Cosmic model: BIGBANG is a cosmological model, which describes the initial conditions for the birth of the universe and its subsequent evolution. This model is supported by the most extensive and accurate scientific research and observation. Cosmologists usually refer to the view of the Big Bang: the universe evolved from an initial state of extremely high density and extremely high temperature a finite time ago, and reached its present state through continuous expansion.
Extended data
Classification of galaxies in the universe:
According to the serial numbers that can reflect the development of galaxies, galaxies can be divided into five types: elliptical galaxies, lens galaxies, spiral galaxies, rod-spiral galaxies and irregular galaxies.
Galaxies gather into large and small groups called galaxy clusters. On average, each cluster has more than 100 galaxies with a diameter of tens of millions of light years. Thousands of galaxy clusters have been discovered. A small cluster of galaxies consisting of about 40 galaxies, including the Milky Way, is called the local cluster.
A higher-level celestial system composed of several galaxy clusters is called supercluster. Supergalaxy clusters often have a flat shape, and their long diameter can reach hundreds of millions of light years. Usually, superclusters contain only a few clusters, and only a few superclusters have dozens of clusters.
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