he history of technology from antiquity to the present. It seeks to contribute to our understanding of technology as embedded in society, exploring its links between science, on the one hand, and the cultural, economic, political and institutional contexts on the other. Within that framework, and while not favouring any particular school or methodological approach, it welcomes papers which think about the relations between technology and society in new ways (e.g. the social construction of technologies, large technical systems, technology and business history). The composition of its editorial board reflects, to some extent, these concerns. Special procedures have been put in place to facilitate the publication of work by young researchers, and scholars who would not normally publish in an English language journal. The book reviews section will pay particular attention to material not published in English.
The history of technology is the history of the invention of tools and techniques for doing practical things. Its modern history is intimately related with the history of science, as the discovery of new background knowledge has enabled us to create new things, and conversely, many scientific endeavors have become possible through technologies which assist humans to travel to places we could not otherwise go, and probe the nature of the universe in more detail than our natural senses allow.Technological artifacts are products of an economy, a force for economic growth, and a large part of everyday life. Technological innovations affect, and are affected by, a society's cultural traditions. They also are a means to develop and project military powerThe Paleolithic or Palaeolithic (Greek παλαιός paleos=old and λίθος lithos=stone or the 'Old Stone Age') was the first period in the development of human technology of the Stone Age. It began with the introduction of the first stone tools by hominids such as Homo habilis (around 2,000,000 years ago) and lasted until the introduction of agriculture. It ended with the Mesolithic, or in areas with an early neolithisation, the Epipaleolithic.In general, late Paleolithic people were hunters and food gatherers.Their technological skills are demonstrated by artifacts made from chipped stone and flint, and the use of wood, clay, and animal parts. Their tool kit was extensive: knives, axes, scrapers, hammers, awls, needles, spears, harpoons, clubs, blowguns, and bows and arrows.Depending upon the climate and/or region, paleolithic people probably made kayaks, snow-houses and outrigger canoes and knew poisons such as hydrocyanic acid, curare, snake venom, hemlock, and alkaloids. They also used all the means which we use to preserve food: freezing, drying, sealing (in clay or bees wax).Religion was apotropaic; specifically, it involved sympathetic magic. In Europe, the first art seems to have appeared toward the end of the Paleolithic period (35,000 B.C.E). Paleolithic peoples painted and sculpted. The level of skill in painting and sculpting animals was remarkably high. It is theorised that one of the functions of art within their societies was to ensure success in hunting.A large bonfire.
A building on fire in Columbus, Ohio.Fire is simply glowing gas. 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.For more detailed information on the color of flames, see flame.
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 color 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 color 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 color 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 CO2 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. [2] 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. [3] These discoveries have potential applications in applied science and industry, especially concerning fuel efficiency.

from :wikipedia.com