When was electricity invented? The question itself doesn’t make much sense as electricity is a natural phenomenon and therefore wasn’t “invented” as we typically understand the term. However, electricity was discovered and later harnessed.
Benjamin Franklin is typically given credit for the discovery of electricity while Michael Faraday is typically credited with making electricity harnessable and viable for use in technology. That said, even these stories simplify the harnessing of electricity somewhat. Taking a more comprehensive look at the history of electricity will make it clearer how electricity’s history involves the contribution of many individuals over hundreds of years.
A Timeline Of Electrical Research
In approximately 600 BCE, an ancient Greek scientist by the name of Thales of Miletus conducted experiments where he discovered that the process of rubbing animal fur and amber together caused an attraction between the two items. Thales of Miletus wrote about this discovery, and what he was describing was the phenomenon of static electricity. It would be over a millennium later, during the 1600s when William Gilbert coined the phrase “electricity” in English, translating it from the Latin word “electricus”, referring to the force exerted by particular substances rubbed together. By this point, many electricity-related discoveries have been made in the intervening centuries. The differentiation between negative and positive currents as well as early electrostatic generators have been achieved. A few years after Gilbert coined the phrase electricity, the scientist Thomas Browne used the term electricity when reporting about Gilbert’s work and his own research on the subject.
In approximately 1660 a machine that produced static electricity was created by Otto von Guericke. More experiments with electrical phenomenon would continue over the next century and a half, with Robert Boyle experimenting with electrical repulsion and attraction during the year 1675. Stephen Gray discovered the property of electrical conduction in 1729, and four years later in 1733 the scientist Charles François du Fay reported that electricity could be in one of two forms, either vitreous or resinous. These terms that would later be renamed positive and negative.
In 1745 the Leyden jar, an object that stored static electricity, was invented by Pieter van Musschenbroek. Leyden jars could discharge the static electricity they had stored up at a single moment in time. William Watson experimented with Leyden jars in 1747 to discover that the charge stored up by the jar could be discharged across a circuit, and his reports on the discovery gave us the terms “circuit” and “current”, which laid the groundwork for further research and experimentation into electrical conduction. Around the same time, Henry Cavendish began measuring the conductivity of different materials and publishing these conductivity levels for the benefit of others who worked with electricity.
In 1752, Benjamin Franklin conducted his famous experiment with a kite and a key during a lightning storm. Franklin had a theory that lightning was electrical in nature, and during a lightning storm, he attached a wet hemp string to a kite and attached a key to the wet string. The key itself was attached to a Leyden jar. When he flew the kit during a lightning storm, Franklin observed that the loose threads of the string were repelling one another, and upon moving his hand towards the key he saw an electrical spark. This experiment demonstrated that tiny electrical sparks released by the discharge of static and lightning were the same basic phenomenon.
Around 1876, the scientist Luigi Galvani worked to demonstrate that nerve impulses had an electrical basis, which he showed by attaching electrodes to frog muscles and causing them to twitch by running a current through them.
In 1800, the Italian physicist Alessandra Volta found that certain chemical reactions could give rise to electrical charges. Volta created an early electric battery, the voltaic pile, and in doing so Volta was later able to create a steady flow of electricity from one point to another. Volta accomplished this by linking negatively charged connectors and positively charged connectors together, then pushing the voltage through them.
In 1831, the English scientist Michael Faraday, who had been studying electrochemistry and electromagnetism, succeeded in creating the first ever electric dynamo. Dynamos are power generators, and Faraday created the first one by using a magnet suspended in a coil of copper wire. This set up enabled a small electrical current to flow across the wire, which cracked the problem of generating a constant electrical current. Thanks to Faraday’s discovery, later scientists such as Joseph Swan and Thomas Edison were able to apply electrical currents and power various inventions such as the incandescent filament for light bulbs. Light bulbs had been created by other individuals, but the incandescent bulb powered by electrical filaments was the first bulb that was practical, that would actually provide late for multiple hours in a row. Edison and Swan would later team up to create a company responsible for producing the filament lamps, and Edison would use the direct current system along with these lamps to power the first-ever electrical streetlamps in 1882.
Another individual responsible for making contributions to the study of electricity was Nicola Tesla, who carried out many experiments during the late 1800s and early 1900s. Tesla created many different electrical systems such as the polyphase distribution system, and alternating current motors. Tesla also invented the Tesla coil, and even collaborated with Edison on some projects. The industrialist George Westinghouse would later build on Tesla’s motors for generating alternating current.
Other individuals who contributed to the development of electrical technology include the Scottish inventor James Watt, French mathematician Andre Ampere, and the German physicist George Ohm, whose legacies can be seen in the units with which we quantify various properties of electricity.
When viewing the history of electricity like this, it becomes apparent that our understanding and utilization of electricity is what it is today not because of any one individual, but because of the work of many different people each making their own contributions over thousands of years.
Understanding Electrical Current
Technically, an electrical current is any electrical charge in motion. This means that electrical currents can be things like the sparks that occur when you touch a piece of metal in a dry environment or lightning bolts. However, in common usage electrical currents are the controlled motions of electricity utilized in things like batteries and generators.
Electrical charges are carried by the protons and electrons located inside of atoms. Electrons have negative charges while protons have positive charges. The actual movement of charges from one point to another point is carried out by electrons, as protons are mainly stationary within the nucleus of the atom. The electrons found in conductive materials can jump from one atom to another atom along bands of conduction, which are the outermost electron orbits. When there is a strong enough electromotive force, or voltage, the electrons move through the conductive material as an electrical current.
If you want a metaphor, you can think of electrical currents operating similarly to water flowing through a pipe. Electrons can be described as flowing through a wire in a similar fashion as water flowing through a pipe, although this metaphor does have its limitations. In the case of a pipe full of water, opening the valve at one end of the pipe will instantly let the water in the pipe out because the water behind it displaces it. Similarly, electrical currents move through wire thanks to the conduction electrons already present in the wire being displaced as more electrons rush into the wire. They move at a few millimeters per second, although the direction of flow for the electron isn’t straight across. Rather, the electron bounces around at random, only maintaining a general direction down the wire, making a little progress with every further bounce. The rate at which the electron moves on the wire is referred to as the drift velocity. In contrast, the rate at which electrons exit the other end of the wire after the switch is flipped and an electrical current is started is around 300 mm/s, or about the speed of light.
A charge imbalance can happen in various ways. A static charge can be created by rubbing together two different types of materials, such as rubbing amber and animal fur together. This would build up a charge in the amber, which could then be discharged by touching the amber to an object that has less charge. This was the way that static charges were initially discovered.
However, a superior method of credit charge and balances was discovered by the Italian physicist Alessandro Volta, who created the first electrochemical battery. The voltaic pile invented by Volta was created by stacking alternating layers of copper and zinc together and then soaking the stack in salt water. This ended up producing a steady source of current, direct current (or DC). While direct current has its uses, most electricity we use today is supplied in the form of Alternating Current (or AC). Alternating current is generated with electrical generators, such as a turbine heated by natural gas, that operates according to Faraday’s Law of Induction. This Law of Induction means that a shifting magnetic field can create electrical currents in the right conductor, and in a turbine, the coils rotate. The rotation of the coils corresponds to the magnetic field, and the coils reverse direction every half turn, producing an electrical current.