Part 6/10:
Studying the tiny temperature fluctuations in the CMB reveals crucial information about the early universe's density variations. By analyzing these patterns, scientists have deduced that dark matter must be present, as ordinary matter alone cannot explain the gravitational forces required for the universe's structure. The fluctuations showcase where dark matter must exist, forming clumps that acted as seeds for galaxies and clusters, ultimately leading to the universe's formation as we know it.