Sunday, June 3, 2007
The wheel - the greatest invention in history
A wheel is a circular device capable of rotating on its axis, facilitating movement or transportation or performing labor in machines. A wheel together with an axle overcomes friction by facilitating motion by rolling. Common examples are found in transport applications. More generally the term is also used for other circular objects that rotate or turn, such as a ship's wheel and flywheel. Most authorities regard the wheel as one of the oldest and most important inventions, which originated in ancient Sumer in Mesopotamia (modern Iraq) in the 5th millennium BC, originally in the function of potter's wheels. The wheel reached India and Pakistan with the Indus Valley Civilization in the 3rd millennium BC. Near the northern side of the Caucasus several graves were found, in which since 3700 BC people had been buried on wagons or carts (both types). The earliest depiction of what may be a wheeled vehicle (a wagon consisting of four wheels and two axles), is on the Bronocice pot, a ca. 3500 BC clay pot excavated in southern Poland. The invention of the wheel has also been important for technology in general, important applications including the water wheel, the cogwheel (see also antikythera mechanism), the spinning wheel, and the astrolabe or torquetum. More modern descendants of the wheel include the propeller, the jet engine, the flywheel (gyroscope) and the turbine. The wheel has also become a strong cultural and spiritual metaphor for a cycle or regular repetition, including chakra, reincarnation, Yin and Yang, among others.
The winged wheel is a symbol of progress, seen in many contexts including the coat of arms of Panama.
The introduction of spoked (chariot) wheels in the Middle Bronze Age appear to have carried somewhat of a prestige. The solar wheel appears to have a significance in Bronze Age religion, replacing the earlier concept of a Solar barge with the more "modern" and technologically advanced solar chariot.
The wheel is also the prominent figure on the Indian Flag. The wheel in this case represents law.