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As regards the origins of the universe, the scientific community traditionally believed in its eternal existence. Going as far back as Ancient Greek thought, the prevailing scientific concept was that the universe always existed and would continue to do so. Everything changed when Albert Einstein introduced his General Theory of Relativity (1915, 1917), and especially when the Russian mathematician Alexander Friedmann (1888-1925) solved its field equations, in 1922, with results which indicated an expanding universe.
A few years later, in 1927, the Belgian Roman Catholic priest and physicist Georges Lemaître (1894-1966), working independently of Friedmann, reached similar conclusions. Initially, his ideas were met with general indifference (in the case of Einstein with downright hostility), but an impressive discovery brought his proposition into the limelight. The astronomer, Edwin Hubble, noticed that all the galaxies, no matter what their position in the firmament, were moving away from us. Given the fact, also, that the Earth did not occupy a privileged position in the universe, the conclusion which could immediately be drawn was that the universe is expanding at an equal rate in all directions.
In 1931, Abbé Lemaître went one step further. He postulated that if, in an expanding universe such as ours, time were to go into reverse, we would end up with a state in which this universe, (that is all its material) would, at the beginning of time, be contained in a super-dense and super-hot state, which, in the course of its evolution, gave rise to everything which emerged thereafter. In contradistinction to these views was the model of the Steady State Universe, developed by the astronomer Fred Hoyle (1915-2001). His central idea was in line with the traditional scientific convictions concerning the eternal nature of the universe, and he interpreted the expansion as being due to the continuous creation of matter. Oddly enough, with the maelstrom of his efforts to combat the theory of Abbé Lemaître, Hoyle unwittingly became its ‘godfather’ when, during the course of a radio broadcast in 1949, he referred to it dismissively as the ‘Big Bang’ the term by which it has since become best known.
The theoretical calculations which were made in the meantime, increasingly favoured the form of the Big Bang. There was competition over the years between the two opposing views until, in 1965, another astronomical discovery gave impetus to the Big Bang: the radio astronomers Arno Penzias and Robert Wilson located something which was forecast in the Big Bang Theory, Cosmic Microwave Background Radiation. CMBR goes through all the space in the universe and is the relic of the separation of material from radiation.
Since then, the established cosmological model has been the Big Bang Some further problems which have been identified are to be found within the so-called ‘Inflation’ theory, according to which, in its first moments, the universe underwent a phase of exponential expansion.
As we mentioned earlier, the successes we’ve described do not mean that there are no more unresolved issues. From as early as the 1930s, many alternative suggestions have been formulated- apart from the Steady State universe- which have attempted to explain the observational data without adopting positions similar to those of Abbé Lemaître. In recent times, particularly, what is of most concern to specialists is the initial state of the universe, which seems to be non-manageable, since it not transparent to the known laws of physics. This is precisely why it’s called an anomaly or ‘singularity’. Research propositions have been formulated to by-pass its presence, though none of these has gained universal approval.
(to be continued)