Isaac Newton

Early life and the Woolsthorpe years

Isaac Newton was born on Christmas Day 1642 (January 4, 1643 in the modern Gregorian calendar) at Woolsthorpe Manor in Lincolnshire, England. His father, also named Isaac Newton, had died three months before his birth. His mother Hannah remarried when Isaac was 3 and left him with his maternal grandmother until he was 11.

Newton attended the King's School in Grantham from about age 12. His school record was not particularly distinguished - he is reported to have been initially poor at academic work and to have improved substantially after a physical confrontation with a top-ranked classmate. The early-improvement story is from Newton's own much-later recollection and is variously interpreted in biographies.

In 1661 Newton entered Trinity College, Cambridge, where he had to work as a sizar (a poor student who paid lower fees in exchange for service to wealthier students) for his first years. He took his bachelor's degree in 1665. He remained at Cambridge for most of his subsequent life, becoming Lucasian Professor of Mathematics in 1669 at age 26.

The annus mirabilis (1665-1666) and the early discoveries

In 1665-1666 Cambridge was closed because of the Great Plague of London. Newton returned to Woolsthorpe Manor for approximately 18 months. He later described this period as one of extraordinary intellectual productivity - he developed early versions of his calculus (which he called the "method of fluxions"), his theory of universal gravitation, and significant parts of his work on optics and the composition of white light.

The famous apple story - that Newton was prompted to the theory of gravitation by watching an apple fall in his mother's orchard at Woolsthorpe - is partly historical and partly anecdotal. Newton himself told the story late in life. The orchard at Woolsthorpe is preserved and the apple tree (or its descendant) is still visible. The story's value is more pedagogical than historical: gravitation was not deduced from a single apple but from sustained engagement with planetary-orbit problems.

Newton did not publish most of his Woolsthorpe-era work for decades. The calculus was not published in any form until 1693 and not in a complete form until 1736. His delay in publication contributed to a long and ugly priority dispute with Leibniz, who had independently developed calculus and published his version first (in 1684).

The Principia (1687)

The Principia Mathematica was published in 1687. Newton wrote it at the urging of Edmond Halley, who had visited Newton in Cambridge in 1684 to ask about the orbital paths that would result from an inverse-square gravitational force. Newton answered immediately that the answer was an ellipse, then went to his papers to find his earlier derivation. Halley financed the publication of the resulting book.

The Principia presents the three laws of motion, the law of universal gravitation, the derivation of Kepler's planetary-orbit laws from the inverse-square force, the orbit of the Moon, the tides, and a substantial mathematical apparatus that influenced 18th-century physics for the following century. The book is dense, written in Latin, and uses a geometric-style derivation that is harder to read than the later calculus-based reformulations. It is nonetheless among the most consequential single books in the history of science.

The Principia produced for Newton an enormous reputation across Europe within his lifetime. He was elected President of the Royal Society in 1703 and held the position for 24 years until his death. He was knighted in 1705, the first scientist to be knighted in this way.

The Master of the Royal Mint years

In 1696 Newton accepted the position of Warden of the Royal Mint, and in 1699 he was promoted to Master of the Mint. The position was originally seen as a comfortable patronage role rewarding his scientific reputation. Newton turned it into a substantive administrative job.

He oversaw the Great Recoinage of 1696, in which the existing silver coinage (heavily clipped and degraded) was replaced. He prosecuted counterfeiters - sending several to the gallows - and developed an unusually successful intelligence network for investigating counterfeiting cases. His Mint correspondence reveals a side of Newton not usually emphasized in popular accounts: a meticulous, sometimes vindictive administrator who took the prosecution work personally.

The Mint position paid substantially better than the Lucasian professorship. Newton retained both positions for some years but became increasingly Mint-focused. By the time he died in 1727 he was a wealthy man by 18th-century standards, with significant property and investments in addition to his Mint salary.

Alchemy, theology, and the Cox estimate problem

Newton's surviving manuscripts include enormous quantities of alchemical and theological writing - more than his published scientific writing by some estimates. He spent decades on alchemical experiments and on attempts to decode the dating of Old Testament prophecies. The alchemical work has been variously characterized in modern history-of-science writing: some see it as the rational pursuit of natural philosophy by the standards of his time, others see it as a substantial divergence from his scientific work.

His theological writing was unorthodox - he was Arian (rejecting the Trinity) and would not have qualified for ordination, a problem he managed at Cambridge by securing a special exemption from the standard requirement that Lucasian Professors take holy orders. His theological views were kept private during his lifetime; their disclosure after his death generated controversy in the 18th-century Anglican establishment.

The Cox estimate problem with Newton illustrates the central methodological challenge of the entire 1926 study. Newton's childhood was poorly documented - he was a rural-Lincolnshire farm boy whose mother could barely read. By Cox's method this gave him a childhood-records estimate of 130. His adult achievements were enormous; Cox's adult-corrected estimate was 190. The 60-point difference is not a measurement of anything - it is an artifact of the documentation available about Newton's childhood, which had nothing to do with his actual childhood cognitive ability.

Timeline

• 1643Born at Woolsthorpe Manor, Lincolnshire (December 25, 1642 Julian).
• 1661Enters Trinity College, Cambridge, as a sizar.
• 1665Bachelor's degree. Cambridge closes due to Great Plague.
• 1666Annus mirabilis at Woolsthorpe: calculus, optics, gravitation work begins.
• 1669Lucasian Professor of Mathematics at Cambridge at age 26.
• 1672Elected Fellow of the Royal Society.
• 1687Publishes Philosophiæ Naturalis Principia Mathematica.
• 1696Warden of the Royal Mint.
• 1699Master of the Royal Mint.
• 1703President of the Royal Society.
• 1704Publishes Opticks.
• 1705Knighted by Queen Anne.
• 1727Dies in Kensington at age 84. Buried in Westminster Abbey.
• 1926Cox estimates childhood IQ at 130, adult-corrected at 190.

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