Dreaming accounts for 20% of our sleeping time.

Poor sleeping habits are not a modern problem.

Our bodies are synchronized with the day-night cycle as our planet rotates. Our circadian rhythms continue even in the absence of any external input. Even plants that are kept in a dark cupboard at a stable temperature open and close their leaves as though they can sense the sun.

About 80% of our sleeping is of the SWS variety, identified by slow brain waves, relaxed muscles and deep breathing.

Sleep deprivation has been shown to change the body’s basic metabolism and the balance between fat and muscle mass.

A day or two of sleep deprivation can cause healthy people to suffer hallucinations and physical symptoms.

We have a gene that releases a protein that builds up in cells overnight and gets broken down in the daytime. The clock gene is active in almost every cell type in the body and under circadian control.