The fluctuations indicate the density distribution of the universe at the time of the formation of the background, which has been redshifted greatly due to the expansion of the universe pulling it apart. Over the course of the last 14 billion years, this expansion has relegated the CMB to nearly uniform microwave frequencies. | The fluctuations indicate the density distribution of the universe at the time of the formation of the background, which has been redshifted greatly due to the expansion of the universe pulling it apart. Over the course of the last 14 billion years, this expansion has relegated the CMB to nearly uniform microwave frequencies. |