Whenever a major new scientific theory comes along, there is a tendency to mix it together with religion, and the outcome is often both unexpected and unfavorable. When the distinction between science and religion is clearly understood, such problems can be avoided. The history of the Big Bang theory is a fine example of how to do it right, thanks to one man who had that clear understanding.

A century ago, we had no idea of separate galaxies. There were some fuzzy objects out there, but telescopes weren't good enough to resolve what they actually were. Astronomy was still a fascinating field, but there was not yet a field of cosmology. Then in 1916 came Albert Einstein's General Theory of Relativity, which was a comprehensive theory uniting space, time and gravity.

That theory was totally different from what people had previously assumed. However, Einstein's previous accomplishments (four important new theories in 1905) assured that many scientists at least paid attention. By 1919, a prediction of Einstein's theory was verified via an experiment conducted during a solar eclipse, and that greatly enhanced the credibility of General Relativity.

Soon many more scientists got interested, because it was possible to associate the huge amount of observed astronomical data with a theory that made sense of it all. The measurable difference in light arriving from some very distant stars (the “red shift”) provided convincing evidence that the universe was expanding – and that begged for an explanation. Einstein's equations of General Relativity involved tensor calculus, which was unfamiliar to most scientists at the time; but a few set out to solve those equations for special conditions of the universe. Einstein, who once said, “I want to know God's thoughts...the rest are details,” himself believed that the universe was in a “steady state,” hardly changing at all.

In 1922, the Russian Alexander Friedmann worked out a solution for a universe expanding from a singular starting point; unfortunately, he died soon thereafter and his work wasn't noticed. Working independently, Georges Lemaitre, a Belgian Catholic priest, solved Einstein's equations for a universe starting at time t = 0 and expanding from a singular point to its present size. He submitted that as his doctoral thesis to both Harvard and M.I.T. in 1925, and that was quickly noticed in the western scientific world.

When Einstein heard of Lemaitre's work, he scoffed at it; and that disdain put Lemaitre into an uphill struggle. The notion of a “Steady State” unchanging universe out there was very strong in those days, where new particles just came into existence as the universe expanded. The thought of everything starting off at a single tiny point was incomprehensible to most physicists.

The disdain for Lemaitre didn't last long. Better telescopes were built, and other galaxies beyond our own Milky Way were discovered. By 1929, Edwin Hubble's observations permitted a calculation of how fast the universe was expanding, and it was all consistent with Lemaitre's theory. Einstein himself eventually came to agree with Lemaitre – for the simple and honorable scientific reason that Lemaitre's theoretical solution accounted for the data. Einstein's Theory of General Relativity, meanwhile, became fully accepted throughout the scientific world. The term “Big Bang theory” didn’t come along until decades later.

With his scientific respectability secure, Fr. Georges Lemaitre moved in higher circles within the Catholic Church, and became a key scientific advisor to Pope Pius XII. In 1950, a most interesting backstage drama took place, which shows what real scientists think about even the best scientific theories. Pope Pius XII saw that the Big Bang theory coincided nicely with the narrative in Chapter one of the Book of Genesis, and considered making it a doctrine of faith, declaring it true. Obviously that would have been a huge accolade for Lemaitre, a permanent vindication of his theory.

Instead of rejoicing at this, Lemaitre himself talked the Pope out of it. Lemaitre explained that NO theory in physics, however elegant or reliable, is truly final. Every theory can always be revised; every theory can be contradicted (and thereby destroyed) by a single experiment. Lemaitre knew his history well: only a century earlier, “the ether” seemed a sure thing.

In 1963, new evidence from radio astronomy gave further confirmation that indeed the universe originated in a sudden explosion, and the competing “Steady State” theory was abandoned. The Big Bang became the only game in town. However, with the passage of yet another half-century, recent observations have indicated that some correction may be necessary to Einstein's theory: there may well be some additional force (customarily termed “dark energy”) that causes the expansion of the universe to accelerate. In the years ahead, will General Relativity or the Big Bang be corrected? Stay tuned.

It is enormously to the credit of Fr. Georges Lemaitre that he stood up to sustain the independence of science and religion. Lemaitre had an enduring confidence that both science and religion are complementary pathways to knowledge, but scientific theories can stand or fall on their own, and don't need religion to referee. As Albert Einstein said, "Science without religion is lame; religion without science is blind."

More recently (1987), Pope John Paul II stated their complementary relationship very cogently: “Science can purify religion from error and superstition. Religion can purify science from idolatry and false absolutes. Each can draw the other into a wider world, a world in which both can flourish.”

Dr. Thomas P. Sheahen is the Director of the Institute for Theological Encounter with Science & Technology.