One standard way of thinking about the big bang is to imagine the universe as being analogous to a huge vat of rising bread dough in a bakery. If raisins scattered through the dough represents galaxies, and if you are standing on one of those raisins, then you would look around you and see other raisins moving away from you. You could watch as nearby raisin moves away because the dough between you and it is expanding. A nearby raisin would not be moving very fast, because there is not much expanding dough between you and the raisin.
The raisin-bread dough analogy is very useful because it makes it easy to visualize how everything could seem to be moving away from us, with objects that are farther away moving faster. If you stand on any raisin in the dough, all the other raisins look as through there are moving away from you. This analogy thus explains why the Earth seems to be the center of the universe. It also explains why the fact is not significant---every point appears to be at the center of the universe.
But the expanding dough analogy fails to address one of the most commonly asked questions about the Hubbell expansion: What is outside the expansion? A mass of bread dough, after all, has a middle and an outer surface; some raisins as nearer the center than others. But we believe that the universe has no surface, no outside and inside, and no unique central position. In this regard, the surface of an expanding balloon provides a better analogy.
T he raisin-bread dough analogy of the expanding universe states that as the dough expands, all raisins move apart from each other. The farther apart the raisins, the faster the distance increases.
However where is the evidence? Go to the next link for the rest of the story!
