Okay, so I know there is this whole circadium rhythm thing, but we need melatonin to sleep, and seratonin to wake. That's why we wake up when the sun enters our rooms and such? For example, usually no matter what time I go to sleep, I wake up at 8 am. Even if I go to bed at 3 am I wake up at 8, even if I use a sleeping mask and black out curtains. How does this make any sense? Clearly I need more sleep than that? It seems like the rhythm is only hurting me.
And if we need darkness to sleep, how can people, or animals sleep during the day with light then? I just don't get how if we are tired, why we don't sleep. I doesn't seem as simple as that.
I was reading on jet lag for example, and if someone didn't get enough sleep, then why don't they just sleep? I don't understand?
And like me...some days I'll be fine going to bed after work at 3 and wake up at 8 like no problem. I'm not even tired. But then a few days later I get tired during the day and so want a nap. I do not understand this at all.
Because our bodies don't work like that, and bright light resets our circadian clocks. Once you're used to waking at a certain hour, despite going to sleep at 3am - which you shouldn't have done in the first place, you'll wake. You can get away with it for a while, but at some point, damage is done.
The circadian rhythm is essentially our body's reaction to our schedule to encourage sleep. As you shift your schedule your circadian rhythm can shift. It take time, because our bodies crave homeostatis (which of course makes sense). So with jet lag, that's just our body trying to catch up with our schedule. Naps, and other recuperative breaks, help the body heal -- they don't alter our circadian rhythm.
Whether someone can adapt to a night schedule is questionable. I don't think you could phase your circadian rhythm 8 hours.
Coincidentally, I happened to be listening to this book:
Sync: How Order Emerges From Chaos In the Universe, Nature, and Daily Life Paperback
by Steven H. Strogatz
Starting in Chapter 3, and 4 there's a huge discussion about sleep, it's correlation to body temperature, long sleep vs short sleep and forbidden zones - hours of the day/night where sleep is nearly impossible.
It's an amazingly thoroughly detailed analysis of sleep. You might benefit from this book (or not).
The earlier chapters are about how certain things sync together - like metronomes, fireflies, menstrual cycles, etc. But the sleep chapters are really interesting. I haven't heard any part that would directly help you, though you might be able to leverage the temperature thing and the forbidden zones.
It easily explains why you'd go to bed at 3am and wake up at 5am - you'd hit both a "forbidden zone" as well as a low body temperature, as well as your previous normal wake up time.
I also ran across this episode of the BulletProof Exec podcast that's relevant:
There's a point about using piracetam in a very large dose very early morning to reset your circadian rhythm and examples of using color changing lights.