Thursday, January 11, 2007

History of technology

History of technology
Paleolithic flint spearThe history of Technology is at least as old as humanity. Some primitive forms of tools have been discovered with almost every find of ancient human remains dating from the time off. The history of technology follows a progression from simple tools and simple (mostly human) energy sources to complex high-technology tools and energy sources.
The earliest technologies converted readily occurring natural resources (such as rock, wood and other vegetation, bone and other animal byproducts) into simple tools. Processes such as carving, chipping, scraping, weaving, knotting, rolling (the wheel), and sun-baking are simple means for the conversion of raw materials into usable products. Anthropologists have uncovered many early human habitations and tools made from natural resources. Birds and other animals often build elaborate nests and some simple tools out of various materials. We normally don't consider them to be performing a technological feat, primarily because such behavior is largely instinctive. There is some evidence of occasional cultural transferrence, especially among the other, nonhuman primates. Nevertheless, there is now considerable evidence of such simple technology among animals other than humans.
The use, and then mastery, of fire (circa 1,000,000 - 500,000 BC) was a turning point in the technological evolution of humankind, affording a simple energy source with many profound uses.[5] Perhaps the first use of fire beyond providing heat was the preparation of food. This enabled a significant increase in the vegetable and animal sources of food, while greatly reducing perishability.
The use of fire extended the capability for the treatment of natural resources and allowed the use of natural resources that require heat to be useful. (The oldest projectile found is a wooden spear with fire hardened point, circa 250,000 BC.) Wood and charcoal were among the first known materials used as a fuel. Wood, clay, and rock (such as limestone), were among the earliest materials shaped or treated by fire, for making artifacts such as weapons, pottery, bricks, and cement. Continuing improvements led to the furnace and bellows and provided the ability to smelt and forge native metals (naturally occurring in relatively pure form).[6] Gold, copper, silver, and lead, were such early metals. The advantages of copper tools over stone, bone, and wooden tools were quickly apparent to early humans, and native copper was probably used from near the beginning of Neolithic times (about 8000 BCE). Native copper does not naturally occur in large amounts, but copper ores are quite common and some of them produce metal easily when burned in wood or charcoal fires.
The wheel was invented in circa 4000 BCE.Eventually, the working of metals led to the discovery of alloys such as bronze and brass (about 4000 BCE). The first uses of iron alloys such as steel dates to around 1400 BCE.
Meanwhile, humans were learning to harness other forms of energy. The earliest known use of wind power is the sailboat. The earliest record of a ship under sail is shown on an Egyptian pot dating back to 3200 BCE. From prehistoric times, Egyptians probably used "the power of the Nile" annual floods to irrigate their lands, gradually learning to regulate much of it through purposely built irrigation channels and 'catch' basins. Similarly, the early peoples of Mesopotamia, the Sumerians, learned to use the Tigris and Euphrates rivers for much the same purposes. But more extensive use of wind and water (and even human) power required another invention.
According to archaeologists, the wheel was invented about 4000 B.C. The wheel was likely independently invented in Mesopotamia (in present-day Iraq) as well. Estimates on when this may have occurred range from 5500 to 3000 B.C., with most experts putting it closer to 4000 B.C. The oldest artifacts with drawings that depict wheeled carts date from about 3000 B.C.; however, the wheel may have been in use for millennia before these drawings were made. There is also evidence from the same period of time that wheels were used for the production of pottery. (Note that the original potter's wheel was probably not a wheel, but rather an irregularly shaped slab of flat wood with a small hollowed or pierced area near the center and mounted on a peg driven into the earth. It would have been rotated by repeated tugs by the potter or his assistant.) More recently, the oldest-known wooden wheel in the world was found in the Ljubljana marshes of Slovenia.
The invention of the wheel revolutionized activities as disparate as transportation, war, and the production of pottery (for which it may have been first used). It didn't take long to discover that wheeled wagons could be used to carry heavy loads and fast (rotary) potters' wheels enabled early mass production of pottery. But it was the use of the wheel as a transformer of energy (through water wheels, windmills, and even treadmills) that revolutionized the application of nonhuman power sources.
Tools include both simple machines (such as the lever, the screw, and the pulley), and more complex machines (such as the clock, the engine, the electric generator and the electric motor, the computer, radio, and the Space Station, among many others).
Integrated circuitAs tools increase in complexity, so does the type of knowledge needed to support them. Complex modern machines require libraries of written technical manuals of collected information that has continually increased and improved - their designers, builders, maintainers, and users often require the mastery of decades of sophisticated general and specific training. Moreover, these tools have become so complex that a comprehensive infrastructure of technical knowledge-based lesser tools, processes and practices (complex tools in themselves) exist to support them, including engineering, medicine, and computer science. Complex manufacturing and construction techniques and organizations are needed to construct and maintain them. Entire industries have arisen to support and develop succeeding generations of increasingly more complex tools.

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