Segmented Sleep-The myth of 8 hour sleeps

The idea that normal people sleep for at least 8 hours every night well may be a myth. In ancient times many people slept in two divided sleep segments, a first sleep, some time awake then a second sleep. Given less evening stimulation and forced daytime industrial hours, I could probably go for this. The way it is, I go to sleep at 2300 hours and get up by alarm at 0430 hours during the week. I do Ok with this schedule so long as I get a brief nap after my commute. On the weekend I sleep about eight hours but it's pretty much because I'm exhausted from weekly activity. It might even be nice to have some "playtime" between sleep segments. Maybe grandma and I could experiment in my post-industrial retirement.