harmonic science definition
Noun Periodic motion whose frequency is a whole-number multiple of some fundamental frequency. The motion of objects or substances that vibrate or oscillate in a regular fashion, such as the strings of musical instruments, can be analyzed as a combination of a fundamental frequency and higher harmonics.
♦ Harmonics above the first harmonic (the fundamental frequency) in sound waves are called overtones. The first overtone is the second harmonic, the second overtone is the third harmonic, and so on.
Adjective Related to or having the properties of such periodic motion.

harmonic
Possible harmonics in the periodic motion of a vibrating guitar string.
Top: first harmonic (or fundamental),
center: second harmonic,
bottom: sixth harmonic.
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