By which I mean, I am experiencing bi-phasic sleep. I sleep for four hours, wake up, do stuff for 2-3 hours and go back to sleep again for another four hours. So far doesn't seem to be a problem.
Apparently this was the NORM before electric light - people would go to bed when it was dark, wake up, potter about doing stuff for a couple of hours (guided by candle-light I assume) and then go back to sleep until dawn.
Who's to say this isn't a better sleep pattern - we did it for hundreds/thousands of years?