Britannica
Sources used in this answer
How does electromagnetism relate electric fields, magnetic fields, and light?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
physics
As conceived by Daniel Bernoulli in Hydrodynamica (1738), gases consist of numerous particles in rapid random motion. He assumed that the pressure of a gas is produced by the direct impact of the particles on the walls of the container.
In physics, electromagnetism unifies electricity, magnetism, and optics by describing light as a propagating wave of coupled electric and magnetic fields.12
The relationship is defined by the principle that time-varying fields generate one another: a changing magnetic field induces an electric field, and a changing electric field induces a magnetic field. When these oscillations occur in free space, they propagate as [electromagnetic waves].134
Key characteristics of this relationship include:
- Mutual Induction: Maxwell’s equations demonstrate that these fields are intrinsically linked; a time-varying electric field acts as a source for a magnetic field, and vice versa.53
- Wave Propagation: These coupled oscillations travel through space as electromagnetic waves at the [speed of light].12
- Transverse Nature: In an ideal vacuum, the electric field, the magnetic field, and the direction of wave propagation are mutually perpendicular, forming a right-handed coordinate system.4
- Unified Spectrum: Light is simply one portion of the [electromagnetic spectrum], which encompasses all electromagnetic radiation—from radio waves to gamma rays—all of which share this fundamental electromagnetic wave nature.61