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

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 model

Basic 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.

bodysleepcycleultradian