Georges Lemaître - The father of the big bang theory

The theory of the Big Bang was proposed by Georges Lemaitre a Belgian priest. Lemaitre was born in 1894 to devout Roman Catholic parents and at the young age of nine, expressed his wish to become a priest. Georges was a cheerful boy and excelled in mathematics and physics. It is said that there are three main branches in science; mathematics, physics and chemistry and everything else is variations to these three fundamental bases. Chemists answer only to physicists, physicists to mathematicians and mathematicians to God for mathematics is the language of God. Georges was equally devoted to God as to science and this was a rarity, for scientists did not show much patience to religion and religions just a passing interest in science. In July 1914, World War I broke out with Germany invading Belgium and France, Georges and his brother Jacques enrolled in the army and were on the front line fighting the war. Whenever there was a break in fighting and gun firing, Georges would pull out his physics book and start reading, something his fellow soldiers found very amusing. Georges and his brother survived the war, and he was awarded the Croix de guerre medal for bravery. He would have become an artillery officer but was expelled from training after telling an instructor that his ballistics calculations were wrong! With the war behind him, Georges followed up on his childhood dream of becoming a priest and began training for the Roman catholic priesthood. He was ordained a priest in September 1923 at the age of 29. Georges however continued his studies in science.  

 

Cosmological constant 

Einstein had proposed that the universe is static but when he applied his theory to the model of the universe, the outcome was an unstable universe, indicating that the universe was either expanding or contracting and to solve this problem, Einstein introduced a cosmological constant. Georges while studying Einstein’s equation, did his own observations and proposed his theory of an expanding universe, not only that, but he also went a step further and said that if the universe is in expansion, it must have started from some initial point. Scientists were not comfortable about the idea that the universe started from some initial point, for a universe with a beginning meant that creation had a creator. Fred Hoyle another scientist sarcastically coined the term Big Bang, and it stuck.   

During the first fraction of a second of the big bang, the universe would have been filled with matter and antimatter, example the positively charged positron is the antimatter for the negatively charged electron, matter and antimatter are created in pairs but today all that we see in the visible universe is made up of matter and what happened to antimatter? If matter and antimatter had been created in equal parts, they would have annihilated each other when they came in contact leaving behind energy or radiation, but some unknown entity intervened in the early process and one particle per billion survived and the result is the universe we live in. This asymmetry of matter and antimatter is a mystery in physics.  

 

Cosmic Microwave Background (CMB) 

In 1948, Ralph Amer working with Robert Herman and George Gamow on the big bang theory proposed that had there been a big bang then the annihilation of matter and antimatter would have left behind radiation, an afterglow and called it the cosmic microwave background or CMB. In 1965 researchers Arno Penzias and Robert Wilson of Bell Labs were studying signals from the Milky Way Galaxy, however their radio receiver was picking up a lot of noise, thinking it to be from the pigeon droppings on their antenna, they cleaned it up and chased off the pigeons but still the noise persisted, and it was then that they realized this was not noise but actual signals from space or the cosmic microwave background signals. It was later in 1929 that Edwin Hubble through his powerful telescopes and light shift theories discovered that the universe was expanding, which forced Einstein to discard the cosmological constant stating that it was the greatest blunder in his life. The theory Of Georges Lemaitre was proved right, that the universe started from atomic scale with the big bang and that the universe is in expansion.  

Lemaitre's theory of the big bang is iconic, and we are in the right direction in understanding the birth of the universe. Perhaps the best tribute to Father Lemaitre was that made by a visiting professor of Physics at the Catholic University of America. In 1933, Rev. Vecchiarello, O.F.M. said: "It is a point of great interest nowadays, when there is so much loose thinking and still looser writing and talking about the non-existence of God, of the immortal soul, and of a host of eternal verities, to see a man who is both a priest and a scientist fraternizing on the most intimate terms with the world’s most illustrious scientific geniuses. He not only associates with them, but he is their peer; and in that is the lie given to the old and empty charge that the study of science means the loss of belief in religion. Lemaitre, of course, is usually an object of great curiosity – not so much to his co-religionists as to many not of the Faith who marvel at the ‘phenomenon’ of a Catholic priest being a scientist, yes, not only a scientist of the regular run, but a genius whose theories are most daring."