Nicolas Fatio de Duillier

Nicolas Fatio de Duillier was a Swiss mathematician, astronomer, and natural philosopher, best known for his close collaboration with Isaac Newton and his innovative, though ultimately flawed, theory on the origin of the zodiacal light. A brilliant but erratic figure, his career was marked by significant early promise in the Republic of Letters, intense personal relationships within the Royal Society, and a later descent into religious controversy. His life bridges the Scientific Revolution and the fervent millenarianism of the early 18th century.

Early life and education

Born into a prominent family in Basel, Fatio was a child prodigy who published his first mathematical work at age fourteen. He traveled to Paris in 1682, where he was introduced to the leading intellectual circles of the French Academy of Sciences and formed a significant friendship with the renowned Dutch physicist Christiaan Huygens. Under Huygens's mentorship, Fatio engaged with cutting-edge problems in mechanics and optics, including debates over the nature of light and gravity. His early work on the cycloid and contributions to the study of isochronous curves demonstrated considerable talent, earning him recognition from eminent figures like John Wallis at the University of Oxford.

Relationship with Isaac Newton

Fatio moved to London in 1687 and quickly became an intimate friend and fervent supporter of Isaac Newton, following the publication of Newton's seminal work, Philosophiæ Naturalis Principia Mathematica. He assisted Newton in his priority dispute with Gottfried Wilhelm Leibniz over the invention of calculus, and their correspondence reveals a period of intense emotional and intellectual closeness. Fatio proposed a collaborative revision of the Principia and was considered by some contemporaries, including Edmond Halley, to be Newton's most likely successor. However, the relationship cooled after 1693, a period coinciding with Newton's nervous breakdown, though the precise reasons remain a subject of scholarly debate.

Scientific contributions and theories

Beyond his association with Newton, Fatio made several independent scientific proposals. He developed an early kinetic theory of gravity, suggesting it was caused by a flux of minute particles, an idea that later influenced the gravitational theories of Georges-Louis Le Sage. In mathematics, he devised an original method for calculating pi and worked on problems related to geodesics. He also engaged in practical projects, including an ambitious but failed scheme to determine longitude at sea using precise celestial timekeepers, a problem that occupied many scientists of the era, including John Harrison.

The Zodiac light hypothesis

Fatio's most famous and controversial scientific contribution was his 1684 hypothesis explaining the zodiacal light. He proposed that this faint, diffuse glow in the night sky was caused by sunlight reflecting from a vast cloud of small particles surrounding the Sun, a ring analogous to the rings of Saturn but on a solar scale. While prescient in its basic mechanical model, his theory was attacked by contemporaries like Edmond Halley and Jacques Cassini, who argued it was incompatible with Keplerian orbital dynamics. Despite its rejection, Fatio's model is now recognized as a precursor to the modern understanding of the zodiacal cloud and the interplanetary dust cloud.

Later life and religious pursuits

After the zenith of his scientific career, Fatio became deeply involved with the French Prophets (or Camisards), a group of Huguenot millenarians exiled in London. He became their chief theological defender and publicist, authoring tracts that led to his conviction for sedition and his punishment in the pillory in 1707. This association effectively ended his standing within mainstream scientific institutions like the Royal Society. He spent his later decades in relative obscurity, working as a private tutor and continuing to write on eschatology, biblical chronology, and his own interpretations of prophecy until his death in Worcester.

Category:1664 births Category:1753 deaths Category:Swiss mathematicians Category:Swiss astronomers Category:People from Basel