posted on Apr, 19 2011 @ 09:54 PM
There've been a lot of responses in the philosophical realm about the spirit and soul, so here's a response from the psychological/scientific realm.
I'm sure most of you have heard of the REM cycle, but if you haven't, it is an approximately 90 minute cycle during sleep where you are in a deep
sleep during the middle parts, and in a lighter sleep at the beginning and end parts, and it is usually at the end part when you dream.
Waking up in the middle of the REM cycle is a shock to the body because the body was in a deep sleep. If someone forcefully wakes you up he is
probably disturbing your REM cycle, and this can cause drowsiness and a general feeling of incomplete rejuvenation.
There are also cycles called circadian rhythyms, and these are sleep cycles that encompass the whole day. A good circadian rhythym is one in which you
sleep 8 hours at night because the night is the most rejuvenating sleep period. There are 2 main dips in the circadian rhythym cycle, and these are at
night and right after lunch, and these are when it is best to sleep because it is when you are most tired. If you take a nap during the day, it is
best for your circadian rhythym if you do it early morning or early afternoon when you are naturally tired. Naps should be 15 minutes or 90 minutes...
15 minutes because that is not enough time to enter the REM cycle, or 90 minutes because that allows you to complete a full REM cycle.
If you don't have a consistent circadian rhythym cycle, you won't be getting the most out of sleep, so drowsiness and tiredness may happen
constantly as a result of sleep deprivation.