HISTORY OF THE MODEL: The story of the Universe started around 13.83 billion years ago, although as accuracy improves that figure seems to be revised every so often. It started in what has become known derisively as the Big Bang, a name coined by an opponent named Fred Hoyle in conjunction with Bondi and Gold who were proposing a Steady State model of the Universe. The other competing theory in the early fifties was the Oscillating theory. Perhaps Fred Hoyle's opposition stems from the fact that the BB insinuates that the Universe had a beginning in time, and in actuality was first proposed by Father George LeMaitre, a Belgian priest. The early part of the 20th century it was thought the Universe was static. Even Albert Einstein could not accept what his own equations were telling him with regards to a dynamic Universe, hence his additional Cosmological Constant to maintain the static belief of the day. This was until the great Edwin Hubble in 1929 discovered that the Universe was expanding. He showed firstly that the nebulae that were often observed and taken to be part of the Milky Way, were actually far beyond our galaxy, and secondly, he then showed that by comparing EMR redshifts, and distances, that these galaxies beyond the MW were apparently moving away from us. The BB is predicted by four pillars of Astronomy.  The observed Expansion:  The Discovery of the Cosmic Microwave Background Radiation at a precise 2.7 K.  The abundance of lighter elements such as Hydrogen and Helium. Galactic formation and large scale structure. The Detail Theory of the Model: We must first begin by saying that the closer to the moment of the BB, the less certain we are of what actually occurred. In fact during the first Planck instant of t+10-43 seconds after the event, we know nothing: General relativity and our laws of physics fail us at this quantum level. We call this a Singularity of space and time, as distinct from a BH Singularity, which is imbedded in spacetime. The BB was not what one would imagine as a traditional explosion. It was simply an evolution of space and time in the first instant, and a "Superforce" a unification of the four known forces we know today. As spacetime expanded the Superforce started to decouple. [keep in mind we are still only around t+10-33 seconds after the BB] Gravity was first. This created what is called phase transitions and false vacuums with excesses in energy going into creating our first fundamental particles probably electrons and quarks. As the Universe continued to grow from this very hot dense state, the other forces decoupled, and our fundamental particles started to do the opposite and couple together. At around the first 3 minute mark after the BB, our first atomic nuclei were formed....protons and neutrons abounded with loose electrons. During this still very hot and dense period, the Universe was Opaque, and it wasn't until around 380,000 years later, when temperatures had dropped sufficiently to allow electrons to couple with atomic nuclei, that our first elements were formed. From that point on it was a breeze as to how our Universe evolved and how our first generation of stars were formed from accreting masses of giant clouds of Hydrogen and some Helium. These stars and eventual galaxies grew from the tiny variations in temperatures in the CMBR that acted as seeds for such condensation. The stars were giant behemoths and lived short life's measured in 10's of millions of years before going S/Nova creating our first stellar size BH's that accreted to form SMBH's, while at the same time spread their enriched guts of heavier elements throughout the Universe, which in turn accreted to form second and third Gen stars and planets of the heavier elements that was available for building. :Modification of the Big Bang: I see that as the greatest Story ever told but science being what it is and the continuing search for answers, realised that this epic tale still had some faults which could not be explained by the accepted BB model. These were what cosmology calls the horizon problem, Flatness Isotropic and homogeneous observations. This was explained by the addition of Inflation theory formulated by Alan Guth which explained these anomalies by invoking a very rapid expansion rate at the first instant of the evolution of spacetime. This also explains the even distribution of the CMBR. Another addition was the discovery of the expansion accelerating, first discovered from data received from WMAP [ Wilkinson Microwave Anisotropy Probe] This same notable state of the art probe, also gave us data indicating our Universe is flat, within very small tolerance range, gave us more precise measurement as to its age, and detailing the CMBR in even greater detail than its predecessor COBE. At this time, the BB/Inflationary model stands as unchallenged in this remarkable story and its details.