Red is the color at the end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of 625–740 nanometres, it is a primary color in the RGB color model and the CMYK color model, is the complementary color of cyan. Reds range from the brilliant yellow-tinged scarlet and vermillion to bluish-red crimson, vary in shade from the pale red pink to the dark red burgundy; the red sky at sunset results from Rayleigh scattering, while the red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide. Iron oxide gives the red color to the planet Mars; the red colour of blood comes from protein hemoglobin, while ripe strawberries, red apples and reddish autumn leaves are colored by anthocyanins. Red pigment made from ochre was one of the first colors used in prehistoric art; the Ancient Egyptians and Mayans colored their faces red in ceremonies. It was an important color in China, where it was used to colour early pottery and the gates and walls of palaces.
In the Renaissance, the brilliant red costumes for the nobility and wealthy were dyed with kermes and cochineal. The 19th century brought the introduction of the first synthetic red dyes, which replaced the traditional dyes. Red became the color of revolution. Since red is the color of blood, it has been associated with sacrifice and courage. Modern surveys in Europe and the United States show red is the color most associated with heat, passion, anger and joy. In China and many other Asian countries it is the color of symbolizing happiness and good fortune. See below for shades of pink The human eye sees red when it looks at light with a wavelength between 625 and 740 nanometers, it is a primary color in the RGB color model and the light just past this range is called infrared, or below red, cannot be seen by human eyes, although it can be sensed as heat. In the language of optics, red is the color evoked by light that stimulates neither the S or the M cone cells of the retina, combined with a fading stimulation of the L cone cells.
Primates can distinguish the full range of the colors of the spectrum visible to humans, but many kinds of mammals, such as dogs and cattle, have dichromacy, which means they can see blues and yellows, but cannot distinguish red and green. Bulls, for instance, cannot see the red color of the cape of a bullfighter, but they are agitated by its movement.. One theory for why primates developed sensitivity to red is that it allowed ripe fruit to be distinguished from unripe fruit and inedible vegetation; this may have driven further adaptations by species taking advantage of this new ability, such as the emergence of red faces. Red light is used to help adapt night vision in low-light or night time, as the rod cells in the human eye are not sensitive to red. Red illumination was used as a safelight while working in a darkroom as it does not expose most photographic paper and some films. Today modern darkrooms use an amber safelight. On the color wheel long used by painters, in traditional color theory, red is one of the three primary colors, along with blue and yellow.
Painters in the Renaissance mixed red and blue to make violet: Cennino Cennini, in his 15th-century manual on painting, wrote, "If you want to make a lovely violet colour, take fine lac, ultramarine blue with a binder" he noted that it could be made by mixing blue indigo and red hematite. In modern color theory known as the RGB color model, red and blue are additive primary colors. Red and blue light combined together makes white light, these three colors, combined in different mixtures, can produce nearly any other color; this is the principle, used to make all of the colors on your computer screen and your television. For example, magenta on a computer screen is made by a similar formula to that used by Cennino Cennini in the Renaissance to make violet, but using additive colors and light instead of pigment: it is created by combining red and blue light at equal intensity on a black screen. Violet is made on a computer screen in a similar way, but with a greater amount of blue light and less red light.
So that the maximum number of colors can be reproduced on your computer screen, each color has been given a code number, or sRGB, which tells your computer the intensity of the red and blue components of that color. The intensity of each component is measured on a scale of zero to 255, which means the complete list includes 16,777,216 distinct colors and shades; the sRGB number of pure red, for example, is 255, 00, 00, which means the red component is at its maximum intensity, there is no green or blue. The sRGB number for crimson is 220, 20, 60, which means that the red is less intense and therefore darker, there is some green, which leans it toward orange; as a ray of white sunlight travels through the atmosphere to the eye, some of the colors are scattered out of the beam by air molecules and airborne particles due to Rayleigh scattering, changing the final color of the beam, seen. Colors with a shorter wavelength, such as blue and green, scatter more and are removed from the light that reaches the eye.
At sunrise and sunset, when the
Porcelain is a ceramic material made by heating materials including kaolin, in a kiln to temperatures between 1,200 and 1,400 °C. The toughness and translucence of porcelain, relative to other types of pottery, arises from vitrification and the formation of the mineral mullite within the body at these high temperatures. Though definitions vary, porcelain can be divided into three main categories: hard-paste, soft-paste and bone china; the category that an object belongs to depends on the composition of the paste used to make the body of the porcelain object and the firing conditions. Porcelain evolved in China and was achieved at some point about 2,000 to 1,200 years ago slowly spread to other East Asian countries, Europe and the rest of the world, its manufacturing process is more demanding than that for earthenware and stoneware, the two other main types of pottery, it has been regarded as the most prestigious type of pottery for its delicacy and its white colour. It combines well with both glazes and paint, can be modelled well, allowing a huge range of decorative treatments in tablewares and figurines.
It has many uses in technology and industry. The European name, porcelain in English, come from the old Italian porcellana because of its resemblance to the surface of the shell. Porcelain is referred to as china or fine china in some English-speaking countries, as it was first seen in imports from China. Properties associated with porcelain include low elasticity. Porcelain has been described as being "completely vitrified, impermeable, white or artificially coloured and resonant". However, the term "porcelain" lacks a universal definition and has "been applied in an unsystematic fashion to substances of diverse kinds which have only certain surface-qualities in common". Traditionally, East Asia only classifies pottery into low-fired wares and high-fired wares, without the European concept of stoneware, high-fired but not white or translucent. Terms such as "proto-porcelain", "porcellaneous" or "near-porcelain" may be used in cases where the ceramic body approaches whiteness and translucency.
Kaolin is the primary material from which porcelain is made though clay minerals might account for only a small proportion of the whole. The word paste is an old term for both the fired materials. A more common terminology for the unfired material is "body"; the composition of porcelain is variable, but the clay mineral kaolinite is a raw material. Other raw materials can include feldspar, ball clay, bone ash, quartz and alabaster; the clays used are described as being long or short, depending on their plasticity. Long clays have high plasticity. In soil mechanics, plasticity is determined by measuring the increase in content of water required to change a clay from a solid state bordering on the plastic, to a plastic state bordering on the liquid, though the term is used less formally to describe the ease with which a clay may be worked. Clays used for porcelain are of lower plasticity and are shorter than many other pottery clays, they wet quickly, meaning that small changes in the content of water can produce large changes in workability.
Thus, the range of water content within which these clays can be worked is narrow and must be controlled. The following section provides background information on the methods used to form, finish and fire ceramic wares. Unlike their lower-fired counterparts, porcelain wares do not need glazing to render them impermeable to liquids and for the most part are glazed for decorative purposes and to make them resistant to dirt and staining. Many types of glaze, such as the iron-containing glaze used on the celadon wares of Longquan, were designed for their striking effects on porcelain. Biscuit porcelain is unglazed. Porcelain wares may be decorated under the glaze using pigments that include cobalt and copper or over the glaze using coloured enamels. Like many earlier wares, modern porcelains are biscuit-fired at around 1,000 °C, coated with glaze and sent for a second glaze-firing at a temperature of about 1,300 °C or greater. Another early method is "once-fired", where the glaze is applied to the unfired body and the two fired together in a single operation.
In this process, "green" ceramic wares are heated to high temperatures in a kiln to permanently set their shapes. Porcelain is fired at a higher temperature than earthenware so that the body can vitrify and become non-porous. Porcelain originated in China, it took a long time to reach the modern material; until recent times all East Asian porcelain was of the hard-paste type. There is no precise date to separate the production of proto-porcelain from that of porcelain. Although proto-porcelain wares exist dating from the Shang dynasty, by the time of the Eastern Han dynasty period, glazed ceramic wares had developed into porcelain, which Chinese defined as high-fired ware. By the late Sui dynasty and early Tang dynasty the additional Western requirements of whiteness and translucency had b
A flag is a piece of fabric with a distinctive design and colours. It is used for decoration; the term flag is used to refer to the graphic design employed, flags have evolved into a general tool for rudimentary signalling and identification in environments where communication is challenging. The study of flags is known as "vexillology" from the Latin vexillum, meaning "flag" or "banner". National flags are patriotic symbols with varied interpretations that include strong military associations because of their original and ongoing use for that purpose. Flags are used in messaging, advertising, or for decorative purposes; some military units are called "flags" after their use of flags. A flag is equivalent to a brigade in Arab countries. In Spain, a flag is a battalion-equivalent in the Spanish Legion. In antiquity, field signs or standards were used in warfare that can be categorised as vexilloid or'flag-like'; this is considered originated in Assyria. Examples include the Sassanid battle standard Derafsh Kaviani, the standards of the Roman legions such as the eagle of Augustus Caesar's Xth legion, or the dragon standard of the Sarmatians.
Flag as recognized today, made of a piece of cloth representing a particular entity, is considered invented in the Indian subcontinent or Chinese Zhou dynasty. Chinese flags depicted animals decorated in certain colors. A royal flag is considered being used as well, required to be treated with a similar level of respect attributed to the ruler. Indian flags were triangular shaped and decorated with attachments such as yak's tail and the state umbrella; these usages spread to Southeast Asia as well, considered transmitted to Europe through the Muslim world where plainly colored flags were being used due to Islamic prescriptions. In Europe, during the High Middle Ages, flags came to be used as a heraldic device in battle, allowing more to identify a knight than only from the heraldic device painted on the shield. During the high medieval period, during the Late Middle Ages, city states and communes such as those of the Old Swiss Confederacy began to use flags as field signs. Regimental flags for individual units became commonplace during the Early Modern period.
During the peak of the age of sail, beginning in the early 17th century, it was customary for ships to carry flags designating their nationality. Flags became the preferred means of communications at sea, resulting in various systems of flag signals. Use of flags outside of military or naval context begins only with the rise of nationalist sentiment by the end of the 18th century. One of the most popular uses of a flag is to symbolise a country; some national flags have been inspirational to other nations, countries, or subnational entities in the design of their own flags. Some prominent examples include: The flag of Denmark, the Dannebrog, is attested in 1478, is the oldest national flag still in use, it inspired the cross design of the other Nordic countries: Norway, Finland and regional Scandinavian flags for the Faroe Islands, Åland and Bornholm, as well as flags for the non-Scandinavian Shetland and Orkney. The flag of the Netherlands is the oldest tricolour, its three colours of red and blue go back to Charlemagne's time, the 9th century.
The coastal region of what today is the Netherlands was known for its cloth in these colours. Maps from the early 16th century put flags in these colours next to this region, like Texeira's map of 1520. A century before that, during the 15th century, the three colours were mentioned as the coastal signals for this area, with the three bands straight or diagonal, single or doubled; as state flag it first appeared around 1572 as the Prince's Flag in orange–white–blue. Soon the more famous red–white–blue began appearing, becoming the prevalent version from around 1630. Orange made a comeback during the civil war of the late 18th century, signifying the orangist or pro-stadtholder party. During World War II the pro-Nazi NSB used it. Any symbolism has been added to the three colours, although the orange comes from the House of Orange-Nassau; this use of orange comes from Nassau, which today uses orange-blue, not from Orange, which today uses red-blue. However, the usual way to show the link with the House of Orange-Nassau is the orange pennant above the red-white-blue.
It is said that the Dutch Tricolour has inspired many flags but most notably those of Russia, New York City, South Africa. As the probable inspiration for the Russian flag, it is the source too for the Pan-Slavic colours red and blue, adopted by many Slavic states and peoples as their symbols; the national flag of France was designed in 1794. As a forerunner of revolution, France's tricolour flag style has been adopted by other nations. Examples: Italy, Costa Rica, Dominican Republic, Haiti and Mexico; the Union Flag of the United Kingdom is the most used. British colonies flew a flag bas
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word refers to visible light, the visible spectrum, visible to the human eye and is responsible for the sense of sight. Visible light is defined as having wavelengths in the range of 400–700 nanometres, or 4.00 × 10−7 to 7.00 × 10−7 m, between the infrared and the ultraviolet. This wavelength means a frequency range of 430–750 terahertz; the main source of light on Earth is the Sun. Sunlight provides the energy that green plants use to create sugars in the form of starches, which release energy into the living things that digest them; this process of photosynthesis provides all the energy used by living things. Another important source of light for humans has been fire, from ancient campfires to modern kerosene lamps. With the development of electric lights and power systems, electric lighting has replaced firelight; some species of animals generate their own light, a process called bioluminescence.
For example, fireflies use light to locate mates, vampire squids use it to hide themselves from prey. The primary properties of visible light are intensity, propagation direction, frequency or wavelength spectrum, polarization, while its speed in a vacuum, 299,792,458 metres per second, is one of the fundamental constants of nature. Visible light, as with all types of electromagnetic radiation, is experimentally found to always move at this speed in a vacuum. In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays and radio waves are light. Like all types of EM radiation, visible light propagates as waves. However, the energy imparted by the waves is absorbed at single locations the way particles are absorbed; the absorbed energy of the EM waves is called a photon, represents the quanta of light. When a wave of light is transformed and absorbed as a photon, the energy of the wave collapses to a single location, this location is where the photon "arrives."
This is. This dual wave-like and particle-like nature of light is known as the wave–particle duality; the study of light, known as optics, is an important research area in modern physics. EM radiation, or EMR, is classified by wavelength into radio waves, infrared, the visible spectrum that we perceive as light, ultraviolet, X-rays, gamma rays; the behavior of EMR depends on its wavelength. Higher frequencies have shorter wavelengths, lower frequencies have longer wavelengths; when EMR interacts with single atoms and molecules, its behavior depends on the amount of energy per quantum it carries. EMR in the visible light region consists of quanta that are at the lower end of the energies that are capable of causing electronic excitation within molecules, which leads to changes in the bonding or chemistry of the molecule. At the lower end of the visible light spectrum, EMR becomes invisible to humans because its photons no longer have enough individual energy to cause a lasting molecular change in the visual molecule retinal in the human retina, which change triggers the sensation of vision.
There exist animals that are sensitive to various types of infrared, but not by means of quantum-absorption. Infrared sensing in snakes depends on a kind of natural thermal imaging, in which tiny packets of cellular water are raised in temperature by the infrared radiation. EMR in this range causes molecular vibration and heating effects, how these animals detect it. Above the range of visible light, ultraviolet light becomes invisible to humans because it is absorbed by the cornea below 360 nm and the internal lens below 400 nm. Furthermore, the rods and cones located in the retina of the human eye cannot detect the short ultraviolet wavelengths and are in fact damaged by ultraviolet. Many animals with eyes that do not require lenses are able to detect ultraviolet, by quantum photon-absorption mechanisms, in much the same chemical way that humans detect visible light. Various sources define visible light as narrowly as 420–680 nm to as broadly as 380–800 nm. Under ideal laboratory conditions, people can see infrared up to at least 1050 nm.
Plant growth is affected by the color spectrum of light, a process known as photomorphogenesis. The speed of light in a vacuum is defined to be 299,792,458 m/s; the fixed value of the speed of light in SI units results from the fact that the metre is now defined in terms of the speed of light. All forms of electromagnetic radiation move at this same speed in vacuum. Different physicists have attempted to measure the speed of light throughout history. Galileo attempted to measure the speed of light in the seventeenth century. An early experiment to measure the speed of light was conducted by Ole Rømer, a Danish physicist, in 1676. Using a telescope, Rømer observed one of its moons, Io. Noting discrepancies in the apparent period of Io's orbit, he calculated that light takes about 22 minutes to traverse the diameter of Earth's orbit. However, its size was not known at that time. If Rømer had known the diameter of the Earth's orbit, he would have calculated a speed of 227,000,000 m/s. Another, more accurate, measurement of the speed of light was performed in Europe by Hippolyte Fizeau in 1849.
Azure is a bright cyan-blue color, described as the color of the sky on a clear day. On the RGB color wheel, "azure" is defined as the color at 210 degrees, i.e. the hue halfway between blue and cyan. In the RGB color model, used to create all the colors on a television or computer screen, azure is created by adding a little green light to blue light; the complementary color of azure is orange. In the X11 color system which became a standard for early web colors, azure is depicted as a pale cyan or white cyan; the color azure takes its name from the intense blue mineral lapis lazuli. Lapis is the Latin word for "stone" and lāzulī is the genitive form of the Medieval Latin lāzulum, taken from the Arabic لازورد lāzaward, itself from the Persian لاژورد lāžaward, the name of the stone in Persian and of a place where lapis lazuli was mined; the name of the stone came to be associated with its color. The French azur, the Italian azzurro, the Polish lazur, Romanian azur and azuriu, the Portuguese and Spanish azul, Hungarian azúr, the Catalan atzur, all come from the name and color of lapis lazuli.
The word was adopted into English from the French, the first recorded use of it as a color name in English was in 1374 in Geoffrey Chaucer's work Troilus and Criseyde, where he refers to "a broche and asure". Azure describes the color of the mineral azurite, both in its natural form and as a pigment in various paint formulations. In order to preserve its deep color, azurite was ground coarsely. Fine-ground azurite produces a lighter, washed-out color. Traditionally, the pigment was considered unstable in oil paints, was sometimes isolated from other colors and not mixed; the use of the term spread through the practice of heraldry, where "azure" represents a blue color in the system of tinctures. In engravings, it is represented as a region of parallel horizontal lines, or by the abbreviation az. or b. In practice, azure has been represented by any number of shades of blue. In heraldic practice a lighter blue, called bleu celeste, is sometimes specified. According to the logic of the RGB color wheel, indigo colors are those colors with hue codes between 255 and 225, azure colors are those colors with hue codes between 195 and 225, cyan colors are those colors with hue codes between 165 and 195.
Another way of describing it could be that cyan is a mixture of blue and green light, azure is a mixture of blue and cyan light, indigo is a mixture of blue and violet light. All of the colors shown below in the section shades of azure are referenced as having a hue between 195 and 225 degrees, with the exception of the pale X11 web color azure - RGB - which, with a hue of 180 degrees, is a tone of cyan, but follows the artistic meaning of azure as sky blue. InsectsAzure damselfly, damselfly found in Europe Azure hawker, dragonfly in the family AeshnidaeBirdsAzure gallinule, bird in the rail family, Rallidae Azure jay bird in the crow family, Corvidae Azure kingfisher, bird in the river kingfisher family, Alcedinidae Azure tit, bird in the tit family, Paridae Azure-crowned hummingbird, a hummingbird in the family Trochilidae Azure-hooded jay, bird in the crow family, Corvidae Azure-naped jay, bird in the crow family, Corvidae Azure-rumped tanager, bird in the family Thraupidae Azure-shouldered tanager, bird in the family Thraupidae Azure-winged magpie, bird in the crow family, Corvidae Côte d'Azur is a name used for the French Riviera, part of France's southeastern coast on the Mediterranean.
In Chinese mythology, the Azure Dragon is one of the Four Symbols of the Chinese constellations. It is sometimes called the Azure Dragon of the East, it is known as Seiryū in Japan and Cheongryong in Korea, it represents the east and the spring season. Azure is a traditional national color for Italy, taken from the traditional colors of the House of Savoy, the ruling house of the Kingdom of Piedmont-Sardinia that established the first modern united Italian state; the association between azure and Italian nationalism led to the Italian national football team donning azure jerseys, giving them the nickname, the Azzurri. It is color of the Italian state police. Shades of Azure List of colors
Hinduism is an Indian religion and dharma, or way of life practised in the Indian subcontinent and parts of Southeast Asia. Hinduism has been called the oldest religion in the world, some practitioners and scholars refer to it as Sanātana Dharma, "the eternal tradition", or the "eternal way", beyond human history. Scholars regard Hinduism as a fusion or synthesis of various Indian cultures and traditions, with diverse roots and no founder; this "Hindu synthesis" started to develop between 500 BCE and 300 CE, after the end of the Vedic period, flourished in the medieval period, with the decline of Buddhism in India. Although Hinduism contains a broad range of philosophies, it is linked by shared concepts, recognisable rituals, shared textual resources, pilgrimage to sacred sites. Hindu texts are classified into Smṛti; these texts discuss theology, mythology, Vedic yajna, agamic rituals, temple building, among other topics. Major scriptures include the Vedas and Upanishads, the Bhagavad Gita, the Ramayana, the Āgamas.
Sources of authority and eternal truths in its texts play an important role, but there is a strong Hindu tradition of questioning authority in order to deepen the understanding of these truths and to further develop the tradition. Prominent themes in Hindu beliefs include the four Puruṣārthas, the proper goals or aims of human life, namely Dharma, Artha and Moksha. Hindu practices include rituals such as puja and recitations, meditation, family-oriented rites of passage, annual festivals, occasional pilgrimages; some Hindus leave their social world and material possessions engage in lifelong Sannyasa to achieve Moksha. Hinduism prescribes the eternal duties, such as honesty, refraining from injuring living beings, forbearance, self-restraint, compassion, among others; the four largest denominations of Hinduism are the Vaishnavism, Shaivism and Smartism. Hinduism is the world's third largest religion. Hinduism is the most professed faith in India and Mauritius, it is the predominant religion in Bali, Indonesia.
Significant numbers of Hindu communities are found in the Caribbean, North America, other countries. The word Hindū is derived from Indo-Aryan/Sanskrit root Sindhu; the Proto-Iranian sound change *s > h occurred between 850–600 BCE, according to Asko Parpola. It is believed that Hindu was used as the name for the Indus River in the northwestern part of the Indian subcontinent. According to Gavin Flood, "The actual term Hindu first occurs as a Persian geographical term for the people who lived beyond the river Indus", more in the 6th-century BCE inscription of Darius I; the term Hindu in these ancient records did not refer to a religion. Among the earliest known records of'Hindu' with connotations of religion may be in the 7th-century CE Chinese text Record of the Western Regions by Xuanzang, 14th-century Persian text Futuhu's-salatin by'Abd al-Malik Isami. Thapar states that the word Hindu is found as heptahindu in Avesta – equivalent to Rigvedic sapta sindhu, while hndstn is found in a Sasanian inscription from the 3rd century CE, both of which refer to parts of northwestern South Asia.
The Arabic term al-Hind referred to the people. This Arabic term was itself taken from the pre-Islamic Persian term Hindū, which refers to all Indians. By the 13th century, Hindustan emerged as a popular alternative name of India, meaning the "land of Hindus"; the term Hindu was used in some Sanskrit texts such as the Rajataranginis of Kashmir and some 16th- to 18th-century Bengali Gaudiya Vaishnava texts including Chaitanya Charitamrita and Chaitanya Bhagavata. These texts used it to distinguish Hindus from Muslims who are called Yavanas or Mlecchas, with the 16th-century Chaitanya Charitamrita text and the 17th-century Bhakta Mala text using the phrase "Hindu dharma", it was only towards the end of the 18th century that European merchants and colonists began to refer to the followers of Indian religions collectively as Hindus. The term Hinduism spelled Hindooism, was introduced into the English language in the 18th century to denote the religious and cultural traditions native to India. Hinduism includes a diversity of ideas on spirituality and traditions, but has no ecclesiastical order, no unquestionable religious authorities, no governing body, no prophet nor any binding holy book.
Because of the wide range of traditions and ideas covered by the term Hinduism, arriving at a comprehensive definition is difficult. The religion "defies our desire to define and categorize it". Hinduism has been variously defined as a religion, a religious tradition, a set of religious beliefs, "a way of life". From a Western lexical standpoint, Hinduism like other faiths is appropriately referred to as a religion. In India the term dharma is preferred, broader than the Western term religion; the study of India and its cultures and religions, the definition of "Hinduism", has been shaped by th