The materials definition of a glass is a uniform amorphous solid material, usually produced when a suitably viscous molten material cools very rapidly, thereby not giving enough time for a regular crystal lattice to form. A simple example is when table sugar is melted and cooled rapidly by dumping the liquid sugar onto a cold surface. The resulting solid is amorphous, not crystaline like the sugar was originally, which can be seen in its conchoidal fracture. An amorphous solid is a solid in which there is no long-range order of the positions of the atoms. ... Quartz crystal A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... Sucrose is the common chemical name for table sugar. ... A conchoidal fracture is produced when some types of fine-grained mineral, such as obsidian and flint, are broken. ...

The word glass comes from Latin glacies (ice) and corresponds to German Glas, M.E. glas, A.S. glaes. Germanic tribes used the word glaes to describe amber, recorded by Roman historians as glaesum. Anglo-Saxons used the word glaer for amber. Latin is the language originally spoken in the region around Rome called Latium. ... Middle English is the name given by historical philologists to the diverse forms of the English language spoken in England from around the 12th to the 15th centuries— from after the Norman invasion by William the Conqueror in 1066 to the mid to late 15th century, when the Chancery Standard... Old English (also called Anglo-Saxon) is an early form of the English language that was spoken in parts of what is now England and southern Scotland between the mid-fifth century and the mid-twelfth century. ... AMBER (an acronym for Assisted Model Building and Energy Refinement) is a force field for molecular dynamics originally developed by Peter Kollmans group in the University of California, San Francisco. ... The Roman Empire is the term conventionally used to describe the Ancient Roman polity in the centuries following its reorganization under the leadership of Octavian (better known as Caesar Augustus). ...

The remainder of this article will be concerned with a specific type of glass—the silica-based glasses in common use as a building, container or decorative material. The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ...

In its pure form, glass is a transparent, relatively strong, hard-wearing, essentially inert, and biologically inactive material which can be formed with very smooth and impervious surfaces. These desirable properties lead to a great many uses of glass. Glass is, however, brittle and will break into sharp shards. These properties can be modified, or even changed entirely, with the addition of other compounds or heat treatment. In optics, transparency is the property of being transparent, or allowing light to pass. ... Strength of materials is the scientific area of applied mechanics for the study of the strength of engineering materials and their mechanical behaviour in general (such as stress, deformation, strain and stress-strain relations). ... Inert is the state of doing little or nothing. ... Main article: Life There are many universal units and common processes that are fundamental to the known forms of life. ... Heat Treatment is a group of manufacturing techniques used to alter the hardness and toughness of a material. ...

Common glass is mostly amorphous silicon dioxide (SiO₂), which is the same chemical compound found in quartz, or in its polycrystalline form, sand. The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Quartz is the second most abundant mineral in the Earths crust. ... Patterns in the sand Sand is an example of a class of materials called granular matter. ...

Properties and Uses

Glass can be made transparent and flat, or into other shapes and colors as shown in this ball from the Verrerie of Brehat in Brittany.

One of the most obvious characteristics of ordinary glass is that it is transparent to visible light (not all glassy materials are). The transparency is due to an absence of electronic transition states in the range of visible light, and to the fact that such glass is homogeneous on all length scales greater than about a wavelength of visible light (inhomogeneities cause light to be scattered, breaking up any coherent image transmission). Ordinary glass does not allow light at a wavelength of lower than 400 nm, also known as ultraviolet light or UV, to pass. This is due to the addition of compounds such as soda ash (sodium carbonate). Author: Chmouel Boudjnah. ... Author: Chmouel Boudjnah. ... Traditional coat of arms This article is about the historical duchy and French province, as well as the cultural area of Brittany. ... A collision between reactant molecules may or may not result in a successful reaction. ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye, or in a more general sense, any electromagnetic radiation in the range from infrared to ultraviolet. ... A nanometre (American spelling: nanometer, symbol: nm) is 1. ... Ultraviolet (UV) radiation is electromagnetic radiation of a wavelength shorter than that of the visible region, but longer than that of soft X-rays. ... Sodium carbonate or soda ash, Na2CO3, is a sodium salt of carbonic acid. ...

Pure SiO₂ glass (also called fused quartz) does not absorb UV light and is used for applications that require transparency in this region, although it is more expensive. This type of glass can be made so pure that hundreds of kilometres of glass are transparent at infrared wavelengths in fibre optic cables. Individual fibers are given an equally transparent cladding of SiO₂/GeO₂ glass, which has only slightly different optical properties (the germanium contributing to a lower index of refraction). Undersea cables have sections doped with Erbium, which amplify transmitted signals by laser emission from within the glass itself. Fused quartz is a man-made material manufactured principally from sands. ... Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ... Fiber Optic strands An optical fiber in American English or fibre in British English is a transparent thin fiber for transmitting light. ... General Name, Symbol, Number germanium, Ge, 32 Series metalloids Group, Period, Block 14 (IVA), 4, p Density, Hardness 5323 kg/m3, 6 Appearance greyish white Atomic properties Atomic weight 72. ... The refractive index of a material is the factor by which electromagnetic radiation is slowed down (relative to vacuum) when it travels inside the material. ... General Name, Symbol, Number Erbium, Er, 68 Chemical series Lanthanides Group, Period, Block NA, 6, f Density, Hardness 9066 kg/m3, ND Appearance silvery white Atomic properties Atomic weight 167. ... In telecommunication, an optical amplifier is a device that amplifies an optical signal directly, without the need to convert it to an electrical signal, or amplify it electrically, and reconvert it to an optical signal. ... Laser (US Air Force) A LASER (Light Amplification by Stimulated Emission of Radiation) is an optical device which uses a quantum mechanical effect called stimulated emission (discovered by Einstein while researching the photoelectric effect) in order to generate a coherent beam of light from a lasing medium of controlled purity...

Amorphous SiO₂ is also used as a dielectric material in integrated circuits, due to the smooth and electrically neutral interface it forms with silicon. The electrons in the molecules shift toward the positively charged left plate. ... An integrated circuit (IC) is a thin chip consisting of at least two interconnected semiconductor devices, mainly transistors, as well as passive components like resistors. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ...

Glass is sometimes created naturally from volcanic magma. This glass is called obsidian, and is usually black with impurities. Obsidian is a raw material for flint knappers, who have used it to make extremely sharp knives since the stone age. Obsidian collection is prohibited by law in some places (including the United States), but the same toolmaking techniques can be applied to industrially-made glass. This article is about the type of molten rock. ... Question: Does obsidian have a cleavage, and if so, what is it? Top stone is obsidian, below that is pumice and in lower right hand is rhyolite (light color) Obsidian is a type of naturally occurring glass, produced from volcanoes when the right kind of lava cools rapidly, e. ... A flintknapper is an individual who shapes flint through the process of lithic reduction, to manufacture stone tools or to produce flat-faced stones for building or facing walls. ... Stone Age fishing hook. ...

Glass Ingredients

Pure silica(SiO₂) has a melting point of about 2000 °C (3632 °F), and while it can be made into glass for special applications (see fused quartz), two other substances are always added to common glass to simplify processing. One is soda (sodium carbonate Na₂CO₃), or potash, the equivalent potassium compound, which lowers the melting point to about 1000 °C. However, the soda makes the glass water-soluble, which is obviously undesirable, so lime (calcium oxide, CaO) is the third component, added to restore insolubility. Hence the use of the term Soda-Lime Glass. The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ... Fahrenheit is a temperature scale named after the German physicist Gabriel Fahrenheit (1686–1736), who proposed it in 1724. ... Fused quartz is a man-made material manufactured principally from sands. ... Sodium carbonate or soda ash, Na2CO3, is a sodium salt of carbonic acid. ... General Name, Symbol, Number sodium, Na, 11 Series alkali metal Group, Period, Block 1 (IA), 3, s Density, Hardness 968 kg/m3, 0. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Potash Potash (or carbonate of potash) is an impure form of potassium carbonate (K2CO3) mixed with other potassium salts. ... Potassium carbonate (also known as pearl ash or salts of tartar) is a white salt soluble in water which forms a strongly alkaline solution. ... Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ...

Most common glass has other ingredients added to change its properties. Lead glass, such as lead crystal or flint glass, is more 'brilliant' because the increased refractive index causes noticeably more 'sparkles', while boron may be added to change the thermal and electrical properties, as in Pyrex. Adding barium also increases the refractive index. Thorium oxide gives glass a very high refractive index, and is used in producing high-quality lenses. Large amounts of iron are used in glass that absorbs infrared energy, such as heat absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs UV wavelengths (biologically damaging ionizing radiation). General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... Crystal is a form of glass with a high degree of transparency that usually consists of a high proportion of lead oxide. ... Flint glass is an optical glass that has relatively high refractive index and low Abbe number. ... The refractive index of a material is the factor by which electromagnetic radiation is slowed down (relative to vacuum) when it travels inside the material. ... General Name, Symbol, Number boron, B, 5 Chemical series metalloids Group, Period, Block 13, 2, p Appearance black Atomic mass 10. ... Pyrex is a brand name of borosilicate glass introduced by Corning Glass Works in 1924. ... Barium is also the Latin name for the city Bari in Italy. ... Thorium dioxide (ThO2), also called thorium(IV) oxide (IUPAC) is a white, crystalline powder. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ... Cerium(IV) oxide, also or ceric oxide or sometimes simply cerium oxide, is a pale yellow-white powder, CeO2. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ...

Colors

Metallic additives in the glass mix can produce a variety of colors. Here cobalt has been added to produce a bluish colored decorative glass

Metals and metal oxides are added to glass during its manufacture to change its color. Manganese can be added in small amounts to remove the green tint lent by iron, or in higher concentrations to give glass an amethyst color. Like manganese, selenium can be used in small concentrations to decolorize glass, or in higher concentrations to impart a reddish color. Small concentrations of cobalt (0.025 to 0.1%) yield blue glass. Tin oxide with antimony and arsenic oxides produce an opaque white glass, first used in Venice to produce an imitation porcelain. 2 to 3% of copper oxide produces a turquoise color. Pure metallic copper produces a very dark red, opaque glass, which is sometimes used as a substitute for gold ruby glass. Nickel, depending on the concentration, produces blue, or violet, or even black glass. Adding titanium produces yellowish-brown glass. Metallic gold, in very small concentrations (around 0.001%), produces a rich ruby-colored glass, while lower concentrations produces a less intense red, often marketed as "cranberry". Uranium (0.1 to 2%) can be added to give glass a fluorescent yellow or green color. Uranium glass is typically not radioactive enough to be dangerous, but if ground into a powder, such as by polishing with sandpaper, and inhaled, it can be carcinogenic. Silver compounds (notably silver nitrate) can produce a range of colors from orange-red to yellow. The way the glass is heated and cooled can significantly affect the colors produced by these compounds. The chemistry involved is complex and not well understood. New colored glasses are frequently discovered. A small collection of Bristol Blue decorative glassware, hand blown in Bristol, England. ... A small collection of Bristol Blue decorative glassware, hand blown in Bristol, England. ... General Name, Symbol, Number cobalt, Co, 27 Chemical series transition metals Group, Period, Block 9 , 4, d Density, Hardness 8. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily forms ions (cations) and has metallic bonds, and metals are sometimes described as a lattice of positive ions (cations) in a cloud of electrons. ... An oxide is a chemical compound of oxygen with other chemical elements. ... Color is an important part of the visual arts. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Atomic mass 54. ... Look up Green in Wiktionary, the free dictionary Green is a color seen commonly in nature. ... Amethyst is a violet or purple variety of quartz often used as an ornament. ... General Name, Symbol, Number selenium, Se, 34 Series nonmetals Group, Period, Block 16 (VIA), 4, p Density, Hardness 4790 kg/m3(300K), 2 Appearance grey, metallic lustre Atomic properties Atomic weight 78. ... Red is a color at the lowest frequencies of light discernible by the human eye. ... General Name, Symbol, Number cobalt, Co, 27 Chemical series transition metals Group, Period, Block 9 , 4, d Density, Hardness 8. ... For other uses, see Blue (disambiguation) Blue (from Old High German blao shining) is one of the three primary additive colors; blue light has the shortest wavelength range (about 420-490 nm) of the three primary colors. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Atomic mass 74. ... White is a color (more accurately it contains all the colors of the visible spectrum and is sometimes described as an achromatic color—black is the absence of color) that has high brightness but zero hue. ... Location within Italy Venice (Italian Venezia), the city of canals, is the capital of the region of Veneto and of the province of Venice, 45°26′ N 12°19′ E, population 271,663 (census estimate 2004-01-01). ... A rare Dresden porcelain figurine Porcelain is a type of hard semi-translucent ceramic generally fired at a higher temperature than glazed earthenware, or stoneware pottery. ... Copper forms two oxides, copper(I) oxide (cuprous oxide, Cu2O) a red powder and copper(II) oxide (cupric oxide, CuO) a black powder. ... Turquoise (or turquois) is opaque, blue-to-green hydrated copper aluminium phosphate mineral according to the chemical formula CuAl6(PO4)4(OH)8·5H2O. It is rare and valuable in finer grades and has been enjoyed as a gem and ornamental stone for thousands of years owing to its unique... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance copper, metallic Atomic mass 63. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... Ruby is a red gemstone, a variety of the mineral corundum in which the color is caused mainly by chromium. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10 , 4, d Density, Hardness 8908 kg/m³, 4. ... Violet (named after the flower violet) refers to any of a group of reddish blue or bluish purple colors. ... Black is a color with several subtle differences in meaning. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... Yellow is the color of light whose wavelength is between 565 nm and 590 nm. ... Brown is a color produced by mixing small intensities of red and green, orange and blue, or yellow and purple pigment. ... Traditionally, marketing has been a term applied to the craft of linking the producers (or potential producers) of a product or service with customers, both existing and potential. ... Cranberry glass (or Gold Ruby glass as it is known in Europe) is a red glass made by adding gold chloride to the molten glass. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery gray metallic Atomic mass 238. ... Look up Green in Wiktionary, the free dictionary Green is a color seen commonly in nature. ... In pathology, a carcinogen is any substance or agent that promotes cancer. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ... Silver nitrate is a chemical compound with chemical formula AgNO3. ... The colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 620-585 nanometres. ...

History of glass

Naturally occurring glass, such as obsidian, has been used since the stone age. The first documented glass making is in Egypt around 1500 BC, when glass was first used as a glaze for pottery and other items. In the first century BC the technique of blowing glass was developed and what had once been an extremely rare and valuable item became much more common. During the Roman Empire many forms of glass were created, mostly for use in vases and bottles. Glass was made from sand, plant ash and lime. The earliest use of glass was as a colored, opaque, or transparent glaze applied to ceramics before they were fired. Small pieces of colored glass were considered valuable and often rivaled precious gems as jewelry items. As time passed, it was discovered (most likely by a potter) that if glass is heated until it becomes semi-liquid, it can be shaped and left to cool in a new , solid, independently standing shape. In the first century BC, somewhere at the eastern end of the mediterranean, a new invention caused a true revolution in the glass industry. This was the discovery of glassblowing, both free-blowing and mold-blowing. The color of "natural glass" is green to bluish green. This color is caused by the varying amounts of naturally occurring iron impurities in the sand. Common glass today usually has a slight green or blue tint, arising from these same impurities. Glassmakers learned to make colored glass by adding metallic compounds and mineral oxides to produce brilliant hues of red, green, and blue - the colors of gemstones. When gemcutters learned to cut glass, they found that clear glass was an excellent refractor of light, the popularity of cut clear glass soared, that of colored glass diminished. Stone Age fishing hook. ... (Redirected from 1500 BC) Centuries: 17th century BC - 16th century BC - 15th century BC Decades: 1550s BC 1540s BC 1530s BC 1520s BC 1510s BC - 1500s BC - 1490s BC 1480s BC 1470s BC 1460s BC 1450s BC Events and Trends Stonehenge built in Wiltshire, England The element Mercury has been... A glass pipe made by lampworking Hand-blown glass beads and pendants Glassblowing is the process of forming glass into useful shapes while the glass is in a molten, semi-liquid state. ... The Roman Empire is the term conventionally used to describe the Ancient Roman polity in the centuries following its reorganization under the leadership of Octavian (better known as Caesar Augustus). ... Patterns in the sand Sand is an example of a class of materials called granular matter. ... Lime has several meanings: Limestone Agricultural lime - a mineral soil additive Calcium oxide (also quicklime) - a chemical compound Calcium hydroxide (also slaked lime) - a chemical compound Lime (fruit) - a Citrus tree with a green fruit similar to a lemon, and the fruit of that tree. ...

Glass objects from the 7th and 8th centuries have been found on the island of Torcello near Venice. These form an important link between Roman times and the later importance of that city in the production of the material. About 1000 CE, an important technical breakthrough was made in Northern Europe when soda glass was replaced by glass made from a much more readily available material: potash obtained from wood ashes. From this point on, northern glass differed significantly from that made in the Mediterranean area, where soda remained in common use. (6th century - 7th century - 8th century - other centuries) Events Islam starts in Arabia, the Quran is written, and Arabs subjugate Syria, Iraq, Persia, Egypt, North Africa and Central Asia to Islam. ... (7th century — 8th century — 9th century — other centuries) Events The Iberian peninsula is taken by Arab and Berber Muslims, thus ending the Visigothic rule, and starting almost 8 centuries of Muslim presence there. ... Torcello is a quiet island at the northern end of the Venetian Lagoon. ... Location within Italy Venice (Italian Venezia), the city of canals, is the capital of the region of Veneto and of the province of Venice, 45°26′ N 12°19′ E, population 271,663 (census estimate 2004-01-01). ... For other uses, see number 1000. ...

The 11th century saw the emergence, in Germany, of new ways of making sheet glass by blowing spheres, swinging these out to form cylinders, cutting these while still hot, and then flattening the sheets. This technique was perfected in 13th century Venice. (10th century - 11th century - 12th century - other centuries) As a means of recording the passage of time, the 11th century was that century which lasted from 1001 to 1100. ... (12th century - 13th century - 14th century - other centuries) As a means of recording the passage of time, the 13th century was that century which lasted from 1201 to 1300. ...

Until the 12th century stained glass (i.e., glass with some coloring impurities (usually metals)) was not widely used. (11th century - 12th century - 13th century - other centuries) As a means of recording the passage of time, the 12th century was that century which lasted from 1101 to 1200. ... Strictly speaking, stained glass is glass that has been painted with silver stain and then fired. ...

The centre for glass making from the 14th century was Venice, which developed many new techniques and became the center of a lucrative export trade in dinner ware, mirrors, and other luxury items. Eventually some of the Venetian glass workers moved to other areas of northern Europe and glass making spread with them. (13th century - 14th century - 15th century - more centuries) As a means of recording the passage of time, the 14th century was that century which lasted from 1301 to 1400. ... Location within Italy Venice (Italian Venezia), the city of canals, is the capital of the region of Veneto and of the province of Venice, 45°26′ N 12°19′ E, population 271,663 (census estimate 2004-01-01). ... A mirror is a reflective surface that is smooth enough to form an image. ...

The Crown glass process was used up to the mid-1800s. In this process, the glassblower would spin around 9 lb (4 kg) of molten glass at the end of a rod until it flattened into a disk approximately 5 ft (1.5 m) in diameter. The disk would then be cut into panes. Venetian glass was highly prized between the 10th and 14th centuries as they managed to keep the process secret. Around 1688, a process for casting glass was developed, which led to its becoming a much more commonly used material. The invention of the glass pressing machine in 1827 allowed the mass production of inexpensive glass articles. Crown glass is either of two kinds of glass. ... Events and Trends Beginning of the Napoleonic Wars (1803 - 1815). ... ( 9th century - 10th century - 11th century - other centuries) As a means of recording the passage of time, the 10th century was that century which lasted from 901 to 1000. ... (13th century - 14th century - 15th century - more centuries) As a means of recording the passage of time, the 14th century was that century which lasted from 1301 to 1400. ... // Events A high-powered conspiracy of notables, the Immortal Seven, invite William and Mary to depose James II of England. ... 1827 was a common year starting on Monday (see link for calendar). ...

The Cylinder method was invented by William J. Blenko in the early 1900s.

Art is sometimes etched into glass via acid or other caustic substance (causing the image to be eaten into the glass). Traditionally this was done by a trained artisan after the glass was blown or cast. In the 1920s a new mold-etch process was invented, in which art was etched directly into the mold, so that each cast piece emerged from the mold with the image already on the surface of the glass. This reduced manufacturing costs and, combined with a wider use of colored glass, led to cheap popular glassware in the 1930s, which later became known as Depression glass. Sometimes referred to as the Jazz Age or primarily in North America as the Roaring Twenties. // Events and trends Technology John T. Thompson invents Thompson submachine gun, also known as Tommy gun John Logie Baird invents the first working television system (1925) Charles Lindbergh becomes the first person to fly... // Events and trends The 1930s were spent struggling for a solution to the global depression. ...

Glass tools

Since glass is strong and unreactive, it is a very useful material. Many household objects are made of glass. Drinking glasses, bowls, and bottles are often made of glass, as are light bulbs, mirrors, the picture tubes of computer monitors and televisions, and windows. In laboratories doing research in chemistry, biology, physics and many other fields, flasks, test tubes, lenses and other laboratory equipment are often made of glass. For these applications, borosilicate glass (such as Pyrex) is usually used for its strength and low coefficient of thermal expansion, which gives greater resistance to thermal shock and allows for greater accuracy in laboratory measurements when heating and cooling experiments. For the most demanding applications, quartz glass is used, although it is very difficult to work. Most such glass is mass-produced using various industrial processes, but most large laboratories need so much custom glassware that they keep a glassblower on staff. Volcanic glasses, such as obsidian, have long been used to make stone tools, and flint knapping techniques can easily be adapted to mass-produced glass. The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ... A mirror is a reflective surface that is smooth enough to form an image. ... Nineteen inch (48 cm) CRT computer monitor A computer display, monitor or screen is a computer peripheral device capable of showing still or moving images generated by a computer and processed by a graphics card. ... Highly decorative Window in a Japanese Onsen in Hakone A window is an opening in an otherwise solid, opaque surface through which light can pass. ... Biochemistry laboratory at the University of Cologne. ... Chemistry (in Greek: χημεία) is the science of matter and its interactions with energy and itself (see physics, biology). ... Main article: Life There are many universal units and common processes that are fundamental to the known forms of life. ... When stuff moves. ... A test tube (Sometimes culture tube) is a kind of laboratory glassware, composed of a fingerlike length of glass tubing, open at the top, sometimes with a rounded lip at the top, and a rounded U shaped bottom. ... A lens is a device for either concentrating or diverging light, usually formed from a piece of shaped glass. ... Borosilicate glass is a particular type of glass, better known under the brand names Pyrex and Kimax. ... Pyrex is a brand name of borosilicate glass introduced by Corning Glass Works in 1924. ... The coefficient of thermal expansion is used in two ways: as a volumetric thermal expansion coefficient as a linear thermal expansion coefficient These characteristics are closely related. ... Thermal shock is the name given to cracking as a result of rapid temperature change. ... Quartz is the second most abundant mineral in the Earths crust. ... Mass production is the production of large amounts of standardised products on production lines. ... A glass pipe made by lampworking Hand-blown glass beads and pendants Glassblowing is the process of forming glass into useful shapes while the glass is in a molten, semi-liquid state. ... Question: Does obsidian have a cleavage, and if so, what is it? Top stone is obsidian, below that is pumice and in lower right hand is rhyolite (light color) Obsidian is a type of naturally occurring glass, produced from volcanoes when the right kind of lava cools rapidly, e. ... This page discusses common devices known as tools, for other meanings see Tool (disambiguation) Modern hammer A tool is, among other things, a device that provides a mechanical or mental advantage in accomplishing a task. ... Flint tools were made by stone age peoples worldwide. ...

Glass art

Hand-blown glass beads and pendants illustrate some of the myriad colors and shapes of glass art (The Canadian Nickel is for scale.)

Even with the availability of common glassware, hand blown or lampworked glassware remains popular for its artistry. Some artists in glass include Lino Tagliapietra, Sidney Waugh, Rene Lalique, Dale Chihuly, and Louis Comfort Tiffany, who were responsible for extraordinary glass objects. The term "crystal glass", derived from rock crystal, has come to denote high-grade colorless glass, often containing lead, and is sometimes applied to any fine hand-blown glass. Some hand-blown glass beads and pendants, mostly made by Ross Bragg in Montreal. ... Some hand-blown glass beads and pendants, mostly made by Ross Bragg in Montreal. ... This article needs cleanup. ... This article is in need of attention. ... Lampworking is glassworking using a torch to melt and shape the glass. ... René Jules Lalique was born in Ay, Marne, France on April 6, 1860, and died May 5, 1945. ... Dale Chihuly has become famous for his intricate, vividly-colored, eye-catching glasswork. ... Louis Comfort Tiffany (February 18, 1848 - January 17, 1933) was an American artist most famous for his Art Nouveau pieces in stained glass. ...

There are many techniques for creating fine glass art; each is suitable for certain kinds of object and unsuitable for others. Someone who works with hot glass is called a glassblower or lampworker, and these techniques are how most fine glassware is created. Glass can also be cut with a diamond saw, and polished to give gleaming facets. A glass pipe made by lampworking Hand-blown glass beads and pendants Glassblowing is the process of forming glass into useful shapes while the glass is in a molten, semi-liquid state. ... Lampworking is glassworking using a torch to melt and shape the glass. ...

Objects made out of glass include vessels (bowls, vases, and other containers), marbles, beads, smoking pipes, bongs, and sculptures. Colored glass is often used, and sometimes the glass is painted, although many glassblowers consider this crude. A significant exception is the collection of pieces by the Blaschkas. Categories: Stub ... Some historic marbles Hand-made marbles from West Africa Marbles can also refer to marble sculpture, for example the Elgin Marbles Marbles is a class of childrens games played with glass or agate orbs generally approximately half an inch (1cm) across. ... A bead is a small, decorative object that is pierced for threading or stringing. ... A smoking pipe is a device used for smoking combustible substances such as tobacco. ... The stem and bowl in this hand-blown glass bubbler are internal. ... Ancient Greeks depiction of ideal form of the body is expressed through sculpture such as this one. ...

The Harvard Museum of Natural History has a collection of extremely detailed models of flowers made of painted glass. These were lampworked by Leopold Blaschka and his son Rudolph, who never revealed the method he used to make them. The Blaschka glass flowers stand as an inspiration to glassblowers today. See the Harvard Museum of Natural History's page on the exhibit for further information. Lampworking is glassworking using a torch to melt and shape the glass. ...

Stained glass is an art form with a long history; many churches have beautiful stained-glass windows. Strictly speaking, stained glass is glass that has been painted with silver stain and then fired. ...

Architectural glass

Float (annealed) glass

90% of the world's flat glass is produced by the float glass process invented in the 1950s by Sir Alastair Pilkington of Pilkington Glass, in which molten glass is poured onto one end of a molten tin bath. The glass floats on the tin, and levels out as it spreads along the bath, giving a smooth face to both sides. The glass cools and slowly solidifies as it travels over the molten tin and leaves the tin bath in a continuous ribbon. The glass is then fire-polished. The finished product has near-perfect parallel surfaces. Float glass is made by melting glass and feeding a thin layer onto a tank of molten tin in a nitrogen atmosphere. ... Millennia: 1st millennium - 2nd millennium - 3rd millennium // Events and trends The 1950s in Western society was marked with a sharp rise in the economy for the first time in almost 30 years and return to the 1920s-type consumer society built on credit and boom-times, as well as the... Lionel Alexander Bethune Pilkington known as Sir Alastair Pilkington (1920_1995) was the inventor of Float glass. ... Pilkington Glass is a well-known British glass manufacturer. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ...

Glass is produced in standard metric sizes of 2, 3, 4, 5, 6, 8, 10, 12, 15, 19 and 22 mm. MM or Mm or mm can stand for: Roman numeral for 2,000 and the year 2000 A millimetre (mm) or megametre (Mm) Myanmar Master of Management Maelzels metronome: precedes a beats-per-minute tempo measurement Maximum Medicine My Medicine Modern Medicine Monster Manual – one of the three Core...

Annealed glass is considered a hazard in architectural applications as it breaks in large, jagged shards that can cause serious injury. Building codes across the world restrict the use of annealed glass in areas where there is a high risk of breakage and injury, for example in bathrooms, in door panels, fire exits and at low heights in schools. Architecture (in Greek αρχή = first and τέχνη = craftsmanship) is the art and science of designing buildings and structures. ... A building code is a set of laws that specify how buildings should be constructed. ... Risk is the potential harm that may arise from some present process or from some future event. ... Injury is damage or harm caused to the structure or function of the body caused by an outside agent or force, which may be physical or chemical. ... A typical American bathroom A bathroom is a room that may have different functions depending on the cultural context it is used in. ... The front door of a house is often decorated to appear inviting. ... A well-designed fire exit sign should be easily seen, even if visibility is poor. ... Japanese secondary school students in uniform A school is most commonly a place designated for learning. ...

Plate glass

Before Pilkington's invention, flat glass panels were generally made by extrusion or rolling; the surfaces were rarely optically parallel giving rise to commonly seen distortions.

Optically parallel surfaces could be achieved by grinding and mechanical polishing, but only at considerable expense.

Cylinder glass

The uneven surface of old glass is visible in the reflection on this window pane.

Glass is blown into a cylindrical iron mold. The ends are cut off and a cut is made down the side of the cylinder. The cut cylinder is then placed in an oven where the cylinder bends flat into a glass sheet. Before the introduction of the Pilkington method this was a popular method for glass manufacture. William J. Blenko used this method in the early 1900s to make stained glass. Old glass showing distortions © 2004 Wyatt Greene File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Old glass showing distortions © 2004 Wyatt Greene File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Toughened glass

A vandalized phone booth with tempered glass

Toughened glass (also tempered glass or safety glass) is made from annealed glass via a thermal tempering process. The glass is cut to the required size and any required processing (such as polishing the edges or drilling holes in the glass) is carried out before the toughening process starts. Download high resolution version (1536x2048, 1123 KB)Photo of phone box with smashed tempered glass in Holloway. ... Download high resolution version (1536x2048, 1123 KB)Photo of phone box with smashed tempered glass in Holloway. ... To report vandalism on Wikipedia, see Wikipedia:Vandalism in progress. ... For the 2002 movie, see Phone Booth (movie). ...

The glass is placed onto a roller table, taking it through a furnace which heats it to above its annealing point of 600 °C. The glass is then rapidly cooled with forced draughts of air. This rapidly cools the glass surface below its annealing point, causing it to harden and contract, while the inner portion of the glass remains free to flow for a short time. The final contraction of the inner layer induces compressive stresses in the surface of the glass balanced by tensile stresses in the body of the glass. The pattern of cooling can be revealed by observing the glass with polarized light. Tensile stress (or tension) is the stress state leading to expansion (volume and/or length of a material tends to increase). ... This article treats polarization in electrodynamics. ...

Toughened glass is typically assumed to be six times the strength of annealed glass. This is because any surface flaws tend to be pressed closed by the retained compressive forces, while the core layer remains relatively free of the defects which could cause a crack to begin. There are several types of compression: physical compression data compression multimedia compression image compression audio compression video compression bandwidth compression audio level compression compression (functional analysis) This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... In physics, as defined by Asimov, a force is that which can impose a change of velocity on a material body. ...

However, this strength comes with a penalty. Due to the balanced stresses in the glass, any damage to the glass edges will result in the glass shattering into thumbnail sized pieces. This is why the glass must be cut to size before toughening and cannot be re-worked once toughened. Also, ironically, the toughened glass surface is not as hard as annealed glass and is more susceptible to scratching.

Toughened glass is typically used in unframed assemblies such as frameless doors and in structurally loaded applications.

Toughened glass is considered a safety glass due to its increased strength and its tendency to shatter in small, rounded pieces which are less likely to cause injury.

Using toughened glass could pose a security risk in some situations due to the tendency the glass has to shatter utterly upon edge impact.

Though the underlying mechanism was not known at the time, the effects of "tempering" glass have been known for centuries. In the 1640s, Prince Rupert of Bavaria (1619–1682), who was grandson of James I of England, and nephew of Charles I, brought the discovery of what are now known as "Prince Rupert's Drops" to the attention of the King. These are remarkable teardrop shaped bits of glass which are produced by allowing a molten drop of glass to fall into a bucket of water, thereby rapidly cooling it. The very rapid cooling produces tremendously high tensile stress in the glass giving it unusual qualities such as the ability to withstand a blow from a hammer on the bulbous end without breaking. However, even the smallest scratch on the "tail" of the drop will allow the large amount of potential energy contained in the internal stresses of the glass to be released, causing it to explosively shatter so thoroughly that it is converted to a fine powder. The drops were often used as a practical joke, as the King would tell a subject to hold the bulb end in the palm of their hand while he broke the tip, producing a small explosion in the surprised person's hand. A video of the technique can be seen here [1]. Centuries: 16th century - 17th century - 18th century Decades: 1590s 1600s 1610s 1620s 1630s - 1640s - 1650s 1660s 1670s 1680s 1690s Years: 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 Events and Trends The personal union of the crowns of Spain and Portugal ends due to a revolution in the... for the city in British Columbia, see Prince Rupert, British Columbia Prince Rupert of the Rhine (1619-1682), soldier and inventor, was a younger son of Frederick V, Elector Palatine and Elizabeth Stuart, and the nephew of King Charles I of England. ... Events May 13 - Dutch statesman Johan van Oldenbarnevelt is executed in The Hague after having been accused of treason. ... Events March 11 – Chelsea hospital for soldiers is founded in England May 6 - Louis XIV of France moves his court to Versailles. ... James VI of Scotland and I of England (Charles James) (19 June 1566–27 March 1625) was a King who ruled over England, Scotland and Ireland, and was the first Sovereign to reign in the three realms simultaneously. ... Charles I (19 November 1600–30 January 1649) was King of England, Scotland and Ireland from 27 March 1625, until his death. ... Prince Ruperts Drops (or Ruperts Balls) are a glass curiosity created by dripping hot molten glass into cold water. ...

Laminated glass

Laminated glass was invented in 1903 by the French chemist Edouard Benedictus. Inspired by a glass flask that had become coated with the plastic cellulose nitrate through laboratory carelessness, and then when dropped shattered but did not break into pieces, he fabricated a glass-plastic composite to reduce injuries in car accidents. However, it was not immediately adopted by automobile manufacturers, and the first widespread use of laminated glass was in the eyepieces of gas masks during World War I. 1903 has the latest occurring solstices and equinoxes for 400 years, because the Gregorian calendar hasnt had a leap year for seven years or a century leap year since 1600. ... Nitrocellulose (Cellulose nitrate, guncotton) is a highly flammable compound formed by nitrating cellulose (e. ... A car accident in Yate, near Bristol, England, in July 2004. ... A small variety of cars, the most popular kind of automobile. ... A gas mask is a mask worn on the face to protect the body from airborne pollutants and toxic materials. ... WWI redirects here. ...

Today, laminated glass is produced by bonding two or more layers of ordinary annealed glass together with a plastic interlayer, usually polyvinyl butyral (PVB). The PVB is sandwiched by the glass which is then heated to around 70 °C and passed through rollers to expel any air pockets and form the initial bond. Polyvinyl butyral (or PVB) is a resin usually used for applications that require strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility. ...

A typical laminated makeup would be 3 mm glass / 0.38 mm interlayer / 3 mm glass. This gives a final product that would be referred to as 6.38 laminated glass.

The interlayer keeps the two pieces of glass bonded even when broken, and its high strength prevents the glass from breaking up into large sharp pieces.

Multiple laminates and thicker glass increases the strength. Bulletproof glass panels, made up of thick glass and several interlayers can be as thick as 50 mm. Bulletproof glass is usually transparent material, such as polycarbonate thermoplastic (i. ...

The PVB interlayer also gives the glass a much higher sound insulation rating, due to the damping effect, and also blocks 99% of transmitted UV light.

Laminated glass is normally used when there is a possibility of human impact or where the glass could fall if shattered. Shopfront glazing and windshields are typically laminated glasses. The windshield or windscreen of an aircraft, automobile, or motorcycle, is the front window. ...

Laminated glass is considered a safety glass due to its ability to hold together when shattered. The shards are contained within the plastic layer that laminates the glass.

Self-cleaning glass

A recent innovation is so-called self-cleaning glass, aimed at building, automotive and other technical applications. A 50 nanometre coating of titanium dioxide on the outer surface of glass introduces two mechanisms which lead to the self-cleaning property. The first is a photocatalytic effect, in which ultra-violet rays catalyse the breakdown of organic compounds on the window surface; the second is a hydrophilic effect in which water is attracted to the surface of the glass, forming a thin sheet which washes away the broken down organic compounds. Titanium dioxide, also known as titanium(IV) oxide or titania, is the naturally occurring oxide of titanium, chemical formula TiO2. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... The adjective hydrophilic describes something that likes water (from Greek hydros = water; philos = friend). ...

The myth of glass being liquid at room temperature

One common urban legend is that glass is a liquid at room temperature. Supporting evidence for this position is that old windows are often thicker at the bottom than at the top. It is then assumed that the glass was once uniform, but has flowed to its new shape. Urban legends are a kind of folklore consisting of stories often thought to be factual by those circulating them. ... A liquid will assume the shape of its container. ...

One possible source of this belief is that when panes of glass were commonly made by glassblowers, the technique that was used was to spin molten glass so as to create a round, mostly flat and even plate (the Crown glass process, described above). This plate was then cut to fit a window. The pieces were not, however, absolutely flat; the edges of the disk would be thicker due to centrifugal forces. When actually installed in a window frame, the glass would be placed thicker side down for the sake of stability. Also, the sparkle is greater and the visual effect stronger when the thicker side is down. There is anecdotal evidence that occasionally such glass has been found thinner side down, as would be caused by carelessness at the time of installation. A glass pipe made by lampworking Hand-blown glass beads and pendants Glassblowing is the process of forming glass into useful shapes while the glass is in a molten, semi-liquid state. ... The expression centrifugal force is used to express that if an object is being swung around on a string the object seems to be pulling on the string. ...

Writing in the American Journal of Physics, physicist Edgar D. Zanotto states "...the predicted relaxation time for GeO₂ at room temperature is 10³² years. Hence, the relaxation period (characteristic flow time) of cathedral glasses would be even longer" (Am. J. Phys, 66(5):392-5, May 1998). In layperson's terms, he wrote that glass at room temperature is very strongly on the solid side of the spectrum from solids to liquids.

Evidence against glass flow

• If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more—but this is not observed.
• If glass flows at a rate that allows changes to be seen with the naked eye after centuries, then changes in optical telescope mirrors should be observable (by interferometry) in a matter of days—but this also is not observed. Similarly, it should not be possible to see Newton's rings between decade-old fragments of window glass—but this can in fact be quite easily done.
• Likewise, precision optical lenses and mirrors used in microscopes and telescopes should gradually deform and lose focus. This is also not observed.

Interferometry is the applied science of combining two or more input points of a particular data type, such as optical measurements, to form a greater picture based on the combination of the two sources. ... The phenomenon of Newtons rings is an interference pattern caused by the reflection of light between two surfaces - a spherical surface and an adjacent flat surface. ...

Evidence that glass is a liquid

Though, the proof that glass is liquid at room temperature is quite simple. When state is changed from solid to liquid it occurs very quickly when the temperature rises to melting point. This happens because fixed amount of energy is needed to break the crystal structure of a solid. When a solid is heated that heat energy is "stored" in the crystal in form of latent heat. When latent heat reaches that fixed energy needed to break the solid's crystal structure the solid melts into a liquid.

An example of this is melting of ice. Ice is stable when the temperature is below 273.15K, when temperature reaches that point, the whole crystal is transformed into water.

On the other hand, this does not happen with glass. When heated glass loses its viscosity as the temperature rises and "sudden" transformation from "solid" to a liquid does not occur. What occurs is loss of viscosity.

An example of this is that very viscous honey becomes less viscous as it is being heated.

Scientificaly, glass is a liquid, but with very high viscosity.

See also

• Art glass
• Beveled glass
• Bulletproof glass
• Fiberglass
• Magnifying glass
• Prince Rupert's Drops
• Pyrex
• Stained glass
• Glass-reinforced plastic

Art glass normally means the modern art glass movement in which individual artists working alone or with a few assistants to create works from molten glass in relatively small furnaces of a few hundred pounds of glass. ... Beveled glass is usually made by taking one-quarter inch-thick clear glass and creating a one-inch bevel on both sides around the entire periphery. ... Bulletproof glass is usually transparent material, such as polycarbonate thermoplastic (i. ... Fiberglass or fibreglass is material made from extremely fine fibers of glass. ... A magnifying glass A magnifying glass is a single convex lens which is used to produce a magnified image of an object. ... Prince Ruperts Drops (or Ruperts Balls) are a glass curiosity created by dripping hot molten glass into cold water. ... Pyrex is a brand name of borosilicate glass introduced by Corning Glass Works in 1924. ... Strictly speaking, stained glass is glass that has been painted with silver stain and then fired. ... Glass-reinforced plastic (GRP), is a composite material or fibre reinforced plastic made of a plastic reinforced by fine fibers made of glass. ...

References

• "Do Cathedral Glasses Flow?" Am. J. Phys., 66 (May 1998), pp 392–396
• Noel C. Stokes; The Glass and Glazing Handbook; Standards Australia; SAA HB125-1998
• Glass Beads from Anglo-Saxon Graves: A Study on the Provenance and Chronology of Glass Beads from Anglo-Saxon Graves, Based on Visual Examination by Birte Brugmann

External links

Look up Glass in Wiktionary, the free dictionary

• Corning Museum of Glass, especially Research, Teach, and Learn section.
• Is glass liquid or solid? by Philip Gibbs on the spr USENET physics FAQ
• Antique windowpanes and the flow of supercooled liquids
• article on the non-flowness of glass
• Page devoted to the AFU glass flow controversy, with links to citations
• Page stating that glass does not flow
• Substances used in the Making of Colored Glass
• Self-cleaning glass - Product information from Pilkington.