Definition
The maximum displacement of a wave or oscillation from its rest or zero position. In an electrical or radio signal, amplitude is the strength or height of the wave measured from its midline to its peak.
Plain English
How big the wave is. If you imagine a wave going up and down, amplitude is how far it reaches above (or below) the middle line. Bigger amplitude means a stronger signal or a louder sound.
Context Anchor
Seen in aircraft radio, electrical, sound, and vibration discussions.
Derivation
From the Latin amplitudo, meaning 'wideness' or 'largeness.' The original sense -- 'how wide or how large something is' -- carries directly into the technical meaning: the size of a wave's swing.
Why Pilots Care
Determines the strength of radio signals used for navigation and communication.
Analogy
Think of waves on water: taller waves have greater amplitude than small ripples. The spacing between the waves is a different idea; amplitude is only about how tall or large the wave is.
Grounding Statement
Picture a rope being shaken up and down. The taller the wave, the larger the amplitude.
Intuition Check
Amplitude is not the same as frequency. Amplitude is size or strength; frequency is how often the wave repeats.
Example Sentence 1
AM radio works by varying the amplitude of the carrier wave to carry the voice signal.
Example Sentence 2
In amplitude modulation the height of the carrier wave changes to carry voice information to the cockpit.