Structure formation
Videos
In physical cosmology, structure formation is the formation of galaxies, galaxy clusters and larger structures from small early density fluctuations. The universe, as is now known from observations of the cosmic microwave background radiation, began in a hot, dense, nearly uniform state approximately 13.8 billion years ago. However, looking at the night sky today, structures on all scales can be seen, from stars and planets to galaxies. On even larger scales, galaxy clusters and sheet-like structures of galaxies are separated by enormous voids containing few galaxies. Structure formation attempts to model how these structures were formed by gravitational instability of small early ripples in spacetime density or another emergence.
Snapshot from a computer simulation of large scale structure formation in a Lambda-CDM universe.
Chronology of the universe
Videos
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology.
The Hubble Ultra Deep Fields often showcase galaxies from an ancient era that tell us what the early Stelliferous Era was like.
Another Hubble image shows an infant galaxy forming nearby, which means this happened very recently on the cosmological timescale. This shows that new galaxy formation in the universe is still occurring.
Phases of the reionization
Computer simulated view of the large-scale structure of a part of the universe about 50 million light-years across