Electromagnetic Waves
Transverse self-propagating oscillations of coupled electric and magnetic fields traveling through space at the speed of light.
Governing formula
c = 1 / √(μ₀ ε₀) ≈ 3 × 10⁸ m/s, E = c B
SI unit
m/s (Velocity)
In depth
A time-varying electric field generates a time-varying magnetic field (Maxwell-Ampere law) and vice versa (Faraday's law), creating self-sustaining waves requiring no physical medium.
Examples in the real world
Radio signals broadcasting music, Wi-Fi data transmission at 2.4 GHz and 5 GHz, and solar visible light illuminating Earth.