Variety and change in the reality of life

In the universe,there is nothing that may be without system and activity.Millions of changes are occurring every moment.The sun, the moon and the stars, all are the parts of their systems.we find a unique system and harmony in the whole universe.Insidea man,there also exists a system which is named as micro world.When a man sleeps, apparently he becomes motionless but there function many systems inside him.