Electricity

Introduction:

Electricity is so common in our lives that we sometimes take it for granted.

• How would our lives be different if we did not have electricity?

  • Imagine washing your clothes by hand? What would that look like?

  • How about hot water? How would you take a hot shower or bath?

  • What about heat? Imagine what it would be like to go to school without heat or air conditioning... what about if we didn't have lights?

In the dim, dark past...

Long before any knowledge of electricity existed, people were aware of shocks from electric fish. Ancient Egyptian texts dating from 2750 BCE referred to these fish as the "Thunderer of the Nile", and described them as the "protectors" of all other fish. Electric fish were again reported millennia later by ancient Greek, Roman and Arabic naturalists and physicians.

Several ancient writers, such as Pliny the Elder and Scribonius Largus, attested to the numbing effect of electric shocks delivered by electric catfish and electric rays, and knew that such shocks could travel along conducting objects. Patients suffering from ailments such as gout or headache were directed to touch electric fish in the hope that the powerful jolt might cure them.

Possibly the earliest and nearest approach to the discovery of the identity of lightning, and electricity from any other source, is to be attributed to the Arabs, who before the 15th century had the Arabic word for lightning ra‘ad (رعد) applied to the electric ray.

Ancient cultures around the Mediterranean knew that certain objects, such as rods of amber, could be rubbed with cat's fur to attract light objects like feathers. Thales of Miletus made a series of observations on static electricity around 600 BCE, from which he believed that friction rendered amber magnetic, in contrast to minerals such as magnetite, which needed no rubbing.

Why it is called “Electricity”

Electricity would remain little more than an intellectual curiosity for millennia until 1600, when the English scientist William Gilbert wrote De Magnete, a text in which he made a careful study of electricity and magnetism, distinguishing the lodestone effect from static electricity produced by rubbing amber.

He coined the New Latin word electricus ("of amber" or "like amber", from ἤλεκτρον, elektron, the Greek word for "amber") to refer to the property of attracting small objects after being rubbed.

This association gave rise to the English words "electric" and "electricity.”

History of Electricity

in the 18th century, Benjamin Franklin conducted extensive research in electricity, selling his possessions to fund his work. In June 1752 he is reputed to have attached a metal key to the bottom of a dampened kite string and flown the kite in a storm-threatened sky.[14] A succession of sparks jumping from the key to the back of his hand showed that lightning was indeed electrical in nature.

In 1791, Luigi Galvani published his discovery of bioelectromagnetics, demonstrating that electricity was the medium by which neurons pass signals to the muscles.

Alessandro Volta's battery, or voltaic pile, of 1800, made from alternating layers of zinc and copper, provided scientists with a more reliable source of electrical energy than the electrostatic machines previously used.

The recognition of electromagnetism, the unity of electric and magnetic phenomena, is due to Hans Christian Ørsted and André-Marie Ampère in 1819–1820.

Michael Faraday invented the electric motor in 1821, and Georg Ohm mathematically analysed the electrical circuit in 1827.

Electricity and magnetism (and light) were definitively linked by James Clerk Maxwell, in particular in his "On Physical Lines of Force" in 1861 and 1862.

Young Edison sold candy and newspapers on trains running from Port Huron to Detroit, and sold vegetables. Although he frustrated teachers and went in and out of various schools in Ohio and Michigan, he read steadily and voraciously under his mother's supervision.

He became a telegraph operator after he saved three-year-old Jimmie MacKenzie from being struck by a runaway train. Jimmie's father, station agent J. U. MacKenzie of Mount Clemens, Michigan, was so grateful that he trained Edison as a telegraph operator. Edison's first telegraphy job away from Port Huron was at Stratford Junction, Ontario, on the Grand Trunk Railway.

He was held responsible for a near collision.

Edison obtained the exclusive right to sell newspapers on the road, and, with the aid of four assistants, he set in type and printed the Grand Trunk Herald, which he sold with his other papers.

This began Edison's long streak of entrepreneurial ventures, as he discovered his talents as a businessman. These talents eventually led him to found 14 companies, including General Electric, still one of the largest publicly traded companies in the world.

Edison was legally attributed with most of the inventions produced there, though many employees carried out research and development under his direction. His staff was generally told to carry out his directions in conducting research, and he drove them hard to produce results.

Edison surrounded himself with people at Menlo Park who would assist him, such as Frank Sprague, a mathematical genius. Many people believed this was because Edison was either unwilling, or unable, to do math.

Over his desk, Edison had a placard with a quote from Sir Joshua Reynolds. The quote said:

"There is no expedient to which a man will not resort to avoid the real labor of thinking."

Edison's name is registered on 1,093 patents.

Electric Light

In 1878, Edison began working on a system of electrical illumination, something he hoped could compete with gas and oil based lighting. While many claim Edison invented the lightbulb, many others before him had made incandescent light, including:

• Henry Woodward

• Mathew Evans

• Alessandro Volta

• Humphry Davy

• James Lindsay

• Moses Farmer

Still, most of these lights had issues -- namely they either were expensive to create or did they did not last long.

After many experiments, first with carbon filaments and then with platinum and other metals, Edison returned to a carbon filament. The first successful test was on October 22, 1879.

It lasted 13.5 hours. Edison continued to improve this design and on November 4, 1879 filed a patent for the “electric lamp.”

Although the patent described several ways of creating the carbon filament including "cotton and linen thread, wood splints, papers coiled in various ways", it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1,200 hours.

Edison got this idea while on a science trip with a science team. He claims that he got the idea after thinking about fishing and remembering the bamboo pole he used.

Electricity in Rural Towns

Although the majority of people living in larger towns and cities had electricity by 1930, only 10 percent of Americans who lived on farms and in rural areas had electric power. At this time, electric companies were all privately owned and run to make money. These companies argued that it would be too expensive to string miles of electric lines to farms. They also thought farmers were too poor to pay for electric service.

President Franklin D. Roosevelt believed strongly that America's farming areas should have the same access to electricity as cities did. In 1935 the Rural Electric Administration was created to bring electricity to rural areas like the Tennessee Valley.

By 1939 the percentage of rural homes with electricity had risen to 25 percent. The Tennessee Valley Authority also set up the Electric Home and Farm Authority to help farmers buy electric appliances like stoves and washing machines. Farm families of that time found that these helpful electric appliances made their lives much easier.