Last week I reported on a strange illusion I had in the middle of the night. Upon waking early in the morning I experienced a sensation where I felt as though I had been asleep for 5 or 6 hours, but had actually only been asleep for an hour and a half. The experience disappeared for about a week, and returned for a single night 8 or 9 days later. I'm pretty sure no-one was sneaking LSD into my milo, so I wanted to figure out what was going on.

I asked people what they thought in my last post. Commenter Beauness said that our timekeeping was regulated by our circadian rhythms. Commenter Kate pointed me in the direction of an article about the Suprachiasmatic Nucleus (wiki link). The SCN plays a role in regulating the circadian rhythms.

Now every school kid knows we have Circadian Rhythms, and that they are basically our 'body clock'. But knowing that isn't very useful. What is a Circadian Rhythm? How does it work? and is it grounded in something beyond our biology?

In my last post I posed three questions that I thought would help illuminate my strange sensation. I'm addressing them here, briefly, as be . . . More