Sir Isaac Newton was an English physicist, mathematician, astronomer, natural philosopher, alchemist and theologian.
His Philosophiæ Naturalis Principia Mathematica, published in 1687, is said to be the greatest single work in the history of science.
In this work, Newton described universal gravitation and the three laws of motion, laying the groundwork for classical mechanics, which dominated the scientific view of the physical universe for the next three centuries and is the basis for modern engineering.
Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws by demonstrating the consistency between Kepler's laws of planetary motion and his theory of gravitation,
thus removing the last doubts about heliocentrism and advancing the scientific revolution.
In mechanics, Newton enunciated the principles of conservation of momentum and angular momentum.
In optics, he invented the reflecting telescope and developed a theory of colour based on the observation that a prism decomposes white light into a visible spectrum.
He also formulated an empirical law of cooling and studied the speed of sound.
In mathematics, Newton shares the credit with Gottfried Leibniz for the development of calculus.
He also demonstrated the generalized binomial theorem, developed the so-called Newton's method for approximating the zeroes of a function,
and contributed to the study of power series.
In a 2005 poll of the Royal Society of who had the greatest effect on the history of science,
Newton was deemed much more influential than Albert Einstein.
Mechanics and gravitation
Newton's own copy of his Principia, with hand-written corrections for the second edition.Further information: Writing of Principia Mathematica In 1677, Newton returned to his work on mechanics, i.e., gravitation and its effect on the orbits of planets, with reference to Kepler's laws of planetary motion, and consulting with Hooke and Flamsteed on the subject. He published his results in De motu corporum in gyrum (1684). This contained the beginnings of the laws of motion that would inform the Principia.
The Philosophiae Naturalis Principia Mathematica (now known as the Principia) was published on 5 July 1687 with encouragement and financial help from Edmond Halley. In this work Newton stated the three universal laws of motion that were not to be improved upon for more than two hundred years.
He used the Latin word gravitas (weight) for the effect that would become known as gravity, and defined the law of universal gravitation. In the same work he presented the first analytical determination, based on Boyle's law, of the speed of sound in air.
With the Principia, Newton became internationally recognized. He acquired a circle of admirers, including the Swiss-born mathematician Nicolas Fatio de Duillier, with whom he formed an intense relationship that lasted until 1693. The end of this friendship led Newton to a nervous breakdown.