"bottom, forming one blob once again. Severe cases can require many heat-cool cycles to clear. In 2015, a new design was introduced into the market that uses ferrofluid in place of wax. British accountant Edward Craven-Walker had the idea for the lava lamp in 1963 after watching a homemade egg timer, which was made from a cocktail shaker filled with liquids, as it was bubbling on a stove top in a pub. He hired British inventor David George Smith to develop the device and the chemical formula required put his idea into practice. Smith is credited as the inventor on"
"discharge is contained in a ceramic tube, usually made of sintered alumina, similar to what has been used in the high pressure sodium lamp. During operation, the temperature of this ceramic tube can exceed 1200 kelvins. The ceramic tube is filled with mercury, argon and metal-halide salts (for example, sodium iodide). Because of the high wall temperature, the metal halide salts are partly vaporized. Inside the hot plasma, these salts are dissociated into metallic atoms and iodine. The metallic atoms are the main source of light in these lamps, creating a bluish light that is close to daylight with a"
"usually provided in the form of light or electric current, but more exotic sources have been used, such as chemical or nuclear reactions. A laser pumped with an arc lamp or a flashlamp is usually pumped through the lateral wall of the lasing medium, which is often in the form of a crystal rod containing a metallic impurity or a glass tube containing a liquid dye, in a condition known as ""side-pumping."" To use the lamp's energy most efficiently, the lamps and lasing medium are contained in a reflective cavity that will redirect most of the lamp's energy into the"
"the knowledge of the ultimate reality – ""tamaso ma jyotirgamaya"". Earlier lamps were made out of stone or seashells. The shape was like a circular bowl with a protruding beak. Later they were replaced by earthen and metal lamps. In the epics Ramayana and Mahabharata, there are references to gold and silver lamps as well. The simple shape evolved and the lamps were created in the shapes of the matsya (fish), kurma (Tortoise) and other incarnations of god Vishnu and also in the shape of the many emblems of gods like conch shells, lotuses and so on. The birds like"
"temples or ""deepams"". These lamps are extensively ornamented. The materials used to make the lamp are box-moulded, wax-moulded, or loam-moulded. These are made in an open space where fire hazards are of the least concern. To facilitate proper moulding, the key component materials used are: the brown vandal sand exclusively drawn from the Cauvery river bed about 1 km from the Nachiarkoil town used in all types of moulding; ""Karuman sand"" (used for wax moulding) of pale red colour, available in the town itself; ""Savuttu sand"", available in light grey colour, used in wax moulding and available in the tank"
"Halogen lamp A halogen lamp, also known as a tungsten halogen, quartz-halogen or quartz iodine lamp, is an incandescent lamp consisting of a tungsten filament sealed into a compact transparent envelope that is filled with a mixture of an inert gas and a small amount of a halogen such as iodine or bromine. The combination of the halogen gas and the tungsten filament produces a halogen cycle chemical reaction which redeposits evaporated tungsten to the filament, increasing its life and maintaining the clarity of the envelope. For this to happen, a halogen lamp must be operated at a higher temperature"
"light lamps work similarly to other fluorescent lamps, but use a phosphor on the inner tube surface which emits UVA radiation instead of visible light. Some lamps use a deep-bluish-purple Wood's glass optical filter that blocks almost all visible light with wavelengths longer than 400 nanometres. Others use plain glass instead of the more expensive Wood's glass, so they appear light-blue to the eye when operating. A black light may also be formed, very inefficiently, by using a layer of Wood's glass in the envelope for an incandescent bulb. Though cheaper than fluorescent UV lamps, only 0.1% of the input"
"atria in the National Air and Space Museum. Sulfur lamp The sulfur lamp (also sulphur lamp) is a highly efficient full-spectrum electrodeless lighting system whose light is generated by sulfur plasma that has been excited by microwave radiation. They are a particular type of plasma lamp, and one of the most modern. The technology was developed in the early 1990s, but, although it appeared initially to be very promising, sulfur lighting was a commercial failure by the late 1990s. Since 2005, lamps are again being manufactured for commercial use. The sulfur lamp consists of a golf ball-sized (30 mm) fused-quartz"
"Camphine Camphine, the burning fluid lamp fuel, not to be confused with camphene, the chemical. Camphine was the trade name of a purified spirit of turpentine formerly used for lamps, generally prepared by distilling turpentine with quicklime. Camphine gives a very brilliant light when burned in a lamp, but, to prevent smoking, the lamp must have a very strong draft. To achieve this special lamps were constructed, called Vesta lamps. Liebig describes camphine as a blend of 1 part purified turpentine with three parts 93 to 94% grain alcohol. “It gives a very white light, not as bright as pure"
"gas containing low-pressure mercury vapor and argon, xenon, neon, or krypton. The pressure inside the lamp is around 0.3% of atmospheric pressure. The inner surface of the lamp is coated with a fluorescent (and often slightly phosphorescent) coating made of varying blends of metallic and rare-earth phosphor salts. The lamp's electrodes are typically made of coiled tungsten and usually referred to as cathodes because of their prime function of emitting electrons. For this, they are coated with a mixture of barium, strontium and calcium oxides chosen to have a low thermionic emission temperature. Fluorescent lamp tubes are typically straight and"
"in the image on the right. Fluorescent lamp A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than incandescent lamps. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. Fluorescent lamp fixtures are more costly"
"distrust of London-based, theoretical, scientific experts. The lamp consists of a wick lamp with the flame enclosed inside a mesh screen. The screen acts as a flame arrestor; air (and any firedamp present) can pass through the mesh freely enough to support combustion, but the holes are too fine to allow a flame to propagate through them and ignite any firedamp outside the mesh. It originally burned a heavy vegetable oil. The lamp also provided a test for the presence of gases. If flammable gas mixtures were present, the flame of the Davy lamp burned higher with a blue tinge."
"Plasma globe A plasma globe or plasma lamp (also called plasma ball, dome, sphere, tube or orb, depending on shape) is a clear glass container filled with a mixture of various noble gases with a high-voltage electrode in the center of the container. When voltage is applied, a plasma is formed within the container. Plasma filaments extend from the inner electrode to the outer glass insulator, giving the appearance of multiple constant beams of colored light (see corona discharge and electric glow discharge). Plasma globes were most popular as novelty items in the 1980s. The plasma lamp was invented by"
"Lava (soap) Lava is a heavy-duty hand cleaner, originally produced in soap bar form, developed by the Waltke Company of St. Louis in 1893. It is currently manufactured by the WD-40 Company, who acquired the brand from Block Drug in 1999, who acquired it from Procter & Gamble in 1995. Unlike typical hand soaps, Lava contains ground pumice, which gave the soap its name. The soap and pumice combination is intended to scour tar, engine grease, paint, dirt, grime, filth, and similar substances from the skin. Lava soap is currently available in three forms, a red wrapper bar , a"
"Plasma lamp Plasma lamps are a type of gas discharge lamp energized by radio frequency (RF) power. They are distinct from the novelty plasma lamps that were popular in the 1980s. The internal-electrodeless lamp was invented by Tesla after his experimentation with high-frequency currents in evacuated glass tubes for the purposes of lighting and the study of high voltage phenomena. The first practical plasma lamps were the sulfur lamps manufactured by Fusion Lighting. This lamp suffered a number of practical problems and did not prosper commercially. Plasma lamps with an internal phosphor coating are called external electrode fluorescent lamps (EEFL);"
"Lava Lava is molten rock generated by geothermal energy and expelled through fractures in planetary crust or in an eruption, usually at temperatures from . The structures resulting from subsequent solidification and cooling are also sometimes described as ""lava"". The molten rock is formed in the interior of some planets, including Earth, and some of their satellites, though such material located below the crust is referred to by other terms. A lava flow is a moving outpouring of lava created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock. The term ""lava flow"""
"Fluorescent lamp A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than incandescent lamps. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. Fluorescent lamp fixtures are more costly than incandescent lamps because they require"
"well as in stage lighting. They were briefly used in some projection televisions. Plasma lamp Plasma lamps are a type of gas discharge lamp energized by radio frequency (RF) power. They are distinct from the novelty plasma lamps that were popular in the 1980s. The internal-electrodeless lamp was invented by Tesla after his experimentation with high-frequency currents in evacuated glass tubes for the purposes of lighting and the study of high voltage phenomena. The first practical plasma lamps were the sulfur lamps manufactured by Fusion Lighting. This lamp suffered a number of practical problems and did not prosper commercially. Plasma"
"and business partner of the inventor. They also showed the biggest lava lamp in the world in London’s South Bank Centre. In 2016 Mathmos launched Neo, the first lava lamp tested for children and adults, and opened a “Special Projects” division offering giant bespoke lava lamps. The first one is in Selfridges, London as part the new accessories department designed by David Chipperfield. Mathmos Mathmos is a British company that sells lighting products, most famously the lava lamp invented by its founder Edward Craven Walker. It is headquartered in its factory in Poole, Dorset. The Astro lamp, or lava lamp,"
"a very low pressure, along with a few milligrams of mercury. The lamp electrodes usually consists of a double or triply coiled tungsten wire covered with substances, such as alkaline metal oxides, that readily emits free electrons, aiding the ionization of the gas and thereby initiating and sustaining the electric arc. The inner walls of the tube are coated with a thin layer of fluorescent substances, which, when they are excited by the line of UV radiation from a mercury arc, emits visible light, usually in the range of 6500K (daylight) colour temperature. The spectral characteristics (coloration) of such a"
"to the gas. Additionally, a high voltage power source is necessary to energize the gas as a trigger event. A charged capacitor is usually used to supply energy for the flash, so as to allow very speedy delivery of very high electrical current when the lamp is triggered. The glass envelope is most commonly a thin tube, often made of fused quartz, borosilicate or Pyrex, which may be straight, or bent into a number of different shapes, including helical, ""U"" shape, and circular (to surround a camera lens for shadowless photography—'ring flashes'). In some applications, the emission of ultraviolet light"
"are sealed into each end and an AC voltage is applied to them through molybdenum foil seals fused in silica. It is the arc between the two electrodes where the light is actually created. Besides mercury vapor, the lamp contains iodides or bromides of different metals. Iodine and bromine are of the halogen group of the periodic table, and so are termed ""halides"" when ionized. Scandium and sodium are also used in some types, with thallium, indium, and sodium in European ""Tri-Salt"" models. More recent types use dysprosium for high color temperature and tin for lower color temperature. Holmium and"
"Sulfur lamp The sulfur lamp (also sulphur lamp) is a highly efficient full-spectrum electrodeless lighting system whose light is generated by sulfur plasma that has been excited by microwave radiation. They are a particular type of plasma lamp, and one of the most modern. The technology was developed in the early 1990s, but, although it appeared initially to be very promising, sulfur lighting was a commercial failure by the late 1990s. Since 2005, lamps are again being manufactured for commercial use. The sulfur lamp consists of a golf ball-sized (30 mm) fused-quartz bulb containing several milligrams of sulfur powder and"
"Shiva laser The Shiva laser was a powerful 20-beam infrared neodymium glass (silica glass) laser built at Lawrence Livermore National Laboratory in 1977 for the study of inertial confinement fusion (ICF) and long-scale-length laser-plasma interactions. Presumably, the device was named after the multi-armed form of the Hindu god Shiva, due to the laser's multi-beamed structure. Shiva was instrumental in demonstrating a particular problem in compressing targets with lasers, leading to a major new device being constructed to address these problems, the Nova laser. The basic idea of any ICF device is to rapidly heat the outer layers of a ""target"","
"Sodium-vapor lamp A sodium-vapor lamp is a gas-discharge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm. Two varieties of such lamps exist: ""low pressure"" and ""high pressure"". Low-pressure sodium lamps are highly efficient electrical light sources, but their yellow light restricts applications to outdoor lighting, such as street lamps. High-pressure sodium lamps emit a broader spectrum of light than the low-pressure lamps, but they still have poorer color rendering than other types of lamps. Low-pressure sodium lamps only give monochromatic yellow light and so inhibit color vision at night. Low-pressure"
"Metal-halide lamp A metal-halide lamp is an electrical lamp that produces light by an electric arc through a gaseous mixture of vaporized mercury and metal halides (compounds of metals with bromine or iodine). It is a type of high-intensity discharge (HID) gas discharge lamp. Developed in the 1960s, they are similar to mercury vapor lamps, but contain additional metal halide compounds in the quartz arc tube, which improve the efficiency and color rendition of the light. The most common metal halide compound used is sodium iodide. Once the arc tube reaches its running temperature, the sodium dissociates from the iodine,"
"with the hot electrons (~50 keV) in the plasma which formed when the outer layers of the target were heated, via stimulated raman scattering. John Holzrichter, director of the ICF program at the time, said: The laser beam generates a dense plasma where it impinges on the target material. The laser light gives up its energy to the electrons in the plasma, which absorb the light. The rate at which that happens depends on the wavelength and the intensity. On Shiva, we were heating up electrons to incredible energies, but the targets were not performing well. We tried a lot"
"High-intensity discharge lamp High-intensity discharge lamps (HID lamps) are a type of electrical gas-discharge lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. This tube is filled with noble gas and often also contains suitable metal or metal salts. The noble gas enables the arc's initial strike. Once the arc is started, it heats and evaporates the metallic admixture. Its presence in the arc plasma greatly increases the intensity of visible light produced by the arc for a given power input, as the"
"is commonly shortened to ""lava"". Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties. Explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word ""lava"" comes from Italian, and is probably derived from the Latin word ""labes"" which means a fall or slide. The first use in connection with extruded magma (molten rock below the Earth's surface) was apparently in a short account written by Francesco Serao on the eruption of"
"iodide. The particular mixture of metal halides influences the correlated color temperature and intensity (making the light more blue or red, for example). When started, the argon gas in the lamp is ionized first, which helps to maintain the arc across the two electrodes with the applied starting voltage. The heat generated by the arc and electrodes then ionizes the mercury and metal halides into a plasma, which produces an increasingly-brighter harsh white light as the temperature and pressure increases to operating conditions. The arc-tube operates at anywhere from 5–50 atm or more (70–700 psi or 500–5000 kPa) and 1000–3000"
"lamp. Still, they are quite bright compared to similar devices. However, they are best viewed in darkness. Their transformers can also be linked to an acoustic modulator, allowing the tubes to 'respond' to music or ambient noise. Crackle tube A crackle tube is a type of plasma lamp that is used most commonly in museums, night clubs, movie sets, and other applications where its appearance may be appealing for entertainment. Such a device consists of a double walled glass tube with a hollow center. The cavity between the inner and outer glass tubes is filled with thousands of small phosphor"
"sodium (LPS) lamps have a borosilicate glass gas discharge tube (arc tube) containing solid sodium, a small amount of neon, and argon gas in a Penning mixture to start the gas discharge. The discharge tube may be linear (SLI lamp) or U-shaped. When the lamp is first started, it emits a dim red/pink light to warm the sodium metal; within a few minutes as the sodium metal vaporizes, the emission becomes the common bright yellow. These lamps produce a virtually monochromatic light averaging a 589.3 nm wavelength (actually two dominant spectral lines very close together at 589.0 and 589.6 nm)."
"Lava dome In volcanology, a lava dome or volcanic dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on earth are lava dome forming. The geochemistry of lava domes can vary from basalt (e.g. Semeru, 1946) to rhyolite (e.g. Chaiten, 2010) although the majority are of intermediate composition (such as Santiaguito, dacite-andesite, present day) The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained"