In cosmology, the Infinite Universe theory is a model developed in 1948 by Fred Hoyle along with Thomas Gold, Hermann Bondi and others as an alternative to the Big Bang theory.
According to this model, as the Universe expands, new matter is constantly created between expanding galaxies, so believed the supporters of the Infinite Universe theory (also known as Steady State theory), which was popular in the 1950-60s. Thus, though the Universe has always existed in an unchanged state, the cosmological principle is respected.
The oscillating universe theory (also known as the cyclic model) was introduced by a Russian scientist A. Friedmann in his seminal papers of 1922 and 1924. Three years after Friedmann’s paper in the Zeitschrift für Physik, an article on the same subject by the Hungarian physicist Cornelius Lanczos appeared in the same journal.
The oscillation theory correlates with the model of an expanding universe and is based on the general relativity equations for a universe with positive curvature (spherical space), which results in the universe expanding for a time and then contracting due to the pull of its gravity, in a perpetual cycle of a Big Bang followed by a Big Crunch. This is then followed by a new cycle of existence.
The Big Bang theory of the Universe was first suggested by a Belgian priest Georges Lemaître in the 1920s. A similar model of the universe had been proposed by a Russian scientist Alexander Friedmann in 1922 (he actually proposed 2 theories, -the theory of the oscillating universe & the theory of the expanding universe (the Big Bang theory).
The theory became even more popular right after Edwin Hubble’s demonstration of the continuously expanding universe in 1929. And finally, the Big Bang became the mainsteam scientific theory after the discovery of cosmic microwave background radiation by Arno Penzias and Robert Wilson in 1965.
The Big Bang theory describes the universe as originating in an infinitely tiny and dense point (or singularity) 13.7 billion years ago, from where it has been expanding ever since. Singularities are thought to exist at the core of black holes. Black holes are areas of intense gravitational pressure. The pressure is thought to be so intense that finite matter is actually squished into infinite density. Continue Reading