you need to sleep when you feel sleepy, but can you explain why, how, what make you wake up withou fail?

Answer 1

Scientists have experimented and found that a body clock ticks within us.When you are sluggish and drowsy it lulls you to sleep.When you have had adequate sleep it sounds an internal alarm which wakes you up automatically. Normally this alarm starts ringing when the body is sufficiently rested, though it is also possible for us,by auto suggestion,to set the ringtone at the proper time and it would comply with it.Normally our sleeping and waking hours coincide with day and night though the tiny clocks of the tiny tots take some time to adjust leading to irregular hours.In workers who have to do long night shifts the body clock is adjusted suitably almost automatically. Initially it may give some trouble like feeling sleep during night working and no sleep coming over despite all persuasions during daytime. However,over a time the body clock gets adjusted accordingly.This day and night setting of the body clock was perhaps body's response to the availability of light during day and its absence during night. A story goes in the Hindu scriptures about a time when there were no night and day as the Sun showed at all hours. This has ;probably a reference when the ancestprs were residing in areas(probably North Pole before the Ice Age when it was habitable where there are long days and longer nights. This absence of a breakup led to a feeling of continuous day and even if an incident occurred long, long ago they had no sense of duration and felt that not much time had passed since it occurred. Yama was the first being who died and his sister went on crying for him --we cannot say day in and day out because there was no such division of time.This adversely affected her health and the Gods then introduced the alternating cycle of day and night. If at all this happened it must have been time immemlorial ago because the waking and sleeping time has conditioned our internal system eons ago. The experimenting scientists referred to above had a man put in a celler deep underground with all the facilitiers . He kept a detailed account of his activities when this was tallied with corresponding above land records it transpired that the body clock ticked as if it was above ground.From this follows the prayer to God who created day for us to work and night for us to sleep.