Matt is definitely on to something here. Electric lights are most certainly screwing with our circadian clock and therefore our whole biology.
If you want to read up on this - these authors take things much further (and likely TOO far): http://www.amazon.com/Lights-Out-Sleep-Sugar-Survival/dp/0671038680
They recc. 9.5 hours of sleep per night - starting with when the sun sets!
LIghts Out
If you want to read up on this - these authors take things much further (and likely TOO far):
http://www.amazon.com/Lights-Out-Sleep-Sugar-Survival/dp/0671038680
They recc. 9.5 hours of sleep per night - starting with when the sun sets!