Liquid oxygen , sometimes abbreviated as LOX or LOXygen , is a clear cyan liquid form of dioxygen O 2 . It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard , an application which has continued to the present.
86-507: Liquid oxygen has a clear cyan color and is strongly paramagnetic : it can be suspended between the poles of a powerful horseshoe magnet . Liquid oxygen has a density of 1.141 kg/L (1.141 g/ml), slightly denser than liquid water, and is cryogenic with a freezing point of 54.36 K (−218.79 °C; −361.82 °F) and a boiling point of 90.19 K (−182.96 °C; −297.33 °F) at 1 bar (15 psi). Liquid oxygen has an expansion ratio of 1:861 and because of this, it
172-410: A blue-green color, while the light-adapted eye is most sensitive about 555 nm, a yellow-green; these are the peak locations of the rod and cone (scotopic and photopic, respectively) luminosity functions . The perception of greenness (in opposition to redness forming one of the opponent mechanisms in human color vision ) is evoked by light which triggers the medium-wavelength M cone cells in
258-425: A camouflage in military and other fields. Substances that may impart a greenish hue to one's skin include biliverdin , the green pigment in bile , and ceruloplasmin , a protein that carries copper ions in chelation . The green huntsman spider is green due to the presence of bilin pigments in the spider's hemolymph (circulatory system fluids) and tissue fluids . It hunts insects in green vegetation, where it
344-518: A color name in English was in 1879. Further origins of the color name can be traced back to a dye produced from the cornflower ( Centaurea cyanus ). In most languages, 'cyan' is not a basic color term and it phenomenologically appears as a greenish vibrant hue of blue to most English speakers. Other English terms for this "borderline" hue region include blue green , aqua , turquoise , teal , and grue . The web color cyan shown at right
430-477: A genuine and widely used term for "green". Related to virere "to grow" and ver "spring", it gave rise to words in several Romance languages , French vert , Italian verde (and English vert , verdure etc.). Likewise the Slavic languages with zelenъ . Ancient Greek also had a term for yellowish, pale green – χλωρός , chloros (cf. the color of chlorine), cognate with χλοερός "verdant" and χλόη " chloe ,
516-450: A green dye for clothing, made from the leaves of the birch tree. It was of very poor quality, more brown than green. Ceramics from ancient Mesopotamia show people wearing vivid green costumes, but it is not known how the colors were produced. In Ancient Egypt , green was the symbol of regeneration and rebirth, and of the crops made possible by the annual flooding of the Nile. For painting on
602-463: A green hue themselves as camouflage . Several minerals have a green color, including the emerald , which is colored green by its chromium content. During post-classical and early modern Europe, green was the color commonly associated with wealth, merchants, bankers, and the gentry, while red was reserved for the nobility. For this reason, the costume of the Mona Lisa by Leonardo da Vinci and
688-429: A highly regarded precious gem. Turquoise comes in a variety of shades from green to blue, but cyan hues are particularly prevalent. Approximately 3,700 years ago, an intricately crafted dragon-shaped treasure made from over 2,000 pieces of turquoise and jade was created. This artifact is widely recognized as the oldest Chinese dragon totem by many Chinese scholars. Turquoise jewelry also held significant importance among
774-494: A meaning that covers both blue and green; blue and green are traditionally considered shades of " 青 ". In more contemporary terms, they are 藍 ( lán , in Mandarin) and 綠 ( lǜ , in Mandarin) respectively. Japanese also has two terms that refer specifically to the color green, 緑 ( midori , which is derived from the classical Japanese descriptive verb midoru "to be in leaf, to flourish" in reference to trees) and グリーン ( guriin , which
860-485: A mix ratio 75:25 of boron and potassium nitrate . Smoke can be turned green by a mixture: solvent yellow 33, solvent green 3, lactose , magnesium carbonate plus sodium carbonate added to potassium chlorate . Green is common in nature, as many plants are green because of a complex chemical known as chlorophyll, which is involved in photosynthesis . Chlorophyll absorbs the long wavelengths of light (red) and short wavelengths of light (blue) much more efficiently than
946-525: A new politics of the left which rejected traditional socialism and communism. (See § In politics section below.) Green can communicate safety to proceed, as in traffic lights . Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erected in 1868 in front of the Houses of Parliament in London. It exploded
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#17328525196261032-494: A printed page. To reproduce the web color cyan in inks, it is necessary to add some white ink to the printer's cyan below, so when it is reproduced in printing, it is not a primary subtractive color. It is called aqua (a name in use since 1598) because it is a color commonly associated with water , such as the appearance of the water at a tropical beach. Cyan is also one of the common inks used in four-color printing , along with magenta , yellow , and black ; this set of colors
1118-457: A tint being a cyan mixed with white, and a shade being mixed with black. Color nomenclature is subjective. Many shades of cyan with a bluish hue are called blue. Similarly, those with a greenish hue are referred to as green. A cyan with a dark shade is commonly known as teal . A teal blue shade leans toward the blue end of the spectrum. Variations of teal with a greener tint are commonly referred to as teal green . Turquoise , reminiscent of
1204-442: A traditional color wheel, based on subtractive color, the complementary color to green is considered to be red. In additive color devices such as computer displays and televisions, one of the primary light sources is typically a narrow-spectrum yellowish-green of dominant wavelength ~550 nm ; this "green" primary is combined with an orangish-red "red" primary and a purplish-blue "blue" primary to produce any color in between –
1290-550: Is a secondary color in the RGB color model , which uses combinations of red, green and blue light to create all the colors on computer and television displays. In X11 colors , this color is called both cyan and aqua . In the HTML color list, this same color is called aqua. The web colors are more vivid than the cyan used in the CMYK color system, and the web colors cannot be accurately reproduced on
1376-738: Is a commonly used coloring in the United Kingdom but is banned in Australia, Japan, Norway and the United States. Green S (E142) is prohibited in many countries, for it is known to cause hyperactivity , asthma , urticaria , and insomnia . To create green sparks, fireworks use barium salts , such as barium chlorate , barium nitrate crystals, or barium chloride , also used for green fireplace logs. Copper salts typically burn blue, but cupric chloride (also known as "campfire blue") can also produce green flames. Green pyrotechnic flares can use
1462-403: Is associated with the east, with sunrise, and with life and growth. In Thailand, the color green is considered auspicious for those born on a Wednesday (light green for those born at night). Green is the color most commonly associated in the United States and Europe with springtime, freshness, and hope. Green is often used to symbolize rebirth and renewal and immortality. In Ancient Egypt ;
1548-502: Is blood red and pale yellow, with a green billiard table in the center, and four lamps of lemon yellow, with rays of orange and green. Everywhere it is a battle and antithesis of the most different reds and greens." In the 1980s, green became a political symbol, the color of the Green Party in Germany and in many other European countries. It symbolized the environmental movement , and also
1634-432: Is classified as an industrial gas and is widely used for industrial and medical purposes. Liquid oxygen is obtained from the oxygen found naturally in air by fractional distillation in a cryogenic air separation plant . Air forces have long recognized the strategic importance of liquid oxygen, both as an oxidizer and as a supply of gaseous oxygen for breathing in hospitals and high-altitude aircraft flights. In 1985,
1720-478: Is cognate with the Ancient Greek γλαυκός "bluish green", contrasting with χλωρός "yellowish green" discussed above. In modern Japanese, the term for green is 緑 , while the old term for "blue/green", blue ( 青 , Ao ) now means "blue". But in certain contexts, green is still conventionally referred to as 青, as in blue traffic light ( 青信号 , ao shingō ) and blue leaves ( 青葉 , aoba ) , reflecting
1806-507: Is derived from the English word "green"). However, in Japan, although the traffic lights have the same colors as other countries have, the green light is described using the same word as for blue, aoi , because green is considered a shade of aoi; similarly, green variants of certain fruits and vegetables such as green apples, green shiso (as opposed to red apples and red shiso) will be described with
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#17328525196261892-425: Is missing or faulty, which can cause color blindness , including the common inability to distinguish red and yellow from green, known as deuteranopia or red-green color blindness. Green is restful to the eye. Studies show that a green environment can reduce fatigue. In the subtractive color system, used in painting and color printing, green is created by a combination of yellow and blue, or yellow and cyan ; in
1978-416: Is one such commonly used pigment. A typical formulation of process cyan is shown in the color box on the right. Green Green is the color between cyan and yellow on the visible spectrum . It is evoked by light which has a dominant wavelength of roughly 495–570 nm . In subtractive color systems, used in painting and color printing, it is created by a combination of yellow and cyan; in
2064-478: Is rarely found in Greek art. The Romans had a greater appreciation for the color green; it was the color of Venus , the goddess of gardens, vegetables and vineyards. The Romans made a fine green earth pigment that was widely used in the wall paintings of Pompeii , Herculaneum , Lyon , Vaison-la-Romaine , and other Roman cities. They also used the pigment verdigris, made by soaking copper plates in fermenting wine. By
2150-458: Is referred to as CMYK. In printing, the cyan ink is sometimes known as printer's cyan, process cyan, or process blue. While both the additive secondary and the subtractive primary are called cyan , they can be substantially different from one another. Cyan printing ink is typically more saturated than the RGB secondary cyan, depending on what RGB color space and ink are considered. That is, process cyan
2236-409: Is the color between blue and green on the visible spectrum of light . It is evoked by light with a predominant wavelength between 500 and 520 nm , between the wavelengths of green and blue. In the subtractive color system, or CMYK color model , which can be overlaid to produce all colors in paint and color printing, cyan is one of the primary colors , along with magenta and yellow . In
2322-507: Is the color most commonly associated in Europe and the United States with nature, vivacity and life. It is the color of many environmental organizations, such as Greenpeace , and of the Green Parties in Europe. Many cities have designated a garden or park as a green space, and use green trash bins and containers. A green cross is commonly used to designate pharmacies in Europe. In China, green
2408-689: Is the color most commonly associated with nature , life , health , youth , spring , hope , and envy . In the European Union and the United States , green is also sometimes associated with toxicity and poor health, but in China and most of Asia, its associations are very positive, as the symbol of fertility and happiness. Because of its association with nature, it is the color of the environmental movement . Political groups advocating environmental protection and social justice describe themselves as part of
2494-447: Is then passed through another crystal containing potassium, titanium and phosphorus (KTP), whose non-linear properties generate light at a frequency that is twice that of the incident beam (563.5 THz); in this case corresponding to the wavelength of 532 nm ("green"). Other green wavelengths are also available using DPSS technology ranging from 501 nm to 543 nm. Green wavelengths are also available from gas lasers , including
2580-647: Is used in some commercial and military aircraft as a transportable source of breathing oxygen. Because of its cryogenic nature, liquid oxygen can cause the materials it touches to become extremely brittle. Liquid oxygen is also a very powerful oxidizing agent: organic materials will burn rapidly and energetically in liquid oxygen. Further, if soaked in liquid oxygen , some materials such as coal briquettes, carbon black , etc., can detonate unpredictably from sources of ignition such as flames, sparks or impact from light blows. Petrochemicals , including asphalt , often exhibit this behavior. The tetraoxygen molecule (O 4 )
2666-506: Is usually outside the RGB gamut , and there is no fixed conversion from CMYK primaries to RGB. Different formulations are used for printer's ink, so there can be variations in the printed color that is pure cyan ink. This is because real-world subtractive (unlike additive) color mixing does not consistently produce the same result when mixing apparently identical colors, since the specific frequencies filtered out to produce that color affect how it interacts with other colors. Phthalocyanine blue
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2752-578: Is well camouflaged. There is no green pigment in green eyes; like the color of blue eyes, it is an optical illusion; its appearance is caused by the combination of an amber or light brown pigmentation of the stroma , given by a low or moderate concentration of melanin , with the blue tone imparted by the Rayleigh scattering of the reflected light. Nobody is brought into the world with green eyes. An infant has one of two eye hues: dark or blue. Following birth, cells called melanocytes start to discharge melanin,
2838-584: The Aztecs , who often featured this precious gemstone in vibrant frescoes for both symbolic and decorative purposes. The Aztecs revered turquoise, associating its color with the heavens and sacredness. Additionally, ancient Egyptians interpreted cyan hues as representing faith and truth, while Tibetans viewed them as a symbol of infinity. After earlier uses in various contexts, cyan hues found increased use in diverse cultures due to their appealing aesthetic qualities in religious structures and art pieces. For example,
2924-668: The German word grün , has the same root as the words grass and grow . It is from a Common Germanic *gronja - , which is also reflected in Old Norse grænn , Old High German gruoni (but unattested in East Germanic ), ultimately from a PIE root * ghre- "to grow", and root-cognate with grass and to grow . The first recorded use of the word as a color term in Old English dates to ca. AD 700. Latin with viridis also has
3010-537: The Green movement , some naming themselves Green parties . This has led to similar campaigns in advertising, as companies have sold green, or environmentally friendly , products. Green is also the traditional color of safety and permission; a green light means go ahead, a green card permits permanent residence in the United States. The word green comes from the Middle English and Old English word grene , which, like
3096-433: The RGB color model , used on television and computer screens, it is one of the additive primary colors , along with red and blue , which are mixed in different combinations to create all other colors. By far the largest contributor to green in nature is chlorophyll , the chemical by which plants photosynthesize and convert sunlight into chemical energy. Many creatures have adapted to their green environments by taking on
3182-454: The RGB color model , used on television and computer screens, it is one of the additive primary colors , along with red and blue, which are mixed in different combinations to create all other colors. On the HSV color wheel , also known as the RGB color wheel , the complement of green is magenta ; that is, a color corresponding to an equal mixture of red and blue light (one of the purples ). On
3268-629: The additive color system, or RGB color model , used to create all the colors on a computer or television display, cyan is made by mixing equal amounts of green and blue light . Cyan is the complement of red ; it can be made by the removal of red from white. Mixing red light and cyan light at the right intensity will make white light. Different shades of cyan can vary in terms of hue, chroma (also known as saturation, intensity, or colorfulness), or lightness (or value, tone, or brightness), or any combination of these characteristics. Differences in value can also be referred to as tints and shades, with
3354-622: The helium–neon laser (543 nm), the Argon- ion laser (514 nm) and the Krypton-ion laser (521 nm and 531 nm), as well as liquid dye lasers . Green lasers have a wide variety of applications, including pointing, illumination, surgery, laser light shows , spectroscopy , interferometry , fluorescence , holography , machine vision , non-lethal weapons , and bird control . As of mid-2011, direct green laser diodes at 510 nm and 500 nm have become generally available, although
3440-448: The 16th century was a good green dye produced, by first dyeing the cloth blue with woad, and then yellow with Reseda luteola , also known as yellow-weed. The pigments available to painters were more varied; monks in monasteries used verdigris, made by soaking copper in fermenting wine, to color medieval manuscripts. They also used finely-ground malachite, which made a luminous green. They used green earth colors for backgrounds. During
3526-449: The English adjective orange being in origin not a color term but the name of a fruit). Thus, the Thai word เขียว kheīyw , besides meaning "green", also means "rank" and "smelly" and holds other unpleasant associations. The Celtic languages had a term for "blue/green/grey", Proto-Celtic *glasto- , which gave rise to Old Irish glas "green, grey" and to Welsh glas "blue". This word
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3612-450: The RGB color model. A unique green (green appearing neither yellowish nor bluish) is produced on such a device by mixing light from the green primary with some light from the blue primary. Lasers emitting in the green part of the spectrum are widely available to the general public in a wide range of output powers. Green laser pointers outputting at 532 nm (563.5 THz ) are relatively inexpensive compared to other wavelengths of
3698-664: The Slavic zelenъ is cognate with Sanskrit harithah "yellow, ochre, golden". The Turkic languages also have jašɨl "green" or "yellowish green", compared to a Mongolian word for "meadow". In some languages, including old Chinese , Thai , old Japanese , and Vietnamese , the same word can mean either blue or green. The Chinese character 青 (pronounced qīng in Mandarin , ao in Japanese, and thanh in Sino-Vietnamese ) has
3784-466: The USAF started a program of building its own oxygen-generation facilities at all major consumption bases. Liquid oxygen is the most common cryogenic liquid oxidizer propellant for spacecraft rocket applications, usually in combination with liquid hydrogen , kerosene or methane . Liquid oxygen was used in the first liquid fueled rocket . The World War II V-2 missile also used liquid oxygen under
3870-415: The absence of blue-green distinction in old Japanese (more accurately, the traditional Japanese color terminology grouped some shades of green with blue, and others with yellow tones). In optics, the perception of green is evoked by light having a spectrum dominated by energy with a wavelength of roughly 495–570 nm . The sensitivity of the dark-adapted human eye is greatest at about 507 nm,
3956-403: The analogy to immature and unripe fruit. Examples include green cheese , a term for a fresh, unaged cheese, and greenhorn , an inexperienced person. The color green has been increasingly used by food companies, governments, and practitioners themselves to identify veganism and vegetarianism. The government of India requires food that is vegetarian to be marked with a green circle as part of
4042-610: The benches in the British House of Commons are green while those in the House of Lords are red. It also has a long historical tradition as the color of Ireland and of Gaelic culture . It is the historic color of Islam , representing the lush vegetation of Paradise . It was the color of the banner of Muhammad , and is found in the flags of nearly all Islamic countries. In surveys made in American , European, and Islamic countries , green
4128-417: The blue-green color is likely to be derived from small quantities of lead and water in the feldspar . Copper is the source of the green color in malachite pigments, chemically known as basic copper(II) carbonate . Verdigris is made by placing a plate or blade of copper, brass or bronze, slightly warmed, into a vat of fermenting wine, leaving it there for several weeks, and then scraping off and drying
4214-515: The bride in the Arnolfini portrait by Jan van Eyck . There were no good vegetal green dyes which resisted washing and sunlight for those who wanted or were required to wear green. Green dyes were made out of the fern , plantain , buckthorn berries, the juice of nettles and of leeks , the digitalis plant, the broom plant, the leaves of the fraxinus , or ash tree, and the bark of the alder tree, but they rapidly faded or changed color. Only in
4300-407: The color of the sea and the color of trees. The philosopher Democritus described two different greens: chloron , or pale green, and prasinon , or leek green. Aristotle considered that green was located midway between black, symbolizing the earth, and white, symbolizing water. However, green was not counted among the four classic colors of Greek painting – red, yellow, black and white – and
4386-733: The color of the stone. In the 1870s, the French sculptor Frédéric Bartholdi began the construction of what would later become the Statue of Liberty . Over time, exposure to the elements caused the copper structure to develop its distinctive patina , now recognized as iconic cyan. Following this, there was a significant advancement in the use of cyan during the late 19th and early 20th centuries. Impressionist artists, such as Claude Monet in his renowned Water Lilies , effectively incorporated cyan hues into their works. Deviating from traditional interpretations of local color under neutral lighting conditions,
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#17328525196264472-476: The comparative study of color terms in the world's languages, green is only found as a separate category in languages with the fully developed range of six colors (white, black, red, green, yellow, and blue), or more rarely in systems with five colors (white, red, yellow, green, and black/blue). These languages have introduced supplementary vocabulary to denote "green", but these terms are recognizable as recent adoptions that are not in origin color terms (much like
4558-484: The early Renaissance, painters such as Duccio di Buoninsegna learned to paint faces first with a green undercoat, then with pink, which gave the faces a more realistic hue. Over the centuries the pink has faded, making some of the faces look green. The 18th and 19th centuries brought the discovery and production of synthetic green pigments and dyes, which rapidly replaced the earlier mineral and vegetable pigments and dyes. These new dyes were more stable and brilliant than
4644-681: The earthy colored shade, in the child's irises. This begins happening since melanocytes respond to light in time. Green eyes are most common in Northern and Central Europe . They can also be found in Southern Europe , West Asia , Central Asia , and South Asia . In Iceland , 89% of women and 87% of men have either blue or green eye color. A study of Icelandic and Dutch adults found green eyes to be much more prevalent in women than in men. Neolithic cave paintings do not have traces of green pigments, but neolithic peoples in northern Europe did make
4730-427: The extraction of light were selected to exploit those portions of the spectrum not used by the halobacteria. Animals typically use the color green as camouflage , blending in with the chlorophyll green of the surrounding environment. Most fish, reptiles, amphibians, and birds appear green because of a reflection of blue light coming through an over-layer of yellow pigment. Perception of color can also be affected by
4816-423: The eye more than the long-wavelength L cones. Light which triggers this greenness response more than the yellowness or blueness of the other color opponent mechanism is called green. A green light source typically has a spectral power distribution dominated by energy with a wavelength of roughly 487–570 nm. Human eyes have color receptors known as cone cells, of which there are three types. In some cases, one
4902-413: The focus of artists was on accurately depicting perceived color and the influence of light on altering object hues. Specifically, daylight plays a significant role in shifting the perceived color of objects toward cyan hues. In 1917, the color term teal was introduced to describe deeper shades of cyan. In the late 19th century, while traditional nomenclature of red , yellow , and blue persisted,
4988-557: The following year, injuring the policeman who operated it. In 1912, the first modern electric traffic lights were put up in Salt Lake City , Utah . Red was chosen largely because of its high visibility, and its association with danger, while green was chosen largely because it could not be mistaken for red. Today green lights universally signal that a system is turned on and working as it should. In many video games, green signifies both health and completed objectives, opposite red. Green
5074-451: The god Osiris , king of the underworld, was depicted as green-skinned. Green as the color of hope is connected with the color of springtime; hope represents the faith that things will improve after a period of difficulty, like the renewal of flowers and plants after the winter season. Green the color most commonly associated in Europe and the United States with youth. It also often is used to describe anyone young, inexperienced, probably by
5160-399: The green of new growth". Thus, the languages mentioned above (Germanic, Romance, Slavic, Greek) have old terms for "green" which are derived from words for fresh, sprouting vegetation. However, comparative linguistics makes clear that these terms were coined independently, over the past few millennia, and there is no identifiable single Proto-Indo-European or word for "green". For example,
5246-571: The green powder that forms on the metal. The process of making verdigris was described in ancient times by Pliny . It was used by the Romans in the murals of Pompeii, and in Celtic medieval manuscripts as early as the 5th century AD. It produced a blue-green which no other pigment could imitate, but it had drawbacks: it was unstable, it could not resist dampness, it did not mix well with other colors, it could ruin other colors with which it came into contact, and it
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#17328525196265332-507: The hues evolved, the printing industry maintained the use of the traditional terms red , yellow , and blue . Consequently, pinpointing the exact date of origin for CMYK , in which cyan serves as a primary color, proves challenging . In August 1991, the HP Deskwriter 500C became the first Deskwriter to offer color printing as an option. It used interchangeable black and color (cyan, magenta, and yellow) inkjet print cartridges. With
5418-494: The inclusion of cyan ink in printers, the term "cyan" has become widely recognized in both home and office settings. According to TUP/Technology User Profile 2020, approximately 70% of online American adults regularly use a home printer. Its name is derived from the Ancient Greek word kyanos (κύανος), meaning "dark blue enamel, Lapis lazuli ". It was formerly known as "cyan blue" or cyan-blue, and its first recorded use as
5504-670: The lush green of rural landscapes and forests. Green was contrasted to the smoky grays and blacks of the Industrial Revolution. The second half of the 19th century saw the use of green in art to create specific emotions, not just to imitate nature. One of the first to make color the central element of his picture was the American artist James McNeill Whistler , who created a series of paintings called "symphonies" or "noctures" of color, including Symphony in gray and green; The Ocean between 1866 and 1872. The late 19th century also brought
5590-441: The more notable green minerals, however is the emerald , which is colored green by trace amounts of chromium and sometimes vanadium . Chromium(III) oxide (Cr 2 O 3 ), is called chrome green , also called viridian or institutional green when used as a pigment. For many years, the source of amazonite 's color was a mystery. Widely thought to have been due to copper because copper compounds often have blue and green colors,
5676-659: The name A-Stoff and Sauerstoff . In the 1950s, during the Cold War both the United States' Redstone and Atlas rockets, and the Soviet R-7 Semyorka used liquid oxygen. Later, in the 1960s and 1970s, the ascent stages of the Apollo Saturn rockets , and the Space Shuttle main engines used liquid oxygen. As of 2024, many active rockets use liquid oxygen: Cyan Cyan ( / ˈ s aɪ . ə n , - æ n / )
5762-439: The nitrogen has evaporated from such a vessel, there is a risk that liquid oxygen remaining can react violently with organic material. Conversely, liquid nitrogen or liquid air can be oxygen-enriched by letting it stand in open air; atmospheric oxygen dissolves in it, while nitrogen evaporates preferentially. The surface tension of liquid oxygen at its normal pressure boiling point is 13.2 dyn/cm. In commerce, liquid oxygen
5848-547: The price remains relatively prohibitive for widespread public use. The efficiency of these lasers (peak 3%) compared to that of DPSS green lasers (peak 35%) may also be limiting adoption of the diodes to niche uses. Many minerals provide pigments which have been used in green paints and dyes over the centuries. Pigments, in this case, are minerals which reflect the color green, rather that emitting it through luminescent or phosphorescent qualities. The large number of green pigments makes it impossible to mention them all. Among
5934-496: The printing industry initiated a shift towards utilizing magenta and cyan inks for red and blue hues, respectively. This transition aimed to establish a more versatile color gamut achievable with only three primary colors. In 1949, a document in the printing industry stated: “The four-color set comprises Yellow , Red (magenta) , Blue (cyan) , Black ”. This practice of labeling magenta , yellow , and cyan as red , yellow , and blue persisted until 1961. As
6020-505: The prominent dome of the Goharshad Mosque in Iran , built in 1418, showcases this trend. Additionally, Jacopo da Pontormo's use of a teal shade for Mary's robe in the 1528 painting Carmignano Visitation demonstrates the allure for these hues. During the 16th century, speakers of the English language began using the term turquoise to describe the cyan color of objects that resembled
6106-475: The roots of the woad plant. For the ancient Egyptians, green had very positive associations. The hieroglyph for green represented a growing papyrus sprout, showing the close connection between green, vegetation, vigor and growth. In wall paintings, the ruler of the underworld, Osiris , was typically portrayed with a green face, because green was the symbol of good health and rebirth. Palettes of green facial makeup, made with malachite, were found in tombs. It
6192-459: The same power, and are very popular due to their good beam quality and very high apparent brightness. The most common green lasers use diode pumped solid state ( DPSS ) technology to create the green light. An infrared laser diode at 808 nm is used to pump a crystal of neodymium- doped yttrium vanadium oxide (Nd:YVO4) or neodymium-doped yttrium aluminium garnet (Nd:YAG) and induces it to emit 281.76 THz (1064 nm). This deeper infrared light
6278-548: The second century AD, the Romans were using green in paintings, mosaics and glass, and there were ten different words in Latin for varieties of green. In the Middle Ages and Renaissance, the color of clothing showed a person's social rank and profession. Red could only be worn by the nobility, brown and gray by peasants, and green by merchants, bankers and the gentry and their families. The Mona Lisa wears green in her portrait, as does
6364-434: The stone with the same name, is a shade in the green spectrum of cyan hues. Celeste is a lightly tinted cyan that represents the color of a clear sky. Other colors in the cyan color range are electric blue , aquamarine , and others described as blue-green . Cyan boasts a rich and diverse history, holding cultural significance for millennia. In ancient civilizations, turquoise , valued for its aesthetic appeal, served as
6450-572: The surrounding environment. For example, broadleaf forests typically have a yellow-green light about them as the trees filter the light. Turacoverdin is one chemical which can cause a green hue in birds, especially. Invertebrates such as insects or mollusks often display green colors because of porphyrin pigments, sometimes caused by diet. This can causes their feces to look green as well. Other chemicals which generally contribute to greenness among organisms are flavins (lychochromes) and hemanovadin. Humans have imitated this by wearing green clothing as
6536-420: The systematic study of color theory, and particularly the study of how complementary colors such as red and green reinforced each other when they were placed next to each other. These studies were avidly followed by artists such as Vincent van Gogh . Describing his painting, The Night Cafe , to his brother Theo in 1888, Van Gogh wrote: "I sought to express with red and green the terrible human passions. The hall
6622-400: The vegetable dyes, but some contained high levels of arsenic , and were eventually banned. In the 18th and 19th centuries, green was associated with the romantic movement in literature and art. The German poet and philosopher Goethe declared that green was the most restful color, suitable for decorating bedrooms. Painters such as John Constable and Jean-Baptiste-Camille Corot depicted
6708-426: The walls of tombs or on papyrus, Egyptian artists used finely ground malachite , mined in the west Sinai and the eastern desert; a paintbox with malachite pigment was found inside the tomb of King Tutankhamun . They also used less expensive green earth pigment, or mixed yellow ochre and blue azurite . To dye fabrics green, they first colored them yellow with dye made from saffron and then soaked them in blue dye from
6794-433: The wavelengths that appear green to the human eye, so light reflected by plants is enriched in green. Chlorophyll absorbs green light poorly because it first arose in organisms living in oceans where purple halobacteria were already exploiting photosynthesis. Their purple color arose because they extracted energy in the green portion of the spectrum using bacteriorhodopsin . The new organisms that then later came to dominate
6880-487: The word aoi . Vietnamese uses a single word for both blue and green, xanh , with variants such as xanh da trời (azure, lit. "sky blue"), lam (blue), and lục (green; also xanh lá cây , lit. "leaf green"). "Green" in modern European languages corresponds to about 520–570 nm, but many historical and non-European languages make other choices, e.g. using a term for the range of ca. 450–530 nm ("blue/green") and another for ca. 530–590 nm ("green/yellow"). In
6966-430: Was toxic . Leonardo da Vinci , in his treatise on painting, warned artists not to use it. It was widely used in miniature paintings in Europe and Persia in the 16th and 17th centuries. Its use largely ended in the late 19th century, when it was replaced by the safer and more stable chrome green . Viridian, as described above, was patented in 1859. It became popular with painters, since, unlike other synthetic greens, it
7052-620: Was a new synthetic green created by a chemist named Pannetier in Paris in about 1835. Emerald green was a synthetic deep green made in the 19th century by hydrating chrome oxide. It was also known as Guignet green. There is no natural source for green food colorings which has been approved by the US Food and Drug Administration . Chlorophyll, the E numbers E140 and E141, is the most common green chemical found in nature, and only allowed in certain medicines and cosmetic materials. Quinoline Yellow (E104)
7138-461: Was crushed, washed to remove impurities, then powdered. It was sometimes called Green of Verona. Mixtures of oxidized cobalt and zinc were also used to create green paints as early as the 18th century. Cobalt green , sometimes known as Rinman's green or zinc green, is a translucent green pigment made by heating a mixture of cobalt (II) oxide and zinc oxide. Sven Rinman , a Swedish chemist, discovered this compound in 1780. Green chrome oxide
7224-526: Was first predicted in 1924 by Gilbert N. Lewis , who proposed it to explain why liquid oxygen defied Curie's law . Modern computer simulations indicate that, although there are no stable O 4 molecules in liquid oxygen, O 2 molecules do tend to associate in pairs with antiparallel spins , forming transient O 4 units. Liquid nitrogen has a lower boiling point at −196 °C (77 K) than oxygen's −183 °C (90 K), and vessels containing liquid nitrogen can condense oxygen from air: when most of
7310-681: Was stable and not toxic. Vincent van Gogh used it, along with Prussian blue , to create a dark blue sky with a greenish tint in his painting Café Terrace at Night . Green earth is a natural pigment used since the time of the Roman Empire . It is composed of clay colored by iron oxide , magnesium , aluminum silicate , or potassium . Large deposits were found in the South of France near Nice , and in Italy around Verona , on Cyprus , and in Bohemia . The clay
7396-429: Was worn by both the living and the dead, particularly around the eyes, to protect them from evil. Tombs also often contained small green amulets in the shape of scarab beetles made of malachite, which would protect and give vigor to the deceased. It also symbolized the sea, which was called the "Very Green". In Ancient Greece, green and blue were sometimes considered the same color, and the same word sometimes described
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