Sir Isaac Newton PRS (/ˈnjuːtən/;[6] 25
December 1642 – 20 March 1726/27[1])
was an English physicist andmathematician (described
in his own day as a "natural philosopher") who is widely
recognised as one of the most influential scientists of all time and a key figure
in the scientific revolution. His book Philosophiæ Naturalis Principia
Mathematica ("Mathematical Principles of Natural
Philosophy"), first published in 1687, laid the foundations for classical mechanics. Newton made seminal
contributions to optics, and he shares credit with Gottfried Wilhelm Leibniz for the
development of calculus.
Newton's Principia formulated
the laws of motion and universal gravitation,
which dominated scientists' view of the physical universe for the next three
centuries. By deriving Kepler's laws of planetary motion from
his mathematical description of gravity, and then using the same principles to
account for the trajectories of comets, the tides, theprecession of
the equinoxes, and other phenomena, Newton removed the last doubts
about the validity of theheliocentric model of the Solar System. This work also
demonstrated that the motion of objects on Earth and ofcelestial bodies could be described by the
same principles. His prediction that Earth should be shaped as an oblate spheroid was
later vindicated by the measurements of Maupertuis, La Condamine, and others, which helped
convince most Continental European scientists of the
superiority of Newtonian mechanics over the earlier system of Descartes.
Newton built the first practical reflecting telescope and developed a theory of colour based
on the observation that aprism decomposes
white light into the many colours of the visible spectrum.
He formulated an empirical law of cooling, studied the speed of sound,
and introduced the notion of a Newtonian fluid.
In addition to his work on calculus, as a mathematician Newton contributed to
the study of power series, generalised the binomial theorem to
non-integer exponents, developed a method for
approximating the roots of a function, and classified most of the cubic plane
curves.
Newton was a fellow of Trinity College and the second Lucasian Professor of Mathematics at
the University of Cambridge. He was a devout
but unorthodox Christian,[7] and,
unusually for a member of the Cambridge faculty of the day, he refused to take holy orders in
the Church of England, perhaps because he privately
rejected the doctrine of theTrinity. Beyond his work on the mathematical sciences, Newton
dedicated much of his time to the study of biblical chronology and alchemy,
but most of his work in those areas remained unpublished until long after his
death. In his later life, Newton became president of the Royal Society.
Newton served the British government as Warden and Master of the Royal Mint.
Life
Early life
Main
article: Early life of Isaac Newton
Isaac Newton was born according to the Julian calendar (in use in England at the time) on
Christmas Day, 25 December 1642 (NS 4
January 1643[1]),
at Woolsthorpe
Manor in Woolsthorpe-by-Colsterworth, a hamlet in the county of Lincolnshire.
His father, also named Isaac Newton, had died three months before. Born prematurely,
he was a small child; his mother Hannah Ayscough reportedly said that he could
have fit inside a quart mug.[8] When Newton was three, his mother
remarried and went to live with her new husband, the Reverend Barnabas Smith,
leaving her son in the care of his maternal grandmother, Margery Ayscough. The
young Isaac disliked his stepfather and maintained some enmity towards his
mother for marrying him, as revealed by this entry in a list of sins committed
up to the age of 19: "Threatening my father and mother Smith to burn them
and the house over them."[9] Newton's mother had three children
from her second marriage.[10]
Newton
in a 1702 portrait by Godfrey Kneller
Isaac
Newton (Bolton, Sarah K. Famous Men of Science. NY: Thomas Y. Crowell &
Co., 1889)
From the age of about twelve until he was seventeen,
Newton was educated at The King's School, Grantham which taught Latin and Greek but no
mathematics. He was removed from school, and by October 1659, he was to be
found at Woolsthorpe-by-Colsterworth, where his
mother, widowed for a second time, attempted to make a farmer of him. Newton
hated farming.[11] Henry Stokes, master at the King's
School, persuaded his mother to send him back to school so that he might
complete his education. Motivated partly by a desire for revenge against a
schoolyard bully, he became the top-ranked student,[12] distinguishing himself mainly by
building sundials and models of windmills.[13]
In June 1661, he was admitted to Trinity College, Cambridge, on the
recommendation of his uncle Rev William Ayscough. He started as a subsizar—paying
his way by performing valet's duties—until he
was awarded a scholarship in 1664, which guaranteed him four more years until
he would get his M.A.[14] At that time, the college's teachings
were based on those of Aristotle,
whom Newton supplemented with modern philosophers such as Descartes,
andastronomers such as Galileo and Thomas Street,
through whom he learned of Kepler's
work. He set down in his notebook a series of 'Quaestiones' about
mechanical philosophy as he found it. In 1665, he discovered the generalisedbinomial theorem and began to develop a mathematical
theory that later became calculus.
Soon after Newton had obtained his B.A. degree in August 1665, the university
temporarily closed as a precaution against the Great Plague. Although he had been
undistinguished as a Cambridge student,[15] Newton's private studies at his home
in Woolsthorpe over the subsequent two years saw the development of his
theories on calculus,[16] optics,
and the law of gravitation.
In April 1667, he returned to Cambridge and in October
was elected as a fellow of Trinity.[17][18] Fellows were required to become
ordained priests, although this was not enforced in the restoration years and
an assertion of conformity to the Church of England was sufficient. However, by
1675 the issue could not be avoided and by then his unconventional views stood in
the way.[19]Nevertheless,
Newton managed to avoid it by means of a special permission from Charles II (see
"Middle years" section below).
His studies had impressed the Lucasian professor, Isaac Barrow,
who was more anxious to develop his own religious and administrative potential
(he became master of Trinity two years later), and in 1669, Newton succeeded
him, only one year after he received his M.A. He was elected a Fellow of the
Royal Society (FRS) in 1672.[5]
Middle years
Mathematics
Newton's work has been said "to distinctly advance
every branch of mathematics then studied".[20] His work on the subject usually
referred to as fluxions or calculus, seen in a manuscript of October 1666, is
now published among Newton's mathematical papers.[21] The author of the manuscript De analysi per
aequationes numero terminorum infinitas, sent by Isaac Barrow to John Collins in June 1669, was identified by Barrow
in a letter sent to Collins in August of that year as:[22]
Mr Newton, a fellow of our College, and very
young ... but of an extraordinary genius and proficiency in these things.
Newton later became involved in a dispute with Leibniz over
priority in the development of calculus (the Leibniz–Newton calculus controversy).
Most modern historians believe that Newton and Leibniz developed calculus independently, although with very
different notations. Occasionally it has been suggested that Newton published
almost nothing about it until 1693, and did not give a full account until 1704,
while Leibniz began publishing a full account of his methods in 1684.
(Leibniz's notation and "differential Method", nowadays recognised as
much more convenient notations, were adopted by continental European
mathematicians, and after 1820 or so, also by British mathematicians.) Such a
suggestion, however, fails to notice the content of calculus which critics of
Newton's time and modern times have pointed out in Book 1 of Newton's Principia itself (published 1687) and in its
forerunner manuscripts, such as De motu corporum in gyrum ("On the motion of bodies in
orbit"), of 1684. The Principia is not written in the language of
calculus either as we know it or as Newton's (later) 'dot' notation would write
it. His work extensively uses calculus in geometric form based on limiting
values of the ratios of vanishing small quantities: in the Principia itself, Newton gave demonstration of
this under the name of 'the method of first and last ratios'[23] and explained why he put his
expositions in this form,[24] remarking also that 'hereby the same
thing is performed as by the method of indivisibles'.
Because of this, the Principia has been called "a book dense
with the theory and application of the infinitesimal calculus" in modern
times[25] and "lequel est presque tout de
ce calcul" ('nearly all of it is of this calculus') in Newton's time.[26] His use of methods involving "one
or more orders of the infinitesimally small" is present in his De motu corporum in gyrum of 1684[27] and in his papers on motion
"during the two decades preceding 1684".[28]
Newton had been reluctant to publish his calculus because
he feared controversy and criticism.[29] He was close to the Swiss
mathematician Nicolas Fatio de
Duillier. In 1691, Duillier started to write a new version of
Newton's Principia, and
corresponded with Leibniz.[30] In 1693, the relationship between
Duillier and Newton deteriorated and the book was never completed.
Starting in 1699, other members of the Royal Society (of which Newton was a member) accused
Leibniz of plagiarism.
The dispute then broke out in full force in 1711 when the Royal Society
proclaimed in a study that it was Newton who was the true discoverer and
labelled Leibniz a fraud. This study was cast into doubt when it was later
found that Newton himself wrote the study's concluding remarks on Leibniz. Thus
began the bitter controversy which marred the lives of both Newton and Leibniz
until the latter's death in 1716.[31]
Newton is generally credited with the generalised binomial theorem, valid for any
exponent. He discovered Newton's identities, Newton's method,
classified cubic plane
curves (polynomials of degree three in two variables), made substantial contributions to
the theory of finite differences, and was the first to use
fractional indices and to employ coordinate geometry to derive solutions to Diophantine equations. He approximated partial
sums of the harmonic series by logarithms (a precursor to Euler's summation formula) and was the
first to use power series with confidence and to revert power
series. Newton's work on infinite series was inspired by Simon Stevin's
decimals.[32] A very useful modern account of
Newton's mathematics was written by the foremost scholar on Newton's
mathematics, D.T. Whiteside or Tom Whiteside.
Tom Whiteside translated and edited all of Newton's mathematical writings and
at the end of his life wrote a summing up of Newton's work and its impact. This
was published in 2013 as a chapter in a book edited by Bechler.[33]
When Newton received his MA and became a Fellow of the
"College of the Holy and Undivided Trinity" in 1667, he made the
commitment that "I will either set Theology as the object of my studies
and will take holy orders when the time prescribed by these statutes [7 years]
arrives, or I will resign from the college."[34] Up till this point he had not thought
much about religion and had twice signed his agreement to the thirty-nine articles, the basis of Church of
England doctrine.
He was appointed Lucasian Professor of Mathematics in 1669 on Barrow's recommendation.
During that time, any Fellow of a college at Cambridge or Oxford was required
to take holy orders and become an ordained Anglican priest. However, the terms of the
Lucasian professorship required that the holder not be active in the church (presumably so
as to have more time for science). Newton argued that this should exempt him
from the ordination requirement, and Charles II, whose permission was needed,
accepted this argument. Thus a conflict between Newton's religious views and
Anglican orthodoxy was averted.[35]
Optics
In 1666, Newton observed that the spectrum of colours
exiting a prism in
the position of minimum
deviation is oblong,
even when the light ray entering the prism is circular, which is to say, the
prism refracts different colours by different angles.[36][37] This led him to conclude that colour
is a property intrinsic to light—a point which had been debated in prior years.
Replica
of Newton's secondReflecting telescope that he presented to the Royal Society in 1672[38]
From 1670 to 1672, Newton lectured on optics.[39] During this period he investigated the refraction of light, demonstrating that the
multicoloured spectrum produced by a prism could be recomposed into white light
by a lens and a second prism.[40]Modern
scholarship has revealed that Newton's analysis and resynthesis of white light
owes a debt to corpuscularalchemy.[41]
He also showed that coloured light does not change its
properties by separating out a coloured beam and shining it on various objects.
Newton noted that regardless of whether it was reflected, scattered, or
transmitted, it remained the same colour. Thus, he observed that colour is the
result of objects interacting with already-coloured light rather than objects
generating the colour themselves. This is known as Newton's theory of colour.[42]
Illustration
of a dispersive prismdecomposing
white light into the colours of the spectrum, as discovered by Newton
From this work, he concluded that the lens of any refracting telescope would suffer from the dispersion of
light into colours (chromatic aberration). As a proof of the
concept, he constructed a telescope using reflective mirrors instead of lenses
as the objective to
bypass that problem.[43][44] Building the design, the first known
functional reflecting telescope, today known as a Newtonian telescope,[44] involved solving the problem of a
suitable mirror material and shaping technique. Newton ground his own mirrors
out of a custom composition of highly reflective speculum metal,
using Newton's rings to judge the quality of
the optics for his telescopes. In late 1668[45] he was able to produce this first reflecting telescope. It was
about eight inches long and it gave a clearer and larger image. In 1671, the
Royal Society asked for a demonstration of his reflecting telescope.[46] Their interest encouraged him to
publish his notes, Of Colours,[47] which he later expanded into the workOpticks.
When Robert Hooke criticised some of Newton's ideas,
Newton was so offended that he withdrew from public debate. Newton and Hooke
had brief exchanges in 1679–80, when Hooke, appointed to manage the Royal
Society's correspondence, opened up a correspondence intended to elicit
contributions from Newton to Royal Society transactions,[48] which had the effect of stimulating
Newton to work out a proof that the elliptical form of planetary orbits would
result from a centripetal force inversely proportional to the square of the
radius vector (see Newton's law of universal gravitation
– History and De motu corporum in gyrum). But the
two men remained generally on poor terms until Hooke's death.[49]
Facsimile
of a 1682 letter from Isaac Newton to Dr William Briggs, commenting on Briggs'
"A New Theory of Vision"
Newton argued that light is composed of particles or
corpuscles, which were refracted by accelerating into a denser medium. He
verged on soundlike waves to explain the repeated pattern of reflection and
transmission by thin films (Opticks Bk.II, Props. 12), but still retained his
theory of 'fits' that disposed corpuscles to be reflected or transmitted
(Props.13). However, later physicists favoured a purely wavelike explanation of
light to account for the interference patterns and the general phenomenon of diffraction.
Today's quantum
mechanics, photons,
and the idea of wave–particle duality bear only a minor resemblance to
Newton's understanding of light.
In his Hypothesis
of Light of 1675, Newton posited the existence of the ether to
transmit forces between particles. The contact with the theosophist Henry More,
revived his interest in alchemy.[50] He replaced the ether with occult
forces based on Hermetic ideas of attraction and repulsion
between particles. John Maynard Keynes, who acquired many of
Newton's writings on alchemy, stated that "Newton was not the first of the
age of reason: He was the last of the magicians."[51]Newton's
interest in alchemy cannot be isolated from his contributions to science.[50] This was at a time when there was no
clear distinction between alchemy and science. Had he not relied on the occult idea of action at a distance, across a vacuum, he
might not have developed his theory of gravity. (See also Isaac Newton's occult studies.)
In 1704, Newton published Opticks,
in which he expounded his corpuscular theory of light. He considered light to
be made up of extremely subtle corpuscles, that ordinary matter was made of
grosser corpuscles and speculated that through a kind of alchemical
transmutation "Are not gross Bodies and Light convertible into one
another, ... and may not Bodies receive much of their Activity from the
Particles of Light which enter their Composition?"[52] Newton also constructed a primitive
form of a frictional electrostatic generator, using a glass
globe.[53]
In an article entitled "Newton, prisms, and the
'opticks' of tunable lasers"[54] it is indicated that Newton in his
book Opticks was the first to show a diagram using
a prism as a beam expander. In the same book he describes, via diagrams, the
use of multiple-prism arrays. Some 278 years after Newton's discussion, multiple-prism beam expanders became central to the development of narrow-linewidth tunable lasers.
Also, the use of these prismatic beam expanders led to the multiple-prism dispersion theory.[54]
Subsequent to Newton, much has been amended. Young and Fresnel combined
Newton's particle theory with Huygens' wave
theory to show that colour is the visible manifestation of light's wavelength.
Science also slowly came to realise the difference between perception of colour
and mathematisable optics. The German poet and scientist, Goethe, could not shake the Newtonian
foundation but "one hole Goethe did find in Newton's armour, ...
Newton had committed himself to the doctrine that refraction without colour was
impossible. He therefore thought that the object-glasses of telescopes must for
ever remain imperfect, achromatism and refraction being incompatible. This
inference was proved by Dollond to be wrong."[55]
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 1679, Newton returned to his work on (celestial) mechanics by considering gravitation
and its effect on the orbits ofplanets with
reference to Kepler's laws of planetary motion. This followed
stimulation by a brief exchange of letters in 1679–80 with Hooke, who had been
appointed to manage the Royal Society's correspondence, and who opened a
correspondence intended to elicit contributions from Newton to Royal Society
transactions.[48] Newton's reawakening interest in
astronomical matters received further stimulus by the appearance of a comet in
the winter of 1680–1681, on which he corresponded with John Flamsteed.[56] After the exchanges with Hooke, Newton
worked out proof that the elliptical form of planetary orbits would result from
a centripetal force inversely proportional to the square of the radius vector
(see Newton's law of universal gravitation
– History and De motu corporum in gyrum).
Newton communicated his results to Edmond Halleyand
to the Royal Society in De motu corporum in gyrum, a tract
written on about nine sheets which was copied into the Royal Society's Register
Book in December 1684.[57] This tract contained the nucleus that
Newton developed and expanded to form the Principia.
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. Together, these
laws describe the relationship between any object, the forces acting upon it
and the resulting motion, laying the foundation for classical mechanics. They contributed to many
advances during the Industrial Revolution which soon followed and were not
improved upon for more than 200 years. Many of these advancements continue to
be the underpinnings of non-relativistic technologies in the modern world. 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, Newton presented a calculus-like method
of geometrical analysis using 'first and last ratios', gave the first
analytical determination (based onBoyle's law)
of the speed of sound in air, inferred the oblateness of Earth's spheroidal
figure, accounted for the precession of the equinoxes as a result of the Moon's
gravitational attraction on the Earth's oblateness, initiated the gravitational
study of the irregularities
in the motion of the moon, provided a theory for the determination
of the orbits of comets, and much more.
Newton made clear his heliocentric view of the Solar System—developed in
a somewhat modern way, because already in the mid-1680s he recognised the
"deviation of the Sun" from the centre of gravity of the Solar System.[58] For Newton, it was not precisely the
centre of the Sun or any other body that could be considered at rest, but
rather "the common centre of gravity of the Earth, the Sun and all the
Planets is to be esteem'd the Centre of the World", and this centre of gravity
"either is at rest or moves uniformly forward in a right line"
(Newton adopted the "at rest" alternative in view of common consent
that the centre, wherever it was, was at rest).[59]
Newton's postulate of an invisible force able to act over vast distances led to him being criticised for
introducing "occult agencies" into science.[60] Later, in the second edition of the Principia (1713), Newton firmly rejected such
criticisms in a concluding General Scholium,
writing that it was enough that the phenomena implied a gravitational
attraction, as they did; but they did not so far indicate its cause, and it was
both unnecessary and improper to frame hypotheses of things that were not
implied by the phenomena. (Here Newton used what became his famous expression "hypotheses non-fingo"[61]).
With the Principia,
Newton became internationally recognised.[62] He acquired a circle of admirers,
including the Swiss-born mathematician Nicolas Fatio de
Duillier.
Classification of
cubics and beyond
Descartes was
the most important early influence on Newton the mathematician. Descartes freed
plane curves from the Greek and Macedonian limitation to conic sections, and
Newton followed his lead by classifying the cubic curves in
the plane. He found 72 of the 78 species of cubics. He also divided
them into four types, satisfying different equations, and in 1717 Stirling, probably with Newton's help,
proved that every cubic was one of these four types. Newton also claimed that
the four types could be obtained by plane projection from one of them, and this
was proved in 1731.[63]
According to Tom Whiteside (1932–2008), who published 8 volumes
of Newton's mathematical papers, it is no exaggeration to say that Newton
mapped out the development of mathematics for the next 200 years, and that Euler and others largely carried out his
plan.[64]
Later life
Isaac
Newton in old age in 1712, portrait by Sir James Thornhill
Main
article: Later life of Isaac Newton
In the 1690s, Newton wrote a number of religious tracts dealing with the literal and symbolic
interpretation of the Bible. A manuscript Newton sent to John Locke in which he disputed the fidelity of 1 John 5:7 and its fidelity to the original
manuscripts of the New Testament, remained unpublished until 1785.[65][66]
Even though a number of authors have claimed that the
work might have been an indication that Newton disputed the belief inTrinity,
others assure that Newton did question the passage but never denied Trinity as
such. His biographer, scientist Sir David Brewster, who compiled his
manuscripts for over 20 years, wrote about the controversy in well-known book Memoirs of the Life, Writings, and
Discoveries of Sir Isaac Newton, where he explains that Newton questioned
the veracity of those passages, but he never denied the doctrine of Trinity as
such. Brewster states that Newton was never known as an Arian during his lifetime, it was firstWilliam Whiston (an Arian) who argued that "Sir
Isaac Newton was so hearty for the Baptists, as well as for the Eusebians or
Arians, that he sometimes suspected these two were the two witnesses in the
Revelations," while other like Hopton Haynes (a Mint employee and Humanitarian),
"mentioned to Richard Baron, that Newton
held the same doctrine as himself".[67]
Later works—The Chronology of Ancient Kingdoms
Amended (1728) and Observations Upon the Prophecies of
Daniel and the Apocalypse of St. John (1733)—were
published after his death. He also devoted a great deal of time to alchemy (see above).
Newton was also a member of the Parliament of England for Cambridge
University in 1689–90
and 1701–2, but according to some accounts his only comments were to complain
about a cold draught in the chamber and request that the window be closed.[68][69][70]
Newton moved to London to take up the post of warden of the Royal Mint in 1696, a position that he had
obtained through the patronage of Charles Montagu, 1st Earl of Halifax,
then Chancellor of the Exchequer. He took
charge of England's great recoining, somewhat treading on the toes of Lord
Lucas, Governor of the Tower (and securing the job of deputy comptroller of the temporary Chester branch for
Edmond Halley). Newton became perhaps the best-known Master of the Mint upon the death of Thomas Neale in 1699, a position Newton held for
the last 30 years of his life.[71][72] These appointments were intended as sinecures,
but Newton took them seriously, retiring from his Cambridge duties in 1701, and
exercising his power to reform the currency and punish clippers and counterfeiters.
As Warden, and afterwards Master, of the Royal Mint,
Newton estimated that 20 percent of the coins taken in during the Great Recoinage of 1696 were counterfeit.
Counterfeiting was high treason, punishable
by the felon's being hanged, drawn and quartered. Despite this,
convicting even the most flagrant criminals could be extremely difficult.
However, Newton proved equal to the task.[73]
Disguised as a habitué of bars and taverns, he gathered
much of that evidence himself.[74] For all the barriers placed to
prosecution, and separating the branches of government, English law still had ancient and formidable customs
of authority. Newton had himself made a justice of the peace in all the home counties—there is a
draft of a letter regarding this matter stuck into Newton's personal first
edition of his Philosophiæ
Naturalis Principia Mathematica which
he must have been amending at the time.[75] Then he conducted more than 100
cross-examinations of witnesses, informers, and suspects between June 1698 and
Christmas 1699. Newton successfully prosecuted 28 coiners.[76]
As a result of a report written by Newton on 21 September
1717 to the Lords Commissioners of His Majesty's Treasury the bimetallic
relationship between gold coins and silver coins was changed by Royal
proclamation on 22 December 1717, forbidding the exchange of gold guineas for
more than 21 silver shillings.[77][78]This
inadvertently resulted in a silver shortage as silver coins were used to pay
for imports, while exports were paid for in gold, effectively moving Britain
from thesilver standard to its first gold standard.
It is a matter of debate as whether he intended to do this or not.[79] It has been argued that Newton
conceived of his work at the Mint as a continuation of his alchemical work.[80]
Newton was made President of the Royal Society in 1703 and an associate of the French Académie des Sciences. In his position at
the Royal Society, Newton made an enemy of John Flamsteed,
the Astronomer Royal,
by prematurely publishing Flamsteed's Historia
Coelestis Britannica, which Newton had used in his studies.[81]
Personal
coat of arms of Sir Isaac Newton[82]
In April 1705, Queen Anne knighted Newton during a royal visit to Trinity
College, Cambridge. The knighthood is likely to have been motivated by
political considerations connected with the Parliamentary election in May 1705, rather than any
recognition of Newton's scientific work or services as Master of the Mint.[83] Newton was the second scientist to be
knighted, after Sir Francis Bacon.[84][85]
Newton was one of many people who lost heavily when the South Sea
Company collapsed.
Their most significant trade was slaves, and according to his niece, he lost
around £20,000.[86]
Towards the end of his life, Newton took up residence at Cranbury Park,
near Winchester with his niece and her husband, until
his death in 1727.[87] His half-niece, Catherine Barton Conduitt,[88] served as his hostess in social
affairs at his house on Jermyn Streetin
London; he was her "very loving Uncle,"[89] according to his letter to her when
she was recovering from smallpox.
Newton died in his sleep in London on 20 March 1727 (OS 20
March 1726; NS 31
March 1727)[1] and was buried in Westminster
Abbey.[90] Voltaire may have been present at his funeral.[91] A bachelor, he had divested much of
his estate to relatives during his last years, and died intestate.[92] His papers went to John Conduitt and
Catherine Barton.[93] After his death, Newton's hair was
examined and found to contain mercury,
probably resulting from his alchemical pursuits. Mercury
poisoning could
explain Newton's eccentricity in late life.[92]
Personal relations
Although it was claimed that he was once engaged,[94] Newton never married. The French
writer and philosopher Voltaire,
who was in London at the time of Newton's funeral, said that he "was never
sensible to any passion, was not subject to the common frailties of mankind,
nor had any commerce with women—a circumstance which was assured me by the
physician and surgeon who attended him in his last moments".[95] The widespread belief that he died a virgin has been commented on by writers such
as mathematician Charles Hutton,[96] economist John Maynard Keynes,[97] and physicist Carl Sagan.[98]
Newton did have a close friendship with the Swiss
mathematician Nicolas Fatio de Duillier, whom he met in
London around 1690.[99] Their intense relationship came to an
abrupt and unexplained end in 1693, and at the same time Newton suffered a nervous
breakdown.[100] Some of their correspondence has
survived.[101][102]
In September of that year, Newton had a breakdown which
included sending wild accusatory letters to his friends Samuel Pepys and John Locke.
His note to the latter included the charge that Locke "endeavoured to
embroil me with woemen".[103]
After death
See
also: Isaac Newton in popular culture
Fame
The mathematician Joseph-Louis Lagrange often said that Newton was the
greatest genius who ever lived, and once added that Newton was also "the
most fortunate, for we cannot find more than once a system of the world to
establish."[104] English poet Alexander Pope was moved by Newton's accomplishments
to write the famous epitaph:
Nature and nature's laws lay hid in night;
God
said "Let Newton be" and all was light.
Newton himself had been rather more modest of his own
achievements, famously writing in a letter to Robert Hooke in February 1676:
If I have seen further it is by standing on the shoulders of giants.[105]
Two writers think that the above quotation, written at a
time when Newton and Hooke were in dispute over optical discoveries, was an
oblique attack on Hooke (said to have been short and hunchbacked), rather
than—or in addition to—a statement of modesty.[106][107] On the other hand, the widely known
proverb about standing on the shoulders of giants,
published among others by seventeenth-century poet George Herbert (a former orator of the University of
Cambridge and fellow of Trinity College) in his Jacula Prudentum (1651), had as its main point that
"a dwarf on a giant's shoulders sees farther of the two", and so its
effect as an analogy would place Newton himself rather than Hooke as the
'dwarf'.
In a later memoir, Newton wrote:
I do not know what I may appear to the world, but to
myself I seem to have been only like a boy playing on the sea-shore, and
diverting myself in now and then finding a smoother pebble or a prettier shell
than ordinary, whilst the great ocean of truth lay all undiscovered before me.[108]
In 1816, a tooth said to have belonged to Newton was sold
for £730[109] (us$3,633) in London to an
aristocrat who had it set in a ring.[110] The Guinness World Records 2002 classified it as the most valuable
tooth, which would value approximately £25,000 (us$35,700) in late 2001.[110] Who bought it and who currently has it
has not been disclosed.
Albert Einstein kept a picture of Newton on his study
wall alongside ones of Michael Faraday and James Clerk Maxwell.[111] Newton remains influential to today's
scientists, as demonstrated by a 2005 survey of members of Britain's Royal Society (formerly headed by Newton) asking who
had the greater effect on the history of science, Newton or Einstein. Royal
Society scientists deemed Newton to have made the greater overall contribution.[112] In 1999, an opinion poll of 100 of
today's leading physicists voted Einstein the "greatest physicist
ever;" with Newton the runner-up, while a parallel survey of rank-and-file
physicists by the site PhysicsWeb gave the top spot to Newton.[113]
Commemorations
Newton
statue on display at the Oxford University Museum of Natural
History
Newton's monument (1731) can be seen in Westminster
Abbey, at the north of the entrance to the choir against the choir
screen, near his tomb. It was executed by the sculptor Michael Rysbrack (1694–1770) in white and grey marble
with design by the architectWilliam Kent. The monument features a figure of
Newton reclining on top of a sarcophagus, his right elbow resting on several of
his great books and his left hand pointing to a scroll with a mathematical
design. Above him is a pyramid and a celestial globe showing the signs of the
Zodiac and the path of the comet of 1680. A relief panel depicts putti using instruments such as a telescope
and prism.[114] The Latin inscription on the base
translates as:
Here is buried Isaac Newton, Knight, who by a strength of
mind almost divine, and mathematical principles peculiarly his own, explored
the course and figures of the planets, the paths of comets, the tides of the
sea, the dissimilarities in rays of light, and, what no other scholar has
previously imagined, the properties of the colours thus produced. Diligent,
sagacious and faithful, in his expositions of nature, antiquity and the holy
Scriptures, he vindicated by his philosophy the majesty of God mighty and good,
and expressed the simplicity of the Gospel in his manners. Mortals rejoice that
there has existed such and so great an ornament of the human race! He was born
on 25 December 1642, and died on 20 March 1726/7.—Translation from G.L. Smyth, The Monuments and Genii of St.
Paul's Cathedral, and of Westminster Abbey (1826), ii, 703–4.[114]
From 1978 until 1988, an image of Newton designed by
Harry Ecclestone appeared on Series D £1 banknotes issued by the Bank of England (the last £1 notes to be issued by the
Bank of England). Newton was shown on the reverse of the notes holding a book
and accompanied by a telescope, a prism and a map of the Solar System.[115]
's Newton,
after William Blake (1995),
outside the British Library
A statue of Isaac Newton, looking at an apple at his
feet, can be seen at the Oxford University Museum of Natural
History. A large bronze statue, Newton,
after William Blake, by Eduardo Paolozzi,
dated 1995 and inspired by Blake's etching,
dominates the piazza of the British Library in London.
Religious views
Main
article: Religious views of Isaac Newton
Newton's
tomb inWestminster Abbey
Although born into an Anglican family, by his thirties Newton held a
Christian faith that, had it been made public, would not have been considered
orthodox by mainstream Christianity;[116]in
recent times he has been described as a heretic.[7]
By 1672 he had started to record his theological
researches in notebooks which he showed to no one and which have only recently
been examined. They demonstrate an extensive knowledge of early church writings
and show that in the conflict between Athanasius and Arius which defined the Creed,
he took the side of Arius, the loser, who rejected the conventional view of the Trinity.
Newton "recognized Christ as a divine mediator between God and man, who
was subordinate to the Father who created him."[117] He was especially interested in
prophecy, but for him, "thegreat apostasy was trinitarianism."[118]
Newton tried unsuccessfully to obtain one of the two
fellowships that exempted the holder from the ordination requirement. At the
last moment in 1675 he received a dispensation from the government that excused
him and all future holders of the Lucasian chair.[119]
In Newton's eyes, worshipping Christ as God was idolatry,
to him the fundamental sin.[120] Historian Stephen D.
Snobelen says of
Newton, "Isaac Newton was a heretic.
But ... he never made a public declaration of his private faith—which the
orthodox would have deemed extremely radical. He hid his faith so well that
scholars are still unravelling his personal beliefs."[7] Snobelen concludes that Newton was at
least a Sociniansympathiser
(he owned and had thoroughly read at least eight Socinian books), possibly an Arian and almost certainly an anti-trinitarian.[7]
In a minority view, T.C. Pfizenmaier argues that Newton
held the Eastern Orthodox view on the Trinity.[121] However, this type of view 'has lost
support of late with the availability of Newton's theological papers',[122] and now most scholars identify Newton
as an Antitrinitarian monotheist.[7][123]
Although the laws of motion and universal gravitation
became Newton's best-known discoveries, he warned against using them to view
the Universe as a mere machine, as if akin to a great clock. He said,
"Gravity explains the motions of the planets, but it cannot explain who
set the planets in motion. God governs all things and knows all that is or can
be done."[124]
Along with his scientific fame, Newton's studies of the
Bible and of the early Church Fathers were also noteworthy. Newton wrote
works on textual
criticism, most notably An Historical
Account of Two Notable Corruptions of Scripture. He placed the
crucifixion of Jesus Christ at 3 April, AD 33, which agrees with
one traditionally accepted date.[125]
He believed in a rationally immanent world, but he rejected the hylozoism implicit in Leibniz and Baruch Spinoza.
The ordered and dynamically informed Universe could be understood, and must be
understood, by an active reason. In his correspondence, Newton claimed that in
writing the Principia "I had an eye upon such Principles
as might work with considering men for the belief of a Deity".[126] He saw evidence of design in the
system of the world: "Such a wonderful uniformity in the planetary system
must be allowed the effect of choice". But Newton insisted that divine
intervention would eventually be required to reform the system, due to the slow
growth of instabilities.[127] For this, Leibniz lampooned him:
"God Almighty wants to wind up his watch from time to time: otherwise it
would cease to move. He had not, it seems, sufficient foresight to make it a
perpetual motion."[128]
Newton's position was vigorously defended by his follower Samuel Clarke in a famous correspondence. A century later, Pierre-Simon Laplace's work "Celestial Mechanics" had a natural
explanation for why the planet orbits don't require periodic divine
intervention.[129]
Effect on religious
thought
Newton and Robert Boyle's
approach to the mechanical philosophy was promoted by rationalist pamphleteers as a viable alternative
to the pantheists andenthusiasts,
and was accepted hesitantly by orthodox preachers as well as dissident preachers
like the latitudinarians.[130] The clarity and simplicity of science
was seen as a way to combat the emotional and metaphysical superlatives of both superstitious enthusiasm and the threat of atheism,[131] and at the same time, the second wave
of English deists used Newton's discoveries to
demonstrate the possibility of a "Natural Religion".
, by William Blake;
here, Newton is depicted critically as a "divine geometer". This copy
of the work is currently held by the Tate Collection.[132]
The attacks made against pre-Enlightenment "magical
thinking", and the mystical elements of Christianity, were given
their foundation with Boyle's mechanical conception of the Universe. Newton
gave Boyle's ideas their completion throughmathematical proofs and, perhaps more importantly, was
very successful in popularising them.[133]
Newton saw God as the master creator whose existence
could not be denied in the face of the grandeur of all creation.[134][135][136]
Occult
See
also: Isaac Newton's occult studies and eschatology
In a manuscript he wrote in 1704 in which he describes
his attempts to extract scientific information from the Bible, he estimated
that the world would end no earlier than 2060. In predicting this he said,
"This I mention not to assert when the time of the end shall be, but to
put a stop to the rash conjectures of fanciful men who are frequently
predicting the time of the end, and by doing so bring the sacred prophesies into
discredit as often as their predictions fail."[137]
Alchemy
In the character of Morton Opperly in "Poor
Superman" (1951), speculative fiction author Fritz Leiber says of Newton, "Everyone knows
Newton as the great scientist. Few remember that he spent half his life
muddling with alchemy, looking for the philosopher's stone. That was the pebble by the
seashore he really wanted to find."[138]
Of an estimated ten million words of writing in Newton's
papers, about one million deal with alchemy.
Many of Newton's writings on alchemy are copies of other manuscripts, with his
own annotations.[93] Alchemical texts mix artisanal
knowledge with philosophical speculation, often hidden behind layers of
wordplay, allegory, and imagery to protect craft secrets.[139] Some of the content contained in
Newton's papers could have been considered heretical by the church.[93]
In 1888, after spending sixteen years cataloging Newton's
papers, Cambridge University kept a small number and returned the rest to the
Earl of Portsmouth. In 1936, a descendant offered the papers for sale at
Sotheby’s.[140] The collection was broken up and sold
for a total of about £9,000.[141] John Maynard Keynes was one of about three dozen bidders
who obtained part of the collection at auction. Keynes went on to reassemble an
estimated half of Newton's collection of papers on alchemy before donating his
collection to Cambridge University in 1946.[93][140][142]
All of Newton's known writings on alchemy are currently
being put online in a project undertaken by Indiana University: "The Chymistry of
Isaac Newton".[143] The project is headed by William R.
Newman.[144] Here is a quote from the project web
site.
Newton's fundamental contributions to science include the
quantification of gravitational attraction, the discovery that white light is
actually a mixture of immutable spectral colors, and the formulation of the
calculus. Yet there is another, more mysterious side to Newton that is
imperfectly known, a realm of activity that spanned some thirty years of his
life, although he kept it largely hidden from his contemporaries and
colleagues. We refer to Newton's involvement in the discipline of alchemy, or
as it was often called in seventeenth-century England, "chymistry." [143]
Enlightenment philosophers
Enlightenment philosophers
chose a short history of scientific predecessors – Galileo, Boyle, and
Newton principally – as the guides and guarantors of their applications of
the singular concept of Nature and Natural law to every physical and social field of
the day. In this respect, the lessons of history and the social structures
built upon it could be discarded.[145]
It was Newton's conception of the Universe based upon
Natural and rationally understandable laws that became one of the seeds for
Enlightenment ideology.[146]Locke
and Voltaire applied concepts of Natural Law to
political systems advocating intrinsic rights; the physiocrats and Adam Smith applied Natural conceptions ofpsychology and self-interest to economic systems;
and sociologists criticised the current social order for trying to fit history into Natural
models of progress.Monboddo and Samuel Clarke resisted elements of Newton's work,
but eventually rationalised it to conform with their strong religious views of
nature.
Apple incident
Reputed
descendants of Newton's apple tree,
(from top to bottom) at Trinity College, Cambridge, theCambridge University Botanic Garden,
and theInstituto Balseiro library garden
Newton himself often told the story that he was inspired
to formulate his theory of gravitation by watching the fall of an apple from a
tree.[147][148] Although it has been said that the
apple story is a myth and that he did not arrive at his theory of gravity in
any single moment,[149] acquaintances of Newton (such as William Stukeley,
whose manuscript account of 1752 has been made available by the Royal Society)
do in fact confirm the incident, though not the cartoon version that the apple
actually hit Newton's head. Stukeley recorded in his Memoirs of Sir Isaac Newton's Life a conversation with Newton in
Kensington on 15 April 1726:[150][151]
we went into the garden, & drank thea under the shade
of some appletrees; only he, & my self. amidst other discourse, he told me,
he was just in the same situation, as when formerly, the notion of gravitation
came into his mind. "why should that apple always descend perpendicularly
to the ground," thought he to himself; occasion'd by the fall of an apple,
as he sat in a contemplative mood. "why should it not go sideways, or
upwards? but constantly to the earths center? assuredly, the reason is, that
the earth draws it. there must be a drawing power in matter. & the sum of
the drawing power in the matter of the earth must be in the earths center, not
in any side of the earth. therefore dos this apple fall perpendicularly, or
toward the center. if matter thus draws matter; it must be in proportion of its
quantity. therefore the apple draws the earth, as well as the earth draws the
apple.
John Conduitt, Newton's assistant at the Royal Mint and
husband of Newton's niece, also described the event when he wrote about
Newton's life:[152]
In the year 1666 he retired again from Cambridge to his
mother in Lincolnshire. Whilst he was pensively meandering in a garden it came
into his thought that the power of gravity (which brought an apple from a tree
to the ground) was not limited to a certain distance from earth, but that this
power must extend much further than was usually thought. Why not as high as the
Moon said he to himself & if so, that must influence her motion &
perhaps retain her in her orbit, whereupon he fell a calculating what would be
the effect of that supposition.
In similar terms, Voltaire wrote in his Essay on Epic Poetry (1727), "Sir Isaac Newton walking
in his gardens, had the first thought of his system of gravitation, upon seeing
an apple falling from a tree."
It is known from his notebooks that Newton was grappling
in the late 1660s with the idea that terrestrial gravity extends, in an
inverse-square proportion, to the Moon; however it took him two decades to
develop the full-fledged theory.[153] The question was not whether gravity
existed, but whether it extended so far from Earth that it could also be the
force holding the Moon to its orbit. Newton showed that if the force decreased
as the inverse square of the distance, one could indeed calculate the Moon's
orbital period, and get good agreement. He guessed the same force was
responsible for other orbital motions, and hence named it "universal
gravitation".
Various trees are claimed to be "the" apple
tree which Newton describes. The King's School, Grantham, claims that the tree
was purchased by the school, uprooted and transported to the headmaster's
garden some years later. The staff of the [now] National Trust-owned Woolsthorpe
Manordispute this, and claim that a tree present in their gardens is
the one described by Newton. A descendant of the original tree[154] can be seen growing outside the main
gate of Trinity College, Cambridge, below the room Newton lived in when he
studied there. The National Fruit Collection at Brogdale[155] can supply grafts from their tree,
which appears identical to Flower of Kent,
a coarse-fleshed cooking variety.[156]
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