The galaxies in the universe do the same as the result of the expansion of space itself. Moreover, the galaxies that are initially farther apart expand away from each other faster than the galaxies that are initially closer together, suggesting that the model of spherical or uniform expansion explains Hubble’s observations well. By deflating the balloon, I can also illustrate how the material in the universe would have been closer and closer together at points farther and farther back in the past, suggesting that the matter making up the galaxies would have all come from the same initial point
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