What's the deal with circadian rythms?
This is how it works: The circadian rhythm is your daily bodily cycle, from the latin "circa" and "dies" for "around the day." It's controlled by your body temperature. When your temperature rises you wake up and become more alert. When your temperature lowers, you get sleepy.
When you wake up in the morning your temperature rises. It continues to rise until afternoon. Then it drops a bit. That's the afternoon lull you feel. It rises again into the evening. Then it falls, you get sleepy and go to bed.
The circadian rhythm and be somewhat manipulated by your behavior. Taking a hot bath warms you up, then your body says "Hey, I'm too hot. I need to cool down." You cool down, and get sleepy. If you take a cold shower the opposite happens.
Another thing is your diet. If you eat carbohydrates then your brain releases a chemical called sarotonin. That makes you sleepy. You can minimize the afternoon lull by avoiding carbs at lunch.
But what I want to know is why is my afternoon lull ten times worse than at night? I try to avoid carbs at lunch, but I'm not very good at it. After lunch my lull is usually pretty strong. In the afternoon I have slept through a jackhammer being operated downstairs. I can sleep upright in a chair. I have slept through an air-horn being blown mere feet away from me. I can sleep in bright lights, in heat, cold, anything it seems. Coffee or Pepsi sometimes help, but not always.
At night I need everything to be dark and quiet in order to get any sleep at all. Someone else's music, a bit of talking, the TV, someone walking around above me, the pulsating light on my laptop battery, anything keeps me awake.
I'd sure like to reverse that. I'd like to go to bed and immediately fall asleep at night, and last quiet easily through the afternoon without the aid of substances.