Physicist and mathematician, b. 4 January 1643 (25 December 1642*) (Woolsthorpe, England), d. 31 March (20 March*) 1727 (London).
Newton's father Isaac died three months before young Isaac was born. Less than two years later his mother Hannah Ayscough remarried and consented to her new husband's wish to send Isaac to his grandmother, where he lived for the next nine years. This difficult childhood has been taken as an explanation for Newton's volatile and psychotic character.
In 1661 Newton entered Trinity College of Cambridge University, which was still the bastion of Aristotelian teaching; students discussed Kepler's proposition that the Earth was not the centre of the universe but revolves around the Sun and Galilei's idea that mathematics can be a powerful tool for the study of nature in the corridors but did hear nothing about them in class.
When Newton received his batchelor's degree in 1665 he had learned everything about the new sciences, but it was all entirely self-taught in his spare time. He had read Descartes' La Geéometrie and followed up every lead. His notes showed the subtitle Amicus Plato amicus Aristoteles magis amica veritas "Plato is my friend, Aristotle is my friend, my best friend is thruth").
The university closed in 1665 because of a plague epidemic, and Newton returned home to contemplate what he had read. He discovered the binomial theorem and developed the mathematical method of converging infinite series that formes the basis of calculus, which he published in 1669 as De Analysi per Aequationes Numeri Terminorum Infinitas (On Analysis by Infinite Series).
The university reopened in 1667, and Newton was elected a Fellow of Trinity College. In 1669 he became Professor of Mathematics. During the following years he developed a theory of light based on Descartes' proposition that light is motion transmitted through a medium. Through experiment he showed that white light is composed of all colours.
In about 1679 Newton had changed his perception of nature, which to that point was based on the idea of an ether as transmitter of all action, and accepted the idea of attractive and repulsive forces. This allowed him to make the most groundbreaking discoveries now known as Newton's Laws. Expressed in modern terms the three laws are
Newton combined his laws with Kepler's third law and in 1684 arrived at the Universal Law of Gravitation and used it to correctly explain phenomena such as the orbits of comets, ocean tides and others. His work Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), published in 1687, is one of the most important works of modern science.
In 1696 Newton was appointed warden of the mint and moved to London in 1701, ending his scientific work. He concentrated on bringing counterfeiters to justice and developed an interest in religion. The French Académie des Sciences (Academy of Sciences) made him a foreign associate in 1701, and in 1703 Newton became president of the Royal Society in London. He was knighted in 1705.
Newton had extensive correspondence with other scientists. His letters show him as a man unable to tolerate the slightest criticism. His response was always beyond the normal, full of innuendo and rage, trying to humiliate and destroy.
For some time this could be seen as a personal shortcoming that did not affect Newton's position as a scientist. But Leibnitz had developed the method of calculus independently in Germany and had published it in 1684, before Newton had developed it from his own work. The controversy that sprang from the question of priority showed Newton breaking the norms of science on more than one occasion. He wrote texts in his defence and published them under the names of his students. As president of the Royal Society he appointed a committee to investigate the controversy, wrote the committee's report himself and reviewed it anonymously in the Philosophical Transactions.
It is a testament to the groundbreaking importance of his work that the scientific world still keeps Newton in high regard despite these failings.
* English date of the time. The calendar used in continental Europe did not come into force in England until 1752.