In the first fractions of a second, random quantum jitters were amplified by inflation. These tiny differences in density eventually formed galaxies, stars, and planets. Without them, the universe would be perfectly uniform and lifeless. Fluctuations are visible as tiny variations in the CMB. They bridge quantum mechanics and cosmology. Studying them helps understand how complexity arises from randomness.
It matters because quantum fluctuations created all cosmic structures.
It also demonstrates the link between subatomic physics and the large-scale universe.
The universe’s vast structure owes its origin to microscopic quantum jitters.
European Space Agency [esa.int]