Famous Catholics in Science

Gregor Johann Mendel OSA (/ˈmɛndəl/; Czech: Řehoř Jan Mendel;[2] 20 July 1822[3] – 6 January 1884) was a German-Czech biologist, meteorologist,[4] mathematician, Augustinian friar and abbot of St. Thomas' Abbey in Brno (Brünn), Margraviate of Moravia. Mendel was born in a German-speaking family in the Silesian part of the Austrian Empire (today's Czech Republic) and gained posthumous recognition as the founder of the modern science of genetics.[5] Though farmers had known for millennia that crossbreeding of animals and plants could favor certain desirable traits, Mendel's pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance.[6]

Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, and flower position and color. Taking seed color as an example, Mendel showed that when a true-breeding yellow pea and a true-breeding green pea were cross-bred their offspring always produced yellow seeds. However, in the next generation, the green peas reappeared at a ratio of 1 green to 3 yellow. To explain this phenomenon, Mendel coined the terms "recessive" and "dominant" in reference to certain traits. In the preceding example, the green trait, which seems to have vanished in the first filial generation, is recessive and the yellow is dominant. He published his work in 1866, demonstrating the actions of invisible "factors"—now called genes—in predictably determining the traits of an organism.

The profound significance of Mendel's work was not recognized until the turn of the 20th century (more than three decades later) with the rediscovery of his laws. Erich von Tschermak, Hugo de Vries and Carl Corrensindependently verified several of Mendel's experimental findings in 1900, ushering in the modern age of genetics.

Gregor Mendel was a 19th-century Austrian monk remembered for his experiments with pea plants that led to the discovery of hereditary patterns of traits. By cross-fertilizing plants of different traits—such as height or color—Mendel was able to identify dominant and recessive trains and show that traits were transmitted independently of the others, according to biography.com.

These observations later came to be known as Mendel’s laws, and his accompanying theory was dubbed Mendelism. Although he did not actually discover genes, he hypothesized the existence of gene-like units. His work became the basis for all subsequent studies of genetics. (The word gene was not coined until 1905, decades after Mendel’s death.)

Mendel was born in 1822 to a poor peasant farmer in Austria. After studying physics and mathematics at the University of Olmütz, he entered the Augustinian order at the St. Thomas Monastery in Brno, in the present-day Czech Republic. He was ordained to the priesthood in 1847. He became a substitute teacher but, after failing a certification exam, he went to the University of Vienna, where he studied under physicist Christian Doppler, for whom the Doppler effect is named.

After Vienna, Mendel returned to teaching, becoming the abbot at the high school where he worked. It is also during this period that he started his experiments with the pea plants in the monastery’s garden. He also experimented with bees, but his notes on his results have been lost, according to the Catholic Encyclopedia. He would later present his findings on hereditary traits in a series of lectures at the Natural Science Society in Brno. He died in 1884 and his theories faded into obscurity until their later revival at the start of the twentieth century.

Gregor Mendel was an Augustinian friar who is credited with founding the science of genetics. Mendel was born of a German-speaking family in a part of the Austrian Empire that is now part of the Czech Republic. After university studies, Johann Mendel entered the Augustinian Order, taking as his new “name in religion” Gregor. He studied to become a teacher (at one point taking a class from Christian Doppler at the University of Vienna), but twice (in 1850 and 1856) he failed the oral part of the exam due to nervousness. With the permission of the Abbot of his monastery (St. Thomas’s Abbey in Brno), Mendel undertook research in the monastery’s botanical gardens, which the Abbott had planted many years earlier.  From 1856 to 1863, Mendel carried out experiments breeding pea plants of the species Pisum sativum.  In particular, he chose to study the inheritance of seven traits (seed shape, seed coat tint, flower color, flower location, pod shape, unripe pod color, and plant height).  Altogether Mendel grew and tested about 28,000 plants.  He discovered mathematical patterns in the inheritance of these traits, which he explained in terms of two laws (the “Law of Segregation” and the “Law of Independent Assortment”), which are now called Mendel’s Laws of Inheritance.  These concern what are now called “genes” (Mendel called them “factors”) and are the beginning of the science of genetics.  Mendel gave talks on his discoveries at two scientific meetings in 1865, published his results in a relatively obscure scientific journal, and corresponded with a leading biologist of the time, Carl Wilhelm von Nägeli, about them; but no one appreciated the importance of Mendel’s work or paid attention to it in his lifetime.  By 1900, Mendel’s laws were independently discovered by two other scientists, Hugo de Vries and Carl Correns, who also discovered Mendel’s writings and admitted the priority of his discovery.  The enormous importance of Mendel’s discoveries was immediately appreciated at that time and he achieved posthumous fame as the “father of genetics.”  

Born in Milan, Mercalli was ordained a Roman Catholic priest and soon became a professor of Natural Sciences at the seminary of Milan. The Italian government appointed him a professor at Domodossola, followed by a job at Reggio di Calabria. He was professor of geology at the University of Catania during the late 1880s and finally was given a job at Naples University. He was also director of the Vesuvius Observatoryuntil the time of his death.

Giuseppe Mercalli also observed eruptions of the volcanoes Stromboli and Vulcano in the Aeolian Islands. His descriptions of these eruptions became the basis for two indices of the Volcanic Explosivity Index: 1 – Strombolian eruption, and 2 – Vulcanian eruption. He also photographed Vesuvius immediately after its eruption in 1906.

In 1914, Mercalli burnt to death under suspicious circumstances, allegedly after knocking over a paraffin lamp in his bedroom.[1] He is thought to have been working through the night, as he often did (he once was found working at 11 a.m. when he had set an examination, upon hearing which he replied, "It surely can't be daylight yet!"), when the fatal accident occurred. His body was found, carbonized, by his bed, holding a blanket which he apparently attempted to use to fend off the flames. The authorities, however, stated a few days later that the professor was quite possibly murdered by strangling and soaked in petrol and burned to conceal the crime because they determined that some money (now worth about $1,400) was missing from the professor's apartment.

Giuseppe Mercalli was a 19th-century Italian priest and seminary professor who studied volcanoes. He spent much of his life observing Vesuvius near Naples, where he taught at the University of Naples. He is the inventor of an alternative to the Richter scale for measuring the intensity of earthquakes.

Unlike the Richter scale, which measures the power of earthquakes, the Mercalli scale pinpoints the effects on human habitation. A modified version of his scale is still in use by the U.S. Geological Survey. For example, an earthquake registers at a 2 on the Mercalli scale if it was “felt only by a few persons at rest, especially on upper floors of buildings.” A 10 on the scale means that “Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Rails bent” (source: U.S. Geological Survey).

Born in 1850, Giuseppe died in his apartment in a fire 1914. At the time of his death, he was an internationally known scientist, earning a three-page story in the New York Times. Given the suspicious nature of the blaze that had claimed his life, the Times raised the possibility that he had been murdered.

Stephen M. Barr is President of the Society of Catholic Scientists and Professor Emeritus of theoretical particle physics at the University of Delaware. His research has centered mainly on “grand unified theories” and the cosmology of the early universe.  In 2011, he was elected to be a Fellow of the American Physical Society “for his original contributions to grand unification, CP violation, and baryogenesis”.  He writes and lectures extensively on the relation of science and religion.  He is the author of Modern Physics and Ancient Faith (Univ. of Notre Dame Press, 2003) and The Believing Scientist: essays on science and religion (Eerdmans, 2016).  He was elected in 2010 to the Academy of Catholic Theology and was awarded the Benemerenti Medal by Pope Benedict XVI. 

In his online lectures Prof. Barr shows that the widespread idea that faith and science are opposed to each other is based on serious misconceptions about the history of science, about what the Catholic Church teaches, and about what science has actually discovered about the world.  In the first lecture, he shows how fundamental Catholic beliefs about God dovetail with the basic assumptions of science.  In the second lecture, he shows how the Catholic Church, Catholic clergy, and Catholic lay people powerfully contributed to the founding and development of science.  In the third lecture, he discusses the beginning and creation of the universe from the viewpoint of both Catholic theology and modern cosmology.  In the fourth lecture, he shows that the idea of the human “spiritual soul” is not in conflict with modern science.  In the final lecture he shows how the idea of biological evolution is perfectly consistent with a Christian conception of the universe.

Georges Henri Joseph Édouard Lemaître French:; 17 July 1894 – 20 June 1966) was a Belgian Catholic priest, theoretical physicist, mathematician, astronomer, and professor of physics at the Catholic University of Louvain.[1] He was the first to theorize that the recession of nearby galaxies can be explained by an expanding universe,[2] which was observationally confirmed soon afterwards by Edwin Hubble.[3][4] He first derived "Hubble's law", now called the Hubble–Lemaître law by the IAU,[5][6] and published the first estimation of the Hubble constant in 1927, two years before Hubble's article.[7][8][3][4] Lemaître also proposed the "Big Bang theory" of the origin of the universe, calling it the "hypothesis of the primeval atom",[9] and later calling it "the beginning of the world".

Given contemporary stereotypes about the incompatibility between faith and science it might come as a surprise to some people that the man who developed the Big Bang theory—the basis for the current scientific model of the universe—was a Belgian Catholic priest named Georges Lemaitre.

Born in 1894, Lemaitre studied civil engineering at the Catholic University of Louvain and went on to serve in the artillery division of the Belgian military during World War I. After the war he entered the seminary and was ordained a priest in 1923. He continued his studies in physics at the University of Cambridge. He also studied at the Massachusetts Institute of Technology.

Building upon astronomer Edwin Hubble’s observations about the expansion of the universe and Albert Einstein’s theory of general relativity, Lemaitre hypothesized that the universe had begun from a dense starting point that he dubbed the “primeval atom” or the “cosmic egg.”

The Big Bang theory, as it came to be known, challenged Einstein’s own view of a static universe. The famous scientist told Lemaitre that “Your math is correct, but your physics is abominable.” When Lemaitre’s theory was later confirmed by observation, Einstein recanted his view and reportedly declared that Lemaitre’s theory was “the most beautiful and satisfactory explanation of creation to which I have ever listened” (sources here and here).

Lemaitre died in 1966. His Big Bang theory, in modified form, remains the basic model cosmologists use to describe the universe today.

Georges Henri Joseph Édouard Lemaître  (July 17, 1894 to June 20, 1966)  Lemaître was a Belgian priest, theoretical physicist and mathematician who proposed the Big Bang theory, which is the central pillar of modern cosmology. Einstein published his theory of gravity (called General Relativity)  in 1916.  In 1922, a Russian mathematician Alexander Friedmann and a few years later Georges Lemaître, independently, found solutions to Einstein’s gravitational field equations that described a universe in which space itself is expanding. (The “metric tensor” that describes this is now called the “Friedmann-Lemaître-Robertson-Walker metric” or “FLRW metric.”) Meanwhile, the astronomer Slipher found evidence that galaxies were flying apart from each other at tremendous speeds.  It was Lemaître who combined these observations with the mathematics of General Relativity to propose, in 1927, that the universe is indeed expanding.  He also predicted from this hypothesis that the rate at which remote galaxies are receding from the earth should be proportional to their distance away. Few knew of Lemaître’s prediction at the time, so that when the astronomer Edwin Hubble discovered this relationship from observations in 1929 it came to be called the “Hubble Law” of cosmic expansion. In 2018, an overwhelming vote by the membership of the International Astronomical Union recommended that it be renamed the “Hubble-Lemaître Law.” In 1930, Lemaître suggested that the expansion of the universe began from a state of enormous density, which he called “the Primeval Atom” and which is now called “the Big Bang.” Lemaître’s thinking about cosmology was remarkably prescient in several ways. He predicted that there should be observable radiation left over from the Big Bang explosion, which is correct, though he incorrectly identified it with cosmic rays.  This “cosmic background radiation,” which is now redshifted by the cosmic expansion to the microwave part of the electromagnetic spectrum, was discovered by Arno Penzias and Robert W. Wilson in 1964.  Lemaître also suggested that quantum effects should be of great importance at the time of the Big Bang, which is also believed to be correct (though his particular idea that the Big Bang was a radioactive decay of the “Primeval Atom” is not).  And in order to accommodate a realistic age of the universe, he proposed models in which the “cosmological constant,” a possible term in Einstein’s equations, leads to an accelerating phase of the universe’s expansion.  As it happens, in 1998 it was discovered that the universe’s expansion is indeed accelerating, due to “dark energy,” which is thought most likely to be the cosmological constant (though Lemaître’s particular model is not right in detail).  Lemaître was opposed to linking particular scientific theories, including the Big Bang theory, to theological ideas, as each field must respect its own methods and competences.

André-Marie Ampère was born on 20 January 1775 to Jean-Jacques Ampère, a prosperous businessman, and Jeanne Antoinette Desutières-Sarcey Ampère, during the height of the French Enlightenment. He spent his childhood and adolescence at the family property at Poleymieux-au-Mont-d'Or near Lyon.[3] Jean-Jacques Ampère, a successful merchant, was an admirer of the philosophy of Jean-Jacques Rousseau, whose theories of education (as outlined in his treatise Émile) were the basis of Ampère's education. Rousseau believed that young boys should avoid formal schooling and pursue instead a "direct education from nature." Ampère's father actualized this ideal by allowing his son to educate himself within the walls of his well-stocked library. French Enlightenment masterpieces such as Georges-Louis Leclerc, comte de Buffon's Histoire naturelle, générale et particulière (begun in 1749) and Denis Diderot and Jean le Rond d'Alembert's Encyclopédie (volumes added between 1751 and 1772) thus became Ampère's schoolmasters.[citation needed] The young Ampère, however, soon resumed his Latin lessons, which enabled him to master the works of Leonhard Euler and Daniel Bernoulli.

In addition, Ampère used his access to the latest books to begin teaching himself advanced mathematics at age 12. In later life Ampère claimed that he knew as much about mathematics and science when he was eighteen as ever he knew, but as a polymath, his reading embraced history, travels, poetry, philosophy, and the natural sciences.[4] His mother was a devout Catholic, so Ampère was also initiated into the Catholic faithalong with Enlightenment science. The French Revolution (1789–99) that began during his youth was also influential: Ampère's father was called into public service by the new revolutionary government,[5] becoming a justice of the peace in a small town near Lyon. When the Jacobin faction seized control of the Revolutionary government in 1792, his father Jean-Jacques Ampère resisted the new political tides, and he was guillotinedon 24 November 1793, as part of the Jacobin purges of the period.

In 1796, Ampère met Julie Carron and, in 1799, they were married. Ampère took his first regular job in 1799 as a mathematics teacher, which gave him the financial security to marry Carron and father his first child, Jean-Jacques (named after his father), the next year. (Jean-Jacques Ampère eventually achieved his own fame as a scholar of languages.) Ampère's maturation corresponded with the transition to the Napoleonic regime in France, and the young father and teacher found new opportunities for success within the technocratic structures favoured by the new French First Consul. In 1802, Ampère was appointed a professor of physics and chemistry at the École Centrale in Bourg-en-Bresse, leaving his ailing wife and infant son Jean-Jacques Antoine Ampère in Lyon. He used his time in Bourg to research mathematics, producing Considérations sur la théorie mathématique du jeu (1802; "Considerations on the Mathematical Theory of Games"), a treatise on mathematical probability that he sent to the Paris Academy of Sciences in 1803.

The amp, the base unit of electrical current, was named after André-Marie Ampère, one of the fathers of electromagnetism. This French scientist discovered that a wire carrying an electric current can attract or repel another current-carrying wire, thus generating a magnetic field. This paved the way for the later discovery of electromagnetic radiation, which made possible inventions that we now take for granted, including the radio, microwave, and X-rays.

Ampère was a devout Catholic. While studying at the Sorbonne, the scholar Frédéric Ozanam, later beatified, was going through a period of doubt. One day, he wandered into a parish church in a Paris slum where he unexpectedly saw none other than André-Marie Ampère, one of the most famous scientists of the time, on his knees praying.

“Professor, I see you believe in prayer,” Ozanam said.

“Everyone has to pray,” Ampère replied. This was a turning point in Ozanam’s conversion.

In today’s West, there is a growing inconsistent tendency to, on the one hand, promote the greater inclusion and empowerment of people with physical and intellectual disabilities but, on the other, to lobby for their widespread killing in the womb. In Iceland, for example, nearly 100 percent of unborn children diagnosed with Down syndrome during neonatal testing are aborted.

The French geneticist and pediatrician Jérôme Lejeune compassionately worked with children with disabilities. In 1958, he discovered that Down syndrome is caused by an extra copy of chromosome 21. Previously, scientists had believed that Down syndrome was caused by syphilis, alcohol abuse by the mother, or genes of Asian origin (hence the now-archaic terms “Mongolism” and “Mongoloid”).

In the 1960s and 1970s, Lejeune vocally opposed the legalization of abortion in France and many other Western countries. He wrote: “One cannot protect another from misfortune by committing a crime. And killing a child is murder. You cannot bring relief to one person by killing another.” Lejeune bitterly (but accurately) noted that his pro-life advocacy would prevent him from winning the Nobel Prize in Physiology or Medicine.

Lejeune was a long-time friend of Pope John Paul II, who as the Archbishop of Krakow invited him to give lectures. During his 1997 visit to France for World Youth Day, the Polish pope prayed at the French scientist’s tomb.

Currently, Lejeune’s cause for beatification has advanced. Last year, Pope Francis declared him Venerable, meaning that he will be officially recognized as blessed once a miracle through his intercession is approved.

Very few nineteenth-century scientists left such a lasting impact on our world as Louis Pasteur. He is considered the inventor of vaccines (such as for rabies), which in the twentieth century would prove critical in eliminating many other diseases. Thanks to the polio vaccine, for instance, poliomyelitis is all but obsolete except for in Afghanistan and Pakistan.

Pasteur also discovered pasteurization, the process by which germs are eliminated from food and can therefore be preserved for longer. He is one of the discoverers of germ theory of disease, by which physicians understand the mechanisms of the contraction of maladies.

According to an oft-told story (I recall hearing it during a priest’s sermon at one Mass years ago), Pasteur was praying the rosary on the train one day. His neighbor in the compartment, unaware of his interlocutor’s identity, criticized the old man for believing such superstition and said he would like to mail him some books disproving the existence of God. Pasteur told the youth to send him these materials to his address and pulled a business card out of his coat pocket. The young man was stunned that he had arrogantly lectured one of the true greats of science. Epic fail.

I do not know if this story is authentic or apocryphal, but it illustrates Louis Pasteur’s ardent faith well.

Guglielmo Marconi, the inventor of the radio and the winner of the 1909 Nobel Prize in Physics, was born to an Italian aristocrat and his Irish Protestant wife. Although baptized a Catholic, he had been raised an Anglican; he received the sacrament of confirmation in the Catholic Church so he could marry his wife, Maria Cristina Bezzi-Scali. It was then that he became a zealous Catholic.

Another Catholic played a key role in Marconi’s invention of the radio: Thomas Edison informed Marconi of the experiments of Father Jozef Murgaš, a Slovak priest living in Pennsylvania, who contributed to the wireless transmission of the human voice.

In 1931, Marconi set up Vatican Radio for Pope Pius XI; this was the first radio station that was used to preach the Good News. One year later, he invented a short-wave radio telephone to facilitate communications between the Vatican and the papal summer residence at Castel Gandolfo, an early predecessor to the cellular phone.

Unfortunately, there is a dark side to Marconi. He was a member of the Fascist Party, and growing evidence suggests he supported Mussolini’s anti-Jewish policies. Yet despite these obvious flaws, Marconi was a perfect example of a scientist who used his discovery for the good of the Church.