Every one of us has a mysterious double life.
For about two thirds of the time we are conscious beings, thinking about the world within and without, and negotiating our ways through the obstacles of life.
For the other one third of the time we are nearly lifeless lumps of flesh, unconscious to everything but our own fantasies, as we lie flat in bed asleep.
We all know that sleep is important for health. But for an activity that consumes about 8 hours of everyday of life, surprisingly little is thought about the act of sleeping, or the way our...