1. 15th-12th Century B.C.
The Brahmanda (Cosmic Egg) Universe
The Sanskrit Puranas speak of a cyclical universe in which a “cosmic egg,” or Brahmanda, expands out of a signal point before collapsing again. It is an infinite cycle of expansion and total collapse.
2. 5th Century B.C.
The Anaxagorean Universe
The pre-Socratic Greek philosopher Anaxagoras believed the universe to be ab ovo a primordial mixture of all its ingredients. The whole was ordered and set in whirling motion by the action of vove (“mind”), which formed the universe of separate material objects.
3. Late 5th Century B.C.
The Atomist Universe
Leucippus and Democritus saw the cosmos as composed of tiny, indivisible and Indestructible building blocks known as atoms (from the Greek ………….
4. 4th Century B.C.
The Anaxagorean Universe
According to the geocentric model of Aristotle of Stagira, a fixed, spherical Earth resides at the center of the universe, surrounded by concentric celestial spheres of planets and stars.
5. 3rd Century B.C.
The Heliocentric Universe
In the Hellenistic world, Aristarchus of Samos presented a refreshingly original heliocentric model of the Solar System. The Greek astronomer argued that the Sun, and the Earth’s was at the centre of the universe. He also described Earth’s daily rotation on its axis annual orbit around the sun.
6. 2nd Century A.D.
The Ptolemaic Universe
But the Romano – Egyptian mathematician and astronomer Claudius Ptolemaeus set back the clock – restoring an Aristotelian geocentric model wherein planet and everything else in the universe orbit a stationary Earth by means of tortuous system of epicycles and deferents.
7. Early 16th Century
The Partially Heliocentric Universe
Nilakantha Somayaji of the Kerala school of astronomy in Southern India devised a computational system for a quasi – Tychonic, hybrid heliocentric planetary model in which Mercury, Venus, Mars, Jupiter, and Saturn Orbited the Sun, which in turn orbited Earth.
8. 1543 A.D.
The Copernican Universe
Nicolaus Copernicus Developed a scientific theory of heliocentrism – that motions of celestial object can be accurately explained without requiring a central, stationary Earth. This theory would be refined through the years by the likes of Johannes Kepler and Galileo Galilei.
9. 1687 A.D.
The Static (or Newtonian Universe)
Sir Isaac Newton,in his principia, described a static, steady state universe where matter on a large scale is uniformly distributed. Such a universe is gravitationally balanced, but essentially unstable.
10. Early 20th Century
The Einsteinian Universe
Similar to Newton’s, but Einstein added a “cosmological constant” to his general relativity equations to counteract the effects of gravity, which would have caused the universe to collapse. He later abandoned this notion when Edwin Hubble showed in 1929 that the universe was actually expanding.
The Big Bang Model of the Universe
The Belgian physicist Georges Lemaitre in 1927 proposed his “Primeval Atom” model – wherein the universe originated from an infinitely tiny, dense point in the distant past, and has been expanding ever since. Later corroborated by Hubble’s discovery of the expanding universe in 1929, it has become the mainstream scientific view of the origin of the universe.
Oscillating (or Cyclic) Universe
Alexander Friedmann’s model is based on the general relativity equations for a universe that expands for a time and then contracts due to gravity, cycling perpetually from a Big Bang to a Big Crunch. Einstein favoured this after he rejected his own original model
American physicist Alan Guth proposed a model based on the Big Bang, but that includes a brief, early period of exponential cosmic inflation in order to solve some problems of the standard Big Bang model. This theory remains unproven since many of its detail do not work out in realistic calculations
physicist Andrei Linde’s chaotic inflation theory posits that as the universe was expanding, “Bubbles” grew and formed into separate universes. Other versions suggest our universe is just one tiny part in an infinitely large cosmos, Or a temporary episode in an unending series of chaos and disorder.
A variant of the oscillating universe model, the Ekpyrotic model posits that our universe arose from the collision of two 3D “branes” in a 4D, hyperspatial “bulk.” Time antedates the Big Bang; and new Spacetimes are created afresh through endless “brane collisions.”