And Einstein stood to applaud

Lemaitre with Einstein

The Belgian priest and scientist George Lemaitre is not a household name, but his brilliant work on the origin of the universe challenged the best minds of his day, and continues to inform our understanding of the cosmos.

The work of researchers who reported in March about detecting a signal left behind by the rapid expansion of space billions of years ago is rooted in the efforts of a Belgian priest whose mathematical computations in the 1920s laid the groundwork for the Big Bang theory.

Monsignor George Lemaitre, a mathematician who studied alongside leading scientists of the first half of the 20th century exploring the origins of the universe, suggested that the cosmos began as a super-dense 'primeval atom' that underwent some type of reaction that initiated the expansion of the universe which continues today.

Researchers in cosmology over the decades refined Mons Lemaitre's idea, leading to what became widely known as the Big Bang theory and later ideas that signs of the Big Bang can be detected.

The most recent evidence supporting the Big Bang emerged on 17 March when a team of scientists announced they had detected polarisation in light caused by primordial gravitational waves originating from the Big Bang. The measurements were made with the Background Imaging of Cosmic Extragalactic Polarisation experiment, or Biceps2, located near the South Pole.

Scientists had theorised that such waves would have been produced in the universe's first trillionth of a trillionth of a trillionth of a second as it underwent an exponential expansion 13.8 billion years ago, sending ripples throughout the universe that can still be detected.

Other research teams are seeking to confirm the findings.

Mons Lemaitre’s work focussed on interpreting Einstein’s theory and analysing measurements of galactic motion by astronomer Edwin Hubble. The priest’s computations pointed to a constantly expanding universe and, by extrapolation, backwards to the primeval atom. 

His work has long been held in high regard by generations of scientists. 

Even Einstein, who at first was sceptical of the calculations, literally stood up and applauded Mons Lemaitre's explanation of the origins of the universe during a series of seminars in California in 1933.

Mons Lemaitre, who taught for most of his career at the Catholic University of Louvain in Belgium, died on 22 June, 1966, at 71 knowing that he was on the right trail. He was told just before his death that scientists had measured the cosmic microwave background radiation.

In response to a question about the connection of his work and his faith, Mons Lemaitre said that the Bible’s authors were 'illuminated ... on the question of salvation' and that 'the idea that because they were right in their doctrine of immortality and salvation they must also be right on all other subjects is simply the fallacy of people who have an incomplete understanding of why the Bible was given at all.' 

Read full article: A little-known Belgian priest whose studies of the universe’s origins still guide cosmology (The Catholic Weekly)