HOW LONG WILL THE UNIVERS EXIST?

THE BYGONE AGE

There is no method to determine the bygone age of the universe. Still the scientists have cleverly figured out how long it has been there. This age of the universe is, however, not exact but only approximate.

The estimate of the age of the universe has been possible by measuring speed of the stars in one part of the universe and then measuring speeds of the stars in other distant parts. From, these speeds, the scientists could calculate the speed of the stars billions of years ago.

By comparing the present and old speeds of the stars, the scientists calculated when the stars had begun to move in space. In this way, they estimated that the universe is at least ten billion years old. It may be older/far older even. That is why its age is mentioned to be 10 to 20 billion years old.

FUTURE OF THE UNIVERSE

Scientists differ on how long the universe will exist. Some of them believe that it will go on for ever - even after all the stars have ceased to shine. They hold that the universe will be quite dark and cold then.

But other scientists believe that the universe will go on expanding, no doubt. But ultimately it will reach a stage where further expansion will not be possible. This stage will be followed by a period of contraction and the universe will reach its original state to repeat the process of expansion again. This theory has been named the Oscillation Theory because this behavior of expansion-contraction-expansion (again) will resemble the oscillation of a clock-pendulum.

According to the oscillation theory, the universe will never cease to exist. It will keep expanding and contracting in turn again and again. Thus it will go on for all time to come.

The laws of physics are believed to be applicable to the universe. So, according to the law-matter can never be destroyed the universe has to go on. The theory of contraction has been named--Big Crunch Theory.