The Master

When science and religion appear to be on a collision course, it is good to remember the Catholic priest who was also a great scientist, with a capacity to move with rare mastery between science and faith. To the point of getting the better, in quick succession, of both Einstein and the Pope.

His name was Georges Lemaître. An appropriate enough name, since in French Lemaître sounds like ‘the master’. And yet it was ill suited to a character as reserved and humble as he was. Having been educated by Jesuits, having taken his vows and distinguished himself in his native Belgium, Lemaître was appointed as a lecturer at the Catholic University of Leuven. He had become fascinated by Einstein’s recently published theory of general relativity, and above all by the possibility suggested by Einstein himself of studying the large-scale dynamics of the entire universe: what today is called ‘cosmology’.

Einstein had begun this study but had soon realized that his theory predicted that the universe could not be static. The reason for this is easy to understand: the galaxies attract each other, and if they were not moving they would fall one on top of the other, just like balls that cannot stay suspended in mid-air. Einstein did not have the courage to take the prediction of his own theory seriously: the idea of the large-scale movement of the universe just seemed too audacious.

Lemaître sought to change his mind. A ball does not fall if it has been kicked and is flying upwards. The stars might similarly be in flight, distancing themselves from each other, ‘kicked’ by some tremendous initial impetus. This is the expansion of the universe.

How can we determine whether this is true or not? Lemaître understands that we can do so by observing the light that emanates from distant stars, because the light of something that is receding from us is reddish in colour. He gathers together the small amount of data available on nebulae, the small opalescent discs that appear between stars and which at the time were beginning to be suspected of being very far away indeed, and finds that their light is in fact reddish. Hence this seemed to indicate that the universe is indeed expanding. He publishes these findings in an obscure French scientific journal that no one reads.

A few years later the American astronomer Edwin Hubble studies the nebulae, using the large Mount Palomar Telescope, and shows that they are extremely distant and moving further away from us at great speed. The universe really is expanding! Einstein is obliged to recognize that Lemaître was right.

The young priest extrapolates the consequences of this discovery. If the universe is expanding, it must at first have been extremely small. Lemaître calls this initial state ‘primeval atom’. Today we call it the Big Bang. In the years that follow, the idea that the universe emerged from this Big Bang becomes increasingly well known. On 22 November 1951, Pope Pius XII speaks fulsomely about the theory in a public address. The Pope enters into detail about modern science in order to argue that ‘the more real science advances, contrary to what was vaunted in the past, the more it reveals the presence of God – almost as if He was waiting patiently behind every door that science opens’. At the core of the papal argument is the Big Bang: ‘Creation is thus temporal; therefore there was a Creator; therefore God exists!’

Lemaître is not pleased. In close contact with the Vatican’s scientific adviser, he immediately goes out of his way to convince the Pope not to make any further statements of this kind, and to refrain from making references to possible links between cosmology and divine creation. The well-balanced conviction of Lemaître, developed in many of his writings, was that neither science nor religion should attempt to speak of things in areas in which they have no competence. Religion, according to Lemaître, should concern itself with our soul and with salvation, leaving to science the understanding of nature. He was convinced that it was foolish to defend the idea that whoever wrote Genesis had even the slightest understanding of cosmology. Genesis knows nothing about physics, and physics knows nothing about God. Pope Pius XII was persuaded. He never made any further public reference to his theories.

The idea of using the theory of the Big Bang as an argument in favour of the existence of God reappears in some Protestant contexts in the United States, but the Catholic Church has left it alone. Lemaître, of course, was right: today’s discussions have moved on to consider whether the Big Bang could have been a transition from a prior phase in the life of the universe. It is possible that the universe rebounded after a violent contraction. It would have been embarrassing for the Church to have in effect suggested that the Lord, breathing on the waters, had uttered not his primordial ‘Fiat lux’ but something to the effect of ‘Let there be, again, the light that just went out.’

It doesn’t fall to everyone to prove Einstein wrong, or to successfully contradict and dissuade a Pope. To have engaged with both individually, and to have convinced both that they had erred on such major issues, is surely something of a result. The ‘Master’ really did have something to teach.

And yet what Lemaître had to teach us, perhaps the secret of his greatness, is to be found elsewhere.

In 1931 a group of physicists decided to make known the article in which Lemaître had first announced his Big Bang theory. Translated into English, the article was republished in a well-known journal. And it is at this point that a strange kind of detective story begins, with the solution to the mystery only recently revealed by the astrophysicist Mario Livio. In the English translation of 1931, there are a few crucial phrases missing. Precisely those which make completely clear that Lemaître had already deduced the expansion of the universe on the basis of the sparse data available to him at the time, before Hubble. It was as if someone had deliberately erased precisely the phrases that would have cast doubt on the American Hubble’s claim to have got there first, and that would have showed it was Lemaître who was the real discoverer.

Who did it? When the alteration of the article came to light, suspicions quickly multiplied. Who was interested in having Hubble take the glory? Was it Hubble himself? The editor of the journal who wanted to avoid alienating the Americans? For years, the missing phrases have provoked arguments and accusations – until the truth emerged from the correspondence between the editor and the author. The removal of the crucial phrases, and the misplaced attribution of the major discovery, was the sole responsibility of … Georges Lemaître himself. In a handwritten letter to the editor, he points out that Hubble’s data was superior to what was available to himself, and that therefore there was no reason to refer to less precise data that had now been superseded. In other words, Lemaître was uninterested in taking the credit for the discovery. What mattered to him was not personal recognition but establishing the truth.

The man who first saw the Big Bang, the man who knew how to convince both the Pope and Einstein, was curious about nature, uninterested in his own ego. His message seems to me the deepest and clearest that science has managed to articulate: don’t take yourselves too seriously; stay humble. Even if your name is Einstein, even if you are the Pope himself. Even if you are ‘The Master’.