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Newton
Newton's picture and work
Newton, Sir Isaac (1643-1727), English
mathematician and physicist, considered one of the greatest
scientists in history, who made important contributions to many
fields of science. His discoveries and theories laid the
foundation for much of the progress in science since his time.
Newton was one of the inventors of the branch of mathematics
called calculus (the other was German mathematician Gottfried
Wilhelm Leibniz). He also solved the mysteries of light and
optics, formulated the three laws of motion, and derived from
them the law of universal gravitation.
Newton was born on January 4, 1643, at Woolsthorpe, near Grantham
in Lincolnshire. When he was three years old, his widowed mother
remarried, leaving him in the care of his grandmother. Eventually
his mother, by then widowed a second time, was persuaded to send
him to grammar school in Grantham. Later, in the summer of 1661,
he was sent to Trinity College, at the University of Cambridge.
Newton received his bachelor's degree in
1665. After an intermission of nearly two years to avoid the
plague, Newton returned to Trinity, which elected him to a
fellowship in 1667. He received his master's degree in 1668.
Newton ignored much of the established curriculum of the
university to pursue his own interests: mathematics and natural
philosophy. Proceeding entirely on his own, he investigated the
latest developments in mathematics and the new natural philosophy
that treated nature as a complicated machine. Almost immediately,
he made fundamental discoveries that were instrumental in his
career in science.
Newton's first achievement was in mathematics. He generalized the
methods that were being used to draw tangents to curves and to
calculate the area swept by curves, and he recognized that the
two procedures were inverse operations. By joining them in what
he called the fluxional method, Newton developed in the autumn of
1666 a kind of mathematics that is now known as calculus.
Calculus was a new and powerful method that carried modern
mathematics above the level of Greek geometry.
Although Newton was its inventor, he did
not introduce calculus into European mathematics. In 1675 Leibniz
arrived independently at virtually the same method, which he
called differential calculus. Leibniz proceeded to publish his
method and received sole credit for its invention until Newton
published a detailed exposition of his fluxional method in 1704.
Always fearful of publication and criticism, Newton kept his
discovery to himself. However, enough was known of his abilities
to effect his appointment in 1669 as Lucasian Professor of
Mathematics at the University of Cambridge.
Optics was another area of Newton's early interests. In trying to
explain how colors occur, he arrived at the idea that sunlight is
a heterogeneous blend of different rays—each of which
represents a different color—and that reflections and
refractions cause colors to appear by separating the blend into
its components. Newton demonstrated his theory of colors by
passing a beam of sunlight through a type of prism, which split
the beam into separate colors.
In 1672 Newton sent a brief exposition
of his theory of colors to the Royal Society in London. Its
appearance in the Royal Society's Philosophical Transactions led
to a number of criticisms that confirmed his fear of publication,
and he subsequently withdrew as much as possible into the
solitude of his Cambridge study. In 1704, however, Newton
published Opticks, which explained his theories in detail.
In August 1684 Newton's solitude was interrupted by a visit from
Edmund Halley, the British astronomer and mathematician, who
discussed with Newton the problem of orbital motion. Newton had
also pursued the science of mechanics as an undergraduate, and at
that time he had already entertained basic notions about
universal gravitation. As a result of Halley's visit, Newton
returned to these studies.
During the following two and a half
years, Newton established the modern science of dynamics by
formulating his three laws of motion. Newton applied these laws
to Kepler's laws of orbital motion—formulated by the German
astronomer Johannes Kepler—and derived the law of universal
gravitation. Newton is probably best known for discovering
universal gravitation, which explains that all bodies in space
and on earth are affected by the force called gravity. He
published this theory in his book Philosophiae Naturalis
Principia Mathematica in 1687. This book marked a turning point
in the history of science; it also ensured that its author could
never regain his privacy.
The Principia's appearance also involved
Newton in an unpleasant episode with the English philosopher and
physicist Robert Hooke. In 1687 Hooke claimed that Newton had
stolen from him a central idea of the book: that bodies attract
each other with a force that varies inversely as the square of
their distance. However, most historians do not accept Hooke's
charge of plagiarism.
In the same year, 1687, Newton helped
lead Cambridge's resistance to the efforts of King James II to
make the university a Catholic institution. After the English
Revolution in 1688, which drove James from England, the
university elected Newton one of its representatives in a special
convening of the country's parliament. The following four years
were filled with intense activity for Newton, as, buoyed by the
triumph of the Principia, he tried to put all his earlier
achievements into a final written form. In the summer of 1693
Newton showed symptoms of a severe emotional disorder. Although
he regained his health, his creative period had come to an end.
Newton's connections with the leaders of
the new regime in England led to his appointment as warden, and
later master, of the Royal Mint in London, where he lived after
1696. In 1703 the Royal Society elected him president, an office
he held for the rest of his life. As president, he ordered the
immediate publication of the astronomical observations of the
first Astronomer Royal of England, John Flamsteed. Newton needed
these observations to perfect his lunar theory. This matter led
to a difficult conflict with Flamsteed.
Newton also engaged in a violent dispute
with Leibniz over priority in the invention of calculus. Newton
used his position as president of the Royal Society to have a
committee of that body investigate the question, and he secretly
wrote the committee's report, which charged Leibniz with
deliberate plagiarism. Newton also compiled the book of evidence
that the society published. The effects of the quarrel lingered
nearly until his death in 1727.
In addition to science, Newton also
showed an interest in alchemy, mysticism, and theology. Many
pages of his notes and writings—particularly from the later
years of his career—are devoted to these topics. However,
historians have found little connection between these interests
and Newton's scientific work.
( Ptolemy - Copernicus - Kepler - Galileo - Newton )
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