Electricity
Today's world can not think of its existence without electricity. Indeed the per capita consumption of electricity is an important indicator of a country's development. But the evolution of electricity began as early as 600 B.C. when it was discovered that amber, when rubbed with fur acquired the property to attract tiny objects. In 1600 A.D. it was discovered that many other substances also had this property. Subsequently electric current was defined as the rate of flow of charge through a cross section of any substance as further developments in science took place. Benjamin Franklin in 1752 A.D. discovered that the lightning in the clouded sky was due to electric charge in the clouds. Since early 18th Century A.D. research on electricity gathered momentum with scientists like Michael Faraday and Ohm contributing to knowledge on various aspects of static and current electricity. The late 19th century saw rapid progress in application of knowledge of electricity and with Thomas Edison inventing the Bulb and Alexander Bell using electric current to invent telephone we arrived at the beginning of where we are today.
Electricity like magnetism is a force of nature. All matters in the nature are made of atoms with protons and neutrons in the nucleus and electrons on the periphery of the nucleus. While neutrons are neutral in charge, the protons bear a positive charge. This positive charge of the nucleus is neutralised by an equal quantity of negative charge in the electrons in the periphery of the atom. When due to any reason an electron moves away there is a reduction in the negative charge and the atom is positively charged while the other atom where the electron has gone will become negatively charged. There is a natural tendency for the charge to flow between such atoms which is the flow of electricity. It is to be noted that electrons are on the outer orbit of an atom and have less bonding energy than the nucleus where neutrons and protons are bound by intense energy as the nucleus besides having electrical energy also contains nuclear energy which contains the protons together. But if the number of protons become very big they will not stay together like uranium with 92 protons.
The substances that allow easy flow of this charge are called conductors like aluminium, iron, silver, copper etc. whereas the matter that do not allow the flow of electric charge are called insulators like wood, plastic etc; while some other matters that allow limited or regulated flow of charge are called semi-conductors like silicon, carbon etc. The conductors allow transportation of electricity from one point to another and thus facilitate commercial use of electricity.
The law of conservation of energy says that energy can neither be created nor destroyed. It can only change forms like chemical energy(of a matter) becoming mechanical energy or mechanical energy changing form to electrical, heat or sound energy. On this principle the modern day electricity systems are run by generating immense heat energy from matters, which are converted into mechanical energy either in form of gas or steam which run giant turbines and these turbines convert the mechanical energy into electrical energy by creating immense electrical charge with the help of magnetic fields. This creates huge quantities of electrical energy which was not possible using chemical substances like batteries.
New research is creating more sophisticated equipments to generate and transport electricity for industrial usage. Electricity itself has given birth to new sciences like computer engineering and the electricity distribution models have been at the core of computer operating systems.
