Stephen Gray distinguished between conductors and nonconductors. Du Fay recognized two kinds of electricity, which Benjamin Franklin and Ebenezer Kinnersley of Philadelphia later named positive and negative.
Progress quickened after the Leyden jar was invented in by Pieter van Musschenbroek. The Leyden jar stored static electricity, which could be discharged all at once. In William Watson discharged a Leyden jar through a circuit, and comprehension of the current and circuit started a new field of experimentation.
Henry Cavendish, by measuring the conductivity of materials he compared the simultaneous shocks he received by discharging Leyden jars through the materials , and Charles A. Coulomb, by expressing mathematically the attraction of electrified bodies, began the quantitative study of electricity. A new interest in electric current began with the invention of the battery. Luigi Galvani had noticed that a discharge of static electricity made a frog's leg jerk. Consequent experimentation produced what was a simple electron cell using the fluids of the leg as an electrolyte and the muscle as a circuit and indicator.
Galvani thought the leg supplied electricity, but Alessandro Volta thought otherwise, and he built the voltaic pile, an early type of battery, as proof. Continuous current from batteries smoothed the way for the discovery of G. Ohm's law, relating current, voltage electromotive force , and resistance, and of J.
Joule's law of electrical heating. Ohm's law and the rules discovered later by G. Kirchhoff regarding the sum of the currents and the sum of the voltages in a circuit are the basic means of making circuit calculations.
Learning how to produce and use electricity was not easy. For a long time, there was no dependable source of electricity for experiments. Finally, in , Alessandro Volta, an Italian scientist, made a great discovery. He soaked paper in salt water, placed zinc and copper on opposite sides of the paper, and watched the chemical reaction produce an electric current.
Volta had created the first electric cell. It is in honor of Volta that we rate batteries in volts. Finally, a safe and dependable source of electricity was available, making it easy for scientists to study electricity.
Alessandro Volta. An English scientist, Michael Faraday, was the first one to realize that an electric current could be produced by passing a magnet through a copper wire.
It was an amazing discovery. Almost all the electricity we use today is made with magnets and coils of copper wire in giant power plants. Both the electric generator and electric motor are based on this principle. A generator converts motion energy into electricity. A motor converts electrical energy into motion energy.
In Hans Christian Oersted discovered that a magnetic field surrounds a current-carrying wire. Arago had invented the electromagnet, and Michael Faraday had devised a crude form of electric motor. Practical application of a motor had to wait 10 years, however, until Faraday and earlier, independently, Joseph Henry invented the electric generator with which to power the motor.
A year after Faraday's laboratory approximation of the generator, Hippolyte Pixii constructed a hand-driven model. From then on engineers took over from the scientists, and a slow development followed; the first power stations were built 50 years later. Michael Faraday. These studies were evidently developed following observations on phenomena occurring in certain fishes. The earliest written reference to the so-called electric fish dates back to an ancient Hippocratic treatise.
However, it was not until the beginning of the first millennium of our era that a notable progress in the field of magnetism was achieved: insight into the magnetic polarity. It is plausible that polarity was known to the Arabs in the 11 th century of the Christian era, and that they, in turn, transmitted the knowledge to the Chinese as well as to the dwellers of Western Europe. Towards , Arab sailors used a transitorily magnetized needle over a straw floating on water to recognize the north-south direction thanks to the magnetic orientation.
During the 12 th and 13 th centuries every scientific and encyclopedic text pointed to this property of the magnetic needle. In the 13 th century the work of the French scholar Pierre de Maricourt appeared in his treatise Epistola de magnete dated August 8, Fig.
This monographic article, of considerable length for its time, was written in the South of Italy whilst the army of Charles of Anjou laid siege to the city of Lucera, in Apulia, and constitutes a true scientific treatise. In it, the scientific method reaches its fullest expression and the characteristics of magnets are comprehensively and carefully examined.
A far-reaching improvement was achieved around the system of the floating needle was replaced by one of fixed suspension. The compass rose was added to this new instrument and, thus, the nautical compass emerged, which was of seminal importance to the development of navigation.
Front cover of the book De magnete … by Dr. William Gilbert London, There were no significant advances in the science of magnetism in the time between the publication of the aforementioned Epistola de magnete and that of the work De magnete magneticisque corporibus written by the English physician William Gilbert Robert Norman described magnetic inclination more precisely in and Ultimately, the aforementioned physician William Gilbert achieved not only a significant advancement in the study of magnetism but managed to catch a glimpse into the science of electrology.
His treatise De magnete , along with his Compendium medicinae , were featured in the library of the old University of Mexico. At the time, Gilbert established the following distinction: while the action between a magnet and iron is reciprocal, and rubbed amber may attract smaller objects these do not attract amber. His scientific spirit and methods distinguish Gilbert as one of the most iconic figures of the scientific world of the 16 th century.
This finding, however, remained mostly inadvertent and the concept had nearly been forgotten when it was re-discovered by an illustrious German scientist. Guericke's only printed work Experimenta nova ut vocantur Magdeburgica de vacuo spatio in seven volumes saw the light in His theories on magnetism and electricity as well as related experiments are found in the fourth volume De virtutibus mundanis et aliis rebus independentibus.
According to other documents of that time, this work had been finished before , revealing that the author had built the first electric machine prior to this date. During the 18 th century, reports on the South-American electric ray were increasingly received in Europe. Pieter van Musschenbroek, Professor at the Leyden University, concluded experimentally 11 that the effects observed in the South American ray were similar in nature to the properties displayed by the Leyden jar, an early condenser he had invented.
In turn, the North American Edgard Bancroft, who had observed the effects of the South American electric ray in Venezuela, 12 and had gone to England to join the circle of English electrologists, prompted John Walsh, a member of the London Royal Society, to conduct experiments on the properties of the Torpedo fish. Additionally, the anatomist John Hunter, who had dissected the South American electric ray, published a comprehensive study on the anatomy of the Torpedo fish.
Gray's work started in After numerous experiments with materials that exhibited known properties, he set out to investigate if other materials could also become electrified by friction. His many efforts led him to the important discovery of the property displayed by many objects, particularly metals, to act as conductors the term was introduced by Jean-Theophile Desagulier, , disciple of Gray.
Furthermore, he concluded that there were two types of materials: conductors and insulators. The later were easily electrified by friction, whereas conductors, for example metals, could not be electrified by the procedures employed at the time. Another relevant contribution of Gray's work concerns electrical induction The publications by Du Fay appeared during a briefly spanned period: His fundamental discovery regards the description of two electricities, which he termed vitreous and resinous electricity.
According to him, vitreous electricity was found in glass when rubbed by certain materials, whereas the second electricity was produced in resin, amber, and sealing wax.
Electricities of the same sign are repelled; whereas electricities of the opposite sign are attracted. Louis Guillaume Le Monnier managed to make the mentioned condenser transportable. Soon scientists investigated whether the presence of water in the device was indispensable or if other liquids or metallic armatures as inside and outside linings could replace it. The Leyden jar thus evolved into its current form.
The last edition of this work, to which the author had made numerous changes and additions, dates back to Opposing the idea of two electricities set forward by Du Fay, Franklin proposed that there was one single electrical fluid present in all matter. He posited that friction caused some of this fluid to be displaced, from a negatively charged to a positively charged condition.
However, in the 18 th century this theory was widely accepted by electrologists, including the father Giovanni Battista Beccaria 17 and Volta himself. This theory was substituted by a new theory, admitting the existence of two electrical fluids, which was accepted throughout the 19 th century. According to Robert Symmer? Among the principal electrologist of the 18 th century, a special mention is reserved to the Italian clergyman Giulio Cesare Gattoni , who showed remarkable interest in physics and had mounted a well and expensively equipped laboratory in his house.
Herein, Alessandro Volta was able to perform his first experiments and find all the books he needed. This treatise, which examines the trajectory of the knowledge on electricity with a fine critical spirit, constitutes one of the most valuable and extensive expositions of electrical developments of the time.
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 Previously, light bulbs had been invented by others, but the incandescent bulb was the first practical bulb that would light for hours on end.
Swan and Edison later set up a joint company to produce the first practical filament lamp, and Edison used his direct-current system DC to provide power to illuminate the first New York electric street lamps in September He worked with Edison and later had many revolutionary developments in electromagnetism, and had competing patents with Marconi for the invention of radio. He is well known for his work with alternating current AC , AC motors, and the polyphase distribution system.
Others who worked to bring the use of electricity to where it is today include Scottish inventor James Watt, Andre Ampere, a French mathematician, and German mathematician and physicist George Ohm. And so, it was not just one person who discovered electricity. He stood outside under a shelter while he held on to a silk kite with a key tied to it. When lightning struck, the electricity traveled down the key and its charge was collected in a Leyden jar — an antique electrical component which stores a high-voltage electric charge and can release it at a later date.
Franklin himself later wrote in the Pennsylvania Gazette on October 19, , detailing his findings and offering instructions on how to recreate the experiment:. And when the Rain has wet the Kite and Twine, so that it can conduct the Electric Fire freely, you will find it stream out plentifully from the Key on the Approach of your Knuckle. However, he is credited as the first scientist to draw up the hypothesis and the experimental conditions. In , an Italian doctor named Luigi Galvani found that when a frog touched two different kinds of metals, its leg twitched.
Volta used this insight to invent the first modern batteries. In his honor, we now name one of the properties of electricity, electrical potential or voltage , after him. Davy essentially invented the first light bulb. In , Hans Christian Oersted, A. Arago confirmed the relationship between electricity and magnetism. The basic unit for resistance, the ohm, carries his name. In , Michael Faraday invented the electric dynamo — essentially a crude power generator — that used a magnet that moved inside a coil of copper wire, creating a tiny electric current.
This set the stage for an electrical revolution across the world. In , American inventor Thomas Edison unveiled the first practical incandescent light bulb that could generate light for hours on end. Later, in the late s, Serbian-American inventor Nikola Tesla pioneered work with alternating current, the induction motor , and the polyphase distribution system. Tesla also had competing patents with Marconi for the invention of the radio. The moment humankind harnessed electricity was a milestone in history.
The world would have never been the same and most of the inventions we take for granted today would simply not have been possible without electricity. Today, electricity powers the world.
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