[Advaita-l] States of waking, dream and deep sleep

[sreenivasa murthy]

Dear friends,
>From where do the the states of waking, dream and deep sleep , experienced by human beings, come from and where do they 
merge back when one state is present?
I request the scholarly friends of this august group to clarify 
the above doubts of mine in a non-technical way.
For this kind and generous act I will be deeply indebted to the memberswho respond to this posting of mine.
With respectful namasakars,Sreenivasa Murthy.