Why is universe dark?

Olbers' paradox, a part of astrophysics and physical cosmology, is basically a squabble about the sky being dark at night. This paradox is also phrased as the 'dark night sky paradox'. The paradox states that an inert, considerably old universe with an equal number of stars scattered in the proportionately large space should be bright rather than being dark at night.

The question of sky being dark at night might seem ridiculous with a much obvious answer, and the topical answer might surprise you. This question has been studied by the best physicists who have reached an answer that is simple but not so obvious. In order to find an answer to the Olbers' paradox, the scientists and physicists had to struggle a lot to learn about the behavior of energy involved in the concept.

One argument given by the scientists against the dark night paradox is that the light of distant stars might be hidden by the dust clouds. But this answer is again contradicted by the statement that these dust clouds should reach the temperature of the stars by their heat. Another statement contradicting the Olber's paradox is that these distant stars might be too tiny and far that they can be seen in the vicinity. Besides, there might be numerous stars at increasing distances such that their smaller perceptible size is formed of by their bigger numbers.

Another theory is of the time and age of the universe. Universe is 13.73 billion years old which states that light of the starts had certain time to light up the universe. Most of the starts we see today, in our night sky, do not exist anymore. We can see their light because it takes ages for their light to travel around the universe. So we could say that stars in the universe had certain amount of time to contribute to the illumination of the whole universe.

Please read comments bellow for additional theories. However, as much as we searched this subject, it still remains a paradox.