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Electromagnetism
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Electromagnetism

   

Electromagnetism is the physics of the electromagnetic field, including its effect on electrically charged particles.

While the electric and magnetic forces may sound fairly esoteric, almost all of the phenomena one encounters in daily life (with the exception of gravity) actually result from electromagnetism. The forces between atoms, including the attractive forces between atoms in a solid that give rise to the rigidity of solids, are predominantly electromagnetic, arising from the positive electric charge of the protons in atomic nuclei and the negative electric charge of the electrons surrounding the nuclei. So are the forces acting on the electrons in atoms, whose behavior gives rise to the varied phenomena observed in chemical reactions. Finally, it turns out that light can be described as a set of travelling disturbances in the electromagnetic field (i.e. electromagnetic waves), so all optical phenomena are actually electromagnetic in nature

The theory of classical electromagnetism was developed by various physicists over the course of the 19th century, culminating in the work of James Clerk Maxwell, who unified the preceding developments into a single theory and discovered the electromagnetic nature of light. Classical electromagnetism describes the behavior of the electromagnetic field using a set of equations known as Maxwell's equations. The force that the electromagnetic field exerts on electrically charged particles is described using the Lorentz force law.

Electrodynamics is that subfield of electromagnetism which deals with rapidly changing electric and magnetic fields, and their effects on the motion of charged particles.

The development of quantum mechanics necessitated the invention of a quantum theory of electromagnetism. This theory, which was completed in the 1970s, is known as quantum electrodynamics.

See also


General subfields within physics Edit
Classical mechanics | Condensed matter physics | Continuum mechanics | Electromagnetism |
General relativity | Particle physics | Quantum field theory | Quantum mechanics |
Solid state physics | Special relativity | Statistical mechanics | Thermodynamics