The article discusses common misconceptions about the Big Bang theory and the expansion of the universe. The expansion of the universe may be the most important fact we have ever discovered about our origins. 75 years after its initial discovery, the expansion of the universe is still widely misunderstood. Because expansion is the basis of the big bang model, these misunderstandings are fundamental. Individual galaxies move around at random within clusters, but the clusters of galaxies are essentially at rest. The big bang was not an explosion in space; it was more like an explosion of space. It did not go off at a particular location and spread out from there into some imagined preexisting void. The rate at which the distance between galax...