The Big Bang Model

The goal of this section is to provide a description of the evolutionary timeline of the universe based on the premise of the Big Bang model, for within the framework of this model, cosmologists have speculated that the universe must also have a finite lifespan.

Based on the arguments of quantum physics, a bubble universe with no net energy may have come into existence some 13.7 billion years ago, but by the arguments of the 2nd law of thermodynamics, this universe may ultimately decay into a final entropy state, based on a flat universe assumption, some 10¹⁰⁰ years into the future. The 'present` era, sometimes called the `stelliferous era`, is estimated to last for some 100 trillion years, and while this is an almost unimaginably long period of time, it is but a small faction of the total `lifespan` of the universe.

Era	Phase	Time (Seconds)	Time (Years)
Past	Quantum Beginnings	10^-43	-
Past	Primordial Universe	1	-
Present	Star Formation	10⁺¹⁵	10⁺⁸
Present	Structure Formation	0⁺¹⁵	10⁺⁸
Future	End of Stars	10⁺²¹	10⁺¹⁴
	Black Holes	10⁺⁴⁷	10⁺⁴⁰
	The End of Days	10⁺¹⁰⁷	10⁺¹⁰⁰

In 1950, Sir Fred Hoyle coined the term `The Big Bang` in what was assumed to be a derisorily comment that something, as profoundly complex as the universe, could emerge from such a chaotic concept. While we might also question the aptness of the naming of the ‘Big Bang’ in terms of its description of the actual expansion process, as sound bites go, we might still see some relevance in terms of modern-day slang for the beginnings of ‘life, the universe and everything`.

Acknowledgement
The timeline of the Big Bang to be described in this section was first published, in 1999, in a book written by Professor Fred Adams and Gregory Laughlin called the 'Five Ages Of The Universe'

Timothy Ferris
“The term ‘Big Bang’ was coined with derisive intent by Fred Hoyle, and its endurance testifies to Sir Fred's creativity and wit. Indeed, the term survived an international competition in which three judges, the television science reporter Hugh Downs, the astronomer Carl Sagan, and myself sifted through 13,099 entries from 41 countries and concluded that none was apt enough to replace it. No winner was declared, and like it or not, we are stuck with the ‘Big Bang'."

Stephen Hawking
“Hubble's observation suggested that there was a time, called the big bang, when the universe was infinitesimally small and infinitely dense. Under such conditions all the laws of science, and therefore all ability to predict the future, would break down. If there were events earlier than this time, then they could not affect what happens at the present time. Their existence can be ignored because it would have no observational consequences. One may say that time had a beginning at the big bang, in the sense that earlier times simply would not be defined."