Though some cosmologists have put forward the theories giving a definite beginning of the universe we do not come across any independent calculation which may show when exactly the universe will come to an end. It is the second law of thermo- dynamics,[1] which is responsible for the view which suggests that the universe will come to an end. It follows from the above law that the fundamental processes of nature are irreversible.[2]The amount of matter in the universe is perpetually changing; the change appears to be all in one direction towards dissolution. All the phenomena diffusing like vapour through the insatiable void. The sun is slowly but surely burning out, the stars are dying embers, and everywhere in the cosmos, heat is turning to cold, matter is dissolving into radiation, and energy is being dissipated into empty space. The universe is thus progressing towards an ultimate “heat-death”, or it is technically defined as a condition of “maximum entropy.”[3] When the universe reaches this state some billions of years from now, all the processes of nature will cease. All space will be at the same temperature. There will be no light, no life, no warmth-nothing but perpetual and irrevocable stagnation; time itself will come to an end. And there is no way of avoiding this destiny. Everything, indeed everything visible in nature, or established in theory, suggests that the universe is implacably progressing towards final darkness and decay.[4]
Thus, if the second law of thermodynamics is true, it suggests an end to the universe.
If there is an end to the universe, some scientists think it to be an unescapable inference, that it had a beginning. According to them, somehow and sometime the cosmic processes were started, the stellar light ignited and the whole vast pageant of the universe brought into being.[5]