Thanks to the COVID-19 vaccines, I recently had the opportunity to visit Paris, France, for the first time. In addition to the usual art museums and tourist spots, I approached the city with the goal of visiting some of its scientific and pseudoscientific points of interest. France has a proud history of achievement in science and mathematics, as well as some brushes with pseudoscience and the paranormal, much of which is on display in Paris for the interested traveler. What follows is by no means an exhaustive list.

Musée des Arts et Métiers

I had come to France to speak at the Timeworld 2021 World Congress, which this year was organized around the theme of “randomness.” The congress was held at the Conservatoire National des Arts et Métiers (National Conservatory of Arts and Crafts), which is on the same campus as the Musée des Arts et Métiers. The museum was founded in 1794, during the French Revolution, as a repository of scientific instruments and inventions, and it contains many beautiful objects.

When you visit a science museum in another country, you are immediately aware of how nationalistic these institutions are. However, in the field of science and mathematics, the French have much to be proud of. The museum displays beautiful brass instruments, including an astrolabe made in 1569 by Rennerus Arsenius (shown in the banner photo for this article) and several of Blaise Pascal’s early computing devices.

 

The French made many advances in the field of photography and motion pictures, and the museum contains a number of early cameras and also presents some very early examples of motion pictures.

 

One of Louis Daguerre’s (1787–1851) early cameras (circa 1835). This “two box” camera was designed so the rear box could move back and forth to focus the image on the plate (not shown). Daguerre invented the Daguerreotype, an early photographic method. (Unless otherwise noted, all the photographs in this article were taken by the author.)

A major attraction of the Musée des Arts et Métiers is Foucault’s Pendulum, but I will save this item for the next section.

The Panthéon

A beautiful domed structure, the Panthéon sits at the top of a hill in the Latin Quarter on the former site of the Abbey of St. Genevieve, patron saint of Paris. In 1744, King Louis XV promised to build a structure more fitting for Genevieve, but the building was not completed until 1790, after the beginning of the French Revolution. Initially the structure was to be the Church of Genevieve, but during the revolution it was renamed Temple of the Nation, and many revolutionary figures were buried there, including Voltaire, Jean-Paul Marat, and Jean-Jacques Rousseau. Under Napoleon Bonaparte, the Panthéon returned to being a church. Over the years, as republican governments came and went, the building alternated between religious and secular uses. The Panthéon continued to serve as a mausoleum for notable French figures, including Victor Hugo, Marie Curie, and André Malraux.

Today, in addition to the graves of honored citizens and the stunning architecture of the building, the main attraction of the Panthéon is Foucault’s Pendulum. In 1851, astronomer Léon Foucault (1819–1868) hung a very large pendulum from the dome of the Panthéon as a demonstration of the rotation of the Earth. A few months later, the pendulum was moved to the Musée des Arts et Métiers. Today, the original pendulum is still at the museum—although the original fob fell off and is displayed in a case next to the pendulum—and a somewhat grander replica hangs in the Panthéon. So, visitors to Paris have two opportunities to see Foucault’s Pendulum, in the center of Paris at the Musée des Arts et Métiers or on the Left Bank at the Panthéon. Both are impressive, but the Panthéon’s architecture is far more dramatic.

 

 

 

Saint-Étienne-du-Mont

Just behind the Panthéon is Saint-Étienne-du-Mont, a beautiful church whose construction began in the late fifteenth century and was not completed until 1624. Saint-Etienne contains the tomb of St. Genevieve, but for the skeptical tourist, the most notable interment is mathematician and philosopher Blaise Pascal (1623–1662).

Pascal was a child prodigy who made many contributions in the field of mathematics and science. While still a teenager, he built his first calculators in an effort to help out his father, who had been appointed the King’s tax collector in the city of Rouen. Several of his calculators are on display in the Musée des Arts et Métiers. Pascal is considered a father of modern computing, and the Pascal computing language is named in his honor.

Pascal experienced a religious conversion in his twenties, and he is famous for having described “Pascal’s wager,” which represents an early application of expected value to rational decision making (Ross 2004). The expected value of a bet can be determined by the product of the value of the possible outcomes and the probabilities of those outcomes. In the posthumously published work Pensées (“Thoughts”) Pascal argued that if God existed and you believed, there was the possibility of infinite gain through eternal salvation. Against this are the finite costs of needlessly living a Christian life if God does not exist. Pascal argued that even if the probability of God’s existence were very small, the potential benefits of faith made the wager that God was real worth it. Pascal’s wager has been criticized on several grounds, but it is clear Pascal took the bet. His burial in Saint-Étienne-du-Mont is marked by a plaque.

 

 

Musée d’Histoire de la Médecine

Of all the stops on my list, one of the most anticipated was the Musée d’Histoire de la Médecine (Museum of the History of Medicine), which is housed at the Université Paris Descartes. The museum has a large collection of antique surgical instruments, and I was particularly interested in seeing the original 1887 painting Une leçon clinique à la Salpêtrière (“A clinical lesson at the Salpêtrière”) by André Brouillet (1857–1914), which hangs in the museum. The large canvas shows neurologist Jean Martin Charcot (1825–1893) demonstrating hypnosis with a famous hysterical patient, Marie “Blanche” Wittman (1859–1915). Many famous physicians of the day are depicted in the painting, most notably Charcot, standing to the left of Wittman, and Georges Gilles de la Tourette, the discoverer of Tourette syndrome, seated to Charcot’s left, wearing an apron.

 

Following in the footsteps of Franz Mesmer (1734–1813), who had previously ignited interest in “animal magnetism” in Paris, Charcot believed that the ability to become hypnotized was an important feature of hysteria (Bogousslavsky et al. 2009). Une leçon clinique à la Salpêtrière is considered one of the most famous paintings in the history of medicine. Sigmund Freud kept a lithograph of it in his office.

Unfortunately, when I arrived at the university in early July, I was informed that the museum was being renovated and would not reopen until August. A missed connection. I was able to tour the grand lobby of the university building, which is lined with busts of famous faculty members, and among those in attendance was a bust of the great anatomist and anthropologist Paul Broca (1824–1880). Broca made many medical discoveries and innovations, but he is most famous for identifying an area on the left frontal lobe, now called Broca’s area, that is associated with speech production. People with damage to Broca’s area understand language but have profound difficulties in forming meaningful words and sentences (Larson 2011).

Despite his many contributions, Broca’s image is tarnished by his promotion of a number of racist theories of human differences. He promoted the view that human ethnic and racial groups rose independently and did not share a common ancestry. He also engaged in comparative studies of skulls in an effort to find measurements that were correlated with intelligence and race (Gould 1996).

 

 

Père Lachaise Cemetery

Père Lachaise is the most famous cemetery in Paris, and it is a popular stop for pilgrims visiting the graves of Jim Morrison, lead singer of the 1960s rock group The Doors, or the writers Gertrude Stein, Alice B. Toklas, Oscar Wilde, or Richard Wright. Because, by coincidence, the day I visited was the fiftieth anniversary of Morrison’s death, there was a gaggle of baby boomers gathered around his gravesite burning incense and singing Doors songs. However, my most important stop was another grave just a stone’s throw away.

Sophie Germain (1776–1831) was a remarkable French mathematician, as much for the obstacles she overcame to become a mathematician as for her mathematical achievements, which were considerable (Musielak 2020). Germain was the daughter of a wealthy Parisian merchant who was politically active in the years preceding the French Revolution, having been elected a representative of the Third Estate (the proletariat or common people). Violence broke out in the summer of 1792, and when the new republic started beheading members of the old monarchy, Sophie’s family lived just five hundred meters from the guillotine. Sophie took refuge in her father’s library, where her interest in mathematics was ignited by reading the story of Archimedes. Because mathematics was not considered an appropriate vocation for women, Germain suffered resistance, even from within her own family, and her education would be largely self-guided.

 

 

After the Reign of Terror ended, the L’Ecole Polytechnique opened in Paris in 1794, but Germain was barred from attending because she was a woman. However, at that time, lecture notes (cahiers) were published, and as a result, she was able to use them to study. According to legend, Germain submitted problem solutions to one of the professors, the great mathematician Joseph-Louis Lagrange, under the assumed name Monsieur Le Blanc. Lagrange eventually demanded an audience with the brilliant M. Le Blanc, and Germain was forced to reveal herself. But Lagrange was delighted to meet her and went on to become her mentor and friend.

Because she was a woman, Germain never got a degree or held an academic position and remained an independent, largely self-taught student her entire life. Eventually, though, she became known by her own name in the mathematical community. In 1816, she won the Institut de France prize for her theory of vibration of curved and elastic surfaces—the first woman to do so—and she also contributed foundational work toward a proof of Fermat’s Last Theorem. The German mathematician Carl Friedrich Gauss, with whom Germain corresponded, recommended her for an honorary degree from the University of Götteningen, but she succumbed to breast cancer in 1831 before the award could be arranged.

Germain continued to suffer indignities after her death. When the Eiffel Tower was constructed in 1887–1889, Gustave Eiffel engraved the names of seventy-two French scientists around the base. All of them were men. Although Germain’s work in elasticity was necessary for the construction of the tower, her name was omitted (Gray 1987). It is assumed by many that, once again, she was excluded on the basis of her sex.

When I visited her grave, which was quite difficult to find, I discovered that there was a large tree growing out of it. There is a plaque mounted on her gravestone, awarded by the students of a girls school named in her honor, but it was difficult to get a good look at the stone due to the tree.

 

 

I visited two other notable graves in Père Lachaise. Samuel Hahnemann (1755–1843), the inventor of the now discredited medical theory homeopathy, was living in Paris at the end of his life, and he is interred in a large monument/mausoleum on the side of a hill. Upon his death in 1843, his wife, Melanie Hahnemann, kept his burial a secret and had him buried in a simple grave in Montmartre Cemetery in Paris. When she died in 1878, her body was placed next to his. Near the end of the nineteenth century, an international group of homeopathic physicians arranged for both Hahnemanns to be exhumed and reburied in the far more prestigious Père Lachaise Cemetery under a very large monument (Arora 2020).

 

 

Also at Père Lachaise is the grave of the French physiologist Claude Bernard, who championed experimentation in medicine and, recognizing the danger of scientists who have a stake in the outcome recording their own data, introduced the concept of blind testing in experiments (Daston 2005). Bernard also did foundational work on the internal environment of organisms that paved the way for Walter Cannon’s introduction of the concept of homeostasis.

 

 

Montparnasse Cemetery

The Montparnasse cemetery is the second most famous in Paris. It’s smaller than Père Lachaise but also very beautiful. It is known for containing the graves of American actress Jean Seberg, poet Charles Baudelaire, playwrights Samuel Becket and Eugene Ionesco, and philosophers Jean-Paul Sartre and Simone de Beauvoir.

In addition, several important French mathematicians and scientists are buried there, among them Henri Poincaré (1854–1912), the brilliant mathematician who made contributions to many areas of pure and applied mathematics (Verhulst 2005). He is most remembered for Poincaré’s conjecture, published in a 1904 paper, which proposed that, “Every simply connected, closed 3-manifold is homeomorphic to the 3-sphere.” (I don’t understand it either.)

Although the conjecture inspired considerable effort on the part of mathematicians all over the world, almost a century elapsed before a reclusive Russian, Grigori Perelman, posted a solution that was later credited with proving the conjecture, now a theorem. For his work on the Poincaré conjecture, Perelman was awarded the Fields Medal and the Millennium Prize, both of which he declined.

In his day, Poincaré was a public figure who often made himself available to journalists, and he injected himself into the famous Dreyfus Affair. In 1894, Alfred Dreyfus, a Jewish army officer, was falsely accused of being a spy for Germany. Due, in part, to the public controversy created by this episode, Dreyfus was awarded a second trial in 1899, at which pseudoscientific graphology and a dubious probability analysis were offered as evidence against him. In response, Poincaré wrote a letter commenting on this evidence, which was read in court. It included the following passage:

 

Nothing in it has any scientific character. I do not know if the defendant will be sentenced, but if he is, it must be on other evidence. It is impossible that such an argument makes any impression on free-minded people who have received a solid scientific education. (Verhulst 2005, 1042)

 

Unfortunately, Dreyfus was convicted a second time, and he would not be fully exonerated and restored to military rank until 1906.

The previously mentioned anatomist and anthropologist Paul Broca is buried in Montparnasse Cemetery, as is the great French sociologist, Émile Durkheim. Durkheim is considered a founder of sociology who wrote important works on suicide and the sociology of religion.

 

 

Random Encounter—Georgiana Houghton

As part of my tourism in Paris, I visited the art museum at the Centre Pompidou, and as luck would have it, there was an exhibition titled “Women in Abstraction,” which highlighted relatively unsung women pioneers of abstract art. Among the featured artists was Georgiana Houghton (1814–1884)—British, not French—who was a spirit medium and who painted “automatically.” During the nineteenth century, women were subjected to prejudice and disenfranchisement, but they were afforded relatively high status in certain activities, including the reform movements (e.g., temperance and suffrage) and spiritualism. Many nineteenth-century mediums were women, and Houghton fell into this group.

In addition to creating her spiritualism-inspired artwork, she was a proponent of spirit photography and near the end of her life published a book on the subject: Chronicles of the Photographs of Spiritual Beings and Phenomena Invisible to the Material Eye (Houghton 1882). Spiritualist or not, her paintings and drawings were quite beautiful. “Women in Abstraction” continues at the Pompidou through August 23, 2021.

 

 

Le Musée Pasteur

One of the greatest of all French scientists was Louis Pasteur, whom we all know for the anti-bacterial process, pasteurization, that bears his name. Fewer people know that, appropriate to his nationality, Pasteur first developed the process as a protection against “diseases” of wine. Later it was extended to many other spoilable foods.

Pasteur also made enormously important discoveries in the development of vaccines (Bowden et al. 2003). In 1881, he demonstrated that inoculating sheep with two doses of a weakened anthrax bacilli could protect them from anthrax. This work led directly to his development of a lifesaving vaccine for rabies.

Pasteur founded L’Institut Pasteur, which continues as a research facility in Paris. It houses, in the apartment that Pasteur occupied during the last seven years of his life, the Le Musée Pasteur, which contains many of his laboratory instruments. Unfortunately for this tourist, like the Musée d’Histoire de la Médecine, the Pasteur museum was closed for renovations when I was in town. I will definitely put this on the list for a future trip.

If you have a trip to Paris in your future, you will undoubtedly want to go to all the usual places, but if you find science and a little bit of pseudoscience intriguing, Paris will not disappoint.

References

Arora, Yashika. 2020. Tribute to Master Samuel Hahnemann on his death anniversary. Homeopathy360 (July 2). Available online at https://www.homeopathy360.com/2020/07/02/tribute-to-master-samuel-hahnemann-on-his-death-anniversary/.

Bogousslavsky, Julien, Olivier Walusinski, and Denis Veyrunes. 2009. Crime, hysteria and belle époque hypnotism: The path traced by Jean-Martin Charcot and Georges Gilles de La Tourette. European Neurology 62(4): 193–99.

Bowden, Mary Ellen, Amy Beth Crow, and Tracy Sullivan. 2003. Pharmaceutical Achievers: The Human Face of Pharmaceutical Research. Philadelphia, PA: Chemical Heritage Press.

Daston, Lorraine. 2005. Scientific error and the ethos of belief. Social Research 72(1): 1–28.

Gould, Stephen Jay. 1996. The Mismeasure of Man (2nd ed). New York, NY: WW Norton.

Gray, Mary. 1987. Sophie Germain (1776–1831). In Louise S. Grinstein and Paul Campbell (eds.). Women of Mathematics: A Bibliographic Sourcebook. New York, NY: Greenwood Press, 47–55.

Houghton, Georgiana. 1882. Chronicles of the Photographs of Spiritual Beings and Phenomena Invisible to the Material Eye. London, United Kingdom: E. W. Allen.

Larson, Michael J. 2011. Broca, Pierre Paul (1824–1880). In Jeffrey S. Kreutzer, John DeLuca, and Bruce Caplan (eds.) Encyclopedia of Clinical Neuropsychology. New York, NY: Springer, 453–457.

Musielak, Dora. 2020. Sophie Germain: Revolutionary Mathematician (2nd ed.). Cham, Switzerland: Springer.

Ross, John F. 2004. Pascal’s legacy. EMBO Reports 5: S5–10.

Verhulst, Ferdinand. 2005. Henri Poincaré: A scientific biography. Notices of the AMS 52(9): 1036–44.