Universe
Universe is very deep. No one know the start and end of universe. Big-Bang concept tell us that universe is expending. Another concept, Black-Hole tells that dying stars and plants fell into black hole and new stars take birth. So, expansion and squeezing take place simultaneously.
Its always the subject of great interest for astrologers. Universe, stars, plants, comets all these are the objects of study from the ancient times, but very few things are known to us. In modern days astronauts space visits and high resolution telescopes data tell hidden secrets of universe. Radio technology is also used from starting for the study of living creatures like us in the universe.