Biological Rhythms
Ultradian Rhythm (90 min)
1.85e-4 Hz
Cosmic Octave Color
Derived visible color (703 nm)
Display swatch #bf372b
Octave-shifted: 24.25 Hz (+17 octaves)
EstablishedPhysical Measurement
Evidence Level
Established
Source Count
1
Last Reviewed
March 23, 2026
Directly measured, standardized, or well-supported in mainstream scientific or technical literature.
This entry documents a measurable or standardized frequency reference. The atlas is a research and practice guide, not a medical diagnostic instrument.
Review the evidence modelBasic rest-activity cycle (~90 minutes). Governs sleep stages (NREM-REM cycle) and daytime alertness fluctuations.
Period
1.5 hours
Wavelength
1854.1 km
Claim Type
Physical Measurement
Cosmic Octave Color
Derived visible color (703 nm) · #bf372b
Source
Sleep science
Sources
Neuroscience and EEG Research
1 atlas references
Used for brainwave frequency bands and broad EEG ranges, rather than for mystical or therapeutic certainty.
Neuroscience / EEG research.
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.
Earth Synodic Day (Cosmic Octave)Cosmic Cycles
194.18 Hz+1.7¢
DNA Resonance MaximumCosmic Cycles
854.0 THz+1.7¢
Circadian RhythmBiological Rhythms
1.16e-5 Hz+5.6¢
Earth Sidereal Day (Cosmic Octave)Cosmic Cycles
194.71 Hz+6.4¢
Paiste Planetary Gong — Sidereal DayInstrument Resonances
194.71 Hz+6.4¢
Theta (Mid)Brainwaves
6.00 Hz-17.8¢
bodysleepcycleultradian