Published in 1600, Gilbert's work, De Magnete, helped to establish magnetism as a science. ===Mathematical development=== In 1750, John Michell stated that magnetic poles attract and repel in accordance with an inverse square law Charles-Augustin de Coulomb experimentally verified this in 1785 and stated explicitly that north and south poles cannot be separated.

Published in 1600, Gilbert's work, De Magnete, helped to establish magnetism as a science. ===Mathematical development=== In 1750, John Michell stated that magnetic poles attract and repel in accordance with an inverse square law Charles-Augustin de Coulomb experimentally verified this in 1785 and stated explicitly that north and south poles cannot be separated.

In this model, a magnetic -field is produced by magnetic poles and magnetism is due to small pairs of north–south magnetic poles. Three discoveries in 1820 challenged this foundation of magnetism.

Building on this force between poles, Siméon Denis Poisson (1781–1840) created the first successful model of the magnetic field, which he presented in 1824.

Laplace later deduced a law of force based on the differential action of a differential section of the wire, which became known as the Biot–Savart law, as Laplace did not publish his findings. Extending these experiments, Ampère published his own successful model of magnetism in 1825.

Also in this work, Ampère introduced the term electrodynamics to describe the relationship between electricity and magnetism. In 1831, Michael Faraday discovered electromagnetic induction when he found that a changing magnetic field generates an encircling electric field, formulating what is now known as Faraday's law of induction.

In the process, he introduced the magnetic vector potential, which was later shown to be equivalent to the underlying mechanism proposed by Faraday. In 1850, Lord Kelvin, then known as William Thomson, distinguished between two magnetic fields now denoted and .

Further, he derived how and relate to each other and coined the term permeability. Between 1861 and 1865, James Clerk Maxwell developed and published Maxwell's equations, which explained and united all of classical electricity and magnetism.

The first set of these equations was published in a paper entitled On Physical Lines of Force in 1861.

Further, he derived how and relate to each other and coined the term permeability. Between 1861 and 1865, James Clerk Maxwell developed and published Maxwell's equations, which explained and united all of classical electricity and magnetism.

Maxwell completed his set of equations in his later 1865 paper A Dynamical Theory of the Electromagnetic Field and demonstrated the fact that light is an electromagnetic wave.

The short-circuited turns of the rotor develop eddy currents in the rotating field of the stator, and these currents in turn move the rotor by the Lorentz force. In 1882, Nikola Tesla identified the concept of the rotating magnetic field.

The motor used polyphase current, which generated a rotating magnetic field to turn the motor (a principle that Tesla claimed to have conceived in 1882).

In 1885, Galileo Ferraris independently researched the concept.

In 1885, Galileo Ferraris independently researched rotating magnetic fields and subsequently published his research in a paper to the Royal Academy of Sciences in Turin, just two months before Tesla was awarded his patent, in March 1888. The twentieth century showed that classical electrodynamics is already consistent with special relativity, and extended classical electrodynamics to work with quantum mechanics.

Heinrich Hertz published papers in 1887 and 1888 experimentally confirming this fact. ===Modern developments=== In 1887, Tesla developed an induction motor that ran on alternating current (AC).

In 1888, Tesla gained for his work.

Also in 1888, Ferraris published his research in a paper to the Royal Academy of Sciences in Turin. ===Hall effect=== The charge carriers of a current-carrying conductor placed in a transverse magnetic field experience a sideways Lorentz force; this results in a charge separation in a direction perpendicular to the current and to the magnetic field.

Heinrich Hertz published papers in 1887 and 1888 experimentally confirming this fact. ===Modern developments=== In 1887, Tesla developed an induction motor that ran on alternating current (AC).

Tesla received a patent for his electric motor in May 1888 as .

In 1885, Galileo Ferraris independently researched rotating magnetic fields and subsequently published his research in a paper to the Royal Academy of Sciences in Turin, just two months before Tesla was awarded his patent, in March 1888. The twentieth century showed that classical electrodynamics is already consistent with special relativity, and extended classical electrodynamics to work with quantum mechanics.

Albert Einstein, in his paper of 1905 that established relativity, showed that both the electric and magnetic fields are part of the same phenomena viewed from different reference frames.

Finally, the emergent field of quantum mechanics was merged with electrodynamics to form quantum electrodynamics (QED), which first formalized the notion that electromagnetic field energy is quantized in the form of photons. As of October 2018, The largest magnetic field produced over a macroscopic volume outside a lab setting is 2.8 kT (VNIIEF in Sarov, Russia, 1998).

theory.uwinnipeg.ca. Hoadley, Rick, "What do magnetic fields look like?" 17 July 2005. Magnetism Physical quantities

Finally, the emergent field of quantum mechanics was merged with electrodynamics to form quantum electrodynamics (QED), which first formalized the notion that electromagnetic field energy is quantized in the form of photons. As of October 2018, The largest magnetic field produced over a macroscopic volume outside a lab setting is 2.8 kT (VNIIEF in Sarov, Russia, 1998).

As of October 2018, the largest magnetic field produced in a laboratory over a macroscopic volume was 1.2 kT by researchers at the University of Tokyo in 2018. The largest magnetic fields produced in a laboratory occur in particle accelerators, such as RHIC, inside the collisions of heavy ions, where microscopic fields reach 1014 T.

All text is taken from Wikipedia. Text is available under the Creative Commons Attribution-ShareAlike License .

Page generated on 2021-08-05