The third of your life you've been ignoring

Until the twentieth century, sleep was thought to be an absence, the brain switched off. In 1939 a physiologist at the University of Chicago named Nathaniel Kleitman published Sleep and Wakefulness, the first scientific book on the subject, and in 1953 his student Eugene Aserinsky, watching his own son sleep, discovered that the eyes move rapidly at certain times and the brain is intensely active: REM. Sleep wasn't an absence. It was a sequence of stages, each doing work. In 1970 another of Kleitman's students, William Dement, opened the first sleep clinic at Stanford and founded sleep medicine as a field.

What they found is now the consensus. Sleep has stages, light, deep and REM, cycling about every ninety minutes. Deep sleep repairs the body and clears the brain. REM processes memory and emotion. Adults need seven to nine hours, and the research on short sleep is grim and consistent: it damages memory, mood, immunity, blood sugar, blood pressure and judgment, and it shortens life.

Here's the Awareness connection. Everything this chamber has taught about attention runs on sleep. A sleep-deprived brain can't attend. It can't regulate emotion. The person who meditates for twenty minutes and sleeps for five hours is pouring water into a bucket with a hole in it.

Your log has been asking about sleep since day two. Eighty-eight nights of data is more than most doctors ever see from a patient. Tonight, read it.