Most People Believe that In the beginning of this past century, we found out in amazement that the entire universe is expanding. This led physicists to deduce that the universe started out in the finite past with a minuscule size. Realizing that the universe had a beginning, and awed by its vastness and its creations, people have asked: How did the universe begin? After all, we are here to be amazed by it because the universe eventually created lives like us. Now, after decades of observing and thinking, we have come to answer confidently the question of the origin of our universe... with what is known as the "big bang".