A lot of the discussion so far has focused on ensuring that the universe is homogeneous, which it is, on large scales. But if we look around the universe, there is a lot of evidence of inhomogeneity too (after all, the Sun is over there, and Jupiter is way over there — these are small-scale inhomogeneities). What do you think can account for these non-uniformities? (Professor Guth will answer this later in the course, but try to think of some possible explanations.)