In the past human history, we were only able to see in our universe that some few thousand stars shine in the dark night and this was the only thing which gave us the evidence of night. Then, the discovery of telescope changed the whole situation.
We observed the planets from telescope. Planets near to earth and far from it and galaxies were observed with telescope. And so in this way the unpredictable secrets of this universe started opening. Today, we have extraordinary telescopes through which we have seen such things that even ancient scientists could not think of them.
Man is always curious about sky. We observed the sky and its depth and complexity surprised us. Space is the world of stars, galaxies and planets. Where time is measured in million and billion years and distance is measured in multiplier of million and billions of years. This calculated figure looks unbelievable and sometimes this universe looks imaginary. But the truth is that it is the most glorious thing of God which has made the senses of man to think about it. It is believe of many scientists that our universe came into existence just some 14 million years ago due to some Big Bang. At that time universe consisted of a singularity whose volume was as less as the tip of a nail. It was completely closed and this singularity had the temperature and mass up to anything that man can ever think of. It was completely dark.
According to some theories there was a great big blast in this unity and that great big mass was destroyed into small masses and our universe came into existence. This is what known as Big Bang theory.
Time, space came into existence because of this mass which is known as universe. Within a second even some scientist says that less than in a second this universe stretched itself and became so big that even a single atom is small enough in front of it and thousands of galaxies are smaller in front of this single universe. And from that time it is still stretching itself and the process of vastness of universe is not controlled.
15 times bigger suns than our sun when complete their life cycle and die, they are converted into Black Holes. Their gravitational force attract them to a small single place where they become massless. Because of this gravitational force, mass convert itself into Supernova.
Its internal gravitational force is so powerful that it attract every single particle towards itself. Even the light is trapped by black hole and in its result complete darkness is observed. Because of this reason it is known as Black Hole. According to some observations the amount of mass present in black hole is 14 million times more than a mass of a single sun.
In the study of Astronomy, the knowledge of these things was not an easy task. Just to know that our earth rotates around the sun, man took hundreds of years to study this. In ancient times, those who considered this study carefully observed that the stars rises each night before 4 minutes. This four minute difference added and summed up into 2 hours difference for one month and it became 24 hour difference for one year. That’s why if any star rises at 8 pm at night on some date then after one year it will again rise at 8 pm on same date. The reason behind this is that our earth completes one revolution around the sun in one year. This also gave evidence to the scientists that our earth was not a center of this universe.
The people of ancient times looked at the stars and carefully observed them and came to a result that there are some stars that do not follow this rule to rise every night before 4 minutes.
It is worth considering that from thousands of stars just few of five stars do not follow this rule and to point out them was a great achievement as at that time there were no advance technologies to observe this. so they named them as “wanderers” as they keep on moving.
Actually these five stars are planets which are named as Mercury, Venus, Mars, Jupiter and Saturn. Scientists spend their whole lives in finding where every star is located, when it rises and this thing with the passage of time became stronger that our earth is not the center of this universe.