The Big Bang theory traces the universe back to a single infinitely dense point, and this program lays out the case built for it over the past century. Georges Lemaître, a Belgian priest and astronomer, proposed the expanding-universe idea in 1927, and Edwin Hubble's observations in the following years showed galaxies actually receding from one another, giving the theory its first hard evidence. The film spends real time on cosmic microwave background radiation, the faint afterglow Arno Penzias and Robert Wilson picked up by accident in 1964, a discovery that later earned them the Nobel Prize in Physics. It also walks through the abundance of hydrogen and helium in the universe as a second, independent confirmation, since heavier elements only appear later through stellar fusion. Stephen Hawking's work on black holes and cosmic origins closes out the survey of key contributors. The result is a chronological build of theory and evidence rather than a narrative with a single character, aimed at viewers who want the physics laid out plainly.