Definition
Waves of energy made up of linked electric and magnetic fields that travel through space at the speed of light. They span a wide range of frequencies, from radio waves and microwaves through visible light to X-rays, and they do not require a physical medium to propagate.
Plain English
Invisible waves of energy that travel through the air or empty space, carrying things like radio signals, light, and heat from one place to another.
Context Anchor
Seen in aircraft radio, antenna, radar, lighting, and electrical system discussions.
Derivation
From 'electromagnetic,' combining 'electric' and 'magnetic.' The term reflects the discovery that changing electric fields produce magnetic fields and vice versa, and that the two travel together as a single wave.
Why Pilots Care
All aircraft radio, radar, GPS, and wireless systems depend on these waves to send and receive signals.
Analogy
A radio signal is a little like a ripple spreading across a pond, except it is energy spreading through space instead of water moving on a surface.
Grounding Statement
When you key the mic and your voice reaches another aircraft a hundred miles away, electromagnetic waves are doing the carrying.
Intuition Check
Electromagnetic waves are not sound waves. They do not need air to travel, and they carry energy as electric and magnetic patterns.
Example Sentence 1
VHF radios transmit voice communication using electromagnetic waves in the 118 to 137 MHz range.
Example Sentence 2
Weather radar sends out electromagnetic waves that reflect off precipitation and return to show storm locations on the display.