Newton, Isaac (1642-1727)

In about 1670 Isaac Newton constructed the first reflecting telescope, which uses a concave mirror to collect and focus incoming light.

A portrait of the English physicist and mathematician Isaac Newton, painted before the end of the 17th century. From 1665 to 1666, when he was 23, Newton stayed at home to avoid an outbreak of plague; during that year he is believed to have formulated many of his most important ideas.

English physicist and mathematician who laid the foundations of physics as a modern discipline. During 1665-66, he discovered the binomial theorem, differential and integral calculus, and that white light is composed of many colours. He developed the three standard laws of motion (Newton's laws of motion) and the universal law of gravitation, set out in Philosophiae naturalis principia mathematica (1687), usually referred to as the Principia. He was knighted for his work in 1705.

Newton's greatest achievement was to demonstrate that scientific principles are of universal application. Using these principles, scientists could predict the results of their experiments when carried out in controlled conditions, enabling the more rapid development of new ideas. He clearly defined the nature of mass, weight, force, inertia, and acceleration.

In 1679 Newton calculated the Moon's motion on the basis of his theory of gravity and also found that his theory explained how the planets, including the Earth, orbited the Sun. The laws of planetary motion had been worked out by German astronomer Johannes Kepler on the basis of observations of the planets; Newton provided the scientific evidence to back up Kepler's theory.

Newton's universal law of gravitation states: ‘Every particle of matter in the universe attracts every other particle with a force whose direction is that of the joining of the two, and whose magnitude is directly as [proportional to] the product of the masses, and inversely as [proportional to] the square of their distance from each other.’

Newton was born at Woolsthorpe Manor, Lincolnshire, and studied at Cambridge, where he became professor at the age of 26. He resisted James II's attacks on the freedoms and independence of the universities and was elected to one of the two seats in the House of Commons controlled by the University of Cambridge, sitting in the parliaments of 1689 and 1701-02 as a Whig. Newton was a major figure in British public life by this stage, combining his groundbreaking scientific work with a political career. He was famous throughout Europe as a mathematician, and took part in discussions and debates with mathematicians from all over the continent. Appointed warden of the Royal Mint in 1696, and master in 1699, he organized a reform of the coins issued by the British government. Most of the last 30 years of his life were taken up by studies of theology and chronology, and experiments in alchemy. Although Newton's work challenged traditional religious belief regarding the workings of the universe, he was deeply religious, believing that his scientific discoveries simply showed the power and complexity of God's creation.

In 1703 Newton was elected president of the Royal Society, a position that reflected his status as the leading mathematician and scientist of his age, and which he held until his death in 1727. In 1705 Newton became the first scientist to be rewarded with a knighthood for his scientific work.

Newton and German mathematician Gottfried Leibniz worked independently on the development of a differential calculus, both making significant advances, but Newton claimed to be its sole inventor. When Leibniz appealed to the Royal Society for a fair hearing, Newton appointed a committee of his own supporters and even wrote their report himself. The result of this controversy was to isolate English mathematics and to set it back many years, for it was Leibniz's terminology that came to be used in the rest of Europe. A similar dispute arose between Newton and English scientist Robert Hooke, who claimed prior discovery of the inverse square law of gravitation.

Newton began to investigate the phenomenon of gravitation in 1665, inspired, legend has it, by seeing an apple fall from a tree - he sought successfully to explain why this happened. At the same time Newton was also active in algebra and number theory, classical and analytical geometry, computation, approximation, and even probability.

One result of his experiments with light and prisms was the development of the reflecting telescope. Newton investigated many other optical phenomena, including thin-film interference effects, one of which, Newton's rings, is named after him.

De motu corporum in gyrum/On the Motion of Bodies in Orbit was written in 1684. The publication of the Principia was financed by his friend Edmond Halley. In 1704 Newton summed up his life's work on light in Opticks.

Newton research into mathematical rules and physical processes, and his creation of new experiments and scientific apparatus, helped him to make discoveries that drastically changed the way that scientists understood the world.

Newton, Isaac (1800-1867)

US agriculturalist. Born in Burlington County, New Jersey, by his mid-20s he was managing two farms in Springfield, Pennsylvania, so successfully that he opened a confectionery shop and sold ice cream made from his dairy surplus. Active in the state and national Agricultural Society, he urged Congress to establish a department of agriculture. In 1861 President Lincoln appointed him supervisor of the agricultural division of the Patent Office. In 1862 Congress created the Department of Agriculture with Newton as its first commissioner. In his annual reports he emphasized the importance of weather and climate to agriculture. He died from the effects of a sunstroke he received while working in the department's experimental field.