Alessandro Giuseppe Antonio Anastasio Volta was an Italian physicist and chemist who was a pioneer of electricity and power, and is credited as the inventor of the electric battery and the discoverer of methane. He invented the voltaic pile in 1799, and reported the results of his experiments in a two-part letter to the president of the Royal Society, which was published in 1800. With this invention, Volta proved that electricity could be generated chemically and debunked the prevalent theory that electricity was generated solely by living beings. Volta's invention sparked a great amount of scientific excitement and led others to conduct similar experiments, which eventually led to the development of the field of electrochemistry.
In physics, electromagnetism is an interaction that occurs between particles with electric charge via electromagnetic fields. The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interactions of atoms and molecules. Electromagnetism can be thought of as a combination of electrostatics and magnetism, which are distinct but closely intertwined phenomena. Electromagnetic forces occur between any two charged particles. Electric forces cause an attraction between particles with opposite charges and repulsion between particles with the same charge, while magnetism is an interaction that occurs between charged particles in relative motion. These two forces are described in terms of electromagnetic fields. Macroscopic charged objects are described in terms of Coulomb's law for electricity and Ampère's force law for magnetism; the Lorentz force describes microscopic charged particles.
Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. Electric charge can be positive or negative. Like charges repel each other and unlike charges attract each other. An object with no net charge is referred to as electrically neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects.
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a positive test charge from the first point to the second point. In the International System of Units (SI), the derived unit for voltage is the volt (V).
The voltaic pile was the first electrical battery that could continuously provide an electric current to a circuit. It was invented by Italian chemist Alessandro Volta, who published his experiments in 1799. Its invention can be traced back to an argument between Volta and Luigi Galvani, Volta's fellow Italian scientist who had conducted experiments on frogs' legs. Use of the voltaic pile enabled a rapid series of other discoveries, including the electrical decomposition (electrolysis) of water into oxygen and hydrogen by William Nicholson and Anthony Carlisle (1800), and the discovery or isolation of the chemical elements sodium (1807), potassium (1807), calcium (1808), boron (1808), barium (1808), strontium (1808), and magnesium (1808) by Humphry Davy.
Timeline of electromagnetism and classical optics lists, within the history of electromagnetism, the associated theories, technology, and events.
In electromagnetism and electronics, electromotive force is an energy transfer to an electric circuit per unit of electric charge, measured in volts. Devices called electrical transducers provide an emf by converting other forms of energy into electrical energy. Other electrical equipment also produce an emf, such as batteries, which convert chemical energy, and generators, which convert mechanical energy. This energy conversion is achieved by physical forces applying physical work on electric charges. However, electromotive force itself is not a physical force, and ISO/IEC standards have deprecated the term in favor of source voltage or source tension instead.
A pitch drop experiment is a long-term experiment which measures the flow of a piece of pitch over many years. "Pitch" is the name for any of a number of highly viscous liquids which appear solid, most commonly bitumen, also known as asphalt. At room temperature, tar pitch flows at a very low rate, taking several years to form a single drop.
Giuseppe Zamboni was an Italian Roman Catholic priest and physicist who invented the Zamboni pile, an early electric battery similar to the voltaic pile.
The Beverly Clock is a clock in the 3rd-floor lift foyer of the Department of Physics at the University of Otago, Dunedin, New Zealand. The clock is still running despite never having been manually wound since its construction in 1864 by Arthur Beverly.
Nicolae Vasilescu Karpen was a Romanian engineer and physicist, who worked in telegraphy and telephony and had achievements in mechanical engineering, elasticity, thermodynamics, long-distance telephony, electrochemistry, and civil engineering.
The Kelvin water dropper, invented by Scottish scientist William Thomson in 1867, is a type of electrostatic generator. Kelvin referred to the device as his water-dropping condenser. The apparatus is variously called the Kelvin hydroelectric generator, the Kelvin electrostatic generator, or Lord Kelvin's thunderstorm. The device uses falling water to generate voltage differences by electrostatic induction occurring between interconnected, oppositely charged systems. This eventually leads to an electric arc discharging in the form of a spark. It is used in physics education to demonstrate the principles of electrostatics.
Electrochemistry, a branch of chemistry, went through several changes during its evolution from early principles related to magnets in the early 16th and 17th centuries, to complex theories involving conductivity, electric charge and mathematical methods. The term electrochemistry was used to describe electrical phenomena in the late 19th and 20th centuries. In recent decades, electrochemistry has become an area of current research, including research in batteries and fuel cells, preventing corrosion of metals, the use of electrochemical cells to remove refractory organics and similar contaminants in wastewater electrocoagulation and improving techniques in refining chemicals with electrolysis and electrophoresis.
The history of electromagnetic theory begins with ancient measures to understand atmospheric electricity, in particular lightning. People then had little understanding of electricity, and were unable to explain the phenomena. Scientific understanding and research into the nature of electricity grew throughout the eighteenth and nineteenth centuries through the work of researchers such as André-Marie Ampère, Charles-Augustin de Coulomb, Michael Faraday, Carl Friedrich Gauss and James Clerk Maxwell.
Batteries provided the primary source of electricity before the development of electric generators and electrical grids around the end of the 19th century. Successive improvements in battery technology facilitated major electrical advances, from early scientific studies to the rise of telegraphs and telephones, eventually leading to portable computers, mobile phones, electric cars, and many other electrical devices.
The Zamboni pile is an early electric battery, invented by Giuseppe Zamboni in 1812.
Franklin bells are an early demonstration of electric charge designed to work with a Leyden jar or a lightning rod. Franklin bells are only a qualitative indicator of electric charge and were used for simple demonstrations rather than research. The bells are an adaptation to the first device that converted electrical energy into mechanical energy in the form of continuous mechanical motion: in this case, the moving of a bell clapper back and forth between two oppositely charged bells.
The frog galvanoscope was a sensitive electrical instrument used to detect voltage in the late 18th and 19th centuries. It consists of a skinned frog's leg with electrical connections to a nerve. The instrument was invented by Luigi Galvani and improved by Carlo Matteucci.
Franklin's electrostatic machine is a high-voltage static electricity-generating device used by Benjamin Franklin in the mid-18th century for research into electrical phenomena. Its key components are a glass globe which turned on an axis via a crank, a cloth pad in contact with the spinning globe, a set of metal needles to conduct away the charge developed on the globe by its friction with the pad, and a Leyden jar – a high-voltage capacitor – to accumulate the charge. Franklin's experiments with the machine eventually led to new theories about electricity and inventing the lightning rod.
The Maxwell-Lodge effect is a phenomenon of electromagnetic induction in which an electric charge, near a solenoid in which current changes slowly, feels an electromotive force (e.m.f.) even if the magnetic field is practically static inside and null outside. It can be considered a classical analogue of the quantum mechanical Aharonov–Bohm effect, where instead the field is exactly static inside and null outside.
