Isaac Newton
Key Facts
- Formule les bases du calcul infinitésimal, de la gravitation universelle et de l'optique lors de la peste de 1665-1666
- Invente le télescope à réflexion en 1668, réduisant les aberrations chromatiques
- Publie les Principia Mathematica en 1687 : trois lois du mouvement + gravitation universelle
- Nommé professeur Lucasian de mathématiques à Cambridge en 1669 (poste de Hawking plus tard)
- Directeur de la Monnaie royale (1696) : réforme le système monétaire britannique
- Anobli par la reine Anne en 1705, premier scientifique à recevoir cet honneur en Grande-Bretagne
Biography
Isaac Newton was born on 4 January 1643 in Woolsthorpe, Lincolnshire, a few months after his father's death. A sickly, premature child, his mother remarried and left him in the care of his grandmother for several years, an absence that lastingly shaped his solitary and introverted character. Admitted to Trinity College, Cambridge, in 1661, he discovered mathematics and natural philosophy there, immersing himself in the works of Descartes, Kepler and Galileo. His thirst to understand natural phenomena from their deepest causes would define his entire career.
During the great plague epidemic of 1665-1666, which closed Cambridge University, Newton retreated to his family farm in Woolsthorpe. These eighteen months of isolation proved extraordinarily fruitful. He laid the foundations of calculus (which he called the "method of fluxions"), formulated his theory of universal gravitation by observing falling objects, and decomposed white light into a spectrum of colours using a prism. The famous anecdote of the apple — which he supposedly saw fall and which led him to reflect on gravitational attraction — dates from this period.
Returning to Cambridge, Newton invented the reflecting telescope (1668), which allowed celestial bodies to be observed without the chromatic aberrations of refractive lenses. He was appointed Lucasian Professor of Mathematics in 1669, a chair previously held by Isaac Barrow and later by Stephen Hawking. In 1687, he published his masterpiece, the Philosophiae Naturalis Principia Mathematica, considered one of the most important books in the history of science. This work formulates the three laws of motion and the law of universal gravitation, providing a unified mathematical framework for describing the motion of planets, the Moon and terrestrial objects.
Newton also played a prominent public role. Appointed Warden of the Royal Mint in 1696, he applied the same rigour to reforming the British monetary system and combating counterfeiting. Elected President of the Royal Society in 1703, he became the supreme arbiter of British science. In 1705, Queen Anne knighted him — a rare honour for a scientist at the time. However, his rivalry with Leibniz over the authorship of calculus embittered the final decades of his life.
Isaac Newton died on 31 March 1727 in London. His worldview, known as "Newtonian mechanics", dominated physics for more than two centuries and remains valid for the vast majority of phenomena at the human scale. It was only amended with Einstein's relativity and quantum mechanics in the twentieth century. Newton himself modestly summarised his approach with the words: "If I have seen further, it is by standing on the shoulders of giants."