How a Catholic priest gave us the Big Bang Theory
By Alex Higgins
JANUARY 4, 2008 () - The history of cosmology – the study of the Universe – for the last five hundred years is often portrayed as a clash between science on the one hand, and the cold hand of religious dogma on the other.
Part of this is rooted in fact – the Catholic Church of the Counter-Reformation for instance was suspicious of intellectual innovation and experiment, with its harsher elements longing for the certainties of the age before Martin Luther and the Protestant Reformation. The desire to make the Universe fit into a pre-ordained and orderly scheme that needed no correction reached its infamous, idiotic height as the Dominican Order and the Inquisition persecuted Galileo for his accurate insistence that the Earth orbited the Sun. Galileo's fate at the hands of Pope Urban VIII was not inevitable - but for various historical contingencies, the Church might have not have set its face against him. But this is far from the only episode of a reactionary Church choosing to block knowledge and progress instead of contributing towards it.
Yet the relationship between the Church and science has not always been so bad. And if we wanted an example of an alternative model of co-operation rather than antagonism, we could take as an example the most famous theory in cosmology today – the Big Bang Theory, whose surprising origins lie with a Catholic priest toiling away in a Catholic University in Belgium.
I once attended a youth club in Colchester, a town in England where I grew up as a teenager. Run by fundamentalist evangelicals (generous, kind people incidentally), who are rare in Britain, the night's activities of five-a-side football, cricket or pool would come only after some kind of Bible-reading or an unsuccessful attempt at debunking the Theory of Evolution, which was a particular bugbear of theirs.
One night, a local volunteer was explaining why the Big Bang Theory was obviously nonsense with a cutesy, homely analogy – "If you blow up a pile of bricks, you don’t get a building, it’s stupid." In your face, Stephen Hawking!
He didn’t know why scientists might have come up with the idea of the Big Bang, except perhaps as a sneaky rationalisation for undermining Christianity. He wasn’t even clear as to why he thought it posed a theological problem for Christians in the first place, though he is not alone in thinking that it does.
The irony is extraordinary - aside from being uninformed about the Theory itself, fundamentalists are usually unaware of its religious origins, and the fact that the Big Bang Theory successfully replaced a theory much less compatible with Christian ideas about the beginning of time - the Steady State Theory.
The groundwork for the Big Bang Theory was laid in the early twentieth century by the paradigm-crunching work of Edwin Hubble (as in Hubble telescope) and Albert Einstein.
Einstein’s crucial contribution was part of the fallout of his work on gravity in Switzerland around the time of the First World War. By showing that gravity was a curve in space-time caused by the distorting impact of matter, the implication was that in a Universe where everything stayed in one place, gravity would gradually draw all matter together in an almighty collision. This meant that, contrary to the prevailing view of contemporary cosmologists, the Universe could not be static - it had to be either expanding or contracting.
Einstein didn’t much like this implication and was wedded to the notion of an unchanging Universe that had always existed. So he assumed there must be a problem with his theory, and compensated for it in his equations by inventing an artificial cosmological constant while he tried to figure out what was going on.
And on the other side of the Atlantic, from 1919 and through the 20s, Edwin Hubble was busy spending all night, night after night, making minor adjustments to the 100-inch Hooker Telescope on Mount Wilson, then the largest in the world. By photographing some of the most distant objects in view he resolved an earlier debate and demonstrated conclusively that the Universe, far from consisting of a single galaxy – ours, the Milky Way – actually contained a huge number of galaxies, each consisting of billions of stars. Our collective view of the Universe had to be adjusted as people realised it was a billion times larger than previously thought.
In addition to discovering these galaxies, Hubble also discovered something significant about them. Just as the pitch of a siren on an emergency vehicle changes as it drives past us - because the length of the sound waves change as they become more distant according to the Doppler effect - so too the light from distant objects can tell us whether they are moving closer or drifting away. Together with Milton L. Humason, Hubble showed that the galaxies were moving further away from us – part of what is today called Hubble’s Law concerning the light emitted by moving galaxies. The conclusion Hubble had to draw was that the Universe was expanding, and everything in it was on the move.
But, unknown to either of them, Hubble was actually beaten to the basic idea of Hubble’s Law by a Belgian priest, Fr. Georges Lemaitre. Lemaitre trained as a Jesuit priest, served in the Belgian Army during the remorseless slaughter of World War One, and then became a student of astronomy and mathematics. He studied in Cambridge in England, then in Cambridge, Massachusetts for the Harvard Observatory and finally the Massachusetts Institute of Technology.
Returning to Belgium in 1925, where he worked at the Catholic University of Leuven as a part-time lecturer, his big break came two years later in 1927 when he proposed his theory of an expanding Universe to explain the movement of the galaxies, published in the Annals of the Scientific Society of Brussels.
Lemaitre was still pretty hazy about how the process of expansion could have begun. Like many scientists, he was still committed to the idea of a static Universe of unchanging size, so he proposed that it might have begun like this but then started to expand. Since his ideas were not getting very much attention, he decided to arrange a meeting with Einstein at the Solvay Conference in Brussels in October 1927.
Einstein, though interested, was largely dismissive, telling Lemaitre that, "Your calculations are good, but your physics is terrible". Einstein was also a little suspicious of the religious implications of these ideas. He declined to describe himself as an atheist (or a theist, or a pantheist) and liked to use the vocabulary of religion, most famously in his misguided rejection of much of quantum physics, "God does not play dice!" But his complex and shifting view of God was of something impersonal behind fixed laws that governed the Universe, partly influenced by the 17th century philosopher Spinoza.
Einstein had previously dismissed the work of Russian mathematician, Alexander Friedman, who had proposed an expanding universe as an abstract mathematical solution to his equations in 1922. Einstein offered Lemaitre some suggestions for further investigations but left unconvinced.
Lemaitre’s old teacher, the British astronomer Arthur Eddington, was more encouraging and published a commentary on his 1927 paper in English in 1930, describing it as a brilliant solution to some of the outstanding problems astronomers faced. In 1931, Lemaitre was invited to London by the British Association to discuss cosmology and spirituality. There he described his new solution – that the Universe had begun from a tiny and incredibly dense singularity containing all its existing matter. This he called 'the primeval atom' or a "Cosmic Egg exploding at the moment of the creation".
The Primeval Atom theory was born (or Cosmic Egg theory if you like). It wouldn’t be known as the Big Bang Theory until the British physicist, Fred Hoyle, did a radio series in 1949 in which he attempted to debunk it. He failed to change many people’s minds by then, but he did give it a better name.
Neither Eddington nor Einstein were persuaded by this idea – as Stephen Hawking, perhaps the world’s most famous living astrophysicist, has said, "few people [meaning scientists] took the idea of the beginning of the Universe seriously". But Lemaitre was a passionate and persuasive man, and he was gaining a wider audience as he began to travel the US. He decided to surprise Hubble and Einstein by turning up to meet them both unexpectedly in 1931 and push his idea again. This time he won them over, demonstrating how their work led to his conclusion. It was a dramatic event – Hawking has said that, "The basis of modern cosmology was established at this meeting. Looking back I can recognise this as the foundations for my own work". Einstein regarded his initial rejection of an expanding Universe as the "biggest blunder of my life".
The Big Bang did not gain easy acceptance. Like any dramatic new concept in science, it had to be tested against the evidence and alternative hypotheses. Opponents adopted the Steady State theory of the Universe which proposed that the Universe stayed fundamentally the same over time. Since the galaxies were clearly moving apart from each other, the theory suggested that new galaxies must be constantly formed somewhere in the Universe and propelled outwards. But Steady State theorists could not explain where many of the chemical elements we see in the Universe could have been formed, if not in the extreme conditions of the Big Bang. They also struggled to explain where the hydrogen fuel to create these elements was being formed in the Universe, and why there was so much helium in the cosmos – the leftovers of hydrogen fusion. But the Big Bang Theory could answer that hydrogen was created in gigantic quantities in the original explosion, and the helium was part of the aftermath. The jury came back in and a new consensus was formed.
The existence of God, of course, is not settled by the truth of the Big Bang Theory, nor should religion rest its case on any scientific theory. But what can be said is that the Big Bang fits surprisingly well with the religious idea that the Universe had a distinct beginning, willed by a Creator. Betraying some bemusement, the astrophysicist Robert Jastrow put it like this:
"For the scientist… the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been there for centuries."
In reality, both the scientists and the theologians are still busy hauling themselves over the mountains of ignorance. Hopefully, they will help each other out.
Sadly, we hear little of Lemaitre today. Arguably, the way the evidence was pointing in the late 1920s, someone else might have come up with the same idea, taking up where Hubble, Friedman and Einstein left off. But the fact remains that one of the best known of all modern scientific theories was his. In his own lifetime, his achievement was recognised. He received the Francqui Prize in Belgium, the highest honour for a scientist in the country, with Einstein and Eddington among his proposers and judges respectively. The Vatican chose him to be a member of the Pontifical Academy of Sciences in 1936 (founded that year), where he worked and taught until becoming its president in 1960.
The Pontifical Academy of Sciences had its origins in an institution called the Academy of Lynxes (so-called because of the lynx’s keen eyesight), founded in 1603 under Pope Clement VIII by an Italian prince, Federico Cesi. The first president of that institution had been Galileo – an unfortunate reminder of what might have been, but for the Inquisition.
Pope John XXIII appointed Lemaitre, to his surprise, to lead the Second Vatican Council’s commission on birth control. His commission was the first ever to appoint lay people and women and to undertake a sociological investigation of the lives of Catholic families to help come to a truly fair and grounded decision. Lemaitre died before the commission completed its report – it famously recommended acceptance of the use of birth control and contraception, a view rejected by a minority report and Pope Paul VI.
Just before Lemaitre died in 1966, he learned of the first discovery of 'cosmic background radiation' – the predicted fallout from the Big Bang, and further confirmation of his theory.
It surprises me then, that many Christians still find the idea of the Big Bang problematic. They might instead try and take the credit for it and - why not? - get on with doing some science themselves.