Letting sleeping birds lie...

BoingBoing highlighted this article on managing your body's hardwired "biological clock" that determines sleep cycles. It explains why the only time I usually see the sunrise is when I stay up for it.

The body tells time with a master clock in the brain, a pinhead-sized cluster of neurons in the hypothalamus that takes cues from optic nerves that signal sunlight. By sticking people in isolation chambers, scientists discovered that most people's internal clocks run a bit longer — about a half-hour on average — than the sun's 24-hour cycle. That's why, for most people, it's easier to stay up later and compensate by sleeping in than to force yourself to sleep early and wake early, explains Dr. Eliza Sutton, an acting assistant professor of medicine at the University of Washington. Morning larks are those rarer birds whose body clock is shorter than 24 hours, so they wake up raring to go.