, Ἡ Καινὴ Διαθήκη, transl. ; la, Novum Testamentum. (NT) is the second division of the Christian biblical canon. It discusses the teachings and person of Jesus, as well as events in first-century Christ ...
reference in 1 Corinthians 13
1 Corinthians 13 is the thirteenth chapter of the First Epistle to the Corinthians in the New Testament of the Christian Bible. It is authored by Paul the Apostle and Sosthenes in Ephesus. This chapter covers the subject of Love. In the original ...
to seeing "as in a mirror, darkly."
The Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
philosopher
A philosopher is a person who practices or investigates philosophy. The term ''philosopher'' comes from the grc, φιλόσοφος, , translit=philosophos, meaning 'lover of wisdom'. The coining of the term has been attributed to the Greek th ...
Socrates
Socrates (; ; –399 BC) was a Greek philosopher from Athens who is credited as the founder of Western philosophy and among the first moral philosophers of the ethical tradition of thought. An enigmatic figure, Socrates authored no te ...
urged young people to look at themselves in mirrors so that, if they were beautiful, they would become worthy of their beauty, and if they were ugly, they would know how to hide their disgrace through learning.[
]Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...
began to be used for mirrors in the 1st century CE, with the development of soda-lime glass
Soda lime is a mixture of NaOH and CaO chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent ...
and glass blowing
Glassblowing is a glassforming technique that involves inflating molten glass into a bubble (or parison) with the aid of a blowpipe (or blow tube). A person who blows glass is called a ''glassblower'', ''glassmith'', or ''gaffer''. A '' lampworke ...
.[ The Roman scholar ]Pliny the Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic '' ...
claims that artisans in Sidon
Sidon ( ; he, צִידוֹן, ''Ṣīḏōn'') known locally as Sayda or Saida ( ar, صيدا ''Ṣaydā''), is the third-largest city in Lebanon. It is located in the South Governorate, of which it is the capital, on the Mediterranean coast. ...
(modern-day Lebanon
Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus li ...
) were producing glass mirrors coated with lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
or gold leaf
Gold leaf is gold that has been hammered into thin sheets (usually around 0.1 µm thick) by goldbeating and is often used for gilding. Gold leaf is available in a wide variety of karats and shades. The most commonly used gold is 22-kara ...
in the back. The metal provided good reflectivity, and the glass provided a smooth surface and protected the metal from scratches and tarnishing.[ However, there is no archeological evidence of glass mirrors before the third century.][
These early glass mirrors were made by blowing a glass bubble, and then cutting off a small circular section from 10 to 20 cm in diameter. Their surface was either concave or convex, and imperfections tended to distort the image. Lead-coated mirrors were very thin to prevent cracking by the heat of the molten metal.][ Due to the poor quality, high cost, and small size of glass mirrors, solid-metal mirrors (primarily of steel) remained in common use until the late nineteenth century.][
Silver-coated metal mirrors were developed in China as early as 500 CE. The bare metal was coated with an ]amalgam
Amalgam most commonly refers to:
* Amalgam (chemistry), mercury alloy
* Amalgam (dentistry), material of silver tooth fillings
** Bonded amalgam, used in dentistry
Amalgam may also refer to:
* Amalgam Comics, a publisher
* Amalgam Digital, an in ...
, then heated until the mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
boiled away.[
]
Middle Ages and Renaissance
The evolution of glass mirrors in the Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...
followed improvements in glassmaking
Glass production involves two main methods – the float glass process that produces sheet glass, and glassblowing that produces bottles and other containers. It has been done in a variety of ways during the history of glass.
Glass container ...
technology. Glassmakers in France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
made flat glass plates by blowing glass bubbles, spinning them rapidly to flatten them, and cutting rectangles out of them. A better method, developed in Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
and perfected in Venice
Venice ( ; it, Venezia ; vec, Venesia or ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 small islands that are separated by canals and linked by over 400 ...
by the 16th century, was to blow a cylinder of glass, cut off the ends, slice it along its length, and unroll it onto a flat hot plate.[ Venetian glassmakers also adopted ]lead glass
Lead glass, commonly called crystal, is a variety of glass in which lead replaces the calcium content of a typical potash glass. Lead glass contains typically 18–40% (by weight) lead(II) oxide (PbO), while modern lead crystal, historically als ...
for mirrors, because of its crystal-clarity and its easier workability. By the 11th century, glass mirrors were being produced in Moorish Spain
Al-Andalus translit. ; an, al-Andalus; ast, al-Ándalus; eu, al-Andalus; ber, ⴰⵏⴷⴰⵍⵓⵙ, label= Berber, translit=Andalus; ca, al-Àndalus; gl, al-Andalus; oc, Al Andalús; pt, al-Ândalus; es, al-Ándalus () was the Mu ...
.[
During the early ]Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
Renaissance
The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ideas ...
, a fire-gilding
Gilding is a decorative technique for applying a very thin coating of gold over solid surfaces such as metal (most common), wood, porcelain, or stone. A gilded object is also described as "gilt". Where metal is gilded, the metal below was tradi ...
technique developed to produce an even and highly reflective tin
Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal.
Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...
coating for glass mirrors. The back of the glass was coated with a tin-mercury amalgam, and the mercury was then evaporated by heating the piece. This process caused less thermal shock
Thermal shock is a type of rapidly transient mechanical load.
By definition, it is a mechanical load caused by a rapid change of temperature of a certain point.
It can be also extended to the case of a thermal gradient, which makes different par ...
to the glass than the older molten-lead method.[ The date and location of the discovery is unknown, but by the 16th century Venice was a center of mirror production using this technique. These Venetian mirrors were up to square.
For a century, Venice retained the monopoly of the tin amalgam technique. Venetian mirrors in richly decorated frames served as luxury decorations for palaces throughout Europe, and were very expensive. For example, in the late seventeenth century, the Countess de Fiesque was reported to have traded an entire wheat farm for a mirror, considering it a bargain.][ However, by the end of that century the secret was leaked through industrial espionage. French workshops succeeded in large-scale industrialization of the process, eventually making mirrors affordable to the masses, in spite of the ]toxicity
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
of mercury's vapor.[
]
Industrial Revolution
The invention of the ribbon machine
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...
in the late Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
allowed modern glass panes to be produced in bulk.[ The ]Saint-Gobain
Compagnie de 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 ...
factory, founded by royal initiative in France, was an important manufacturer, and Bohemia
Bohemia ( ; cs, Čechy ; ; hsb, Čěska; szl, Czechy) is the westernmost and largest historical region of the Czech Republic. Bohemia can also refer to a wider area consisting of the historical Lands of the Bohemian Crown ruled by the Bohem ...
n and German glass, often rather cheaper, was also important.
The invention of the silvered-glass mirror is credited to German chemist Justus von Liebig
Justus Freiherr von Liebig (12 May 1803 – 20 April 1873) was a German scientist who made major contributions to agricultural and biological chemistry, and is considered one of the principal founders of organic chemistry. As a professor at t ...
in 1835.[ His ]wet deposition
In the physics of aerosols, deposition is the process by which aerosol particles collect or deposit themselves on solid surfaces, decreasing the concentration of the particles in the air. It can be divided into two sub-processes: ''dry'' and ''w ...
process involved the deposition of a thin layer of metallic silver onto glass through the chemical reduction of silver nitrate
Silver nitrate is an inorganic compound with chemical formula . It 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. It was once called ''lunar caustic' ...
. This silvering process was adapted for mass manufacturing and led to the greater availability of affordable mirrors.
Contemporary technologies
Mirrors are often produced by the wet deposition of silver, or sometimes nickel or chromium (the latter used most often in automotive mirrors) via electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ...
directly onto the glass substrate.[
Glass mirrors for optical instruments are usually produced by ]vacuum deposition
Vacuum deposition is a group of processes used to deposit layers of material atom-by-atom or molecule-by-molecule on a solid surface. These processes operate at pressures well below atmospheric pressure (i.e., vacuum). The deposited layers can r ...
methods. These techniques can be traced to observations in the 1920s and 1930s that metal was being ejected from electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). Electrodes are essential parts of batteries that can consist of a variety of materials de ...
s in gas discharge lamp
Gas-discharge lamps are a family of artificial light sources that generate light by sending an electric discharge through an ionized gas, a plasma.
Typically, such lamps use a
noble gas (argon, neon, krypton, and xenon) or a mixture of these ...
s and condensed on the glass walls forming a mirror-like coating. The phenomenon, called sputtering
In physics, sputtering is a phenomenon in which microscopic particles of a solid material are ejected from its surface, after the material is itself bombarded by energetic particles of a plasma or gas. It occurs naturally in outer space, and can ...
, was developed into an industrial metal-coating method with the development of semiconductor
A semiconductor is a material which has an electrical resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glas ...
technology in the 1970s.
A similar phenomenon had been observed with incandescent light bulbs
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxidat ...
: the metal in the hot filament would slowly sublimate and condense on the bulb's walls. This phenomenon was developed into the method of evaporation coating by Pohl and Pringsheim in 1912. John D. Strong
John Donovan Strong (1905-1992) was an American physicist and astronomer. Strong, one of the world’s foremost optical scientists, was known for being the first to detect water vapor in the atmosphere of Venus and for developing a number of innov ...
used evaporation coating to make the first aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...
-coated telescope mirrors in the 1930s.[ The first ]dielectric mirror
A dielectric mirror, also known as a Bragg mirror, is a type of 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 thickne ...
was created in 1937 by Auwarter using evaporated rhodium
Rhodium is a chemical element with the symbol Rh and atomic number 45. It is a very rare, silvery-white, hard, corrosion-resistant transition metal. It is a noble metal and a member of the platinum group. It has only one naturally occurring isoto ...
.[
The metal coating of glass mirrors is usually protected from abrasion and corrosion by a layer of paint applied over it. Mirrors for optical instruments often have the metal layer on the front face, so that the light does not have to cross the glass twice. In these mirrors, the metal may be protected by a thin transparent coating of a non-metallic (]dielectric
In electromagnetism, a dielectric (or dielectric medium) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the mate ...
) material. The first metallic mirror to be enhanced with a dielectric coating of silicon dioxide
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
was created by Hass in 1937. In 1939 at the Schott Glass
Schott AG is a German multinational glass company specializing in the manufacture of glass and glass-ceramics. Headquartered in Mainz, Germany, it is owned by the Carl Zeiss Foundation. The company's founder and namesake, Otto Schott, is credi ...
company, Walter Geffcken invented the first dielectric mirrors to use multilayer coatings.[
]
Burning mirrors
The Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
in Classical Antiquity
Classical antiquity (also the classical era, classical period or classical age) is the period of cultural history between the 8th century BC and the 5th century AD centred on the Mediterranean Sea, comprising the interlocking civilizations of ...
were familiar with the use of mirrors to concentrate light. Parabolic mirror
A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface generated ...
s were described and studied by the mathematician Diocles in his work ''On Burning Mirrors''.[ ]Ptolemy
Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importanc ...
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 ]Caliphate
A caliphate or khilāfah ( ar, خِلَافَة, ) is an institution or public office under the leadership of an Islamic steward with the title of caliph (; ar, خَلِيفَة , ), a person considered a political-religious successor to th ...
mathematician Ibn Sahl in the tenth century.[ The scholar ]Ibn al-Haytham
Ḥasan Ibn al-Haytham, Latinized as Alhazen (; full name ; ), was a medieval mathematician, astronomer, and physicist of the Islamic Golden Age from present-day Iraq.For the description of his main fields, see e.g. ("He is one of the prin ...
discussed concave and convex mirrors in both cylindrical
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
and spherical geometries,[ 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.][
]
Types of mirrors
Mirrors can be classified in many ways; including by shape, support, reflective materials, manufacturing methods, and intended application.
By shape
Typical mirror shapes are planar
Planar is an adjective meaning "relating to a plane (geometry)".
Planar may also refer to:
Science and technology
* Planar (computer graphics), computer graphics pixel information from several bitplanes
* Planar (transmission line technologies), ...
, convex
Convex or convexity may refer to:
Science and technology
* Convex lens, in optics
Mathematics
* Convex set, containing the whole line segment that joins points
** Convex polygon, a polygon which encloses a convex set of points
** Convex polytope ...
, and concave
Concave or concavity may refer to:
Science and technology
* Concave lens
* Concave mirror
Mathematics
* Concave function, the negative of a convex function
* Concave polygon, a polygon which is not convex
* Concave set
* The concavity
In ca ...
.
The surface of curved mirrors is often a part of a sphere
A sphere () is a Geometry, geometrical object that is a solid geometry, three-dimensional analogue to a two-dimensional circle. A sphere is the Locus (mathematics), set of points that are all at the same distance from a given point in three ...
. Mirrors that are meant to precisely concentrate parallel rays of light into a point are usually made in the shape of a paraboloid of revolution
In geometry, a paraboloid is a quadric surface that has exactly one axis of symmetry and no center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has a similar property of symmetry.
Every plane ...
instead; they are used in telescopes (from radio waves to X-rays), in antennas to communicate with broadcast satellite
Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum (radio waves), in a one-to-many model. Broadcasting began wi ...
s, and in solar furnace
A solar furnace is a structure that uses concentrated solar power to produce high temperatures, usually for industry. Parabolic mirrors or heliostats concentrate light (Insolation) onto a focal point. The temperature at the focal point may rea ...
s. A segmented mirror
A segmented mirror is an array of smaller mirrors designed to act as segments of a single large curved mirror. The segments can be either spherical or asymmetric (if they are part of a larger parabolic reflector). They are used as objectives for ...
, consisting of multiple flat or curved mirrors, properly placed and oriented, may be used instead.
Mirrors that are intended to concentrate sunlight onto a long pipe may be a circular cylinder
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
or of a parabolic cylinder
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
.
By structural material
The most common structural material for mirrors is glass, due to its transparency, ease of fabrication, rigidity, hardness, and ability to take a smooth finish.
Back-silvered mirrors
The most common mirrors consist of a plate of transparent glass, with a thin reflective layer on the back (the side opposite to the incident and reflected light) backed by a coating that protects that layer against abrasion, tarnishing, and corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...
. The glass is usually soda-lime glass, but lead glass may be used for decorative effects, and other transparent materials may be used for specific applications.
A plate of transparent plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...
may be used instead of glass, for lighter weight or impact resistance. Alternatively, a flexible transparent plastic film may be bonded to the front and/or back surface of the mirror, to prevent injuries in case the mirror is broken. Lettering or decorative designs may be printed on the front face of the glass, or formed on the reflective layer. The front surface may have an anti-reflection coating
An antireflective, antiglare or anti-reflection (AR) coating is a type of optical coating applied to the surface of lenses, other optical elements, and photovoltaic cells to reduce reflection. In typical imaging systems, this improves the effic ...
.
Front-silvered mirrors
Mirrors which are reflective on the front surface (the same side of the incident and reflected light) may be made of any rigid material.[ The supporting material does not necessarily need to be transparent, but telescope mirrors often use glass anyway. Often a protective transparent coating is added on top of the reflecting layer, to protect it against abrasion, tarnishing, and corrosion, or to absorb certain wavelengths.
]
Flexible mirrors
Thin flexible plastic mirrors are sometimes used for safety, since they cannot shatter or produce sharp flakes. Their flatness is achieved by stretching them on a rigid frame. These usually consist of a layer of evaporated aluminum between two thin layers of transparent plastic.
By reflective material
In common mirrors, the reflective layer is usually some metal like silver, tin, nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
, or chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.
Chromium metal is valued for its high corrosion resistance and hardne ...
, deposited by a wet process; or aluminium,[ deposited by sputtering or evaporation in vacuum. The reflective layer may also be made of one or more layers of transparent materials with suitable indices of refraction.
The structural material may be a metal, in which case the reflecting layer may be just the surface of the same. Metal concave dishes are often used to reflect infrared light (such as in ]space heater
A space heater is a device used to heat a single, small to medium sized area.
Operation
Electric space heaters fall into four main categories: fan heaters, ceramic, infrared, and oil-filled.
* Fan heaters are the cheapest, but are often the ...
s) or microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
s (as in satellite TV antennas). Liquid metal telescopes use a surface of liquid metal such as mercury.
Mirrors that reflect only part of the light, while transmitting some of the rest, can be made with very thin metal layers or suitable combinations of dielectric layers. They are typically used as beamsplitter
A beam splitter or ''beamsplitter'' is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding wide ...
s. A dichroic mirror
A dichroic filter, thin-film filter, or interference filter is a color filter used to selectively pass light of a small range of colors while reflecting other colors. By comparison, dichroic mirrors and dichroic reflectors tend to be characteri ...
, in particular, has surface that reflects certain wavelengths of light, while letting other wavelengths pass through. A 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 ...
is a dichroic mirror that efficiently reflects the entire visible light spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' or simply light. A typical human eye will respond to wav ...
while transmitting infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
wavelengths. A 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. Hot mirrors can be designed to be inserte ...
is the opposite: it reflects infrared light while transmitting visible light. Dichroic mirrors are often used as filters to remove undesired components of the light in cameras and measuring instruments.
In X-ray telescopes
An X-ray telescope (XRT) is a telescope that is designed to observe remote objects in the X-ray spectrum. In order to get above the Earth's atmosphere, which is opaque to X-rays, X-ray telescopes must be mounted on high altitude rockets, balloon ...
, the X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...
s reflect off a highly precise metal surface at almost grazing angles, and only a small fraction of the rays are reflected.[ In flying relativistic mirrors conceived for ]X-ray laser
An X-ray laser is a device that uses stimulated emission to generate or amplify electromagnetic radiation in the near X-ray or extreme ultraviolet region of the spectrum, that is, usually on the order of several tens of nanometers (nm) wavelength ...
s, the reflecting surface is a spherical shockwave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...
(wake wave) created in a low-density plasma
Plasma or plasm may refer to:
Science
* Plasma (physics), one of the four fundamental states of matter
* Plasma (mineral), a green translucent silica mineral
* Quark–gluon plasma, a state of matter in quantum chromodynamics
Biology
* Blood pla ...
by a very intense laser-pulse, and moving at an extremely high velocity.[
]
Nonlinear optical mirrors
A phase-conjugating mirror uses nonlinear optics
Nonlinear optics (NLO) is the branch of optics that describes the behaviour of light in ''nonlinear media'', that is, media in which the polarization density P responds non-linearly to the electric field E of the light. The non-linearity is typica ...
to reverse the phase difference between incident beams. Such mirrors may be used, for example, for coherent beam combination. The useful applications are self-guiding of laser beams and correction of atmospheric distortions in imaging systems.[
]
Physical principles
When a sufficiently narrow beam of light is reflected at a point of a surface, the surface's normal direction will be the bisector of the angle formed by the two beams at that point. That is, the direction vector
In mathematics, a unit vector in a normed vector space is a vector (often a spatial vector) of length 1. A unit vector is often denoted by a lowercase letter with a circumflex, or "hat", as in \hat (pronounced "v-hat").
The term ''direction ve ...
towards the incident beams's source, the normal vector , and direction vector of the reflected beam will be coplanar
In geometry, a set of points in space are coplanar if there exists a geometric plane that contains them all. For example, three points are always coplanar, and if the points are distinct and non-collinear, the plane they determine is unique. Howe ...
, and the angle between and will be equal to the angle of incidence between and , but of opposite sign.[
This property can be explained by the physics of an ]electromagnetic
In physics, electromagnetism is an interaction that occurs between particles with electric charge. It is the second-strongest of the four fundamental interactions, after the strong force, and it is the dominant force in the interactions of a ...
plane wave
In physics, a plane wave is a special case of wave or field: a physical quantity whose value, at any moment, is constant through any plane that is perpendicular to a fixed direction in space.
For any position \vec x in space and any time t, th ...
that is incident to a flat surface that is electrically conductive
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...
or where the speed of light
The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit ...
changes abruptly, as between two materials with different indices of refraction.
* When parallel
Parallel is a geometric term of location which may refer to:
Computing
* Parallel algorithm
* Parallel computing
* Parallel metaheuristic
* Parallel (software), a UNIX utility for running programs in parallel
* Parallel Sysplex, a cluster of IBM ...
beams of light are reflected on a plane surface, the reflected rays will be parallel too.
* If the reflecting surface is concave, the reflected beams will be convergent, at least to some extent and for some distance from the surface.
* A convex mirror, on the other hand, will reflect parallel rays towards divergent directions.
More specifically, a concave parabolic mirror (whose surface is a part of a paraboloid of revolution) will reflect rays that are parallel to its axis
An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to:
Mathematics
* Axis of rotation: see rotation around a fixed axis
*Axis (mathematics), a designator for a Cartesian-coordinate ...
into rays that pass through its focus
Focus, or its plural form foci may refer to:
Arts
* Focus or Focus Festival, former name of the Adelaide Fringe arts festival in South Australia Film
*''Focus'', a 1962 TV film starring James Whitmore
* ''Focus'' (2001 film), a 2001 film based ...
. Conversely, a parabolic concave mirror will reflect any ray that comes from its focus towards a direction parallel to its axis. If a concave mirror surface is a part of a prolate ellipsoid, it will reflect any ray coming from one focus toward the other focus.[
A convex parabolic mirror, on the other hand, will reflect rays that are parallel to its axis into rays that seem to emanate from the focus of the surface, behind the mirror. Conversely, it will reflect incoming rays that converge toward that point into rays that are parallel to the axis. A convex mirror that is part of a prolate ellipsoid will reflect rays that converge towards one focus into divergent rays that seem to emanate from the other focus.][
Spherical mirrors do not reflect parallel rays to rays that converge to or diverge from a single point, or vice versa, due to ]spherical aberration
In optics, spherical aberration (SA) is a type of optical aberration, aberration found in optical systems that have elements with spherical surfaces. Lens (optics), Lenses and curved mirrors are prime examples, because this shape is easier to man ...
. However, a spherical mirror whose diameter is sufficiently small compared to the sphere's radius will behave very similarly to a parabolic mirror whose axis goes through the mirror's center and the center of that sphere; so that spherical mirrors can substitute for parabolic ones in many applications.[
A similar aberration occurs with parabolic mirrors when the incident rays are parallel among themselves but not parallel to the mirror's axis, or are divergent from a point that is not the focus – as when trying to form an image of an objet that is near the mirror or spans a wide angle as seen from it. However, this aberration can be sufficiently small if the object image is sufficiently far from the mirror and spans a sufficiently small angle around its axis.][
]
Mirror images
Mirrors reflect an image to the observer. However, unlike a projected image on a screen, an image does not actually exist on the surface of the mirror. For example, when two people look at each other in a mirror, both see different images on the same surface. When the light waves converge through the lens of the eye they interfere with each other to form the image on the surface of the retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...
, and since both viewers see waves coming from different directions, each sees a different image in the same mirror. Thus, the images observed in a mirror depend upon the angle of the mirror with respect to the eye. The angle between the object and the observer is always twice the angle between the eye and the normal, or the direction perpendicular to the surface. This allows animals with binocular vision
In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Binocular vision does not typically refer to vision where an ...
to see the reflected image with depth perception
Depth perception is the ability to perceive distance to objects in the world using the visual system and visual perception. It is a major factor in perceiving the world in three dimensions. Depth perception happens primarily due to stereopsis an ...
and in three dimensions.
The mirror forms a ''virtual image'' of whatever is in the opposite angle from the viewer, meaning that objects in the image appear to exist in a direct line of sight
The line of sight, also known as visual axis or sightline (also sight line), is an imaginary line between a viewer/observer/spectator's eye(s) and a subject of interest, or their relative direction. The subject may be any definable object taken ...
—behind the surface of the mirror—at an equal distance from their position in front of the mirror. Objects behind the observer, or between the observer and the mirror, are reflected back to the observer without any actual change in orientation; the light waves are simply reversed in a direction perpendicular to the mirror. However, when viewer is facing the object and the mirror is at an angle between them, the image appears inverted 180° along the direction of the angle.[''Mastering Physics for ITT-JEE, Volume 2'' By S. Chand & Co. 2012 Er. Rakesh Rathi Page 273--276]
Objects viewed in a (plane) mirror will appear laterally inverted (e.g., if one raises one's right hand, the image's left hand will appear to go up in the mirror), but not vertically inverted (in the image a person's head still appears above their body).[ However, a mirror does not actually "swap" left and right any more than it swaps top and bottom. A mirror swaps front and back. To be precise, it reverses the object in the direction perpendicular to the mirror surface (the normal), turning the three dimensional image inside out (the way a glove stripped off the hand can be turned inside out, turning a left-hand glove into a right-hand glove or vice versa). When a person raises their left hand, the actual left hand raises in the mirror, but gives the illusion of a right hand raising because the imaginary person in the mirror is literally inside-out, hand and all. If the person stands side-on to a mirror, the mirror really does reverse left and right hands, that is, objects that are physically closer to the mirror always appear closer in the virtual image, and objects farther from the surface always appear symmetrically farther away regardless of angle.
Looking at an image of oneself with the front-back axis flipped results in the perception of an image with its left-right axis flipped. When reflected in the mirror, a person's right hand remains directly opposite their real right hand, but it is perceived by the mind as the left hand in the image. When a person looks into a mirror, the image is actually front-back reversed (inside-out), which is an effect similar to the hollow-mask illusion. Notice that a mirror image is fundamentally different from the object (inside-out) and cannot be reproduced by simply rotating the object. An object and its mirror image are said to be ]chiral
Chirality is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object.
An object or a system is ''chiral'' if it is distinguishable from ...
.
For things that may be considered as two-dimensional objects (like text), front-back reversal cannot usually explain the observed reversal. An image is a two-dimensional representation of a three-dimensional space, and because it exists in a two-dimensional plane
Plane(s) most often refers to:
* Aero- or airplane, a powered, fixed-wing aircraft
* Plane (geometry), a flat, 2-dimensional surface
Plane or planes may also refer to:
Biology
* Plane (tree) or ''Platanus'', wetland native plant
* Planes (gen ...
, an image can be viewed from front or back. In the same way that text on a piece of paper appears reversed if held up to a light and viewed from behind, text held facing a mirror will appear reversed, because the image of the text is still facing away from the observer. Another way to understand the reversals observed in images of objects that are effectively two-dimensional is that the inversion of left and right in a mirror is due to the way human beings perceive their surroundings. A person's reflection in a mirror appears to be a real person facing them, but for that person to really face themselves (i.e.: twins) one would have to physically turn and face the other, causing an actual swapping of right and left. A mirror causes an illusion of left-right reversal because left and right were ''not'' swapped when the image appears to have turned around to face the viewer. The viewer's egocentric navigation
Idiothetic literally means "self-proposition" (Greek derivation), and is used in navigation models (e.g., of a rat in a maze) to describe the use of self-motion cues, rather than allothetic, or external, cues such as landmarks, to determine posit ...
(left and right with respect to the observer's point of view; i.e.: "my left...") is unconsciously replaced with their allocentric navigation
Allothetic means being centred in people or places other than oneself. It has been defined as a process of "determining and maintaining a course or trajectory from one place to another. It can be used as a navigational strategy among animals to aid ...
(left and right as it relates another's point of view; "...your right") when processing the virtual image of the apparent person behind the mirror. Likewise, text viewed in a mirror would have to be physically turned around, facing the observer and away from the surface, actually swapping left and right, to be read in the mirror.
Optical properties
Reflectivity
The reflectivity of a mirror is determined by the percentage of reflected light per the total of the incident light. The reflectivity may vary with wavelength. All or a portion of the light not reflected is absorbed by the mirror, while in some cases a portion may also transmit through. Although some small portion of the light will be absorbed by the coating, the reflectivity is usually higher for first-surface mirrors, eliminating both reflection and absorption losses from the substrate.
The reflectivity is often determined by the type and thickness of the coating. When the thickness of the coating is sufficient to prevent transmission, all of the losses occur due to absorption. Aluminium is harder, less expensive, and more resistant to tarnishing than silver, and will reflect 85 to 90% of the light in the visible to near-ultraviolet range, but experiences a drop in its reflectance between 800 and 900 nm. Gold is very soft and easily scratched, costly, yet does not tarnish. Gold is greater than 96% reflective to near and far-infrared light between 800 and 12000 nm, but poorly reflects visible light with wavelengths shorter than 600 nm (yellow). Silver is expensive, soft, and quickly tarnishes, but has the highest reflectivity in the visual to near-infrared of any metal. Silver can reflect up to 98 or 99% of light to wavelengths as long as 2000 nm, but loses nearly all reflectivity at wavelengths shorter than 350 nm.
Dielectric mirrors can reflect greater than 99.99% of light, but only for a narrow range of wavelengths, ranging from a bandwidth of only 10 nm to as wide as 100 nm for tunable laser
A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. While all laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength ran ...
s. However, dielectric coatings can also enhance the reflectivity of metallic coatings and protect them from scratching or tarnishing. Dielectric materials are typically very hard and relatively cheap, however the number of coats needed generally makes it an expensive process. In mirrors with low tolerances, the coating thickness may be reduced to save cost, and simply covered with paint to absorb transmission.[
]
Surface quality
Surface quality, or surface accuracy, measures the deviations from a perfect, ideal surface shape. Increasing the surface quality reduces distortion, artifacts, and aberration in images, and helps increase coherence
Coherence, coherency, or coherent may refer to the following:
Physics
* Coherence (physics), an ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference
* Coherence (units of measurement), a deriv ...
, collimation
A collimated beam of light or other electromagnetic radiation has parallel rays, and therefore will spread minimally as it propagates. A perfectly collimated light beam, with no divergence, would not disperse with distance. However, diffraction pr ...
, and reduce unwanted divergence
In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the quantity of the vector field's source at each point. More technically, the divergence represents the volume density of the ...
in beams. For plane mirrors, this is often described in terms of flatness, while other surface shapes are compared to an ideal shape. The surface quality is typically measured with items like interferometer
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber op ...
s or optical flat
An optical flat is an optical-grade piece of glass lapped and polished to be extremely flat on one or both sides, usually within a few tens of nanometres (billionths of a metre). They are used with a monochromatic light to determine the flatn ...
s, and are usually measured in wavelengths of light (λ). These deviations can be much larger or much smaller than the surface roughness. A normal household-mirror made with 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 other various low- melting-point alloys were used in the past. This method gives the sheet uniform thickness and very flat sur ...
may have flatness tolerances as low as 9–14λ per inch (25.4 mm), equating to a deviation of 5600 through 8800 nanometer
330px, Different lengths as in respect to the molecular scale.
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re ...
s from perfect flatness. Precision ground and polished mirrors intended for lasers or telescopes may have tolerances as high as λ/50 (1/50 of the wavelength of the light, or around 12 nm) across the entire surface.[ The surface quality can be affected by factors such as temperature changes, internal stress in the substrate, or even bending effects that occur when combining materials with different coefficients of ]thermal expansion
Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions.
Temperature is a monotonic function of the average molecular kinetic ...
, similar to a bimetallic strip
A bimetallic strip is used to convert a temperature change into mechanical displacement. The strip consists of two strips of different metals which expand at different rates as they are heated. The different expansions force the flat strip to be ...
.[
]
Surface roughness
Surface roughness
Surface roughness, often shortened to roughness, is a component of surface finish (surface texture). It is quantified by the deviations in the direction of the normal vector of a real surface from its ideal form. If these deviations are large, ...
describes the texture of the surface, often in terms of the depth of the microscopic scratches left by the polishing operations. Surface roughness determines how much of the reflection is specular and how much diffuses, controlling how sharp or blurry the image will be.
For perfectly specular reflection, the surface roughness must be kept smaller than the wavelength of the light. Microwaves, which sometimes have a wavelength greater than an inch (~25 mm) can reflect specularly off a metal screen-door, continental ice-sheets, or desert sand, while visible light, having wavelengths of only a few hundred nanometers (a few hundred-thousandths of an inch), must meet a very smooth surface to produce specular reflection. For wavelengths that are approaching or are even shorter than the diameter of the atoms, such as X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...
s, specular reflection can only be produced by surfaces that are at a grazing incidence The angle of incidence, in geometric optics, is the angle between a ray incident on a surface and the line perpendicular (at 90 degree angle) to the surface at the point of incidence, called the normal. The ray can be formed by any waves, such as o ...
from the rays.
Surface roughness is typically measured in micron
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
s, wavelength, or grit size, with ~80,000–100,000 grit or ~½λ–¼λ being "optical quality".[
]
Transmissivity
Transmissivity is determined by the percentage of light transmitted per the incident light. Transmissivity is usually the same from both first and second surfaces. The combined transmitted and reflected light, subtracted from the incident light, measures the amount absorbed by both the coating and substrate. For transmissive mirrors, such as one-way mirrors, beam splitter
A beam splitter or ''beamsplitter'' is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding wide ...
s, or laser output coupler
An output coupler (OC) is the component of an optical resonator that allows the extraction of a portion of the light from the laser's intracavity beam. An output coupler most often consists of a partially reflective mirror, allowing a certain por ...
s, the transmissivity of the mirror is an important consideration. The transmissivity of metallic coatings are often determined by their thickness. For precision beam-splitters or output couplers, the thickness of the coating must be kept at very high tolerances to transmit the proper amount of light. For dielectric mirrors, the thickness of the coat must always be kept to high tolerances, but it is often more the number of individual coats that determine the transmissivity. For the substrate, the material used must also have good transmissivity to the chosen wavelengths. Glass is a suitable substrate for most visible-light applications, but other substrates such as zinc selenide
Zinc selenide (ZnSe) is a light-yellow, solid compound comprising zinc (Zn) and selenium (Se). It is an intrinsic semiconductor with a band gap of about 2.70 eV at . ZnSe rarely occurs in nature, and is found in the mineral that was named af ...
or synthetic sapphire
Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of elements such as iron, titanium, chromium, vanadium, or magnesium. The name sapphire is derived via the Latin "sapphi ...
may be used for infrared or ultraviolet wavelengths.[
]
Wedge
Wedge errors are caused by the deviation of the surfaces from perfect parallelism. An optical wedge The wedge prism is a prism with a shallow angle between its input and output surfaces. This angle is usually 3 degrees or less. Refraction at the surfaces causes the prism to deflect light by a fixed angle. When viewing a scene through such a prism ...
is the angle formed between two plane-surfaces (or between the principle planes of curved surfaces) due to manufacturing errors or limitations, causing one edge of the mirror to be slightly thicker than the other. Nearly all mirrors and optics with parallel faces have some slight degree of wedge, which is usually measured in seconds
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...
or minutes of arc
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...
. For first-surface mirrors, wedges can introduce alignment deviations in mounting hardware. For second-surface or transmissive mirrors, wedges can have a prismatic effect on the light, deviating its trajectory or, to a very slight degree, its color, causing chromatic
Diatonic and chromatic are terms in music theory that are most often used to characterize scales, and are also applied to musical instruments, intervals, chords, notes, musical styles, and kinds of harmony. They are very often used as a pair, ...
and other forms of aberration. In some instances, a slight wedge is desirable, such as in certain laser systems where stray reflections from the uncoated surface are better dispersed than reflected back through the medium.[
]
Surface defects
Surface defects are small-scale, discontinuous imperfections in the surface smoothness. Surface defects are larger (in some cases much larger) than the surface roughness, but only affect small, localized portions of the entire surface. These are typically found as scratches, digs, pits (often from bubbles in the glass), sleeks (scratches from prior, larger grit polishing operations that were not fully removed by subsequent polishing grits), edge chips, or blemishes in the coating. These defects are often an unavoidable side-effect of manufacturing limitations, both in cost and machine precision. If kept low enough, in most applications these defects will rarely have any adverse effect, unless the surface is located at an image plane where they will show up directly. For applications that require extremely low scattering of light, extremely high reflectance, or low absorption due to high energy levels that could destroy the mirror, such as lasers or Fabry-Perot interferometers, the surface defects must be kept to a minimum.[
]
Manufacturing
Mirrors are usually manufactured by either polishing a naturally reflective material, such as speculum metal, or by applying a reflective coating
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The ' ...
to a suitable polished substrate.[
In some applications, generally those that are cost-sensitive or that require great durability, such as for mounting in a prison cell, mirrors may be made from a single, bulk material such as polished metal. However, metals consist of small crystals (grains) separated by grain boundaries that may prevent the surface from attaining optical smoothness and uniform reflectivity.][
]
Coating
Silvering
The coating of glass with a reflective layer of a metal is generally called "silvering
Silvering is the chemical process of coating a non-conductive substrate such as glass with a reflective substance, to produce a mirror. While the metal is often silver, the term is used for the application of any reflective metal.
Process
Mos ...
", even though the metal may not be silver. Currently the main processes are electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ...
, "wet" chemical deposition, and vacuum deposition
Vacuum deposition is a group of processes used to deposit layers of material atom-by-atom or molecule-by-molecule on a solid surface. These processes operate at pressures well below atmospheric pressure (i.e., vacuum). The deposited layers can r ...
[ Front-coated metal mirrors achieve reflectivities of 90–95% when new.
]
Dielectric coating
Applications requiring higher reflectivity or greater durability, where wide bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
is not essential, use dielectric coatings, which can achieve reflectivities as high as 99.997% over a limited range of wavelengths. Because they are often chemically stable and do not conduct electricity, dielectric coatings are almost always applied by methods of vacuum deposition, and most commonly by evaporation deposition. Because the coatings are usually transparent, absorption losses are negligible. Unlike with metals, the reflectivity of the individual dielectric-coatings is a function of Snell's law
Snell's law (also known as Snell–Descartes law and ibn-Sahl law and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through ...
known as the Fresnel equations
The Fresnel equations (or Fresnel coefficients) describe the reflection and transmission of light (or electromagnetic radiation in general) when incident on an interface between different optical media. They were deduced by Augustin-Jean Fresne ...
, determined by the difference in refractive index
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium.
The refractive index determines how much the path of light is bent, or ...
between layers. Therefore, the thickness and index of the coatings can be adjusted to be centered on any wavelength. Vacuum deposition can be achieved in a number of ways, including sputtering, evaporation deposition, arc deposition, reactive-gas deposition, and ion plating, among many others.[
]
Shaping and polishing
Tolerances
Mirrors can be manufactured to a wide range of engineering tolerance
Engineering tolerance is the permissible limit or limits of variation in:
# a physical dimension;
# a measured value or physical property of a material, manufactured object, system, or service;
# other measured values (such as temperature, hum ...
s, including reflectivity
The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the electronic ...
, surface quality, surface roughness
Surface roughness, often shortened to roughness, is a component of surface finish (surface texture). It is quantified by the deviations in the direction of the normal vector of a real surface from its ideal form. If these deviations are large, ...
, or transmissivity, depending on the desired application. These tolerances can range from wide, such as found in a normal household-mirror, to extremely narrow, like those used in lasers or telescopes. Tightening the tolerances allows better and more precise imaging or beam transmission over longer distances. In imaging systems this can help reduce anomalies ( artifacts), distortion or blur, but at a much higher cost. Where viewing distances are relatively close or high precision is not a concern, wider tolerances can be used to make effective mirrors at affordable costs.
Applications
Personal grooming
Mirrors are commonly used as aids to personal grooming
Grooming (also called preening) is the art and practice of cleaning and maintaining parts of the body. It is a species-typical behavior.
In animals
Individual animals regularly clean themselves and put their fur, feathers or other skin cove ...
.[ They may range from small sizes (portable), to full body sized; they may be handheld, mobile, fixed or adjustable. A classic example of an adjustable mirror is the ]cheval glass
A mirror or looking glass is an object that reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the im ...
, which the user can tilt.
Safety and easier viewing
;Convex mirrors
:Convex mirrors provide a wider field of view
The field of view (FoV) is the extent of the observable world that is seen at any given moment. In the case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation.
Humans a ...
than flat mirrors,[ and are often used on vehicles,][ especially large trucks, to minimize blind spots. They are sometimes placed at ]road junction
A junction is where two or more roads meet.
History
Roads began as a means of linking locations of interest: towns, forts and geographic features such as river fords. Where roads met outside of an existing settlement, these junctions often led ...
s, and at corners of sites such as parking lot
A parking lot (American English) or car park (British English), also known as a car lot, is a cleared area intended for parking vehicles. The term usually refers to an area dedicated only for parking, with a durable or semi-durable surface ...
s to allow people to see around corners to avoid crashing into other vehicles or shopping cart
A shopping cart (American English), trolley (British English, Australian English), or buggy (Southern American English, Appalachian English), also known by a variety of other names, is a wheeled cart supplied by a shop or store, especially ...
s. They are also sometimes used as part of security systems, so that a single video camera
A video camera is an optical instrument that captures videos (as opposed to a movie camera, which records images on film). Video cameras were initially developed for the television industry but have since become widely used for a variety of other ...
can show more than one angle
In Euclidean geometry, an angle is the figure formed by two Ray (geometry), rays, called the ''Side (plane geometry), sides'' of the angle, sharing a common endpoint, called the ''vertex (geometry), vertex'' of the angle.
Angles formed by two ...
at a time. Convex mirrors as decoration are used in interior design to provide a predominantly experiential effect.[
;]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 No. 4 (⌀ 18 mm) and No. 5 (⌀ 20 mm). A No. 2 is sometimes used when a smaller mirr ...
s or "dental mirrors"
:Dentists use mouth mirrors or "dental mirrors" 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 ]mechanic
A mechanic is an artisan, skilled tradesperson, or technician who uses tools to build, maintain, or repair machinery, especially cars.
Duties
Most mechanics specialize in a particular field, such as auto body mechanics, air conditioning and r ...
s to allow vision in tight spaces and around corners in equipment.
;Rear-view mirror
A rear-view mirror (or rearview mirror) is a flat mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's rear window (rear windshield).
In cars, the rear-view mirror is usually affixed to ...
s
:Rear-view mirrors are widely used in and on vehicles (such as automobiles, or bicycles), to allow drivers to see other vehicles coming up behind them.[ On rear-view sunglasses, the left end of the left glass and the right end of the right glass work as mirrors.
]
One-way mirrors and windows
;One-way mirrors
:One-way mirrors (also called two-way mirrors) work by overwhelming dim transmitted light with bright reflected light.[ A true one-way mirror that actually allows light to be transmitted in one direction only without requiring external energy is not possible as it violates the ]second law of thermodynamics
The second law of thermodynamics is a physical law based on universal experience concerning heat and Energy transformation, energy interconversions. One simple statement of the law is that heat always moves from hotter objects to colder objects ( ...
.:
;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 on a clear day. Native American tribes and numerous militaries
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...
used this technique to transmit information between distant outposts.
Mirrors can also be used to attract the attention of search-and-rescue
Search and rescue (SAR) is the search for and provision of aid to people who are in distress or imminent danger. The general field of search and rescue includes many specialty sub-fields, typically determined by the type of terrain the search ...
parties. Specialized types of mirrors are available and are often included in military survival kit
A survival kit is a package of basic tools and supplies prepared as an aid to survival in an emergency. Civil and military aircraft, lifeboats, and spacecraft are equipped with survival kits.
Survival kits, in a variety of sizes, contain supp ...
s.
Technology
Televisions and projectors
Microscopic mirrors are a core element of many of the largest high-definition televisions and video projector
A video projector is an image projector that receives a video signalling (telecommunication), signal and projects the corresponding image on a projection screen using a lens (optics), lens system. Video projectors use a very bright ultra-high-per ...
s. A common technology of this type is Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globall ...
' 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
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device.
In most digital display devices, pixels are the smal ...
on), or toward a light-absorbing surface (pixel off).
Other projection technologies involving mirrors include LCoS
Liquid crystal on silicon (LCoS or LCOS) is a miniaturized reflective active-matrix liquid-crystal display or "microdisplay" using a liquid crystal layer on top of a silicon backplane. It is also referred to as a spatial light modulator. LCoS was ...
. 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 (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. T ...
matrix with up to millions of pixels
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device.
In most digital display devices, pixels are the sm ...
. The picture, formed as light, is either reflected toward the projection surface (pixel on), or absorbed by the activated LCD
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but in ...
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 discussed above) is "folded" by one or more mirrors so that the television set is compact.
Solar power
Mirrors are integral parts of a solar power
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovoltaic e ...
plant. The one shown in the adjacent picture uses concentrated solar power
Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver. Electricity is generated when ...
from an array of parabolic trough
A parabolic trough is a type of solar thermal collector that is straight in one dimension and curved as a parabola in the other two, lined with a polished metal mirror. The sunlight which enters the mirror parallel to its plane of symmetry is foc ...
s.[
]
Instruments
Telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...
s and other precision instruments use ''front silvered'' or first surface mirrors, where the reflecting surface is placed on the front (or first) surface of the glass (this eliminates reflection from glass surface ordinary back mirrors have). Some of them use silver, but most are aluminium, which is more reflective at short wavelengths than silver.
All of these coatings are easily damaged and require special handling.
They reflect 90% to 95% of the incident light when new.
The coatings are typically applied by vacuum deposition
Vacuum deposition is a group of processes used to deposit layers of material atom-by-atom or molecule-by-molecule on a solid surface. These processes operate at pressures well below atmospheric pressure (i.e., vacuum). The deposited layers can r ...
.
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 air. ''Front silvered'' mirrors have to be resurfaced occasionally to maintain their quality. There are optical mirrors such as 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 if certain conditions are met. This reflector was invented i ...
s that are ''second surface mirrors'' (reflective coating on the rear surface) as part of their optical designs, usually to correct optical aberration
In optics, aberration is a property of optical systems, such as lenses, that causes light to be spread out over some region of space rather than focused to a point. Aberrations cause the image formed by a lens to be blurred or distorted, with th ...
s.[
]
The reflectivity of the mirror coating can be measured using a reflectometer and for a particular metal it will be different for different wavelengths of light. This is exploited in some optical
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviole ...
work to make 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 ...
s and 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. Hot mirrors can be designed to be inserte ...
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 (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
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, aluminium 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 is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviole ...
work, dielectric mirror
A dielectric mirror, also known as a Bragg mirror, is a type of 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 thickne ...
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 laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
s.
In astronomy, adaptive optics
Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion. It is used in astronomical tele ...
is a technique to measure variable image distortions and adapt a deformable mirror
Deformable mirrors (DM) are mirrors whose surface can be deformed, in order to achieve wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in ada ...
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
In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) lig ...
are used in
optics and astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...
. Mirrors for radio waves (sometimes known as reflectors) are important elements of radio telescope
A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency ...
s.
Simple periscope
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.
In its simplest form, it consists of an outer case with ...
s use mirrors.
Face-to-face mirrors
Two or more mirrors aligned exactly parallel and facing each other can give an infinite regress of reflections, called an infinity mirror
The infinity mirror (also sometimes called an infinite mirror) is a configuration of two or more parallel or nearly parallel mirrors, creating a series of smaller and smaller reflections that appear to recede to infinity. Often the front mirror ...
effect. Some devices use this to generate multiple reflections:
* Fabry–Pérot interferometer
In optics, a Fabry–Pérot interferometer (FPI) or etalon is an optical cavity made from two parallel reflecting surfaces (i.e.: thin mirrors). Optical waves can pass through the optical cavity only when they are in resonance with it. It is ...
* Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
(which contains an optical cavity An optical cavity, resonating cavity or optical resonator is an arrangement of mirrors or other optical elements that forms a cavity resonator for light waves. Optical cavities are a major component of lasers, surrounding the gain medium and provi ...
)
* 3D Kaleidoscope
A kaleidoscope () is an optical instrument with two or more reflecting surfaces (or mirrors) tilted to each other at an angle, so that one or more (parts of) objects on one end of these mirrors are shown as a regular symmetrical pattern when v ...
to concentrate light[
* momentum-enhanced ]solar sail
Solar sails (also known as light sails and photon sails) are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A number of spaceflight missions to test solar propulsion and navigation have been p ...
[
]
Military applications
Tradition states that Archimedes
Archimedes of Syracuse (;; ) was a Greek mathematician, physicist, engineer, astronomer, and inventor from the ancient city of Syracuse in Sicily. Although few details of his life are known, he is regarded as one of the leading scientists ...
used a large array of mirrors to burn Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*''Epistle to the Romans'', shortened to ''Romans'', a letter ...
ships during an attack on Syracuse. This has never been proven or disproved. On the TV show ''MythBusters
''MythBusters'' is a science entertainment television program, developed by Peter Rees and produced by Australia's Beyond Television Productions. The series premiered on the Discovery Channel on January 23, 2003. It was broadcast internatio ...
'', a team from MIT
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the mo ...
tried to recreate the famous "Archimedes Death Ray". They were unsuccessful at starting a fire on a ship.[ Previous attempts to set a 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; such a scenario could have impeded attackers and have provided the origin of the legend. (See ]solar power tower
A solar power tower, also known as 'central tower' power plant or 'heliostat' power plant, is a type of solar furnace using a tower to receive focused sunlight. It uses an array of flat, movable mirrors (called heliostats) to focus the sun's ra ...
for a practical use of this technique.)
Seasonal lighting
Due to its location in a steep-sided valley, the Italian town of Viganella Viganella in 2005.
Viganella is a ''frazione'' of Borgomezzavalle, a ''comune'' (municipality) in the Province of Verbano-Cusio-Ossola in the Italian region Piedmont, located about northeast of Turin and about northwest of Verbania. It was a s ...
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 ( rm, ) is a village and a former municipalities of Switzerland, municipality in the district of Maloja (district), Maloja in the Switzerland, Swiss Cantons of Switzerland, canton of Grisons. It is now part of the municipality of Bregagli ...
, was considering applying this solution as well.[ In 2013, mirrors were installed to reflect sunlight into the town square in the Norwegian town of ]Rjukan
Rjukan () is a town and the administrative centre of Tinn municipality in Telemark, Norway. It is situated in Vestfjorddalen, between Møsvatn and Lake Tinn, and got its name after Rjukan Falls west of the town. The Tinn municipality council grant ...
.[ Mirrors can be used to produce enhanced lighting effects in greenhouses or conservatories.
]
Architecture
Mirrors are a popular design-theme in architecture, particularly with late modern and post-modernist
Postmodernism is an intellectual stance or mode of discourseNuyen, A.T., 1992. The Role of Rhetorical Devices in Postmodernist Discourse. Philosophy & Rhetoric, pp.183–194. characterized by skepticism toward the " grand narratives" of moderni ...
high-rise buildings in major cities. Early examples include the Campbell Center in Dallas
Dallas () is the List of municipalities in Texas, third largest city in Texas and the largest city in the Dallas–Fort Worth metroplex, the List of metropolitan statistical areas, fourth-largest metropolitan area in the United States at 7.5 ...
, which opened in 1972,[ and the ]John Hancock Tower
200 Clarendon Street, previously John Hancock Tower and colloquially known as The Hancock, is a 60-story, skyscraper in the Back Bay neighborhood of Boston. It is the tallest building in New England. The tower was designed by Henry N. Cobb of ...
(completed in 1976) in Boston.
More recently, two skyscrapers designed by architect Rafael Viñoly
Rafael Viñoly Beceiro (born 1944) is a Uruguayan architect. He is the principal of Rafael Viñoly Architects, which he founded in 1983. The firm has offices in New York City, Palo Alto, London, Manchester, Abu Dhabi, and Buenos Aires.
Viñ ...
, the Vdara
Vdara Hotel & Spa ( ) is a condo-hotel and spa located within the CityCenter complex across from Aria Resort & Casino on the Las Vegas Strip. Vdara opened on December 1, 2009 as a joint venture between MGM Resorts International and Infinity Wo ...
in Las Vegas and 20 Fenchurch Street
20 Fenchurch Street is a commercial skyscraper in London that takes its name from its address on Fenchurch Street, in the historic City of London financial district. It has been nicknamed "The Walkie-Talkie" because of its distinctive shape, ...
in London, have experienced unusual problems due to their concave curved-glass exteriors acting as respectively cylindrical and spherical reflectors for sunlight. In 2010, the ''Las Vegas Review Journal'' reported that sunlight reflected off the Vdara's south-facing tower could singe swimmers in the hotel pool, as well as melting plastic cups and shopping bags; employees of the hotel referred to the phenomenon as the "Vdara death ray",[ aka the "]fryscraper
20 Fenchurch Street is a commercial skyscraper in London that takes its name from its address on Fenchurch Street, in the historic City of London financial district. It has been nicknamed "The Walkie-talkie, Walkie-Talkie" because of its disti ...
." In 2013, sunlight reflecting off 20 Fenchurch Street melted parts of a Jaguar car
Jaguar (, ) is the luxury vehicle brand of Jaguar Land Rover, a British multinational corporation, multinational automaker, car manufacturer with its headquarters in Whitley, Coventry, England. Jaguar Cars was the company that was responsibl ...
parked nearby and scorching or igniting the carpet of a nearby barber-shop.[ This building had been nicknamed the "walkie-talkie" because its shape was supposedly similar to a certain model of two-way radio; but after its tendency to overheat surrounding objects became known, the nickname changed to the "walkie-scorchie".
]
Fine art
Paintings
Painters depicting someone gazing into a mirror often also show the person's reflection. This is a kind of abstraction—in most cases the angle of view is such that the person's reflection should not be visible. Similarly, in movies and still photography an actor or actress is often shown ostensibly looking at him- or herself in a 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. In the psychology of perception, this is known as the Venus effect
The 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'' ...
.
The mirror is the central device in some of the greatest of European paintings:
* Édouard Manet
Édouard Manet (, ; ; 23 January 1832 – 30 April 1883) was a French modernist painter. He was one of the first 19th-century artists to paint modern life, as well as a pivotal figure in the transition from Realism to Impressionism.
Born ...
's ''A Bar at the Folies-Bergère
''A Bar at the Folies-Bergère'' (french: Un bar aux Folies Bergère) is a painting by Édouard Manet, considered to be his last major work. It was painted in 1882 and exhibited at the Paris Salon of that year. It depicts a scene in the Folies B ...
'' (1882)
* Titian
Tiziano Vecelli or Vecellio (; 27 August 1576), known in English as Titian ( ), was an Italians, Italian (Republic of Venice, Venetian) painter of the Renaissance, considered the most important member of the 16th-century Venetian school (art), ...
's ''Venus with a Mirror
''Venus with a Mirror'' (c. 1555) is a painting by Titian, now in the National Gallery of Art in Washington, DC, and it is considered to be one of the collection's highlights.
The pose of the Venus resembles the classical statues of the Venus de' ...
''
* Jan van Eyck
Jan van Eyck ( , ; – July 9, 1441) was a painter active in Bruges who was one of the early innovators of what became known as Early Netherlandish painting, and one of the most significant representatives of Early Northern Renaissance art. Ac ...
's ''Arnolfini Portrait
''The Arnolfini Portrait'' (or ''The Arnolfini Wedding'', ''The Arnolfini Marriage'', the ''Portrait of Giovanni Arnolfini and his Wife'', or other titles) is a 1434 oil painting on oak panel by the Early Netherlandish painter Jan van Eyck. It fo ...
''
* Pablo Picasso
Pablo Ruiz Picasso (25 October 1881 – 8 April 1973) was a Spanish painter, sculptor, printmaker, ceramicist and Scenic design, theatre designer who spent most of his adult life in France. One of the most influential artists of the 20th ce ...
's ''Girl before a Mirror
''Girl before a Mirror'' is an oil on canvas painting by Pablo Picasso, which he created in 1932. The painting is a portrait of Picasso's mistress and muse, Marie-Thérèse Walter, who is depicted standing in front of a mirror looking at her ref ...
'' (1932)
* Diego Velázquez
Diego Rodríguez de Silva y Velázquez (baptized June 6, 1599August 6, 1660) was a Spanish painter, the leading artist in the court of King Philip IV of Spain and Portugal, and of the Spanish Golden Age. He was an individualistic artist of th ...
's ''Rokeby Venus
The ''Rokeby Venus'' (; also known as ''The Toilet of Venus'', ''Venus at her Mirror'', ''Venus and Cupid'', or '' La Venus del espejo'') is a painting by Diego Velázquez, the leading artist of the Spanish Golden Age. Completed between 1647 ...
''
* Diego Velázquez
Diego Rodríguez de Silva y Velázquez (baptized June 6, 1599August 6, 1660) was a Spanish painter, the leading artist in the court of King Philip IV of Spain and Portugal, and of the Spanish Golden Age. He was an individualistic artist of th ...
's ''Las Meninas
''Las Meninas'' (; ) is a 1656 painting in the Museo del Prado in Madrid, by Diego Velázquez, the leading artist of the Spanish Golden Age. It has become one of the most widely analyzed works in Western painting, due to the way its complex an ...
'' (wherein the viewer is both the watcher - of a self-portrait in progress - and the watched) and the many adaptations of that painting in various media
* Veronese's ''Venus with a Mirror''
Artists have used mirrors to create works and to hone their craft:
* Filippo Brunelleschi
Filippo Brunelleschi ( , , also known as Pippo; 1377 – 15 April 1446), considered to be a founding father of Renaissance architecture, was an Italian architect, designer, and sculptor, and is now recognized to be the first modern engineer, p ...
discovered linear perspective with the help of the mirror.[
* ]Leonardo da Vinci
Leonardo di ser Piero da Vinci (15 April 14522 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, Drawing, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially res ...
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
A self-portrait is a representation of an artist that is drawn, painted, photographed, or sculpted by that artist. Although self-portraits have been made since the earliest times, it is not until the Early Renaissance in the mid-15th century tha ...
are made possible through the use of mirrors, such as great self-portraits by Dürer, Frida Kahlo
Magdalena Carmen Frida Kahlo y Calderón (; 6 July 1907 – 13 July 1954) was a Mexican painter known for her many portraits, self-portraits, and works inspired by the nature and artifacts of Mexico. Inspired by the country's popular culture, ...
, Rembrandt
Rembrandt Harmenszoon van Rijn (, ; 15 July 1606 – 4 October 1669), usually simply known as Rembrandt, was a Dutch Golden Age painter, printmaker and draughtsman. An innovative and prolific master in three media, he is generally consid ...
, and Van Gogh
Vincent Willem van Gogh (; 30 March 185329 July 1890) was a Dutch Post-Impressionist painter who posthumously became one of the most famous and influential figures in Western art history. In a decade, he created about 2,100 artworks, inclu ...
. M. C. Escher
Maurits Cornelis Escher (; 17 June 1898 – 27 March 1972) was a Dutch graphic artist who made mathematically inspired woodcuts, lithographs, and mezzotints.
Despite wide popular interest, Escher was for most of his life neglected in t ...
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
''Hand with Reflecting Sphere'', also known as ''Self-Portrait in Spherical Mirror'', is a lithograph by Dutch artist M. C. Escher, first printed in January 1935. The piece depicts a hand holding a reflective sphere. In the reflection, most ...
'' (1935; also known as ''Self-Portrait in Spherical Mirror'').
Mirrors are sometimes necessary to fully appreciate art work:
* István Orosz
István Orosz (born 24 October 1951) is a Hungarian painter, printmaker, graphic designer and animated film director. He is known for his mathematically inspired works, impossible objects, optical illusions, double-meaning images and anamorphosis, ...
's anamorphic
Anamorphic format is the cinematography technique of shooting a widescreen picture on standard 35 mm film or other visual recording media with a non-widescreen native aspect ratio. It also refers to the projection format in which a distorted ...
works are images distorted such that they only become clearly visible when reflected in a suitably shaped and positioned mirror.[
]
Sculpture
* Anamorphosis
Anamorphosis is a distorted projection requiring the viewer to occupy a specific vantage point, use special devices, or both to view a recognizable image. It is used in painting, photography, sculpture and installation, toys, and film special e ...
projecting sculpture into mirrors
Contemporary anamorphic artist Jonty Hurwitz
Jonty Hurwitz (born 2 September 1969 in Johannesburg) is a British South African artist, engineer and entrepreneur. Hurwitz creates scientifically inspired artworks and anamorphic sculptures. He is recognised for the smallest human form ever ...
uses cylindrical
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
mirrors to project distorted sculptures.[
* Sculptures comprised entirely or in part of mirrors include:
** '' Infinity Also Hurts'', a mirror, glass and ]silicone
A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking ...
sculpture by artist Seth Wulsin
Seth Wulsin (born April 15, 1981 in Spring Valley, NY) is an independent journalist and contemporary artist working primarily with space, time and light through large-scale, site-specific, ephemeral sculpture, drawing and architectural perform ...
** ''Sky Mirror
''Sky Mirror'' is a public sculpture by artist Anish Kapoor. Commissioned by the Nottingham Playhouse, it is installed outside the theatre in Wellington Circus, Nottingham, England. ''Sky Mirror'' is a -wide concave lens, concave dish of poli ...
'', a public sculpture
Public art is art in any media whose form, function and meaning are created for the general public through a public process. It is a specific art genre with its own professional and critical discourse. Public art is visually and physically access ...
by artist Anish Kapoor
Sir Anish Mikhail Kapoor (born 12 March 1954) is a British-Indian sculptor specializing in installation art and conceptual art. Born in Mumbai, Kapoor attended the elite all-boys Indian boarding school The Doon School, before moving to the UK ...
Other artistic mediums
Some other contemporary artists use mirrors as the material of art:
* A Chinese magic mirror
The Chinese magic mirror () traces back to at least the 5th century, although their existence during the Han dynasty (206 BC – 24 AD) has been claimed. The mirrors were made out of solid bronze. The front was polished and could be used as a mi ...
is a device in which the face of the bronze mirror projects the same image that was cast on its back. This is due to minute curvatures on its front.[
* ]Specular holography Specular holography is a technique for making three dimensional imagery by controlling the motion of Specularity, specular glints on a two-dimensional surface. The image is made of many specularities and has the appearance of a Stereoscopy, 3D surfa ...
uses a large number of curved mirrors embedded in a surface to produce three-dimensional imagery.
* Paintings on mirror surfaces (such as silkscreen printed glass mirrors)
* Special mirror installations:
** ''Follow Me'' mirror labyrinth by artist, Jeppe Hein
Jeppe Hein (born 1974, Copenhagen, Denmark) is an artist based in Berlin and Copenhagen.[Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...](_blank)
mirrors existed in various shapes for multiple uses. Mostly they were used as an accessory for personal hygiene but also as tokens of courtly love, made from ivory
Ivory is a hard, white material from the tusks (traditionally from elephants) and teeth of animals, that consists mainly of dentine, one of the physical structures of teeth and tusks. The chemical structure of the teeth and tusks of mammals is ...
in the ivory-carving centers in Paris, Cologne and the Southern Netherlands.[ They also had their uses in religious contexts as they were integrated in a special form of pilgrims badges or pewter/lead mirror boxes][ From the late 14th century. Burgundian ducal inventories show us that the dukes owned a mass of mirrors or objects with mirrors, not only with religious iconography or inscriptions, but combined with reliquaries, religious paintings or other objects that were distinctively used for personal piety.][ Considering mirrors in paintings and book illumination as depicted artifacts and trying to draw conclusions about their functions from their depicted setting, one of these functions is to be an aid in personal prayer to achieve self-knowledge and knowledge of God, in accord with contemporary theological sources. For example, the famous ]Arnolfini
Arnolfini is an international arts centre and gallery in Bristol, England. It has a programme of contemporary art exhibitions, artist's performance, music and dance events, poetry and book readings, talks, lectures and cinema. There is also a ...
-Wedding by Jan van Eyck
Jan van Eyck ( , ; – July 9, 1441) was a painter active in Bruges who was one of the early innovators of what became known as Early Netherlandish painting, and one of the most significant representatives of Early Northern Renaissance art. Ac ...
shows a constellation of objects that can be recognized as one which would allow a praying man to use them for his personal piety: the mirror surrounded by scenes of the Passion to reflect on it and on oneself, a rosary
The Rosary (; la, , in the sense of "crown of roses" or "garland of roses"), also known as the Dominican Rosary, or simply the Rosary, refers to a set of prayers used primarily in the Catholic Church, and to the physical string of knots or b ...
as a device in this process, the veiled and cushioned bench to use as a prie-dieu
A prie-dieu ( French: literally, "pray oGod") is a type of prayer desk primarily intended for private devotional use, but which may also be found in churches. A similar form of chair in domestic furniture is called "prie-dieu" by analogy. S ...
, and the abandoned shoes that point in the direction in which the praying man kneeled.[ The metaphorical meaning of depicted mirrors is complex and many-layered, e.g. as an attribute of ]Mary
Mary may refer to:
People
* Mary (name), a feminine given name (includes a list of people with the name)
Religious contexts
* New Testament people named Mary, overview article linking to many of those below
* Mary, mother of Jesus, also calle ...
, the "speculum sine macula" (mirror without blemish), or as attributes of scholarly and theological wisdom and knowledge as they appear in book illuminations of different evangelists
Evangelists may refer to:
* Evangelists (Christianity), Christians who specialize in evangelism
* Four Evangelists, the authors of the four Gospel accounts in the New Testament
* ''The Evangelists
''The Evangelists'' (''Evangheliştii'' in Roma ...
and authors of theological treatises. Depicted mirrors – orientated on the physical properties of a real mirror – can be seen as metaphors of knowledge and reflection and are thus able to remind beholders to reflect and get to know themselves. The mirror may function simultaneously as a symbol and as a device of a moral appeal. That is also the case if it is shown in combination with virtues and vices, a combination which also occurs more frequently in the 15th century: the moralizing layers of mirror metaphors remind the beholder to examine himself thoroughly according to his own virtuous or vicious life. This is all the more true if the mirror is combined with iconography of death. Not only is Death as a corpse or skeleton holding the mirror for the still-living personnel of paintings, illuminations and prints, but the skull appears on the convex surfaces of depicted mirrors, showing the painted and real beholder his future face.[
]
Decoration
Mirrors are frequently used in interior decoration
Interior design is the art and science of enhancing the interior of a building to achieve a healthier and more aesthetically pleasing environment for the people using the space. An interior designer is someone who plans, researches, coordina ...
and as ornaments:
* Mirrors, typically large and unframed, are frequently used in interior decoration
Interior design is the art and science of enhancing the interior of a building to achieve a healthier and more aesthetically pleasing environment for the people using the space. An interior designer is someone who plans, researches, coordina ...
to create an illusion of space and to amplify the apparent size of a room.[ They come also framed in a variety of forms, such as the ]pier glass
A pier glass or trumeau mirror 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 mirro ...
and the overmantel mirror.
* Mirrors are used also in some schools of feng shui, an ancient Chinese
Chinese can refer to:
* Something related to China
* Chinese people, people of Chinese nationality, citizenship, and/or ethnicity
**''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation
** List of ethnic groups in China, people of va ...
practice of placement and arrangement of space to achieve harmony with an environment
Environment most often refers to:
__NOTOC__
* Natural environment, all living and non-living things occurring naturally
* Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...
.
* The softness of old mirrors is sometimes replicated by contemporary artisans for use in interior design
Interior design is the art and science of enhancing the interior of a building to achieve a healthier and more aesthetically pleasing environment for the people using the space. An interior designer is someone who plans, researches, coordina ...
. These reproduction antiqued mirrors are works of art and can bring color and texture to an otherwise hard, cold reflective surface.
* A decorative reflecting sphere
A sphere () is a Geometry, geometrical object that is a solid geometry, three-dimensional analogue to a two-dimensional circle. A sphere is the Locus (mathematics), set of points that are all at the same distance from a given point in three ...
of thin metal-coated glass, working as a reducing wide-angle mirror, is sold as a Christmas ornament
Christmas ornaments, baubles, "Christmas bulbs" or "Christmas bubbles" are decoration items, usually to decorate Christmas trees. These decorations may be woven, blown (glass or plastic), molded (ceramic or metal), carved from wood or expande ...
called a ''bauble''.
* Some pubs and bars hang mirrors depicting the logo of a brand of liquor, beer or drinking establishment.
Entertainment
* Illuminated rotating disco ball
A disco ball (also known as a mirror ball or glitter ball) is a roughly spherical object that reflects light directed at it in many directions, producing a complex display. Its surface consists of hundreds or thousands of facets, nearly all of ...
s covered with small mirrors are used to cast moving spots of light around a dance floor.
* The hall of mirrors, commonly found in amusement park
An amusement park is a park that features various attractions, such as rides and games, as well as other events for entertainment purposes. A theme park is a type of amusement park that bases its structures and attractions around a central ...
s, is an attraction in which a number of distorting mirror
A distorting mirror, funhouse mirror or carnival mirror is a popular attraction at carnivals and fairs. Instead of a normal plane mirror that reflects a perfect mirror image, distorting mirrors are curved mirrors, often using convex and concave sec ...
s produce unusual reflections of the visitor.
* Mirrors are employed in kaleidoscope
A kaleidoscope () is an optical instrument with two or more reflecting surfaces (or mirrors) tilted to each other at an angle, so that one or more (parts of) objects on one end of these mirrors are shown as a regular symmetrical pattern when v ...
s, personal entertainment-devices invented in Scotland
Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
by Sir David Brewster
Sir David Brewster KH PRSE FRS FSA Scot FSSA MICE (11 December 178110 February 1868) was a British scientist, inventor, author, and academic administrator. In science he is principally remembered for his experimental work in physical optics ...
.
* Mirrors are often used in magic to create an illusion
An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people.
Illusions may o ...
. One effect is called Pepper's ghost
Pepper's ghost is an illusion technique used in the theatre, cinema, amusement parks, museums, television, and concerts.
It is named after the English scientist John Henry Pepper (1821–1900) who began popularising the effect with a theatre ...
.
* Mirror maze
A maze is a path or collection of paths, typically from an entrance to a goal. The word is used to refer both to branching tour puzzles through which the solver must find a route, and to simpler non-branching ("unicursal") patterns that lea ...
s, often found in amusement park
An amusement park is a park that features various attractions, such as rides and games, as well as other events for entertainment purposes. A theme park is a type of amusement park that bases its structures and attractions around a central ...
s , 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 Plexiglas
Poly(methyl methacrylate) (PMMA) belongs to a group of materials called engineering plastics. It is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Plexiglas, Acrylite, ...
to prevent breakages.[
]
Film and television
Mirrors appear in many movies and TV shows:
*''Black Swan
The black swan (''Cygnus atratus'') is a large waterbird, a species of swan which breeds mainly in the southeast and southwest regions of Australia. Within Australia, the black swan is nomadic, with erratic migration patterns dependent upon c ...
'' is a psychological horror
Psychological horror is a genre, subgenre of horror fiction, horror and psychological fiction with a particular focus on mental, emotional, and Mental state, psychological states to frighten, disturb, or unsettle its audience. The subgenre frequent ...
film that frequently incorporates mirrors. Fractured mirrors are prominent in the film, and the character Nina stabs herself with a broken piece of mirror.
* ''Candyman'' is a horror film about a malevolent spirit
In mythology and folklore, a vengeful ghost or vengeful spirit is said to be the spirit of a dead person who returns from the afterlife to seek revenge for a cruel, unnatural or unjust death. In certain cultures where funeral and burial or crema ...
summoned by speaking its name in front of a mirror.
* ''Conan the Destroyer
''Conan the Destroyer'' is a 1984 American epic sword and sorcery film directed by Richard Fleischer from a screenplay by Stanley Mann and a story by Roy Thomas and Gerry Conway. Based on the character Conan the Barbarian created by Robert E. ...
'' features a mirror-embedded chamber deep within Thoth-Amon's castle. The mirrors are first used in an illusory fashion to deceive Conan once he is separated by his companions, and during a battle sequence it is discovered that by breaking the mirrors he is able to damage and eventually defeat the otherwise-invulnerable wizard Thoth-Amon.
*''Dead of Night
''Dead of Night'' is a 1945 black and white British anthology horror film, made by Ealing Studios. The individual segments were directed by Alberto Cavalcanti, Charles Crichton, Basil Dearden and Robert Hamer. It stars Mervyn Johns, Googie Wi ...
'' is an anthology
In book publishing, an anthology is a collection of literary works chosen by the compiler; it may be a collection of plays, poems, short stories, songs or excerpts by different authors.
In genre fiction, the term ''anthology'' typically categ ...
horror film with one segment titled "The Haunted Mirror," in which a mirror casts a murderous spell.
*''Doctor Strange
Doctor Stephen Strange is a fictional character appearing in American comic books published by Marvel Comics. Created by Steve Ditko, the character first appeared in ''Strange Tales'' #110 (cover-dated July 1963). Doctor Strange serves as Sorce ...
'', ''Doctor Strange in the Multiverse of Madness
''Doctor Strange in the Multiverse of Madness'' is a 2022 American superhero film based on Marvel Comics featuring the character Doctor Strange. Produced by Marvel Studios and distributed by Walt Disney Studios Motion Pictures, it is the sequel ...
'', and '' Spider-Man: No Way Home'' feature the fictional mirror dimension
The Marvel Cinematic Universe (MCU) media franchise features many fictional elements including locations, weapons, and artifacts. While many of these features are based on elements that originally appeared in the American comic books publishe ...
, a parallel dimension in the Marvel Universe
The Marvel Universe is a fictional shared universe where the stories in most American comic book titles and other media published by Marvel Comics take place. Super-teams such as the Avengers, the X-Men, the Fantastic Four, the Guardians of ...
that reflects objects like a mirror, but in different directions.
*''Enter the Dragon
''Enter the Dragon'' ( zh, t=龍爭虎鬥) is a 1973 martial arts film directed by Robert Clouse and written by Michael Allin. The film stars Bruce Lee, John Saxon and Jim Kelly. It was Lee's final completed film appearance before his death o ...
s iconic and final fight scene occurs in a mirrored room. The mirrors create multiple reflections of the fight movements but are eventually smashed.
*''The Floorwalker
''The Floorwalker'' is a 1916 American silent comedy film, Charlie Chaplin's first Mutual Film Corporation film. The film stars Chaplin, in his traditional Tramp persona, as a customer who creates chaos in a department store and becomes inadve ...
'' and '' Duck Soup'' contain a mirror scene in which one person comically pretends to be the mirror reflection of someone else. This mirror scene has been imitated in other comedy films and TV shows.
*''Hamlet
''The Tragedy of Hamlet, Prince of Denmark'', often shortened to ''Hamlet'' (), is a tragedy written by William Shakespeare sometime between 1599 and 1601. It is Shakespeare's longest play, with 29,551 words. Set in Denmark, the play depicts ...
'' has a throne room with mirrored walls. Hamlet, played by Kenneth Branagh
Sir Kenneth Charles Branagh (; born 10 December 1960) is a British actor and filmmaker. Branagh trained at the Royal Academy of Dramatic Art in London and has served as its president since 2015. He has won an Academy Award, four BAFTAs (plus t ...
, gives his famous speech with the words "to be or not to be," looking into these mirrors.
* ''Harry Potter and the Philosopher's Stone'' includes the magical Mirror of Erised
A mirror or looking glass is an object that reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the im ...
.
*''Inception
''Inception'' is a 2010 science fiction action film written and directed by Christopher Nolan, who also produced the film with Emma Thomas, his wife. The film stars Leonardo DiCaprio as a professional thief who steals information by infiltr ...
'' contains mirrors created in a dream sequence. Ariadne creates two mirrors facing each other that form an infinite number of reflected mirrors.
*''Last Night in Soho
''Last Night in Soho'' is a 2021 British psychological horror film directed by Edgar Wright and co-written by Wright and Krysty Wilson-Cairns. It stars Thomasin McKenzie, Anya Taylor-Joy, Matt Smith, Rita Tushingham, Michael Ajao, Terence St ...
'' is a psychological horror movie with several mirror scenes. The character Ellie occasionally sees her mother's ghost in mirrors.
*''The Matrix
''The Matrix'' is a 1999 science fiction action film written and directed by the Wachowskis. It is the first installment in ''The Matrix'' film series, starring Keanu Reeves, Laurence Fishburne, Carrie-Anne Moss, Hugo Weaving, and Joe Pantolia ...
'' uses various reflections and mirrors throughout the film. Neo watches a broken mirror mend itself, and different objects create reflections.
* ''Mirror
A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...
'' is a drama film by Andrei Tarkovsky
Andrei Arsenyevich Tarkovsky ( rus, Андрей Арсеньевич Тарковский, p=ɐnˈdrʲej ɐrˈsʲenʲjɪvʲɪtɕ tɐrˈkofskʲɪj; 4 April 1932 – 29 December 1986) was a Russian filmmaker. Widely considered one of the greates ...
that includes several scenes with mirrors and several scenes shot in reflection.
*'' Mirror Mirror'' is a fantasy comedy film based on Snow White
"Snow White and the Seven Dwarfs" is a 19th-century German fairy tale that is today known widely across the Western world. The Brothers Grimm published it in 1812 in the first edition of their collection ''Grimms' Fairy Tales'' and numbered as Ta ...
that features a Mirror House and Mirror Queen.
* ''Mirrors'' is a horror film about haunted mirrors that reflect different scenes than those in front of them.
*''Persona
A persona (plural personae or personas), depending on the context, is the public image of one's personality, the social role that one adopts, or simply a fictional Character (arts), character. The word derives from Latin, where it originally ref ...
'' relies on mirror sequences to show how the two women, Bibi and Liv, reflect each other and become more alike.
* ''Poltergeist III
''Poltergeist III'' is a 1988 American supernatural horror film co-written and directed by Gary Sherman, and starring Tom Skerritt, Nancy Allen, and Lara Flynn Boyle in her film debut, with Heather O'Rourke and Zelda Rubinstein reprising their ...
'' features mirrors that do not reflect reality and which can be used as portals to an afterlife.
*'' Psycho'' by Alfred Hitchock has several shots with mirrors that reflect characters.
* ''Oculus'' is a horror film about a haunted mirror that causes people to hallucinate and commit acts of violence.
*''Orpheus
Orpheus (; Ancient Greek: Ὀρφεύς, classical pronunciation: ; french: Orphée) is a Thracian bard, legendary musician and prophet in ancient Greek religion. He was also a renowned poet and, according to the legend, travelled with Jaso ...
'' includes an important theme of mirrors in connection to aging and death.
*''Taxi Driver
''Taxi Driver'' is a 1976 American film directed by Martin Scorsese, written by Paul Schrader, and starring Robert De Niro, Jodie Foster, Cybill Shepherd, Harvey Keitel, Peter Boyle, Leonard Harris, and Albert Brooks. Set in a decaying and ...
'' has a notable scene with a mirror in which the character Travis, played by Robert De Niro
Robert Anthony De Niro Jr. ( , ; born August 17, 1943) is an American actor. Known for his collaborations with Martin Scorsese, he is considered to be one of the best actors of his generation. De Niro is the recipient of various accolades ...
, asks himself the famous line, "You talkin’ to me?"
*''The Lady from Shanghai
''The Lady from Shanghai'' is a 1947 American film noir directed by Orson Welles (uncredited) and starring Welles, his estranged wife Rita Hayworth, and Everett Sloane. It is based on the novel ''If I Die Before I Wake'' by Sherwood King.
Altho ...
'' has a climatic hall of mirrors scene that has become a trope
Trope or tropes may refer to:
Arts, entertainment, and media
* Trope (cinema), a cinematic convention for conveying a concept
* Trope (literature), a figure of speech or common literary device
* Trope (music), any of a variety of different things ...
in cinema narratives.
*''Raging Bull
''Raging Bull'' is a 1980 American biographical sports drama film directed by Martin Scorsese, produced by Robert Chartoff and Irwin Winkler and adapted by Paul Schrader and Mardik Martin from Jake LaMotta's 1970 memoir '' Raging Bull: My St ...
'' ends with the character Jake talking to himself in a mirror, a scene that was reused in ''Boogie Nights
''Boogie Nights'' is a 1997 American period comedy-drama film written and directed by Paul Thomas Anderson. It is set in Los Angeles's San Fernando Valley and focuses on a young nightclub dishwasher who becomes a popular star of pornographic fil ...
''.
*'' The Shining'' is a horror movie that includes several scenes with mirrors. Every time the character Jack encounters a ghost, a mirror is present.
* ''The 10th Kingdom
''The 10th Kingdom'' is an American fairytale fantasy miniseries written by Simon Moore and produced by Britain's Carnival Films, Germany's Babelsberg Film und Fernsehen, and the US's Hallmark Entertainment. It depicts the adventures of a young w ...
'' miniseries
A miniseries or mini-series is a television series that tells a story in a predetermined, limited number of episodes. "Limited series" is another more recent US term which is sometimes used interchangeably. , the popularity of miniseries format h ...
requires the characters to use a magic mirror to travel between New York City (the 10th Kingdom) and the Nine Kingdoms of fairy tale
A fairy tale (alternative names include fairytale, fairy story, magic tale, or wonder tale) is a short story that belongs to the folklore genre. Such stories typically feature magic (paranormal), magic, incantation, enchantments, and mythical ...
.
*''The Twilight Zone
''The Twilight Zone'' is an American media franchise based on the anthology television series created by Rod Serling. The episodes are in various genres, including fantasy, science fiction, absurdism, dystopian fiction, suspense, horror, su ...
'' episode " The Mirror" features a mirror that the character Clemente believes can provide visions and information about enemies.
*'' Us'' is a horror film that includes a girl seeing a doppelgänger
A doppelgänger (), a compound noun formed by combining the two nouns (double) and (walker or goer) (), doppelgaenger or doppelganger is a biologically unrelated look-alike, or a double, of a living person.
In fiction and mythology, a doppelg ...
of herself in a house of mirrors
A house of mirrors or hall of mirrors is a traditional attraction at funfairs (carnivals) 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 mirr ...
in a funhouse
A funhouse or fun house is an amusement facility found on amusement park and funfair midways and is where patrons encounter and interact with various devices designed to surprise, challenge, and amuse them. Unlike thrill rides or dark rides, fu ...
. The mirror images reflect the similarities in the clones throughout the film.
*''Vertigo
Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement. This may be associated with nausea, vomiting, sweating, or difficulties w ...
'' includes several appearances of mirrors with both Scottie and Madeleine in the frame.
Literature
Mirrors feature in literature:
* Christian Bible
The Bible (from Koine Greek , , 'the books') is a collection of religious texts or scriptures that are held to be sacred in Christianity, Judaism, Samaritanism, and many other religions. The Bible is an anthologya compilation of texts of a ...
passages, 1 Corinthians 13:12 (" Through a Glass Darkly") and 2 Corinthians 3:18, reference a dim mirror-image or poor mirror-reflection.
* Narcissus
Narcissus may refer to:
Biology
* ''Narcissus'' (plant), a genus containing daffodils and others
People
* Narcissus (mythology), Greek mythological character
* Narcissus (wrestler) (2nd century), assassin of the Roman emperor Commodus
* Tiberiu ...
of Greek mythology
A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical co ...
wastes away while gazing, self-admiringly, at his reflection in water.
* The Song-dynasty history ''Zizhi Tongjian
''Zizhi Tongjian'' () is a pioneering reference work in Chinese historiography, published in 1084 AD during the Northern Song dynasty in the form of a chronicle recording Chinese history from 403 BC to 959 AD, covering 16 dynast ...
'' ''Comprehensive Mirror in Aid of Governance'' by Sima Guang is so titled because "mirror" (鑑, jiàn) is used metaphorically in Chinese to refer to gaining insight by reflecting on past experience or history.
* In the European fairy tale
A fairy tale (alternative names include fairytale, fairy story, magic tale, or wonder tale) is a short story that belongs to the folklore genre. Such stories typically feature magic (paranormal), magic, incantation, enchantments, and mythical ...
, ''Snow White
"Snow White and the Seven Dwarfs" is a 19th-century German fairy tale that is today known widely across the Western world. The Brothers Grimm published it in 1812 in the first edition of their collection ''Grimms' Fairy Tales'' and numbered as Ta ...
'' (collected by the Brothers Grimm in 1812), the evil queen asks, "Mirror
A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...
, mirror, on the wall... who's the fairest of them all?"
* In the Aarne-Thompson-Uther Index tale type ATU 329, "Hiding from the Devil (Princess)", the protagonist must find a way to hide from a princess, who, in many variants, owns a magical mirror that can see the whole world.
* In Tennyson
Alfred Tennyson, 1st Baron Tennyson (6 August 1809 – 6 October 1892) was an English poet. He was the Poet Laureate during much of Queen Victoria's reign. In 1829, Tennyson was awarded the Chancellor's Gold Medal at Cambridge for one of his ...
's famous poem ''The Lady of Shalott
"The Lady of Shalott" is a lyrical ballad by the 19th-century English poet Alfred Tennyson and one of his best-known works. Inspired by the 13th-century Italian short prose text '' Donna di Scalotta'', the poem tells the tragic story of Elain ...
'' (1833, revised in 1842), the titular character possesses a mirror that enables her to look out on the people of Camelot, as she is under a curse that prevents her from seeing Camelot directly.
* Hans Christian Andersen
Hans Christian Andersen ( , ; 2 April 1805 – 4 August 1875) was a Danish author. Although a prolific writer of plays, travelogues, novels, and poems, he is best remembered for his literary fairy tales.
Andersen's fairy tales, consisti ...
's fairy tale ''The Snow Queen
"The Snow Queen" ( da, Snedronningen) is an original fairy tale by Danish author Hans Christian Andersen. It was first published 21 December 1844 in '' New Fairy Tales. First Volume. Second Collection'' (''Nye Eventyr. Første Bind. Anden Samli ...
'', features the devil, in a form of an evil troll,[ who made a magic mirror that distorts the appearance of everything that it reflects.
* ]Lewis Carroll
Charles Lutwidge Dodgson (; 27 January 1832 – 14 January 1898), better known by his pen name Lewis Carroll, was an English author, poet and mathematician. His most notable works are ''Alice's Adventures in Wonderland'' (1865) and its sequel ...
's ''Through the Looking-Glass
''Through the Looking-Glass, and What Alice Found There'' (also known as ''Alice Through the Looking-Glass'' or simply ''Through the Looking-Glass'') is a novel published on 27 December 1871 (though indicated as 1872) by Lewis Carroll and the ...
and What Alice Found There'' (1871) has become one of the best-loved exemplars of the use of mirrors in literature. The text itself utilizes a narrative that mirrors that of its predecessor, ''Alice's Adventures in Wonderland
''Alice's Adventures in Wonderland'' (commonly ''Alice in Wonderland'') is an 1865 English novel by Lewis Carroll. It details the story of a young girl named Alice (Alice's Adventures in Wonderland), Alice who falls through a rabbit hole into a ...
''.[
* In ]Oscar Wilde
Oscar Fingal O'Flahertie Wills Wilde (16 October 185430 November 1900) was an Irish poet and playwright. After writing in different forms throughout the 1880s, he became one of the most popular playwrights in London in the early 1890s. He is ...
's novel, ''The Picture of Dorian Gray
''The Picture of Dorian Gray'' is a philosophical fiction, philosophical novel by Irish writer Oscar Wilde. A shorter novella-length version was published in the July 1890 issue of the American periodical ''Lippincott's Monthly Magazine''.''Th ...
'' (1890), a portrait
A portrait is a portrait painting, painting, portrait photography, photograph, sculpture, or other artistic representation of a person, in which the face and its expressions are predominant. The intent is to display the likeness, Personality type ...
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.[
* ]W. H. Auden
Wystan Hugh Auden (; 21 February 1907 – 29 September 1973) was a British-American poet. Auden's poetry was noted for its stylistic and technical achievement, its engagement with politics, morals, love, and religion, and its variety in ...
's villanelle "Miranda" repeats the refrain: "My dear one is mine as mirrors are lonely".
* The short story ''Tlön, Uqbar, Orbis Tertius
"Tlön, Uqbar, Orbis Tertius" is a short story by the 20th-century Argentinian writer Jorge Luis Borges. The story was first published in the Argentinian journal '' Sur'', May 1940. The "postscript" dated 1947 is intended to be anachronistic, se ...
'' (1940) by Jorge Luis Borges
Jorge Francisco Isidoro Luis Borges Acevedo (; ; 24 August 1899 – 14 June 1986) was an Argentine short-story writer, essayist, poet and translator, as well as a key figure in Spanish-language and international literature. His best-known bo ...
begins with the phrase "I owe the discovery of Uqbar to the conjunction of a mirror and an encyclopedia" and contains other references to mirrors.
* ''The Trap'', a short story by H.P. Lovecraft and Henry S. Whitehead, centers around a mirror. "It was on a certain Thursday morning in December that the whole thing began with that unaccountable motion I thought I saw in my antique Copenhagen mirror. Something, it seemed to me, stirred—something reflected in the glass, though I was alone in my quarters."[
* Magical objects in the ''Harry Potter'' series (1997–2011) include the ]Mirror of Erised
A mirror or looking glass is an object that reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the im ...
and two-way mirrors
A one-way mirror, also called two-way mirror (or one-way glass, half-silvered mirror, and semi-transparent mirror), is a reciprocal mirror that appears reflective on one side and transparent at the other. The perception of one-way transmission i ...
.
* Under ''Appendix: Variant Planes & Cosmologies'' of the ''Dungeons & Dragons
''Dungeons & Dragons'' (commonly abbreviated as ''D&D'' or ''DnD'') is a fantasy tabletop role-playing game (RPG) originally designed by Gary Gygax and Dave Arneson. The game was first published in 1974 by TSR (company)#Tactical Studies Rules ...
'' ''Manual of the Planes
The ''Manual of the Planes'' (abbreviated MoP) is a manual for the ''Dungeons and Dragons'' role-playing game. This text addresses the planar cosmology of the game universe.
The original book (for use with ''Advanced Dungeons & Dragons'' 1st Ed ...
'' (2000), is The Plane of Mirrors (page 204).[ It describes the Plane of Mirrors as a space existing behind reflective surfaces, and experienced by visitors as a long corridor. The greatest danger to visitors upon entering the plane is the instant creation of a mirror-self with the opposite alignment of the original visitor.
* ''The Mirror Thief'', a novel by Martin Seay (2016),][ includes a fictional account of industrial espionage surrounding mirror-manufacturing in 16th-century Venice.
* '']The Reaper's Image
"The Reaper's Image" is a horror short story by American writer Stephen King, first published in ''Startling Mystery Stories'' in 1969 and collected in ''Skeleton Crew'' in 1985. The story is about an antique mirror haunted by the visage of the ...
'', a short story by Stephen King
Stephen Edwin King (born September 21, 1947) is an American author of horror, supernatural fiction, suspense, crime, science-fiction, and fantasy novels. Described as the "King of Horror", a play on his surname and a reference to his high s ...
, concerns a rare Elizabethan mirror that displays the Reaper's image when viewed, which symbolises the death of the viewer.
* Kilgore Trout, a protagonist of Kurt Vonnegut
Kurt Vonnegut Jr. (November 11, 1922 – April 11, 2007) was an American writer known for his satirical and darkly humorous novels. In a career spanning over 50 years, he published fourteen novels, three short-story collections, five plays, and ...
's novel ''Breakfast of Champions
''Breakfast of Champions, or Goodbye Blue Monday'' is a 1973 novel by the American author Kurt Vonnegut. His seventh novel, it is set predominantly in the fictional town of Midland City, Ohio, and focuses on two characters: Dwayne Hoover, a Midl ...
'', believes that mirrors are windows to other universes, and refers to them as "leaks", a recurring motif in the book.
*In ''The Fellowship of the Ring
''The Fellowship of the Ring'' is the first of three volumes of the epic novel ''The Lord of the Rings'' by the English author J. R. R. Tolkien. It is followed by ''The Two Towers'' and ''The Return of the King''. It takes place in the fiction ...
'' by J. R. R. Tolkien
John Ronald Reuel Tolkien (, ; 3 January 1892 – 2 September 1973) was an English writer and philology, philologist. He was the author of the high fantasy works ''The Hobbit'' and ''The Lord of the Rings''.
From 1925 to 1945, Tolkien was ...
, the Mirror of Galadriel allows one to see things of the past, present and possible future. The mirror additionally appears in the movie adaptation
A film adaptation is the transfer of a work or story, in whole or in part, to a feature film. Although often considered a type of derivative work, film adaptation has been conceptualized recently by academic scholars such as Robert Stam as a dia ...
.
Mirror test
Only a few animal species have been shown to have the ability to recognize themselves in a mirror, most of them mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s. Experiments have found that the following animals can pass the mirror test
The mirror test—sometimes called the mark test, mirror self-recognition (MSR) test, red spot technique, or rouge test—is a behavioral technique developed in 1970 by American psychologist Gordon Gallup Jr. as an attempt to determine whether an ...
:
* All great apes
The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); ''Gorilla'' (the east ...
:
** Human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s. Humans tend to fail the mirror test until they are about 18 months old, or what psychoanalysts
PsychoanalysisFrom Greek: + . is a set of theories and therapeutic techniques"What is psychoanalysis? Of course, one is supposed to answer that it is many things — a theory, a research method, a therapy, a body of knowledge. In what might be ...
call the "mirror stage
The mirror stage (french: stade du miroir) is a concept in the psychoanalytic theory of Jacques Lacan. The mirror stage is based on the belief that infants recognize themselves in a mirror (literal) or other symbolic contraption which induces apper ...
".[
** ]Bonobo
The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee and less often the dwarf chimpanzee or gracile chimpanzee, is an endangered great ape and one of the two species making up the genus '' Pan,'' the other being the comm ...
s[
** ]Chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...
s[
** ]Orangutan
Orangutans are great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in the genus ...
s[
** ]Gorilla
Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or fi ...
s. Initially, it was thought that gorillas did not pass the test, but there are now several well-documented reports of gorillas (such as Koko
Koko or KOKO may refer to:
Animals
*Koko (gorilla) (1971–2018), a gorilla trained to communicate in American Sign Language
*Koko (dog) (2005–2012), the Australian kelpie in the 2011 film ''Red Dog''
*Koko (horse), an Irish racehorse that won ...
[) passing the test.
* ]Bottlenose dolphins
Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the common ...
[
* ]Orcas
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pat ...
[
* ]Elephants
Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae and ...
[
* ]European magpie
The Eurasian magpie or common magpie (''Pica pica'') is a resident breeding bird throughout the northern part of the Palearctic, Eurasian continent. It is one of several birds in the Corvidae, crow family (corvids) designated magpies, and belong ...
s[
]
See also
* Anish Kapoor
Sir Anish Mikhail Kapoor (born 12 March 1954) is a British-Indian sculptor specializing in installation art and conceptual art. Born in Mumbai, Kapoor attended the elite all-boys Indian boarding school The Doon School, before moving to the UK ...
(artist working with mirrors)
* Aranmula kannadi
Aranmula Kannadi, meaning the Aranmula mirror, is a handmade, metal-alloy, first surface mirror made in Aranmula, a small town in Pathanamthitta, today's Kerala, India.
Description
Unlike normal "silvered" glass mirrors, it is a metal-all ...
* Chirality (mathematics)
In geometry, a figure is chiral (and said to have chirality) 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. An object that is not chiral is said to be ...
* Corner reflector
A corner reflector is a retroreflector consisting of three mutually perpendicular, intersecting flat surfaces, which reflects waves directly towards the source, but translated. The three intersecting surfaces often have square shapes. Radar co ...
* Deformable mirror
Deformable mirrors (DM) are mirrors whose surface can be deformed, in order to achieve wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in ada ...
* Digital micromirror device
The digital micromirror device, or DMD, is the microoptoelectromechanical system (MOEMS) that is the core of the trademarked DLP projection technology from Texas Instruments (TI). Texas Instrument's DMD was created by solid-state physicist and ...
* Heliotrope (instrument)
The heliotrope is an instrument that uses a mirror to reflect sunlight over great distances to mark the positions of participants in a land survey. The heliotrope was invented in 1821 by the German mathematician Carl Friedrich Gauss. The word " ...
* Honeycomb mirror
A honeycomb mirror is a large mirror usually used as the primary mirror in astronomy, astronomical reflecting telescopes whose face is supported by a ribbed structure that resembles a honeycomb. The design provides sufficient rigidity for ultra-hig ...
* List of telescope parts and construction Hardware Accessories
*Finderscope
*Iron sight
* Reflector (reflex) sight
* Cheshire collimator: A simple tool to collimate a telescope
Control
*Clock drive
*GoTo
Mechanical construction
*Mirror support cell
*Serrurier truss
*Silvering
Mounts
*Te ...
* Mirror armour
Mirror armour (russian: зерцало, , meaning "mirror"; zh, 护心镜, , meaning "protect-heart mirror"), sometimes referred to as disc armour or as or ( fa, چهاﺮآﻳنه meaning "four mirrors"; whence kk, шар-айна, ), was ...
* Non-reversing mirror
A non-reversing mirror (sometimes referred to as a flip mirror) is a mirror that presents its subject as it would be seen from the mirror. A non-reversing mirror can be made by connecting two regular mirrors at their edges at a 90 degree angle. ...
* Mirror writing
Mirror 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 u ...
* Mirrors in Mesoamerican culture
The use of mirrors in Mesoamerican culture was associated with the idea that they served as portals to a realm that could be seen but not interacted with.Fitzsimmons 2009, pp.96–97. Mirrors in pre-Columbian Mesoamerica were fashioned from stone ...
* Perfect mirror A perfect mirror is a mirror that reflects light (and electromagnetic radiation in general) perfectly, and does not transmit or absorb it.
General
Domestic mirrors are not perfect mirrors as they absorb a significant portion of the light which fal ...
* Periscope
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.
In its simplest form, it consists of an outer case with ...
* Selfie
A selfie () is a self-portrait photograph, typically taken with a digital camera or smartphone, which may be held in the hand or supported by a selfie stick. Selfies are often shared on social media, via social networking services such as F ...
* Spectrophobia
Spectrophobia (derived from Latin: ''spectrum'', n. specio, an appearance, form, image of a thing; an apparition, spectre) or catoptrophobia (from Greek κάτοπτρον ''kátoptron'', "mirror") is a kind of specific phobia involving an abnorm ...
* TLV mirror
A 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 cast in the design. They were produced from around the 2nd century BCE ...
* Venus effect
The 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'' ...
References
Further reading
* ''Le miroir: révélations, science-fiction et fallacies. Essai sur une légende scientifique'', Jurgis Baltrušaitis, Paris, 1978. .
* ''On reflection'', Jonathan Miller
Sir Jonathan Wolfe Miller CBE (21 July 1934 – 27 November 2019) was an English theatre and opera director, actor, author, television presenter, humourist and physician. After training in medicine and specialising in neurology in the late 19 ...
, National Gallery Publications Limited (1998). .
* ''Lo specchio, la strega e il quadrante. Vetrai, orologiai e rappresentazioni del 'principium individuationis' dal Medioevo all'Età moderna'', Francesco Tigani, Roma, 2012. .
*Shrum, Rebecca K. 2017.
In the Looking Glass: Mirrors and Identity in Early America
'. Johns Hopkins University Press.
External links
*
*
*
How Mirrors Are Made (video)
Glass Association of North America (GANA)
July 2019 "The Ugly History of Beautiful Things: Mirrors" by Katy Kelleher for Longreads
{{Authority control
Glass applications
Reflective building components
Wallcoverings