Thales, a Greek, found that when amber was rubbed with silk, it became electrically charged and attracted objects. He had originally discovered static electricity.
Gilbert wrote about the electrification of many substances. He was also the first person to use the terms electric force, magnetic pole, and electric attraction. Ben Franklin U. Alessandro Volta Italy invented the first electric battery.
The quot;volt quot; is named in his honor. Faraday's experiments about how electricity current works led to the understanding of electrical transformers and motors. Joseph Henry U. He also described an electric motor. A unit of thermal energy, the Joule, was named after him. Read the original article. Register or Log In.
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In about BC, the Ancient Greeks discovered that rubbing fur on amber fossilized tree resin caused an attraction between the two — and so what the Greeks discovered was actually static electricity. Similar devices were found in archeological digs near Baghdad meaning ancient Persians may have also used an early form of batteries. But by the 17th century, many electricity-related discoveries had been made, such as the invention of an early electrostatic generator, the differentiation between positive and negative currents, and the classification of materials as conductors or insulators.
In , Ben Franklin conducted his experiment with a kite, a key, and a storm. This simply proved that lightning and tiny electric sparks were the same thing. Italian physicist Alessandro Volta discovered that particular chemical reactions could produce electricity, and in he constructed the voltaic pile an early electric battery that produced a steady electric current, and so he was the first person to create a steady flow of electrical charge.
Volta also created the first transmission of electricity by linking positively-charged and negatively-charged connectors and driving an electrical charge, or voltage, through them. In electricity became viable for use in technology when Michael Faraday created the electric dynamo a crude power generator , which solved the problem of generating electric current in an ongoing and practical way.
This opened the door to American Thomas Edison and British scientist Joseph Swan who each invented the incandescent filament light bulb in their respective countries in about In , French physicist Abbe Nollet arranged a demonstration for the King of Paris in which more than one thousand Carthusian monks were told to hold hands in a circle feet across.
When a massive Leyden jar was discharged into the monks, Nollet noted that all the monks jumped into the air at the same time, thus proving that the speed of an electric discharge is instantaneous, or at least extremely high. Nollet himself did not participate in the experiment. The marked similarity between the white-hot, cracking sparks of the electrostatic machine on the one hand, and lightning bolts on the other, did not escape notice.
In June of , the American diplomat, publisher, and scientist Benjamin Franklin decided to directly test whether or not lightning was a giant electric spark. During a thunderstorm, Franklin and his son sent a kite aloft and used the string to the kite to charge up a Leyden jar. This extremely dangerous experiment proved that the thundercloud was electrically charged, and therefore that lightning was an electric discharge.
Franklin proposed that buildings could be protected from lightning strikes by placing tall metal rods on the tops of the buildings, then connecting the rods to the ground.
Such an arrangement would harmlessly conduct any lightning past the building. This idea - which worked beautifully - came during the full flower of the French Enlightenment, and was hailed in Europe as the epitome of rational man triumphing over nature.
Franklin performed many electrostatic experiments, but it is his theoretical ideas about electricity which have turned out to have the most lasting influence. It is to Franklin that we owe the designations "positive" and "negative" for electric charge, and it was Franklin who first performed experiments demonstrating that the amount of negative charge accumulated on a rubbed object is exactly equal to the positive charge accumulated on the rubbing object.
In other words, it was Franklin who first began to glimpse the concept of conservation of charge. Conservation of charge is an easy concept to grasp if you believe in indivisible particles carrying irreducible units of mass, charge, and other quantities. In Franklin's time, however - when everything from electric charge to heat was thought to consist of mysterious fluids and atoms were not even an accepted idea - the concept that the positive and negative charges generated by an electrostatic machine must always be equal represented a major advance.
Years later, during the American Revolution, it was Franklin's considerable fame as a scientist which opened diplomatic doors to him that would otherwise have been closed to an unofficial ambassador from an unimportant country far from Europe. Lightning Lightning and thunder are created by the same physical processes that make your laundry crackle. It is only the scale of the electrical discharge which distinguishes a lightning bolt from garden-variety static electricity.
In a thunderstorm, circulating air currents replace the rotating wheels of the electrostatic machine, and tiny droplets of ice and water replace the Leyden jar.
Water droplets and water vapor have a marked tendency to acquire electric charge, which is why static electricity is much less noticeable in a humid climate: the water vapor conducts it away. During a thunderstorm, the water droplets and ice crystals on the bottom side of a thunder cloud steadily become more negatively charged as the air circulates, and this leaves the ground immediately below very positively charged.
Air is a very poor conductor of electricity, so for some time the gathering charge just continues to accumulate in the clouds. But sooner or later the attractive force becomes too great, and an invisible, charged column of electrons begins to force its way downward through the air, seeking the shortest path to the ground.
As the column approaches the ground, the intense build-up of static electric charge in the immediate vicinity can cause any people standing there to sense "prickliness" or "electricity in the air".
If the charge becomes great enough, people's hair can stand on end, because each strand has become identically charged and therefore is being repelled from the others. Eventually, the charged column of electrons descends enough to make contact with the highest point in the vicinity - and the result is an electrical dam bursting.
In one titanic stroke, all the accumulated electric charge comes roaring down the column, and a lightning bolt strikes the ground. The lightning bolt simply follows the path of least resistance, which means that it will strike high objects before it strikes low ones, and will move through good conductors such as metals or something soaked with water if it can.
Lightning Safety If you should be outside during a storm, and find your hair standing on end, you must move immediately to safety.
The human body is a fairly good conductor and can attract lightning strokes; even more unfortunately, the part of the human body which conducts electricity best is the nervous system. Even a nearby lightning strike that does not result in death for a human can cause permanent paralysis or other neurological damage, due to electricity running through the nervous system. To find a spot safe from lightning, the first rule is, get inside if you possibly can. A person inside a metal object such as a car is perfectly safe from the effects of a lightning bolt, because electricity can only run down the outside of a conductor.
The same repulsive force that makes static electric charge on a conductor spread out as far as possible also insures that a current of electrons is always forced away from the center of any conducting object.
The second rule of lightning safety is, stay away from tall objects. A tragic number of lightning-relating injuries occur every year on golf courses, when people who have been caught out in the rain try to escape it by standing beneath trees.
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