Magnetic compass

These effects were recorded in Greece around 2500 years ago and not long afterwards Democritus proposed an atomic structure for all matter. The magnetic compass seems to have taken another 1500 years to appear and magnetic theory a further half century. 

Magnetic survey A directional survey in which the direction is determined by a magnetic compass deflecting the earth s magnetic field. 

T our of the most significant developments in the progress of mankind - -are attributed to the Chinese the magnetic compass, gunpowder, printing, and paper (1). The invention of paper by Tsai Lun, a member of the Imperial Guard and Privy Councillor, was announced to the Hai Emperor of China in a.d. 105 (2). It was a unique event. At that time, the Chinese macerated fibers from rice stalks, flax, hemp, and bark in water and drained the suspension on a mold covered with silk cloth. The fiber mats were removed and dried in the sun to form paper. This uniqueness is attested to by its slow communication to other parts of the world five hundred years to reach Korea and Japan six hundred years to Samarkand and the Arab world and one thousand years to Europe,... 

First reported synthesis of perfume by Henchum Seiken The magnetic compass is developed and widely used in Chinatll Gunpowder is designed/synthesized by Rodger Bacon The cannon is invented in China Eyeglasses are first used in Venice... 

The magnetic compass may have been first used during the Qin dynasty in China (ca. 200 B.C.). 

This was also the age of the great explorations, helped on by the discovery, in the thirteenth century, of the magnetic compass. The coast of Africa was explored and the continent was rounded in 1497. With India reached by sea and the world of Islam bypassed, Europe could trade directly with the Far East. Even more startling were the voyages of Christopher Columbus from 1492 to 1504 through which, it was soon discovered (though Columbus himself never admitted the fact), a new half of the world had been revealed. 

Communicative functions of metals magnetic compass, initiator of cell functions, regulation of gene expressions. 

The magnetic field of the Earth and the location of the magnetic poles were of great interest to the seafaring nations of the nineteenth century because the magnetic compass was used to steer ships across the oceans that contained few points of reference. For this reason, several Antarctic explorers of the nineteenth century attempted to map the magnetic field of the Earth and to determine the position of the magnetic pole in Antarctica (e.g., Dumont d Urville and Charles Wilkes). 

While microelectronics can be described as the fabrication of electrical components like transistors, diodes, resistors and capacitors on a semiconductor substrate, mostly silicon, MEMS and MOEMS are using the manufacturing technologies of microelectronics to fabricate mechanical and optical structures as well as sensing or actuating devices. Typical examples are pressure sensors, microphones, acceleration and angular-rate sensors, magnetic compasses, inkjet heads, micro-scanners, micro-fluidic devices, biosensors, etc., to name some. 

Flight instruments originally were separated from the avionics of an aircraft. The compass, perhaps the most basic of the flight instrmnents, was developed by the Chinese in the second century b.c.e. Chinese navy commander Zheng He s voyages from 1405 to 1433 included the first recorded use of a magnetic compass for navigation. 

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