When people think about electricity, different things come to mind. One person may think about household appliances, another might find himself wondering about lightning, and electricity could conjure up thoughts of Thomas Edison, or his famous invention, the electric light, in yet another person. Yet all agree that electricity has become an essential, irreplaceable part of all our lives and its discovery is one of the most important breakthroughs of modern man. It seems that almost everything that we use in our daily lives runs on electricity, including mom’s stove and oven, dad’s laptop computer and wristwatch, and your cell phone and video games. Even some of our most advanced technology, including supercomputers, satellites, and the latest spy technology, have at least one basic need – electricity. Without it, modern civilization cannot function. Communication over long distances, which is vital to our lives, would be paralyzed, and the comforts of our present environment would be rendered unfeasible. Man himself would be virtually helpless without electricity.
Electricity is used in all kinds of diverse ways and is produced from numerous sources. Some sources of electricity are fossil fuels. In a power plant, fossil fuels (mainly coal) are burned. The heat is used to heat water and create steam to turn turbines to generate the electricity. Coal produces about 40% of the electricity used on earth. Another source is water. The electricity, called hydroelectric power, is generated by turbines. Water behind a dam flows into a channel in the dam called a penstock and turns the turbine, which generates electricity. 25% of the electric energy on earth used by humans is hydroelectric. About 16% of the energy in the world is nuclear power. Uranium or plutonium atoms split in the core of a nuclear reactor, producing intense heat. Water, under high pressure, is pumped into the reactor and comes out extremely hot. The water heats more water in a tank, producing steam to turn turbines. Other minor sources of electric energy include the sun (solar energy), wind (wind power) heat from the earth’s interior (geothermal energy), and biomass (energy release by bacteria in cow manure). Batteries also supply electricity. Unfortunately, renewable sources still account for only 12% of the United States’s supply of electricity.
Humans have been trying to harness the great powers of electricity for a long time. The ancients wondered what lightning was, and attributed different gods to thunder and lightning. Thales, a Greek philosopher, noted that rubbing a piece of amber caused bits of straw to stick to it. (This phenomenon is known today as static electricity). By performing his famous experiment with a silk kite and a metal key, Benjamin Franklin proved that lightning was indeed electricity in 1750, two millennia later. 21 years later, in 1771, Luigi Galvani made an interesting discovery when he found that a dead frog would twitch if touched by two pieces of metal, copper and iron. An electric charge traveled through the animal, which caused the movement. This occurrence would be called galvanism, after Galvani. His associate, Alessandro Volta, used this information to develop the voltaic pile, a forerunner of the battery that produced a steady electric current. The volt, a unit of measurement used to measure electric power, was named after him. Finally, Sir Humphrey David connected some voltaic piles and invented the first battery. Modern batteries are similar to this design.
Modern life is helplessly dependent on electricity. Production of electricity has become an indispensable piece our daily lives as we hope to find more renewable and efficient ways to produce it for its many significant purposes.