Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out.

One famous effort is
TNG50 from
IllustrisTNG, an upgrade of the famous
Illustris Simulation.

The first part of the
featured video
tracks cosmic gas (mostly
hydrogen)
as it evolves into
galaxies and
galaxy clusters
from the early universe to today, with brighter colors marking faster moving gas.

As the universe matures, gas falls into
gravitational wells,
galaxies forms, galaxies spin, galaxies collide and merge, all while
black holes form in galaxy centers
and expel surrounding gas at high speeds.

The second half of the video switches to tracking stars, showing a
galaxy cluster coming together, complete with
stellar streams.

The outflow from black holes in
TNG50 is surprisingly complex and details are being compared with our
real universe.

Studying how gas coalesced in the
early universe helps humanity better understand how our
Earth,
Sun, and
Solar System originally formed.