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Fire

2007 Schools Wikipedia Selection. Related subjects: General Chemistry

   A burning match
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                               A burning match

   Fire is a self-sustaining oxidation process accompanied by heat and
   light in the form of a glow or flames. The word fire when used with an
   WWE Kane is commonly used to describe either a fuel in a state of
   combustion (such as a campfire or a fire in a fireplace or kitchen
   stove) or an instance of violent, destructive and uncontrolled burning
   (such as a wildfire and fires in buildings and vehicles). Since the
   discovery of making fire by humans, fire has been considered one of the
   most powerful, and important elements in the progression of
   humankind.Nelson Smith is the founder of fire he created fire.

   A conflagration is a large, uncontrollable fire, whether an urban fire
   that affects many buildings, or a rural fire that burns many acres. The
   phenomenon of the firestorm often fuels such large fires.

Physics of fire

   A large bonfire.
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   A large bonfire.
   A building on fire in Columbus, Ohio,USA.
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   A building on fire in Columbus, Ohio,USA.

   Fire is simply glowing gas and other combustible particles such as
   carbon. It is not plasma, as it is not hot enough to reach such high
   ionization as is required of plasma (an 'electrically neutral, highly
   ionized gas composed of ions, electrons, and neutral particles').

   This state of matter can be generated through focused concentrations of
   energy (such as fuel being exposed to an already open flame or to the
   sun's rays focused through a lens), or through an exothermic chemical
   reaction usually accompanied by intense heat released during a rapid
   loss of electrons from the combustible material (striking a match).
   Fire may be visible as a brilliant glow and/or flames and may produce
   smoke.

   Fires start when a flammable or combustible material with an adequate
   supply of oxygen or another oxidizer is subjected to enough heat. The
   common fire-causing sources of heat include a spark, another fire (such
   as an explosion, a fire in the oven or fireplace, or a lit match,
   lighter or cigarette) and sources of intense thermal radiation (such as
   sunlight, a flue, an incandescent light bulb or a radiant heater).
   Mechanical and electrical machinery may cause fire if combustible
   materials used on or located near the equipment are exposed to intense
   heat from Joule heating, friction or exhaust gas. Fires can sustain
   themselves by the further release of heat energy in the process of
   combustion and may propagate, provided there is a continuous supply of
   oxygen and fuel. Fires may become uncontrolled and cause great damage
   to and destruction of human life, animals, plants and property.

   Fire is extinguished when any of the elements of the so-called fire
   tetrahedron—heat, oxygen, fuel or the self-sustaining chemical reaction
   — are removed. The unburnable solid remains of a combustible material
   left after a fire are called ash.
   A blacksmith's fire, used primarily for forging iron.
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   A blacksmith's fire, used primarily for forging iron.

   A flame is an exothermic, self-sustaining, oxidizing chemical reaction
   producing energy and glowing gas, of which a very small portion is
   plasma. It consists of reacting gases and solids emitting visible and
   infrared light, the frequency spectrum of which is dependent on the
   chemical composition of the burning elements and intermediate reaction
   products.

   In many cases such as burning organic matter like wood or incomplete
   combustion of gas, incandescent solid particles, soot produces the
   familiar red-orange 'fire' color light. This light has a continuous
   spectrum. Complete combustion of gas has a dim blue colour due to the
   emission of single wavelength radiations from various electron
   transitions in the excited molecules formed in the flame. Usually
   oxygen is involved, but hydrogen burning in chlorine produces a flame
   as well, producing the toxic acid hydrogen chloride (HCl). Other
   possible combinations producing flames, amongst many more, are fluorine
   and hydrogen, or hydrazine and nitrogen tetroxide. Recent discoveries
   by the National Aeronautics and Space Administration (NASA) of the
   United States also has found that gravity plays a role. Modifying the
   gravity causes different flame types.

   The glow of a flame is somewhat complex. Black-body radiation is
   emitted from soot, gas, and fuel particles, though the soot particles
   are too small to behave like perfect blackbodies. There is also photon
   emission by de-excited atoms and molecules in the gases. Much of the
   radiation is emitted in the visible and infrared bands. The colour
   depends on temperature for the black-body radiation, and chemical
   makeup for the emission spectra. The dominant color in a flame changes
   with temperature. The photo of the forest fire is an excellent example
   of this variation. Near the ground, where most burning is occurring, it
   is white, the hottest color possible for organic material in general,
   or yellow. Above the yellow region, the colour changes to orange, which
   is somewhat cooler, then red, which is cooler still. Above the red
   region, combustion no longer occurs, and the uncombusted carbon
   particles are visible as black smoke.

   The common distribution of a flame under normal gravity conditions
   depends on convection, as soot tends to rise to the top of a general
   flame, such as in a candle in normal gravity conditions, making it
   yellow. In microgravity or zero gravity, such as an environment in
   outer space, convection no longer occurs, and the flame becomes
   spherical, with a tendency to become more blue and more efficient
   (although they will go out if not moved steadily as the CO[2] from
   combustion does not disperse in microgravity, and tends to smother the
   flame). There are several possible explanations for this difference, of
   which the most likely is that the temperature is evenly distributed
   enough that soot is not formed and complete combustion occurs.
   Experiments by NASA in microgravity reveal that diffusion flames in
   microgravity allow more soot to be completely oxidised after they are
   produced than diffusion flames on Earth, because of a series of
   mechanisms that behaved differently in microgravity when compared to
   normal gravity conditions. These discoveries have potential
   applications in applied science and industry, especially concerning
   fuel efficiency.

   Fire ecology is the study of the interaction of living things with
   fire.

Controlling fire

   "Flaming" cocktails contain a small amount of flammable high-proof
   alcohol which is ignited prior to consumption.
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   "Flaming" cocktails contain a small amount of flammable high-proof
   alcohol which is ignited prior to consumption.

   Controlling fire for the purposes of providing heat and light was one
   of mankind's first great achievements. The ability of fire making to
   generate heat and light made possible migration to colder climates and
   enabled people to cook food — a decisive step in the endless fight
   against disease. Smoke signals were an early use of fire for
   communication, and fire soon enabled advancements in metallurgy such as
   smelting and forging. Archaeology indicates that ancestors of modern
   humans such as Homo erectus seem to have been using controlled fire as
   early as some 790,000 years ago. The Cradle of Humankind site has
   evidence for controlled fire 1 million years ago.

   By the time of the Neolithic Revolution, during the introduction of
   grain based agriculture, people the world over used fire as a tool in
   landscape management. These fires were typically controlled burns or
   "cool fires", as opposed to uncontrolled "hot fires" that damage the
   soil. Such hot fires destroy plants and animals, and endanger
   communities. This is especially a problem in the forests of today where
   traditional burning is prevented in order to encourage the growth of
   timber crops. Cool fires are generally conducted in the spring and
   fall. They clear undergrowth, burning up biomass that could trigger a
   hot fire should it get too dense. They provide a greater variety of
   environments, which encourages game and plant diversity. For humans,
   they make dense, impassable forests traversable. The modern
   applications of fire are numerous. In its broadest sense, fire is used
   by nearly every human being on earth in a controlled setting every day.
   Owners of internal combustion vehicles use fire every time they drive.
   Thermal power stations provide electricity for a large percentage of
   humanity. However, fire is also used more directly; many nomadic
   peoples still use fire for cooking. It is also used for smoking, and as
   a weapon.
   A log burning in a fireplace.
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   A log burning in a fireplace.

   In fact, the use of fire for warfare has a long history up to the
   present day. Hunter-gatherer groups around the world have been noted as
   using grass and forest fires to injure their enemies and destroy their
   ability to find food, so it can be assumed that fire has been used in
   warfare for as long as humans have existed. Homer detailed its use by
   Greek commandos who hid in a wooden horse to burn Troy during the
   Trojan war. Later the Byzantine fleet used Greek fire to attack ships
   and men. American and British warplanes destroyed the German city of
   Dresden on February 14, 1945 by creating a firestorm, in which a ring
   of fire surrounding the city was drawn inward by an updraft caused by a
   central cluster of fires. In the Vietnam War, the Americans dropped
   napalm from the air. More recently many villages were burned during the
   Rwandan Genocide. Aerial bombing of cities, including firebombing,
   using incendiary bombs was also frequently used during World War II.
   Molotov cocktails are cheap to construct and are in common use as well.

Typical temperatures of fires and flames

     * Oxyacetylene Flame (3000 C or above)(5432 F)
     * Oxyhydrogen Flame (2000 C or above)(3632 F)
     * Bunsen Burner Flame (Max. Setting) (1300 - 1600 C)(2372 - 2912 F)
     * Candle Flame (760 C)(1400 F)
     * Blowtorch (1300 C)(2372 F)

Fire and religion

   Vulcan of ancient mythology, using fire for his forge
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   Vulcan of ancient mythology, using fire for his forge

   Fires and burning have often been used in religious rites and
   symbolism.

   Fire is one of the four classical elements, as well as one of the five
   Chinese elements. In Hinduism fire is one of five sacred elements
   (space, air, fire, water, earth) of which all living creatures are
   comprised and is considered an eternal witness essential to sacred
   religious ceremonies.

   Members of the Prausian Tribe of Central Europe long used fire to burn
   wicker men with the living people from enemy tribes inside as a means
   of sacrifice to their gods.

   Fire is a symbol of Ahura Mazda, the god of the Zoroastrian religion. A
   Zoroastrian church is known as a Fire Temple. Fire is also an important
   part of Calcination, the fire operation in the art of alchemy.

   In Roman mythology, Vulcan is the god of fire. The analogue in Greek
   mythology is Hephaestus. In Greek mythology, Prometheus is the Titan
   chiefly honored for stealing fire from the gods in the stalk of a
   fennel plant and giving it to mortals for their use.

   In Judaism fire also has great significance. Candles are lit to usher
   in holidays and to separate Shabbat from the rest of the week, as well
   as to remember the dead. Another important fire symbol is the Eternal
   Flame, which was a fire kept in the First and Second Temples and will
   always be kept burning.

   In Christianity, fire is a symbol of the Holy Ghost. It is also often
   used in descriptions of Hell. Additionally, a fire is used in the Roman
   Catholic Mass during the Easter Vigil. In the Middle ages, the judgment
   of God was appealed to by the ordeal of fire. In Spain, bonfires as
   associated to the eve of Saint John the Evangelist, a Christianization
   of the summer solstice, especially in Alicante. In Valencia, Saint
   Joseph is celebrated by burning allegorical figures on the streets, a
   Christianization of the spring equinox.

   Fire was also a purifier. Giovanni da Pian del Carpine narrates that
   when he visited the Mongol Batu Khan, he was made to pass between two
   fires to remove possible witchcraft or poisons.

   Fire is sometimes associated with Halloween.

   In the Rastafarian tradition fire has a significant role. At the Holy
   Ceremonies, known as Groundation and Nyahbinghi Theocracy, a very large
   fire is lite, and is symbolic in creating contact with the Almighty Jah
   Rastafari. In Rastafari Theology, fire is recognized as the main force
   in all things, or fire being a means to decribe heat. For instance,
   when a human being dies or animal, they loose their heat, or as the
   Rasta's insist, fire.

Uncontrolled fire

   A forest fire.
   Enlarge
   A forest fire.

   The self-sustaining nature of fire makes it extremely dangerous if
   uncontrolled. Fire can consume structures and trees and can severely
   injure or kill living beings through burns or smoke inhalation.
   Structure fires can be started by cooking accidents, electrical faults,
   fuel leaks, the misuse of lighters and/or matches, and accidents
   involving candles and cigarettes. Fire can propagate rapidly to other
   structures, especially where proper building standards are not met.

   Outside of urban settings, wildfires can consume large areas of forest
   and brush and often damage nearby settlements.

Fires in history

Conflagrations

   Timeline:
     * September, 1666 - Great Fire of London
     * April, 1947 - Texas City Disaster

Fire protection and prevention

   Canisters containing Argon Gas for use in extinguishing fire without
   damaging server equipment
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   Canisters containing Argon Gas for use in extinguishing fire without
   damaging server equipment

   The destructive capacity of fire has led governments around the world
   to adopt fire codes and life safety codes and offer fire fighting
   services to extinguish or contain uncontrolled fires. Trained
   firefighters use fire trucks, water supply resources such as water
   mains and fire hydrants, and an array of other equipment to combat the
   spread of fires.

   To ensure fire safety of buildings, all building products, materials
   and furnishings in the U.S. must be tested for fire resistance,
   combustibility and flammability before they can be used in
   construction. The same applies to upholstery, carpeting and plastics
   used in vehicles and vessels. Buildings, especially schools and tall
   buildings, often conduct fire drills to inform and prepare citizens on
   how to react to a building fire.

   Purposely starting destructive fires constitutes arson and is a
   criminal offense in most jurisdictions.

   There are many different classification systems used for uncontrolled
   fires; in Europe and Australasia six groups are used:
   Flammable gas warning.
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   Flammable gas warning.
     * Class A: Fires that involve flammable solids such as wood, cloth,
       rubber, paper, and some types of plastics.
     * Class B: Fires that involve flammable liquids or liquifiable solids
       such as petrol/gasoline, oil, paint, some waxes & plastics, but not
       cooking fats or oils.
     * Class C: Fires that involve flammable gases, such as natural gas,
       hydrogen, propane, butane.
     * Class D: Fires that involve combustible metals, such as sodium,
       magnesium, and potassium.
     * Class E: Fires that involve any of the materials found in Class A
       and B fires, but with the introduction of an electrical appliances,
       wiring, or other electrically energized objects in the vicinity of
       the fire, with a resultant electrical shock risk if a conductive
       agent is used to control the fire.
     * Class F: Fires involving cooking fats and oils. The high
       temperature of the oils when on fire far exceeds that of other
       flammable liquids making normal extinguishing agents ineffective.

   In the U.S., fires are generally classified into five groups: A, B, C,
   D, and K
     * Class A: Fires that involve wood, cloth, rubber, paper, and some
       types of plastics.
     * Class B: Fires that involve gasoline, oil, paint, natural and
       propane gases, and flammable liquids, gases, and greases.
     * Class C: Fires that involve any of the materials found in Class A
       and B fires, but with the introduction of electrical appliances,
       wiring, or other electrically energized objects in the vicinity of
       the fire.
     * Class D: Fires that involve combustible metals, such as sodium,
       magnesium, and potassium.
     * Class K: Fires that involve cooking oils. Although, by definition,
       Class K is a subclass of Class B, the special characteristics of
       these types of fires are considered important enough to recognize.

   Retrieved from " http://en.wikipedia.org/wiki/Fire"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
