In its standard form, the big bang theory assumes that all parts of the universe began expanding simultaneously. But how could all the different parts of the universe synchronize the beginning of their expansion? Who gave the command? 
Andre Linde, Professor of Cosmology 1

A century ago, the creation of the universe was a concept that astronomers as a rule ignored. The reason was the general acceptance of the idea that the universe existed in infinite time. Examining the universe, scientists supposed that it was just a conglomeration of matter and imagined that it had no beginning. There was no moment of "creation"–a moment when the universe and everything in it came into being.

This idea of "eternal existence" fit in well with European notions stemming from the philosophy of materialism. This philosophy, originally advanced in the world of the ancient Greeks, held that matter was the only thing that existed in the universe and the universe existed in infinite time and will exist endlessly. This philosophy survived in different forms during Roman times but in the Late Roman Empire and Middle Ages, materialism went into decline as a result of the influence of the Catholic church and Christian philosophy. It was after Renaissance that materialism began to gain broad acceptance among European scholars and scientists, largely because of their devotion to ancient Greek philosophy.

It was Immanuel Kant who, during the European Enlightenment, reasserted and defended materialism. Kant declared that the universe exists for all time and that every probability, however unlikely, should be regarded as possible. Kant's followers continued to defend his idea of an infinite universe along with materialism. By the beginning of 19th century, the idea that the universe had no beginning–that there was never any moment at which it was created–became widely accepted. It was carried into the 20th century through the works of dialectical materialists such as Karl Marx and Friedrich Engels.

The German philosopher Immanuel Kant was the first person to advance the assertion of "the infinite universe" in the New Age. Scientific discoveries, however, invalidated Kant's assertion.

This notion of an infinite universe fit in very well with atheism. It is not hard to see why. To hold that the universe had a beginning could imply that it was created and that, of course requires a creator–that is, Allah. It was much more convenient and safer to circumvent the issue by putting forward the idea that "the universe exists for eternity", even though there was not the slightest scientific basis for making such a claim. Georges Politzer, who espoused and defended this idea in his books published in the early 20th century, was an ardent champion of both Marxism and materialism.

Putting his trust in the validity of the "infinite universe" model, Politzer opposed the idea of creation in his book Principes Fondamentaux de Philosophie when he wrote:

The theoretical musings of these two scientists did not attract much attention and probably would have been ignored except for new observational evidence that rocked the scientific world in 1929. That year the American astronomer Edwin Hubble, working at the California Mount Wilson observatory, made one of the most important discoveries in the history of astronomy. Observing a number of stars through his huge telescope, he discovered that their light was shifted towards the red end of the spectrum and, crucially, that this shift was directly related to the distance of the stars from Earth. This discovery shook the very basis of the universe model held until then.

According to the recognized rules of physics, the spectra of light beams travelling towards the point of observation tend towards violet while the spectra of light beams moving away from the point of observation tend towards red. (Just like the fading of a train's whistle as it moves away from the observer) Hubble's observation showed that according to this law, the heavenly bodies were moving away from us. Before long, Hubble made another important discovery; The stars weren't just racing away from Earth; they were racing away from each other as well. The only conclusion that could be derived from a universe where everything moves away from everything else is that the universe constantly "expands".

Edwin Hubble discovered that the universe was expanding. Eventually he found evidence of the "the Big Bang", a cataclysmic event whose discovery forced scientists to abandon the notion of an infinite and eternal universe.

Hubble had found observational evidence for something that George Lemaitre had "prophesized" a short while ago and one of the greatest minds of our age had recognized almost fifteen years earlier. In 1915, Albert Einstein had concluded that the universe could not be static because of calculations based on his recently-discovered theory of relativity (thus anticipating the conclusions of Friedman and Lemaitre). 

Shocked by his findings, Einstein added a "cosmological constant" to his equations in order to "make the answer come out right" because astronomers assured him that the universe was static and there was no other way to make his equations match such a model. Years later, Einstein was to admit that his cosmological constant was the biggest mistake of his career.

Hubble's discovery that the universe was expanding led to the emergence of another model that needed no fiddling around with to make the equations work right. If the universe was getting bigger as time advanced, going back in time meant that it was getting smaller; and if one went back far enough, everything would shrink and converge at a single point. The conclusion to be derived from this model was that at some time, all the matter in the universe was compacted in a single point-mass that had "zero volume" because of its immense gravitational force. Our universe came into being as the result of the explosion of this point-mass that had zero volume. This explosion has come to be called the "the Big Bang" and its existence has repeatedly been confirmed by observational evidence.

There was another truth that the Big Bang pointed to. To say that something has zero volume is tantamount to saying that it is "nothing". The whole universe was created from this "nothing". And furthermore this universe had a beginning, contrary to the view of materialism, which holds that "the universe has existed for eternity".

The "Steady-state" Hypothesis

The Big Bang theory quickly gained wide acceptance in the scientific world due to the clear-cut evidence for it. Nevertheless astronomers who favored materialism and adhered to the idea of an infinite universe that materialism seemingly demanded held out against the Big Bang in their struggle to uphold a fundamental tenet of their ideology. The reason was made clear by the English astronomer Arthur Eddington, who said "Philosophically, the notion of an abrupt beginning to the present order of Nature is repugnant to me".3

Another astronomer who opposed the Big Bang theory was Fred Hoyle. Around the middle of the 20th century he came up with a new model, which he called "steady-state", that was an extension of the 19th century's idea of an infinite universe. Accepting the incontrovertible evidence that the universe was expanding, he proposed that the universe was infinite in both dimension and time. According to this model, as the universe expanded new matter was continuously coming into existence by itself in just the right amount to keep the universe in a "steady state". With the sole visible aim of supporting the dogma of "matter existed in infinite time", which is the basis of the materialist philosophy, this theory was totally at variance with the "Big Bang theory", which defends that the universe had a beginning. Supporters of Hoyle's steady state theory remained adamantly opposed to the Big Bang for years. Science, however, was working against them.