Why are there observable fluctuations in the CMB?
The CMB was released when the observable universe was 380,000 years old. Accordingly the diameter of the observable universe was 760,000 light years, or ~14 times the diameter of the Milky Way. Intuition would tell you that, due to the large size, the fluctuations would be at relatively small scales compared to the total size of the observable universe. It would be like looking at TV static from a mile away, all you are going to see is gray. Why can you see the fluctuations without really zooming in?
The CMB was released when the observable universe was 380,000 years old. Accordingly the diameter of the observable universe was 760,000 light years, or ~14 times the diameter of the Milky Way. Intuition would tell you that, due to the large size, the fluctuations would be at relatively small scales compared to the total size of the observable universe. It would be like looking at TV static from a mile away, all you are going to see is gray. Why can you see the fluctuations without really zooming in?
