Step Three: GALAXY-FILLED UNIVERSE
After the two membranes collide, they move apart. The initial fireball expands and cools, with the ripples of the membrane leading to the small temperature fluctuations in microwave background radiation observed in our universe. The subsequent sequence of events echoes the Big Bang model: Lumps of gas give rise to galaxies and other cosmic structures, and space continues to expand. This roughly corresponds to the current state of our universe.