Two Sleeps

Instapundit leads me to an article on the history of sleep, where for much of our recorded existence, we've slept twice a night.  Generally two or three hours, then wakened, then gone back to sleep until morning.

His research found that we didn’t always sleep in one eight hour chunk. We used to sleep in two shorter periods, over a longer range of night. This range was about 12 hours long, and began with a sleep of three to four hours, wakefulness of two to three hours, then sleep again until morning.

Cool!  I do that sometimes, going to bed early, then waking for an hour or so, then falling back to sleep to await the morning alarm.  Milady and I do this frequently enough that we call it "vampire-ing".  As in "I vampired for a couple of hours last night.

As I understand the article, sleeping eight full hours is a fairly recent invention, since the time that electric lights were invented.  It seems that our forefathers thought that sleeping twice per night was perfectly common.

Cool!