Apparently our bodies' natural sleeping pattern is to sleep for four hours, wake for one or two, then sleep again. That's what the BBC reported recently.
I've read something similar before, although I can't remember where. I normally sleep straight through the night, but I'm wondering if I should experiment with this by trying to sleep at nine and setting my alarm to wake me up at, say, 1:00am, then going back to sleep at 2:00am and finally waking for the day at 6:00am. It would be interesting to see if I'd feel more refreshed when I awake, and more alert throughout the day.
On the other hand, I've been severely sleep-deprived this entire week. A few times I've tried sleeping two hours, like from midnight to 2:00am, then getting up and working on my thesis through the night, and going to work once 7:00am rolls by. It's a crazy way to live. I'm absolutely exhausted and couldn't even sleep in this morning because I was attending a whole-day seminar at Elijah House from 9:00am to 6:00pm. On the plus side, my supervisor thinks I should be able to submit my thesis by May! Finally!