Heinrich Olbers, a German philosopher, wrote about the question whether or not the universe might be static and whether it reached to infinity (that was 1823). His reasoning goes like this: if we have an infinite and static universe, looking out into the night sky we should see a star at practically every possible line of sight. Even if the star is only a very tiny dot of silvery light, thus the sky should be completely covered with silvery spots, and as a result the night sky should be as bright as during the daytime when the sun dominates. Our experience tells us that this is not the case. A way out would be if the light of distant stars were absorbed by interstellar matter. Are we save now? No! Over time the intervening matter would heat up and glow just as bright as the stars that sent the light in the first place. So, what gives?
Well, we could assume for example that the stars were not there for all times. At some point in the distant past they were "turned on". All of a sudden we have a universe that had a beginning and that also is of finite size. As we shall see, this concept is basic to the current "Big bang" theory of the universe.
Thus, by asking a seemingly "stupid" question, we may push ourselves towards embracing new avenues of thinking, and towards a breakthrough in our understanding of the world around us.