- published: 22 Mar 2012
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The Silk Road or Silk Route refers to a historical network of interlinking trade routes across the Afro-Eurasian landmass that connected East, South, and Western Asia with the Mediterranean and European world, as well as parts of North and East Africa. The land routes were supplemented by sea routes, which extended from the Red Sea to coastal India, China and Southeast Asia.
Extending 4,000 miles (6,500 km), the Silk Road gets its name from the lucrative Chinese silk trade along it, which began during the Han Dynasty (206 BCE – 220 CE). The central Asian sections of the trade routes were expanded around 114 BCE by the Han dynasty, largely through the missions and explorations of Zhang Qian, but earlier trade routes across the continents already existed.[citation needed] In the late Middle Ages, transcontinental trade over the land routes of the Silk Road declined as sea trade increased,. In recent years, both the maritime and overland Silk Routes are again being used, often closely following the ancient routes.
Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and produced by certain insect larvae to form cocoons. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture). The shimmering appearance of silk is due to the triangular prism-like structure of the silk fiber, which allows silk cloth to refract incoming light at different angles, thus producing different colors.
Silks are produced by several other insects, but generally only the silk of moth caterpillars has been used for textile manufacturing. There has been some research into other silks, which differ at the molecular level. Many silks are mainly produced by the larvae of insects undergoing complete metamorphosis, but some adult insects such as webspinners produce silk, and some insects such as raspy crickets produce silk throughout their lives. Silk production also occurs in Hymenoptera (bees, wasps, and ants), silverfish, mayflies, thrips, leafhoppers, beetles, lacewings, fleas, flies and midges. Other types of arthropod produce silk, most notably various arachnids such as spiders (see spider silk).
A road is a route, thoroughfare or way that supports travel by a means of conveyance.
For purposes of international statistical comparison, the Organisation for Economic Co-operation and Development (OECD) defines a road as "a line of communication (travelled way) using a stabilized base other than rails or air strips open to public traffic, primarily for the use of road motor vehicles running on their own wheels," which includes "bridges, tunnels, supporting structures, junctions, crossings, interchanges, and toll roads, but not cycle paths." In urban areas roads may diverge through a city or village and be named as streets, serving a dual function as urban space easement and route. Modern roads are normally smoothed, paved, or otherwise prepared to allow easy travel. Historically many roads were simply recognizable routes without any formal construction or maintenance.
In the United States, laws distinguish between public roads, which are open to public use, and private roads, which are privately controlled.