matter clumping

As this happened the effects of gravity were being felt, as the matter in the universe was essentially being condensed by this phenomenal force. Gravity began to cluster matter contained in the universe. Matter was not evenly distributed in the universe. It clumped into stars and interstellar gas clouds, which in turn grouped into galaxies. The galaxies congregated in "local groups," clusters, and superclusters. These clusters appear to be arranged in filaments, sheets and bubbles, and contain enormous voids hundreds of millions of light-years across.

- Tt