Question

Olbers’s paradox poses an interesting question: If the universe is infinite, then any line of sight should eventually fall on a star’s surface. Why then is the sky dark at night? Discuss the commonly accepted evolution of the universe as a solution to this paradox.

Short answer

The proposed light, known as cosmic microwave background radiation, exists but is redshifted, making it invisible to the naked eye.

Step-by-step solution

Definition of Olbers’s paradox.

The Olbers’s paradox states that if the universe is infinite then any line of sight should eventually fall on a star’s surface.

Commonly accepted evolution of the universe as a solution of why sky is dark at night?

According to the Big Bang theory, this was true during the early stages of the universe's evolution when the "night sky" was extremely bright, and it is still true in some ways today.

The difference is that, as the universe expands, all of the light is redshifted, resulting in a dark night sky with cosmic microwave background radiation - radiation of constant wavelength perceptible from all directions.