Quantum fluctuations during inflation were stretched to macroscopic scales. These tiny density differences became gravitational wells, guiding matter into filaments and clusters. Without them, the universe would be nearly uniform, lacking galaxies. Observations of the CMB confirm these patterns. Quantum mechanics and cosmology intersect here, showing how tiny randomness leads to vast structure. This explains the patchiness of the universe we see today.
It matters because quantum fluctuations link microphysics to cosmic evolution.
It also allows astronomers to test inflationary models via observed galaxy distributions.
Tiny quantum jitters shaped the entire cosmos.
Planck Collaboration [esa.int]