Final answer:
Olber's paradox is resolved by the understanding that the universe is finite and temporal, with a beginning in the Big Bang and ongoing expansion, leading to a night sky that is dark rather than uniformly lit by distant stars.
Step-by-step explanation:
The resolution of Olber's paradox, which questions why the sky is dark at night if the universe is infinite, lies in the understanding that the universe is not infinite and eternal, but finite and temporal. The paradox was historically challenging because it suggested that if the universe were infinite and uniformly filled with stars, the night sky should be ablaze with light. However, the evolution of the universe, as well as observations like the cosmic microwave background radiation (CMBR), indicate that the universe had a beginning — the Big Bang — and has been expanding ever since. This expansion of the universe leads to the redshift of light from distant galaxies, making them less visible, and also means that not all light has had enough time to reach us, contributing to the darkness of the night sky. Furthermore, the finite age of the universe ensures that it hasn't reached a state of heat death or maximum entropy, which would lead to uniform brightness in the sky.