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Electromagnetism
Article by: Christopher S. Baird, Department of Chemistry and Physics, West Texas A&M University, Canyon, Texas.
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The interaction among all electrically charged objects, ob-
jects with magnetic moments, and electromagnetic fields.
The electromagnetic interaction is one of the four fundamental
interactions of the universe. The interaction encompasses all
physical phenomena related to electricity, magnetism, elec-
tromagnetic fields, light, and atoms (Fig. 1). As such, electro-
magnetism forms the fundamental basis for a wide variety of
sciences including solid-state physics, optics, chemistry, and
molecular biology. All electromagnetic effects arise from the
interaction of electrically charged particles, particles with an
intrinsic magnetic moment, and an electromagnetic field.
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Key Concepts
• Electromagnetism is the physical interaction among electric charges, magnetic moments, and electromagnetic fields.
• An electromagnetic field can be static, slowly changing, or form waves.
• Electromagnetic waves are generally known as light and obey the laws of optics.
• Electromagnetic devices are used ubiquitously in modern society.
Fig. 1: Auroras—seen here in Iceland, and more commonly known as the northern and southern lights—in Earth's atmosphere display numerous aspects of electromagnetism. Auroras are
caused by electrically charged particles from the Sun that travel along magnetic field lines toward Earth's poles. The particles collide with molecules in the air, ionizing the molecules and
resulting in the emission of light. The colors of auroras indicate the different wavelengths emitted, which are in turn determined by the kinds of molecules that were ionized. (Credit: iStock)
