Brain wave frequency

The electrical activity of the brain can be divided into frequency patterns and recorded using an electroencephalograph (or EEG). The brain waves have been classified into four sections:
• Beta waves (frequency 14-18 Hz) active state.
• Alpha waves (8-13 Hz) calm, relaxed or creative state.
• Theta waves (4-8 Hz) drowsiness, state between consciousness and sleep.
• Delta waves (4 Hz) Regenerative state, sleep, dream state.

This state is induced in a floating session. Theta offers access to unconscious material, reverie, free association, sudden insight, and creative inspiration. For a long time, scientists had a difficult time studying it, as it is hard to maintain for a longer period. Most people tend to fall asleep when they generate theta waves.
Using a state of deep relaxation as a source of creativity has been known to mankind since antiquity. The most famous examples for insights and revelation are the bathing Archimedes (the law of equilibrium of fluids), Newton sitting relaxed under an apple tree (discovery of the laws of gravity), and Albert Einstein, who had many of his ideas in the bathtub and used it for “consciousness trips”. There are a great many stories of moments of inspiration and creativity, which arise when people are drifting into sleep, looking at the sky or into the fire. They all speak of drowsiness, relaxation and a rush of vivid mental imagery and other typical characteristics of the theta state.