What Are Electromagnetic Waves?
Electromagnetic waves are oscillations of electric and magnetic fields that propagate through space at the speed of light. They require no medium to travel through.
The Electromagnetic Spectrum
Radio Waves
Longest wavelength, lowest frequency. Used for communication, broadcasting, and radar.
Microwaves
Heat food by causing water molecules to vibrate. Also used in satellite communication.
Infrared
Heat radiation. Everything with temperature emits infrared radiation.
Visible Light
The only part of the spectrum our eyes can see. Red has the longest wavelength, violet the shortest.
Ultraviolet
Can cause sunburn and skin damage, but also helps produce vitamin D.
X-rays
High energy waves that can penetrate soft tissue but are absorbed by bones.
Gamma Rays
Highest energy, most dangerous. Produced by radioactive decay and nuclear reactions.
Maxwell's Equations
James Clerk Maxwell's four equations describe how electric and magnetic fields interact and how electromagnetic waves propagate.