Question

Why is the cosmic background radiation uneven in some places?

Answer 1

matter just wasn't spread out evenly in our universe after 400,000 years.

Explanation:the cmbr picture was as it was 400,000 years after the big bang it still looks the same as it does today though.when early galaxy's started to form they spread the radiation out unevenly with there gravity.

Answer 2

There is more space between our galaxy and distant galaxies, and the whole universe is expanding. ... Red shift shows that the galaxies are moving away from each other. Why is the cosmic background radiation uneven in some places? Matter was not spread out evenly in the early universe.