In 1910, Edwin Hubble arrived from America on a Rhodes scholarship to study at Oxford. He soon fell for the charms of the English aristocracy, enthusiastically adopting their dress and mannerisms, but never quite mastering the accent. Jakob Larsen, a contemporary of Hubble from Iowa said: "We laughed at his effort to acquire an extreme English pronunciation while the rest of us tried to keep the pronunciation we brought from home.
We always claimed that he could not be consistent, so that he might take a bath in a bath tub."
Hubble made his observations at Mount Wilson Observatory in Southern California, which was home to the most powerful telescopes in the world.
His intellect and determination, coupled with these giant telescopes, enabled him to become the most famous astronomer of the first half of the 20th century. Hollywood glitterati would visit Mount Wilson, and in return Hubble would be invited to the hottest LA parties.
Georges Lemaitre was both a Catholic priest and a leading cosmologist. He once said: "There were two ways of arriving at the truth. I decided to follow them both."
Lemaitre's suggestion that the universe emerged and expanded from a hot, compact, dense state in the distant past was too much for many cosmologists to stomach. Not only did they believe in an eternal, unchanging universe, but they were also suspicious of a clergyman proposing something that sounded like Genesis.
In fact, Lemaitre was careful to keep his cosmology and theology separate.
In another memorable quotation, he said that assuming the Bible pretended to teach science was "a good deal like assuming that there must be authentic religious dogma in the binomial theorem". He was so insistent on this distinction that he managed to persuade Pope Pius XII to stop proclaiming on cosmology.
Galileo had also had come to terms with his deep religious faith and his belief in science. He resolved the issue by stating that: "The Bible teaches men how to go to heaven, not how the heavens go."
Arno Penzias and Robert Wilson
Arno Penzias and Robert Wilson were an unlikely pair - the quiet, poor Jewish emigre from Poland, and the confident son of a Texan oil worker - but both backgrounds instilled a commitment to thorough, dedicated work.
From 1963 they worked together at Bell Labs, the pioneering research division of America's ATT company, which had already invented fax machines, lasers and the transistor.
Penzias and Wilson were using a giant horn-shaped antenna to measure radio emissions from space, but were troubled by a constant noise, too faint to disrupt their measurements, which they could not account for. Many radio astronomers would have ignored the annoyance, but Penzias and Wilson spent a year meticulously checking the antenna. They even had to evict a pair of pigeons that had been nesting in the antenna and depositing "white dielectric material" inside.
Eventually, with no other option, Penzias and Wilson concluded that the radio noise was a genuine property of the universe, emanating from every direction in the cosmos. In this faint background hiss, they had accidentally discovered the echo of the Big Bang.
Most scientific progress builds on and refines existing ideas. But according to philosopher of science Thomas S Kuhn, this gradual progress is punctuated from time to time by seismic changes in understanding known as paradigm shifts. The advance from an eternal, static model of the universe to the Big Bang model was one such instance.
A paradigm shift is initiated when new experimental results reveal cracks in a once-satisfactory theory. Further advances reveal new problems until the theory becomes untenable. Those assumptions which gave rise to the established theory are re-examined and a new, competing model emerges.
Reluctant to abandon the theory they were brought up on, the older generation of scientists often holds firm while the younger generation is more willing to question scientific orthodoxy. As the older generation retires, the new theory replaces the old, and what might be a centuries-old tradition is eventually overturned. As physicist Max Planck pointed out:
"An important scientific innovation rarely makes its way by gradually winning over and converting its opponents: it rarely happens that Saul becomes Paul. What does happen is that its opponents gradually die out, and the growing generation is familiarised with the ideas from the beginning."
Along with Thomas Gold and Hermann Bondi, Hoyle developed the Steady State model, which proposed that new matter is created in the gaps left behind as the universe expands and the galaxies recede. While the Big Bang model proposes an ever more sparse universe, the Steady State model continually fills these gaps to yield a non-evolving universe. Fred Hoyle was the greatest critic of the Big Bang theory, but it was he who unwittingly christened the theory during a radio broadcast. Without concealing his disdain for the theory, he referred to it as "this Big Bang idea". Hoyle never accepted the Big Bang model, but his name for it stuck.