Cosmic Cycles
Schumann Resonance (4th harmonic)
27.30 Hz
Cosmic Octave Color
Derived visible color (624 nm)
Display swatch #e77d2e
EstablishedAstronomical Mapping
Evidence Level
Established
Source Count
1
Last Reviewed
March 23, 2026
Directly measured, standardized, or well-supported in mainstream scientific or technical literature.
The underlying cycle is measurable, but the audible tone is an octave-transposed mapping used for comparison, listening, and practice rather than a naturally audible emission.
Review the evidence modelFourth mode of Schumann resonance.
Wavelength
12.56 m
Nearest Note
A0 (-13¢)
Claim Type
Astronomical Mapping
Cosmic Octave Color
Derived visible color (624 nm) · #e77d2e
Source
Geophysics
Sources
Geophysics and Schumann Resonance Literature
4 atlas references
Used for atmospheric resonances, Earth-ionosphere cavity behavior, and related geophysical frequencies.
W.O. Schumann (1952) and later geophysical literature.
Octave Ladder
Every audible octave of this frequency — the same tone, higher and lower.
Nearby in the Atlas
Entries within ±35 cents of this tone when reduced to the same octave — candidates for pairing or comparison.
A0Musical Frequencies
27.50 Hz+12.6¢
A1Musical Frequencies
55.00 Hz+12.6¢
A2Musical Frequencies
110.00 Hz+12.6¢
A3Musical Frequencies
220.00 Hz+12.6¢
A4Musical Frequencies
440.00 Hz+12.6¢
A5Musical Frequencies
880.00 Hz+12.6¢
schumannharmonic