(Solved): Activity 8 1. The observation that almost all galaxies are moving away from us, and that the galaxie ...

1. The observation that almost all galaxies are moving away from us, and that the galaxies that are the farthest away are moving away from us the fastest, is called 2. As the universe expands, galaxies expand as well/do not expand. 3. The horizon problem refers to the fact that different parts of the could not have communicated since the beginning of the universe. 4. The horizon problem blatantly contradicts/is consistent with, but is not explained by the Big Bang theory. 5. The flatness problem refers to the fact that, at early times, the universe must have been very theory does not explain why this would be so. 6. The Big Bang theory correctly predicts the abundances the existence of most all galaxies 7. Before 380,000 years after the Big Bang, atoms could not have formed permanently because the background radiation was too energetic/could not have formed permanently because there were no nuclei/formed permanently, but only formed stars 50,000 years after the Big Bang.