What Is Electromagnetism?
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Electromagmetism is one of the four fundamental forces of nature (the other three are gravity, the strong nuclear force, and the weak nuclear force.)  Electromagnetism acts only on charged particles (e.g. protons, electrons).  Electromagnetism has the ability to act over infinite distances.
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Physics (from the Greek, φύσις (phúsis), "nature" and φυσική (phusiké), "knowledge of nature") is the science concerned with the discovery and understanding of the fundamental laws which govern matter, energy, space and time. That is, physics deals with the elementary constituents of the Universe and their interactions, as well as the analysis of systems which are best understood in terms of these fundamental principles. Physics is a study of the inorganic, physical world, as opposed to the organic world of biology, physiology, etc. [1] Physics overlaps with chemistry concerning the electro-chemical interactions of substances.\nCentral theories\n\nWhile physics deals with a wide variety of systems, there are certain theories that are used by all physicists. Each of these theories were experimentally tested numerous times and found correct as an approximation of nature (within a certain domain of validity). For instance, the theory of classical mechanics accurately describes the motion of objects, provided they are much larger than atoms and moving at much less than the speed of light. These theories continue to be areas of active research; for instance, a remarkable aspect of classical mechanics known as chaos was discovered in the 20th century, three centuries after the original formulation of classical mechanics by Isaac Newton (1642–1727). These "central theories" are important tools for research into more specialized topics, and any physicist, regardless of his or her specialization, is expected to be literate in them.\n\n    * Classical mechanics is a model of the physics of forces acting upon bodies. It is often referred to as "Newtonian mechanics" after Newton and his laws of motion. Classical mechanics is subdivided into statics (which models objects at rest), kinematics (which models objects in motion), and dynamics (which models objects subjected to forces). See also mechanics.\n\n    * Electromagnetism, or electromagnetic theory, is the physics of the electromagnetic field: a field, encompassing all of space, which exerts a force on those particles that possess the property of electric charge, and is in turn affected by the presence and motion of such particles. Electromagnetism encompasses various real-world electromagnetic phenomena.\n\n    * Thermodynamics is the branch of physics that deals with the action of heat and the conversions from one to another of various forms of energy. Thermodynamics is particularly concerned with how these affect temperature, pressure, volume, mechanical action, and work. Historically, it grew out of efforts to construct more efficient heat engines — devices for extracting useful work from expanding hot gases.\n\n    * Statistical mechanics, a related theory, is the branch of physics that analyzes macroscopic systems by applying statistical principles to their microscopic constituents and, thus, can be used to calculate the thermodynamic properties of bulk materials from the spectroscopic data of individual molecules.\n\n    * Quantum mechanics is the branch of mathematical physics treating atomic and subatomic systems and their interaction with radiation in terms of observable quantities. It is based on the observation that all forms of energy are released in discrete units or bundles called quanta. Quantum theory typically permits only probable or statistical calculation of the observed features of subatomic particles, understood in terms of wave functions.\n\n    * The theory of relativity, or relativity theory, is:\n\n    *\n          o A physical theory which is based on two postulates (1) that the speed of light in a vacuum is constant and independent of the source or observer and (2) that it is impossible to determine ones absolute velocity in any inertial systems and which leads to the deduction of the equivalence of mass and energy and of change in mass, dimension, and time with increased velocity — called also spec
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In 1931, P. A. M. Dirac suggested that the existence of magnetic monopoles would explain the quantization of electric charge, the fact that it appears only in units of the electronic charge e (fractional charges appear in certain theories, but are not observed in nature). This article is not about these monopoles, so if the reader should refer to Jackson if interested in them, or to the article Energy Loss of Charged Particles, where the stopping of Dirac monopoles by matter is discussed. Here we will talk about magnetic charges, or isolated poles, or monopoles as an aid in understanding electricity and magnetism by analogy between electric and magnetic fields. We'll also discuss the systems of electromagnetic units, especially those things not appearing in current texts, and how it all hangs together.\n\nThe magnetic field of the earth does not exceed about 1 ørsted, which shows that there is no great amount of unbalanced magnetic charge in its makeup. In fact, isolated magnetic poles have never been observed, and are not accounted for in Maxwell's equations. Magnetic fields are all created by currents, either macroscopic ones or microscopic ones, just as electric fields are created by free or bound charges. Relativity indicates that E and B are the fundamental electromagnetic fields that describe the macroscopic interactions of electromagnetism and are associated in a field tensor that has different expressions in different inertial frames.\n\nThe original concept of electromagnetism was that of "action at a distance" evidenced by the mutual forces exerted by charges or currents at different locations on each other. Faraday's concept was that the influence was transmitted through a medium in which the charges or currents were immersed, and this concept was expressed mathematically by Maxwell, who based the theory on fields satisfying certain differential equations. A source charge created a field, which then acted upon the charge that was influenced. He searched in vain for a suitable medium, which became the famous "luminiferous ether" of pre-relativistic days, and for a suitable mechanism for the propagation of the influence. All attempts to detect the medium failed, and it was replaced by the concepts of relativity, in which there are still fields, but immaterial ones. This was at least a partial return to the earlier ideas, and the "reality" of electromagnetic fields can be a subject of discussion. It appears that the potentials are what travels at the speed of light, and the fields are derived from them. Whatever conclusion may be drawn, they do describe the physics very well indeed.\n\nIn the early days of Maxwell's theory, the equations D = κE and B = μH were thought of as relating a stress (E or H) to a strain (D or B). These four fields D, E, B and H were called displacement, electric intensity, induction and magnetic intensity, respectively. Their units were the familiar absolute electrostatic (esu) or absolute electromagnetic (emu) units. Practical workers, for their part, had arbitrarily defined units of electrical pressure and resistance, and from them derived the units of charge and current. The unit of electrical pressure was that of the Daniell cell, and that of resistance was a mercury column 1 sq. mm. in cross-section and 1 m long.\n\nIt was discovered, by an investigator named Giorgi, that by a certain choice of the units of mass, length and time quantities very close to the practical units could be brought into a consistent and absolute system of units. A consistent system of units is one in which the units are determined by the defining equations for the quantities, and not by arbitrary choice. An absolute system is one in which all units are derived from a set of basic units. The emu and esu were consistent absolute systems based on the centimeter-gram-second (cgs) mechanical units. Giorgi found that simply taking the meter-kilogram-second (mks) as fundam
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Magnetism is actually a relativistic effect caused by moving charge. Current travelling in a wire has a magnetic field surrounding it. Bar magnets are special in that all the magnetic moments (the magnetic effect of electrons orbiting their nucleii) are aligned. In most materials the moments are randomly aligned and cancel each other out.
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Well even though humans have known about magnets for thousands of years, the real reason they work is still somewhat mysterious. Depending on how deep you want to investigate, it can be a very complicated phenomenon. \n\nA magnet is, at its foundation, caused by the movement of electrical charge (yes this is the Biot-Savart Law). When charges (like electrons for example) move, they produce magnetic fields. If a charge moves in a loop, it creates a magnetic field. The magnetic field can be basically represented by an invisible set of arrows in space, that point in a direction. In the case of the loop, the arrows of the magnetic field will point out of the loop for a positive charge moving counter clockwise (this is the so-called "right hand rule"), and into the loop for a charge moving clockwise (some pictures are in the reference attached). \n\nThe magnetic field has a "north" end and a "south end". The little arrows from our moving charge are pointing in the "north" magnetic direction, and away from the "south" magnetic direction. It is a mysterious and interesting property of electromagnetism that two objects with fields that oppose each other, i.e., the little arrows of the field do not line up, so either the north end of one field is facing the north end of the other field, or the two south ends are facing each other, repel, or resist movement of the two objects towards each other with some force. \n\nOn the other hand, if the little arrows line up, the two objects attract each other with some force. \n\nThe forces that result from magnetic fields (and for that matter, electric fields) are fundamental forces, and part of the four fundamental forces of the universe (strong, weak, electromagnetic and gravity).  It is believed that these forces are caused, at their base, by particles passing "messenger particles" back and forth. In the case of electromagnetism, the messenger particle is a photon. How this actually works is still somewhat poorly understood, and is involved with the world of quantum mechanics, which is very counterintuitive but interesting. \n\nHowever, what is important is that we understand it well enough to make models of magnetism, and to make predictions based on those models which we can verify and use. All of electricity and electric motors are based on our ability to design systems with magnets and to be able to build and use them.
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Quantum mechanics is a fundamental physical theory that replaces Newtonian mechanics and classical electromagnetism at the atomic and subatomic levels and is the underlying framework of many fields of physics and chemistry, including condensed matter physics, quantum chemistry, and particle physics. Often, it is the answer to questions when general relativity fails.
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.  Gravity and magnetism are two very different kinds of forces.  Gravity is always attractive and is proportional to the masses of two objects and how close together they are.  Magnetism can be attractive (pulling objects together) or repulsive (pushing them apart).  Magnetism is due to electric fields, either in the atoms of certain materials or electric fields resulting from electric currents in a sizable quantity of material.\n.  The earth might be a large magnet, with a net magnetic orientation in its solid iron inner core making the core a magnet, but its magnetic field is due mostly due to electric currents in the molten iron outer core which are generated by interactions with other magnetic fields.  We know that the earth is not like a permanent magnet because its magnetic field reverses periodically, about every 100,000 to 200,000 years.\n.   There are four basic forces in physics: gravity, the electromagnetic force, the weak nuclear force and the strong nuclear force.  Gravity seems to be quite different from the other forces.  Quantum mechanics can explain the other three forces and demonstrate how, at very high particle energies, they could be a single force.  Gravity,so far, can not be united in theory with the other forces.
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In electrodynamics, polarization (also spelled polarisation) is the property of electromagnetic waves that describes the direction of their transverse electric field. Electromagnetic waves, such as light, exhibit polarization, unlike more familiar wave phenomena such as waves on water or sound waves. Electromagnetic waves are three-dimensional, and it is their vector nature that gives rise to the phenomenon of polarization.\n\nThe polarization of an electromagnetic wave is defined as the orientation of the electric field vector. Recall that the electric field vector is perpendicular to both the direction of travel and the magnetic field vector. The polarization is described by the geometric figure traced by the electric field vector upon a stationary plane perpendicular to the direction of propagation, as the wave travels through that plane. An electromagnetic wave is frequently composed of (or can be broken down into) two orthogonal components
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Paramagnetism is a form of magnetism which only occurs in the presence of an externally applied magnetic field. Paramagnetic materials are attracted to magnetic fields, hence have a relative magnetic permeability greater than unity (or, equivalently, a positive magnetic susceptibility). However, unlike ferromagnets which are also attracted to magnetic fields, paramagnets do not retain any magnetisation in the absence of an externally applied magnetic field.\n\nDiamagnetism is a form of magnetism that is only exhibited by a substance in the presence of an externally applied magnetic field. It is the result of changes in the orbital motion of electrons. Applying a magnetic field creates a magnetic force on a moving electron in the form of F = qv × B. This force changes the centripetal force on the electron, causing it to either speed up or slow down in its orbital motion. This changed electron speed modifies the magnetic moment of the orbital in a direction opposing the external field.
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The electrostatic force is one of the four fundamental forces. It acts between all charged particles, repulsive between like charges and attractive between unalike charges. Going a bit deeper its origin is in the exchange of carrier particles, which in the case of the electrostatic force are photons.\n\nMagnetism is an effect of special relativity on the electrostatic force. Hence it only applies between moving charges. An electron will have no response to a magnetic field if it is not moving and the field is not changing. Otherwise it will move perpendicular to both its path and the magnetic field.
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Well even though humans have known about magnets for thousands of years, the real reason they work is still somewhat mysterious. Depending on how deep you want to investigate, it can be a very complicated phenomenon. \n\nA magnet is, at its foundation, caused by the movement of electrical charge (yes this is the Biot-Savart Law). When charges (like electrons for example) move, they produce magnetic fields. If a charge moves in a loop, it creates a magnetic field. The magnetic field can be basically represented by an invisible set of arrows in space, that point in a direction. In the case of the loop, the arrows of the magnetic field will point out of the loop for a positive charge moving counter clockwise (this is the so-called "right hand rule"), and into the loop for a charge moving clockwise (some pictures are in the reference attached). \n\nThe magnetic field has a "north" end and a "south end". The little arrows from our moving charge are pointing in the "north" magnetic direction, and away from the "south" magnetic direction. It is a mysterious and interesting property of electromagnetism that two objects with fields that oppose each other, i.e., the little arrows of the field do not line up, so either the north end of one field is facing the north end of the other field, or the two south ends are facing each other, repel, or resist movement of the two objects towards each other with some force. \n\nOn the other hand, if the little arrows line up, the two objects attract each other with some force. \n\nThe little arrows are aligned along the so-called "magnetic lines of force". \n\nThe forces that result from magnetic fields (and for that matter, electric fields) are fundamental forces, and part of the four fundamental forces of the universe (strong, weak, electromagnetic and gravity). It is believed that these forces are caused, at their base, by particles passing "messenger particles" back and forth. In the case of electromagnetism, the messenger particle is a photon. How this actually works is still somewhat poorly understood, and is involved with the world of quantum mechanics, which is very counterintuitive but interesting. \n\nHowever, what is important is that we understand it well enough to make models of magnetism, and to make predictions based on those models which we can verify and use. All of electricity and electric motors are based on our ability to design systems with magnets and to be able to build and use them.
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If you get an A with this work please share it with me. If you get an F , forget me.\n\n  \n  Magnetism are 2 sides (+ and -) (like in some relations). Every compass will go to the North because of magentic fields, those fileds are kind of circles like the air waves of radio or Tv.\n\n  2. Electromagentic is a toold like iron that needs electricity to work and work as a magnet, it is important a battery or other source of low voltage. Electromagentics are used to attract old cars, electromagentics are used for people who lost some things on the sand (those kind of electromagnetics are the ones with one circle in the end where the person is attracting something).\n\n 3: Electromagentic needs a switch like light, turn on and off, you let the energy flow and you get the magnetic field or you deny that flow, on the other hand the magnet is always "on", there are magnets where both sides are positive or negative, most of them are positive and negative like in electricity you need both to have electricity.\n\n 4:For instance the motor of one car, inside the motor you will see a lot of pieces and is kind of interesting because thin cables are allowing the flow of electricity, so with that in mind the motor is moving, produces energy then
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In physics, a magnetic field is an entity produced by moving electric charges (electric currents) that exerts a force on other moving charges. (The quantum-mechanical spin of a particle produces magnetic fields and is acted on by them as though it were a current; this accounts for the fields produced by "permanent" ferromagnets.) A magnetic field is a vector field: it associates with every point in space a (pseudo-)vector that may vary in time. The direction of the field is the equilibrium direction of a compass needle placed in the field.
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If you think about the properties of electromagnetism and electricity itself, and you study up on Teslas ideas, it seems as if there is a whole new area of science waiting to be seen by the mainstream. It is not complicated at all and should be looked into.
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gravity, strong force, weak force, and electromagnetivity
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Diamagnetism is a form of magnetism which is only exhibited by a substance in the presence of an externally applied magnetic field.\n\nParamagnetism is the tendency of the atomic magnetic dipoles to align with an external magnetic field. This effect occurs due to quantum-mechanical spin as well as electron orbital angular momentum.  \n\nParamagnetism requires that the atoms individually have permanent dipole moments even without an applied field.\n\nArsenic is not a paramagnetic substance.
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what is physics, you mean? Physics is literally the study of the physical properties of the world, such as speed, light, sound, weight, materials, heat and electrical conductivity, and basically everything else. Physics is the basis of almost every other field of science.