OUR UNIVERSE IS AN EXPANDING FRUIT CAKE

The Big Bang is like baking a fruit cake. As the cake expands, the pieces of fruit all move apart from each other, and so it is with the Universe: space expands and the galaxies all move apart. The idea that space is malleable and can expand may seem a little weird, but it is a consequence of Einstein’s Special and General Theories of Relativity, which we met in the first article in this series. The Big Bang is analogous to the time when the pieces of fruit were very close together, just after the cake was popped into the oven. Today, the cake is still cooking, and the expansion of our Universe even appears to be speeding up. One common misconception regarding the Big Bang is that everything expanded away from a point in space. This is wrong. Indeed, it is likely that the Universe was vast, even at the time of the Big Bang. It was vast and of very high density, which means the particles were very close together. Rather like the case of a very large piece of raw dough prior to baking, when the pieces of fruit were very close together.