Biography of Issac Newton, Discoveries, Inventions, Awards, Books, Quotes, Education, Family, Parents, Death

Issac Newton

Isaac Newton

President of the Royal Society
1703-1727
John Somers Hans Sloane
Member of the Parliament of England Cambridge University
December 1701-1702
Director of Mint
January 1700 - March 31, 1727
Warden of the Mint ( in )
1696 - January 1700
Member of the Parliament of England Cambridge University ( fr )
1689-1690
Member of the 1689-90 Parliament
Member of the 1701-02 Parliament

Biography

Birth	December 25, 1642 Woolsthorpe Mansion
Death	March 20, 1727(at 84) Kensington
Burial	Westminster Abbey
Home	England
Training	The King's School, Grantham ( en ) (1655-1659) Trinity College ( Bachelor of Arts ) (June 1661 - August 1665) Trinity College ( Master of Arts ) (April 1667-1668)
Activities	Mathematician, philosopher
Dad	Isaac Newton ( d )
Mother	Hannah ayscough
Kinship	Catherine Barton ( in ) (niece)

Other information

Worked for	Cambridge University
Chair	Lucasian Professor of Mathematics at Cambridge University
Areas	Physics, mechanics, mathematics, astronomy
Religion	Anglicanism
Member of	Royal Society (1672)
Master	Isaac barrow
Related person	Isaac barrow
Influenced by	René Descartes
Distinction	Knight Bachelor (1705)

Honorary title

Sir

coat of arms

Primary works

Philosophiae Naturalis Principia Mathematica, Fluxion, Opticks

Isaac Newton  is an English, then British, mathematician, physicist, philosopher, alchemist, astronomer, and theologian. An emblematic figure of science, he is especially recognized for having founded classical mechanics, for his theory of universal gravitation and creation, in competition with Gottfried Wilhelm Leibniz, of the infinitesimal calculus. In optics, he developed a theory of color based on the observation that a prism breaks down white light into a visible spectrum. He also invented the reflecting telescope made up of a primary concave mirror called Newton's telescope.

In mechanics, he established the three universal laws of motion which in fact constitute the principles at the base of Newton's great theory concerning the motion of bodies, a theory that is now called “  Newtonian mechanics  ” or even “mechanics. classic ”.

He is also known for the generalization of the binomial theorem and the invention known as Newton's method making it possible to find approximations of zero (or root) of a real function of a real variable.

Newton showed that the movements of objects on Earth and celestial bodies are governed by the same natural laws; based on Kepler's laws of motion of planets, he developed the universal law of gravity.

His work Philosophiæ Naturalis Principia Mathematica, published in 1687, is considered a major work in the history of science. It is in this that he describes the universal law of gravitation, formulates the three universal laws of motion and lays the foundations of classical mechanics. He has also carried out research in the fields of theology and alchemy.

Issac Newton: Biography  

Youth 

As England had not yet adopted the Gregorian calendar, the date of birth of Isaac Newton is recorded as of December 25, 1642, at Woolsthorpe Manor near Grantham, Lincolnshire, England, of farming parents. His birth was eventful: he was born three months after the death of his father, Isaac Newton senior, and prematurely. Later, his mother will tell him that no one thought he could survive. His constitution is so fragile that he would have held, she said, "in a jug. " Little is known of his early years, apart from some data reported by Newton himself.

Newton's happiness did not last long: he was three years old when his mother, Hannah Ayscough remarried to Barnabas Smith, a 63-year-old and economically well-off pastor of the nearby village of North Witham. A conflict arises when her mother moves with her husband to North Witham. As Barnabas does not want to take care of Isaac, he is left in the care of his maternal grandparents, whose family, made up of churchmen and academics, will be responsible for his training. But this separation arouses in him a strong feeling "(of) anguish, aggressiveness and fear" 5which makes him a precocious egocentric. Whenever someone tries to take away what they think is their property, they will retaliate with disproportionate violence. Although he can count on uncles, aunts and cousins who live nearby, he suffers from his lonely childhood and this suffering contributes to his isolation. At five, he attended Skillington and Stoke elementary schools.

He was ten years old when his stepfather Barnabas died. Her mother returns to the family home in Woolsthorpe with the three children she had from the pastor. Alas, the happiness of reuniting with his mother was short-lived: a year later - he was twelve - Newton was sent to Grantham Primary School.(eleven kilometers from his birthplace). He doesn't take his schooling very seriously - he always sits at the back of the classroom - until one day, when he leaves college, he fights with a classmate twice the size and threshes him down. Not content with having knocked him down, he also wants to dominate him intellectually and, from that moment on, he has never ceased to occupy the place of first in the class. This anecdote reveals a crucial trait of his character: the desire to prevail over his rivals whom he considers inferior. He stayed with the pharmacist Clark - whose wife was a friend of his mother's - and he took advantage of the library, which was well stocked with scientific works, to learn the basics of "natural philosophy" (physics). Drawing is also his other passion, as shown by the walls of Pharmacist Clark's house, adorned with portraits of animals, flowers and geometric figures. In this house, there are also sundials for which Newton displays a true devotion. He remained at Grantham College for four years until his mother called him back to Woolsthorpe to become a farmer and learn how to run his estate.

Fortunately, several people around him noticed that Newton was not made for work in the fields and detected his scientific gifts. William Ayscough, his mother's brother, insisted that he continue his studies and later go to university. His main ally is Mrs. Clark's brother, Pastor Humphrey Babington - who ends up forming a close friendship with Newton - and finally, his schoolmaster in Grantham named Stokes, who offers to pay the school fees himself and to welcome young Newton to his home until the end of his training. A year later, his mother accepts that her son will resume his studies. After completing his school education, Newton enrolled in University.

At seventeen, Newton fell in love with a classmate, Miss Storey. He is allowed to date and even become engaged to her, but he must complete his studies before getting married. Finally, marriage is not done, it will remain a pristine and lifelong bachelor.

Newton in Cambridge 

The student and researcher 

Newton arrives in Cambridge on June 4, 1661and the next day he entered Trinity College, an institution to which he remained attached for the next forty years. The choice of Trinity considered the best, is based on several reasons: on the one hand, William Ayscough studied there, on the other hand, Humphrey Babington works there as a fellow. Newton is registered there as subsizar. His university status requires him to share his room with another student, John Wickins, who will show concern and support, helping him carry out his experiments and write his research papers.

He began by preparing for his license in liberal arts. At this time, the university remained anchored in a curriculum based on medieval humanities, in which Newton was not very interested. From his notebooks, we know that he did not complete his compulsory readings and that he began others, clearly more contemporary. References to more modern authors abound in his notebooks, such as Descartes, Galileo, Robert Boyle, Henry More, Hobbes and Gassendi. Although the university program suffers from archaism, the latest scientific books are available, so Newton can consult the latest publications. Newton behaves like an autodidact, devouring everything that comes to hand; he delves into what catches his attention and reproduces a number of experiences. 

In Cambridge, within the framework of mathematics, one gives the quadrivium including the arithmetic of Girolamo Cardano, the geometry of Euclid, the astronomy of Ptolemy, and finally the music. In 1663 and 1664, Newton discovered mathematics miscellanea by Schooten, Geometria by Descartes, Clavis Mathematica by William Oughtred, and the works of John Wallis. In 1663 the Lucasian chair was created in Cambridge, the first holder of which was Isaac Barrow, his master of mathematics, and it is possible that Newton attended his lectures, which opened up new horizons for him, unsuspected until then. In little more than a year, Newton was able to assimilate by himself all the foundations of the analysis developed in the 18th century. From there, he follows his own path which must lead him to discover the infinitesimal calculus. 

In 1664, he wrote in A few philosophical questions “Plato is my friend, Aristotle is my friend, but my best friend is the truth”. At this time, Newton's priority was to continue his studies indefinitely, the only way to satisfy his thirst for knowledge. He chooses Isaac Barrow as an examiner and, on April 28, 1664, obtains a scholarship ( scholarship ) which grants him a fixed salary in addition to living expenses and guarantees him four additional years of study, until the end of his license in liberal arts. In January 1665, he obtained a bachelor's degree in arts and planned to prepare for the master's degree. That year, England suffered an epidemic of the Black Death, so that the university closed its doors in the summer of 1665 and sent the students home. Newton leaves for Woolsthorpe, it is there that he progresses strongly in mathematics, physics, and especially optics. When he returns, he has greatly revolutionized the science of the time.

Newton accelerated in his research, he began in 1666 the study of derivable functions and their derivatives from the layout of tangents on the basis of Fermat's work. He classifies the cubics and gives them correct plots with asymptotes, inflections, and cusps. His research did not prevent him from continuing his academic work. October 2, 1667, he obtains the title of minor fellow awarded to scholarship researchers who are still not very specialized. Eight months later, he achieves the status of staff fellow, and that same year 1668 he obtained the title of Master of Arts, which includes the obligation to take orders in the Anglican Church for a minimum of seven years.

In 1669, he wrote a report on the foundations of the infinitesimal calculus which he called "method of fluxions". Newton thus founded modern mathematical analysis. Still, in 1669, Newton succeeded his master Barrow - who had resigned to devote himself exclusively to theology - 9 and resumed his chair as Lucasian professor of mathematics. Three years later, at the age of 29, he entered the Royal Society in London, where he met Robert Boyle, a very influential man. He achieves the feat of developing a telescope spherical mirror devoid of chromatic aberration. The following year, he made the decision to widely disclose his work on light, which suddenly made him famous. This celebrity makes his discoveries the subject of many controversies and quarrels which he abhors.

In 1675, in his book Opticks (published in 1704), he exhibited his work on light and proved that it is made up of a spectrum of several colors, using his prism. He completes his work by exposing his corpuscular theory. After completing his work in optics, he was contacted in 1684 by the British astronomer Edmond Halley - the discoverer of the famous comet of the same name - about Kepler's laws on the elliptical orbits of the planets. Newton responds convincingly and Halley pushes him to publish his work, even funding the publication of his work.

In 1687, he, therefore, published his major work: Philosophiæ Naturalis Principia Mathematica, (Mathematical principles of natural philosophy) . This work marks the beginning of the mathematization of physics. Indeed, Newton exposes the principle of inertia, the proportionality of forces and accelerations, the equality of action and reaction, the laws of shock, he studies the movement of fluids, tides, etc. But he also and above all exposes his theory of universal attraction. Bodies attract with a force proportional to the product of their mass and inversely proportional to the square of the distance between them. The simplicity and efficiency of this theory will have a very strong influence on other sciences in the 18th century. century, particularly the social sciences as we will see. However, at the time, while the book was well received in Britain, the mainland reaction was hostile.

In 1687 he defended the rights of Cambridge University against King James II . This action earned him to be elected member of the British parliament in 1689 when the king, defeated, had to go into exile. During his tenure, he was very active in debates.

A complex personality 

Newton is blessed with a tormented and complex personality. He is reluctant to communicate his work and often publishes it several years after completing it. He has a tendency to withdraw into himself, lives alone and is a workaholic. Indeed, he sometimes forgets to sleep or eat. In addition, his relationships with others are often problematic. For example, he often clashes with Robert Hooke about light and his theory of gravity. Newton will wait until Hooke dies to publish his work on optics. 

Hooke accuses Newton of having plagiarized him on the theory of inverse squares because the latter began his work in parallel with Hooke's and without telling anyone anything, which makes Hooke furious. Newton then claims not to have been aware of Hooke's research and not to have read his work on gravitation; we now know that Newton lied, not out of guilt, but out of the horror of the character.

In 1677, the death of his mentor Isaac Barrow, that of his friend Henry Oldenburg - his only link with the scientific community - and the loss of all his work on colors in the fire of his apartments, strongly affected him. For many months. He will spend twenty-five years before publishing his theory of light again. In 1679, Newton returned to his birthplace in Woolsthorpe where his mother was dying. During his mother's last days, he takes care of her with a dedication never before seen in their relationship, and witnessing his last days causes great emotion in him. In his life, however, new friendships appear. Perhaps the most important is the one that links him to Edmund Halley who, by persuading Newton to make known his conception of the Universe, made him enter the history of science.

Around 1693, Newton went through a serious depressive period, a series of events lastingly undermined his morale. The tension around the authorship of the discoveries in differential calculus, the exhaustion linked to alchemical work in the laboratory, and above all the sudden break in his friendship with Nicolas Fatio de Duillier, lead him to a psychic tension which leads to a fit of madness. We know this episode from a few letters written in September 1693, whose first put an end to several months of silence during which he lives in a state of prostration and paranoia, subject to hallucinations. 

He admits there that he is in a state of "great turmoil", that he has barely eaten and slept during the previous months, that he feels incapable of "recovering the firmness of his understanding" and declares to her "I believe that it is better that I give up your friendship and that I do not see you again, neither you nor the rest of my friends, never". Without doubt at the origin of this crisis, the exhaustion of its legendary capacity for invention. In fact, from that time on.

Newton in London 

In April 1696, he resigned from Cambridge College and left the city to become director of the Maison de la Monnaie ( Royal Mint ), which brought him a substantial improvement in his economic and social status. He obtained this post thanks to the support of Charles Montagu - a former Cambridge Chancellor then Chancellor of the Exchequer  - who was looking for vacancies for his friends. Unlike his predecessors, he takes his work very seriously, including imprisoning a hundred counterfeiters.

Newton estimated that 20% of the coins in circulation during the Great 1696 monetary reform are counterfeit. The infringement is therefore considered an act of treason, punishable by death by dismemberment if the evidence is irrefutable. Newton, therefore, gathers facts and exposes his theories rigorously. between June 1698and Christmas 1699, he conducted about 200 cross-examinations of witnesses, informants, and suspects and obtained the confessions he needed. He does not have the right to resort to torture, but one wonders about the means employed since Newton himself will subsequently order the destruction of all the interrogation reports. Anyway, he succeeds and wins the conviction of the jury: in February 1699, ten prisoners await their execution.

Newton earned his greatest success as attorney royal against William Chaloner, a particularly crafty crook who is sufficiently enriched to pose as rich bourgeois. In a petition to Parliament, Chaloner accuses the Hôtel des Monnaies of providing tools to counterfeiters - an accusation that was not new - and proposes that he be allowed to inspect the processes of the Hôtel des Monnaies, to improve them. In a petition, he presents to Parliament his plans for an invention that would prevent any counterfeiting. All the while, Chaloner takes the opportunity to mint counterfeit money himself, which Newton ultimately manages to demonstrate in court. The23 March 1699, Chaloner is hanged and quartered.

In 1699, he was appointed member of the board of the Royal Society then, after the death of Robert Hooke, was elected president - a position he would keep for life - in November 1703. In the meantime, in 1701, he read at a meeting the only chemistry memoir he made known and presented his law on conduction cooling, as well as observations on boiling and melting temperatures.

In 1704, he published, in English, his work - which he had kept hidden for twenty years - concerning the light. He will publish a Latin version of Optiks two years later.

In 1705, he was knighted by Queen Anne, perhaps less because of his scientific work or his role at the Mint than because of the proximity of elections. In 1717, he analyzed the coins and derived a gold-silver relationship from them; this relationship is formalized by a law of Queen Anne. In 1720, Newton invested and lost most of his financial fortune in the South Sea Company bubble (but he was not ruined, thanks to his real estate fortune). He would have said then, "I know to predict the movement of heavenly bodies but not the madness of people".

Despite his success in calculus and science in general, Newton preferred to resume his theological studies in his later years. He thoroughly studies the chronology of Bible prophecy and writes texts on ancient heresies and pagan religions. The Princess of Wales asks him to send her this work in progress. To get out of the embarrassment, he writes an excerpt known as the Brief Chronology. In 1725, the Jesuit Étienne Society, published on his own initiative, this abridged version, in French, of The chronology of ancient kingdoms amended -  Chronologie corrigée des kingdoms de l'Antiquité  -, the full text of which, in English, was published in 1728, a year after his death.

During these years of religious studies, his health deteriorated seriously. In addition to minor problems such as kidney stones or weak sphincters, there is inflammation of the lungs and a severe attack of gout. Respiratory problems forced him to move to the countryside where his condition improved significantly. In 1727, Newton, barely recovered from a gout attack, went to London to chair a meeting of the Royal Society. This trip tires him terribly. Back in his country estate in Kensington, he had to stay in bed and died onMarch 31, 1727, at the age of 84. His funeral is sumptuous. His coffin, on display in Westminster Abbey, is carried with great pomp and buried in the nave alongside the kings of England. Voltaire, who is then in London, comments, admiringly: “This famous Newton, this destroyer of the Cartesian system, died in March of the last year 1727. He lived honored by his compatriots and was buried like a king who would have done well to his subjects ”.

Newton is considered to be one of the greatest geniuses and scientists in human history.

Issac Newton: Scientific theories 

As for the method, Newton accepts only the mathematical relations discovered by the rigorous observation of the phenomena. Hence its famous formula:

“I do not pretend hypotheses ( Hypotheses nonfingo). "

He specifies :

“Anything that is not deduced from phenomena should be called a hypothesis; and hypotheses, whether they are metaphysical or physical, whether they concern occult qualities or whether they are mechanical, have no place in experimental philosophy. "

Optics 

It seems that after studying Robert Hooke's work on colors, he rejected his results and set out to develop a different theory. It's January 1666that he made his first experiments on light and its decomposition. During the years 1670 to 1672, Newton studied the refraction of light and demonstrated that a prism decomposes white light into a spectrum of colors and that a lens with a second prism recomposes the multicolored spectrum into white light.

It passes the Sun's rays through a prism, producing the rainbow of colors in the visible spectrum. Previously, this phenomenon was considered as if the glass of the prism had hidden color. Newton then analyzes this experience. As he has already succeeded in reproducing white with a mini rainbow that he passes through a second prism, his conclusion is revolutionary: the color is in the light and not in the glass. Thus, the white light that we see is actually a mixture of all the colors of the spectrum visible to the eye.

He shows that colored light does not change its properties by splitting into color beams and notes that regardless of whether the light beams are reflected, scattered, or transmitted, they always keep the same color (the frequency does not change d 'one medium to another). Thus, he observes that the decomposition of white light is the result of the interaction with the objects that it passes through and that it contains in itself the colors.

In 1704, he published his treatise Opticks in which appear his corpuscular theory of light, the study of refraction, the diffraction of light, and his theory of colors. He demonstrates that white light is made up of several colors and declares that it is made up of particles or corpuscles. In addition, he adds that when it passes through a denser medium, it is refracted by its acceleration. In another place in his treatise, he explains the diffraction of light by associating it with a wave.

In 1671, it improves an optical instrument of its time, the reflecting telescope of Gregory. As a result of his study of refraction - the dispersion of colors - he concludes that any refractive telescope or astronomical telescope presents a dispersion of light or chromatic aberration, which he thinks impossible to correct. 

He solved the problem, however, by inventing the concave mirror reflection telescope, naturally devoid of chromatic aberration, known as the Newtonian telescope. We know from Chester Moore Hall and especially John Dollond that chromatic aberration can be compensated by using several lenses made of glasses of different refractive indices.

Making his own mirrors from bronze with a high reflective power, he judges the quality of the optical image by means of the phenomenon known today as Newton's rings. Thus, he was able to design an instrument superior to Galileo's astronomical telescope, enlarging its diameter without altering the image. He then built the first version of his reflecting telescope composed of a primary concave mirror.

In 1671, Isaac Barrow attended a meeting of the Royal Society and presented Newton's telescope, which plunged the audience into amazement. In addition to avoiding chromatic aberration, the device invented by Newton achieves better magnification, although it is small in size - the first telescope he built was about six inches long and yet increased forty times the magnification. image diameter -. In 1672 and by invitation, Newton presented his reflecting telescope to the Royal Society, which surpassed everything that was known at the time to such an extent that he allowed him to enter it by the main door on January 11, 1672. The Royal Society's greatest concern is to prevent an outsider from copying the telescope. A month after his election as a member of the Royal Society, Newton sent the secretary of this institution a treatise on colors, in which he developed a schematic of his theory based on three experiments.

In his treatise Opticks of 1704, Newton exposes his theory of light. He considers it composed of very subtle corpuscles. Ordinary matter is made up of larger corpuscles. Newton said that light is made up of particles or corpuscles. That when it passes through a denser medium, it is refracted by acceleration. He explains the diffraction of light by associating these particles with waves.

Robert Hooke considered an expert in optics - it was he who manufactured in 1673 the telescope designed by James Gregory in 1663 -, expressed his interest but fiercely criticized the treatise, pointing out the insufficiency of the demonstration. Newton responds furiously, claiming that Hooke did not understand anything about his work and that there is no way he could have replicated his experience in such a short time. It was a sure thing and Hooke later confesses that he only spent a few hours studying the article. The two men remain enemies for life. But Hooke is not the only one to voice criticism. Christian Huygensfirst praises his theory before finding some flaws in it. But undoubtedly the most bitter dispute is that between him and the English Jesuit Francis Hall. Tired of objections that rob him of his most precious possession - his study time - Newton then withdrew from all public debate.

In France, Jacques Gautier d'Agoty in Chroma-genesis or generation of colors, published in 1751, criticizes the Newtonian theory of the generation of colors and the reason for the rainbow. Jean-Jacques Rousseau will support Newton's theory.

Mechanics 

The apple episode

It was towards the end of his life that the apparently legendary episode of the apple falling from the tree on his head would have taken place, revealing to him the laws of universal gravitation. The anecdote is related by the physicist to his biographer and friend, William Stukeley citing a meeting on April 15, 1726 with Newton and who reports it in 1752:

“As the weather turned warm, we went into the garden and drank tea under the shade of a few apple trees, only him and me. During the conversation, he told me that he had been in the same situation when, long ago, the notion of gravity had suddenly come to his mind, as he sat in a contemplative mood. 

Why does this apple always fall perpendicular to the ground, he thought to himself. Why does it not fall sideways or upwards, but constantly towards the center of the Earth? And if matter thus attracts matter, it must be in proportion to its quantity; therefore, the apple draws the Earth in the same way that the Earth draws the apple. "

As for the Moon, which intervened in the reasoning of young Newton, it was John Conduitt (1688-1737), Newton's assistant and husband of Newton's niece, who recounts the scene as follows: “During the year 1666, he left Cambridge again to find his mother in Lincolnshire. As he was meditating in the garden, it occurred to him that the power of gravity (which made the apple fall from the tree to the ground) was not limited to a certain distance from the earth's surface, but that it had to extend much further than we usually thought. Why not as far as the Moon, he told himself, and in this case, this power must influence its movement and even hold it in its orbit; after what Newton began to calculate what would be the consequence of such assumption."

This anecdote, which is difficult to situate at the level of historicity, is subsequently mythologized (Stukeley does not mention an apple that fell on the scientist's head). It is probably an a posteriori reconstruction of Newton to explain the principle of gravitation, which does not prevent visitors to the Woolsthorpe mansion from having their photograph taken in front of a large apple tree that is not even from the time of the scholar: the original tree was felled during a storm in 1816. However, the mansion, acquired by the National Trust, claims to own the "Newton's apple tree", a young tree surrounded by a small protective fence that would have come from a regrowth in 1820 of the original tree.

In 1677, Newton resumed his work on celestial mechanics: that is to say, gravitation and its effects on the orbits of the planets, according to the references on the inertia of Galileo and on Kepler's laws of motion of the planets; and also by consulting Robert Hooke and John Flamsteed on this subject. November 1684, he sent Halley a short treatise of nine pages with the title: De motu corporum in gyrum  (en) ( Movement of rotating bodies ). 

Showing the inverse square law, the centripetal force, it contains the beginnings of Newton's laws of motion that we find in his major work Philosophiæ Naturalis Principia Mathematica - today known as Principia or Principia Mathematica  - which is published in full July 5, 1687, divided into three volumes, thanks to the financial assistance and encouragement of Edmond Halley. The calculation methods he uses there make it a precursor of vector calculus.

In his work, Newton establishes the three universal laws of motion which will remain unchanged, without any improvement for more than two centuries. He uses the word weight, in Latin gravitas, to talk about the effects of what we now call gravity and he defines the laws of universal gravitation. In the same work, he presents the first analysis of determinations based on the speed of sound in air of the laws of Edmond Halley and Robert Boyle.

With the Principia, Newton is recognized internationally. He formed a circle of admirers, including the Genevan mathematician Nicolas Fatio de Duillier, with whom he built an intense relationship that lasted until 1693.

His major work, Mathematical Principles of Natural Philosophy, was published in 1687. The French version in two volumes with a translation of  I and II of the Marquise du Châtelet was published in 1756. Newton's work will be popularized in France, thanks to the dissemination of his ideas by the philosopher of the Enlightenment, Voltaire. However, several quarrels opposed Newtonians and Cartesians for a long time.

This work marks a turning point for physics. He shows the movement of fluids and states the principle of inertia, the proportionality of forces and accelerations, equality of action and reaction, the laws of collisions, and above all the theory of universal attraction.

Isaac Newton is declared "father of modern mechanics" thanks to the three laws of motion which bear his name and stated as they are taught today:

• Principle of inertia
• The fundamental principle of dynamics
• Principle of reciprocal actions

This last law is sometimes called the law of action-reaction, and expression liable to lead to confusion (see the principle of reciprocal actions ).

In everyday language, the mechanics is the area of anything that produces or transmits a movement, a strength, a deformation: machinery, engines, vehicles bodies ( gears, pulleys, belts, crankshafts, shafts of transmission, pistons,  etc. ).

There is talk of general mechanics of mechanical engineering, from auto mechanics to motorsports, of Marine Engineering, of celestial mechanics to quantum mechanics, the strength of materials,  etc.

Today, his three laws of motion, undermined by the development of thermodynamics in the 19th century, are overwhelmed by the relativistic mechanics of Einstein and the principle of duality wave-particle. However, Newton's mechanical genius lies in simplification, which has contributed to the development of research in the field of classical mechanics, where mass is identified with matter and where perfect continuity is assumed.

Mathematics 

In addition to his contributions to physics, Newton, along with Gottfried Wilhelm Leibniz, developed the founding principles of the infinitesimal calculus. While Newton did nothing to edit his method of infinitely small or fluxions and infinite suites before 1687, Leibniz published his work in 1684. If the problem of priority of the invention arose, Newton in his work Principia published in 1687 pays homage to Leibniz's discovery by acknowledging that he achieved the same results as him by a method similar to his. 

Despite this, members of the Royal Society - of which Newton is a member - accuse Leibniz of plagiarism, eventually creating a dispute in 1711. This is how the Royal Society proclaims in a study that Newton is the true discoverer of the method and Leibniz an impostor. This tainted the life of Newton as well as that of Leibniz, until his death in 1716.

From 1688, Newton maintained a very close relationship with the geometer Nicolas Fatio de Duillier who, strongly seduced by his theory of gravitation, became a specialist in his writings and even worked on a new edition of the work Philosophiæ Naturalis Principia Mathematica, but don't finish it. Fatio will play an important role in the controversy between Newton and Leibniz on the differential calculus. In a memoir published in 1699, he will be the first to reproach him - rightly - for not mentioning Newton in his publications and asserts that Leibniz knew of Newton's work, thus insinuating that he plagiarized the English master, designating Newton as the first inventor of the infinitely small method.

Newton is also known for his binomial formula. He is the father of Newton's identities, the Newton method, and cubic curves flat ( polynomials three degrees two variables).

He was the first to use fractional indices in analytical geometry to solve Diophantine equations. He also estimated the partial sums of harmonic series using logarithms - a precursor to a famous Euler formula  - and found a formula to calculate the number pi ( π ). In 1669 he was elected professor Lucasian mathematics of the University of Cambridge.

The universal law of gravitation 

In January 1684, Robert Hooke, Christopher Wren, and Edmond Halley discuss the movement of planets. All three men agree that the Sun attracts the planets with a force inversely proportional to the square of their distance. The question they ask themselves is that of the orbit that a planet subjected to the influence of this force will follow; sheltering behind Kepler's laws, they imagine that it will be an ellipse, but they lack the tools to demonstrate it. 

Hooke announces that he has found the solution, but refuses to reveal it until the other two admit defeat. Halley and Wren admit their failure, but months go by and Hooke still doesn't reveal his secret. So Halley decides to ask Isaac Newton the question, in the presence of the mathematician Abraham de Moivre- a friend of Newton's - whose memories are most reliable. Sir Isaac replied straight away that it would be an ellipse because he calculated it. When Halley wants to see the calculations, Newton assures him that he has lost them. 

Richard S. Westfall (1924-1996), biographer of Newton maintains that this excuse is not very credible, because one preserves today the manuscripts which contain the calculations in question. Anyway, in November, Halley received a brief nine-page manuscript titled De motu corporum in gyrum (On the Movement of Bodies in Orbit) where he found what he expected, and much more than that: a draft of the general science of dynamics. Halley receives permission from Newton to comment to the Royal Society of the work which,, will appear two years later.

Newton thus discovers the universal law of gravitation or universal attraction as the cause of the movements of the planets, thus unifying terrestrial mechanics and celestial mechanics. He expresses this law in a simplified way by the following mathematical expression:

$${\ displaystyle {\ vec {F}} = - G {\ frac {M_ {A} M_ {B}} {AB ^ {2}}} {\ vec {u}}}

or $${\ displaystyle {\ vec {u}}} is the unit vector indicating the direction of movement, $${\ displaystyle {\ vec {F}}} strength, and $${\ displaystyle G}a constant of proportionality or gravitational constant? By his formula resulting from Kepler's three laws, he explains and demonstrates the motions of the planets in their orbit.

In fact, Newton had matured over the years this theory of the movement of planets. Thus, from the time of the plague epidemic - around 1665 - he had begun to study the attraction of the Sun on the planets. Then he moved on to studying the Moon, but with the Earth data he had at the time, the math didn't come outright. When, in 1675, the more exact calculations of terrestrial measurements made by the French astronomer Jean Picard (1620-1682) were published, he was able to resume his calculations and verify that the hypothesis was correct. His view of the movement of celestial bodies continued to evolve, and by the mid-1680s he had generalized the theory of action at a distance to almost all phenomena in nature. At that time,

According to Newton's law of gravity, gravity is not only a force exerted by the Sun on the planets, but all objects in the cosmos attract each other, adding that the planets do not travel the same orbit twice.

Celestial mechanics, which is based on Kepler's three laws and Newton's universal law of gravitation, are still sufficient today to explain by calculating the movements of stars in a local universe, such as the solar system.

Issac Newton: Newton outside the scope of natural science in the strict sense 

Newton and religion 

Newton was deeply religious his whole life. Son of Puritans, he spent more time studying the Bible than science. A study of all he wrote reveals that, of the 3.6 million words he wrote, only one million relate science and theology 1,400,000. He has notably produced writings on the Bible and the Church Fathers, including An Historical Account of Two Notable Corruptions of Scripture, a highly regarded textual critique of the Holy Scriptures. In Cambridge, John Locke, to whom he spoke of his theological writings, urged him to persevere.

He believes in an immanent world, but rejects the implicit hylozoism of Leibniz and Spinoza. He sees evidence of divine design in the solar system: "The admirable uniformity of the planetary system forces us to recognize the effects of a choice". He however insisted that divine intervention would be required to "fix" the system because of the slow growth of its instability.

Isaac Newton belongs to Freemasonry. He is a friend of Jean Théophile Desaguliers and James Anderson, who founded the Grand Lodge of London in 1717, marking the passage of the operative masonry to modern speculative masonry.

According to an opinion disputed by Snobelen, TC Pfizenmaier argues that Newton's view of the Trinity is closer to that of the Orthodox Church than that of Roman Catholics, Anglicans, and most Protestants.

Historian Stephen D. Snobelen says “[that] Isaac Newton was a heretic. However, he never made a public statement of his own faith that the Orthodox would have considered extremely radical. He hid his faith so well that researchers have still not succeeded in elucidating his own beliefs ”. Snobelen concludes that Newton was at least sympathetic to Socinianism - he owned and conscientiously read at least eight Socinian works - probably an Arian and especially an anti-Trinitarian; three ancestral forms of what we now call Unitarianism. At a time notorious for its religious intolerance there are few traces of the public expression of radical views of Newton, the most notable are its rejection of the ordination and on his deathbed, one of the last sacraments.

This attitude takes on a new light with the authoritative opinion expressed by economist John Maynard Keynes, who purchased and analyzed Newton's manuscripts, long kept confidential by Newton's family because of their content. He summarized it in a letter, "Newton, the Man", which was read in July 1946by his brother Georges, during the celebrations of the bicentenary of Newton's death. Keynes concludes his analysis by asserting that Newton: “was rather a Judaizing monotheist of the school of Maimonides. He came to this conclusion, not on so to speak rational or doubtful grounds, but entirely by interpreting the old authorities. He was convinced that the documents revealed gave no support to the doctrines of the Trinity which were due to late falsifications. The revealed God was one God ”.

Newton will thus adopt what one could call "methodological positivism, by virtue of which the autonomy of scientific discourse is recognized, without this attitude in matters of epistemology implying the renunciation of any metaphysical and theological background ". Thus, although the universal law of gravitation is his best-known discovery, Newton warns those who would see the Universe as a mere machine. He says: “Gravity explains the movement of the planets, but it cannot explain what set them in motion. God governs all things and knows all that is or all that can be ”.

Newton wrote an unpublished manuscript, Irenicum, in which he supports a latitudinal view of theology.

Newton and Leibniz 

The controversy between these two great minds at the beginning of the 18th century focused on two points. The rather secondary one concerned their common claim of the discovery of the infinitesimal calculus, the other much more important point, related to the deep reasons for their opposition on the theory of the gravitation. If for Gottfried Wilhelm Leibniz, the movement of the planets around the sun is due to the harmonic circulation of a fluid ether around the sun which would carry the stars, it is because of his conception of the world. 

Indeed, his metaphysics forbids him to conceive of empty space, because that would be "to attribute to God a very imperfect production”. The Cartesians on this point were close to Leibniz so that Rodger Cotesduring the controversy will designate Cartesians and Leibnizians under the term of " plenists ". 

Although he was one of the first supporters ofRené Descartesin England, Henry More,a philosopher of the school known as the platonists of Cambridge, was one of the first to oppose this conception by asserting"the effective existence of space. infinite void”. In a way, it opens a way that Newton will partly follow later.

The controversy will be conducted with the endorsement of Newton by some of his relatives such as Samuel Clarke and Roger Cotes. It was aimed at Leibniz and the Cartesians, but the latter did not respond. It focused on the conception of God and, adjacently, on the notion of freedom and rationality. The meaning of this controversy is important to grasp because for Alexandre Koyré Newton's victory was a Pyrrhic victory won at a disastrous price."This is how the force of attraction - which, for Newton, was the proof of the insufficiency of the pure and simple mechanism, a demonstration of the existence of higher, non-mechanical forces, the manifestation of the presence and the action of God in the world - ceased to play this role to become a purely natural force, the property of matter which only enriched the mechanism instead of supplanting it”.

Concerning the conception of God for Alexandre Koyré “the fundamental opposition is however perfectly clear: the God of Leibniz is not the Newtonian Lord, who makes the world as he sees fit and continues to act on him as the God of the Bible did so during the first six days of Creation. He is if I dare to continue the comparison, the biblical God on the Sabbath day the God who has completed his work and finds that it represents… the best of all possible worlds… ” Unlike Leibniz, as he wrote Samuel Clarke, for Newton the world is reformable and if he has discovered the laws of universal attraction, he has found no need for these laws to be as they are. He simply noted their existence.

This search for necessary laws by the Leibnizian denies for Samuel Clarke the freedom of the agents. Also in his fourth response to Leibniz, he would write: "The Doctrine found here leads to Necessity & Fatality, assuming that the Motives have the same relation to the will of an intelligent Agent as the Weights. to a Libra ... But intelligent Beings are Agents; they are not simply passive & Motives do not act on them, like Weights act on a Libra. They have active forces.”

In Leibniz and in certain French Cartesians like Nicolas Malebranche, there is the idea that by his reason, man "can clearly find what God could do best  ". On the contrary with Newton and the Newtonians, reason tends to seek to observe the facts, to explain them, but there is a certain will not to be dragged away towards total explanations. Newton writes in the Philosophiæ Naturalis Principia Mathematica "I have hitherto explained the celestial phenomena and those of the sea by the force of gravitation, but I have nowhere assigned the cause of this gravitation".

Newton's influence on other sciences in the 18th century 

For Georges Gusdorf, “the imitation of Newton becomes the secret ambition of all scientists, whatever their science. Newton's system of intelligibility is accepted as the prototype of all knowledge which has reached a state of definitive completion ”.

For Dellemotte, in Adam Smith, in The Theory of Moral Sentiments, sympathy occupies the same function in the moral domain as the principle of gravitation. Let us recall that Adam Smith, is an admirer of Newton and that he wrote a History of astronomy of great importance to understand the framework of his thought. For Élie Halévy, the utilitarianism of Jeremy Bentham can be defined as "a Newtonianism, or if you like, an attempt at Newtonianism applied to matters of politics and morality" where the principle of association and that of utility play the role of the principle of universal attraction in Newton.

D'Alembert in the Preliminary Discourse to the Encyclopedia praises Newton, for having taught philosophy (at the time, this word also designates science) "to be wise, and to contain within fair limits this species of audacity that circumstances had forced Descartes to give it”. This approach marks the Encyclopedia which must accept that knowledge is incomplete and that the mind cannot order, measure and tidy up everything. If D'Alembert has heard of Newton's metaphysical works, he considers them unimportant; for him, the Newton of metaphysics is John Locke of whom he says "we can say that ". In France, the reception of Newton's theory of gravity will be slow, because it will take time to supplant René Descartes' theory based on vortices; it came to an end with the publication of the Encyclopedia.

Issac Newton: Newton and alchemy 

The synthesis between mechanism and alchemy 

Newton was introduced to chemistry in 1666 by reading Robert Boyle's book Of Formes, from which he took a chemical glossary. He began to study alchemy very intensively, in 1668 or 1669 and continued his research for at least thirty years, until 1696, following the explosion of his laboratory. His first attempts to publish works (concerning optics) ended in exhausting controversies - with Hooke in particular - he took refuge in silence when he plunged into alchemical research. In addition, he is certainly part of a secret network of alchemists probably formed from the theHartlib circle of London. He also chooses the alchemical pseudonym Ieoua Sanctus Unus which means in French: "Jehovah Unique Saint", but which is also an anagram of Isaac Neuutonus. For more than 25 years, Newton will keep the secret of his activities and especially of his contacts, from which he receives a large number of alchemical works and treatises, which he annotates and recopies until he is one of the largest alchemical libraries of his time.

Much of his unpublished writings in the alchemical tradition will be forgotten or misinterpreted: when in 1872 a descendant of his sister donated writings and books kept by his family to Cambridge University, the librarian referred to that - here a trunk containing the writings "not being of a scientific nature" including a large part of his alchemical works.

The absence, until 1936, the study of a large part of his alchemical manuscripts, the enormous influence of Newton's scientific community and a movement of rejection of alchemy born during the 18th century, bring many of his early biographers to different types of approaches. For example, David Brewster, author of the first scientific biography of reference, tries to separate the alchemy practiced by Newton from that which he considers as a deception while not understanding that such a genius could have lowered himself to this practice; Louis Trenchard More considers himself that Newton's alchemical works were only a way of "relaxing the », That they could have been governed by the greed or that they were the symptom of a mystical tension unrelated to the rest of his scientific work. The alchemy in which Newton was formed and which he practiced for many years is thus an often overlooked facet of his work.

For Keynes, who will bring together most of these scattered writings at an auction in 1936, “Newton is not the first of the Age of Reason. He is the last of the Babylonians and Sumerians, the last great spirit who contemplated the visible and intellectual world with the same eyes as those who began to build our intellectual heritage some 10,000 years ago”. It is only after the rediscovery of these manuscripts that his biographers will replace his alchemical works in all of his scientific work.

In the 17th  century, alchemy has an ambiguous reputation. Often referred to popularly as part of the field of quacks because of the pursuit of metals into gold, alchemy, however, is continuously practiced and studied throughout the 17th  century by many philosophers of nature because it offers a coherent overall vision for all natural phenomena. In this sense, it joins the mechanistic philosophy in its desire for a universal description of Nature.

"The transformation of bodies into light and light body is very consistent in nature, which seems to please the transmutations. "

On the other hand, the two philosophies are fundamentally separated on one point: for mechanists matter is inert, composed of particles characterized by their shape and whose movement is governed solely by the simple laws of shock or pressure; for the alchemists, the matter is only the vehicle of active principles which govern the world according to the laws of attraction and repulsion, of the population of male and female principles, and of which the mind is a stakeholder.

“Let us conceive of the particles of metals […] as endowed with a double force. The first is a force of attraction and is stronger, but it decreases rapidly with distance. The second is a more slowly decreasing repulsive force, and, for this reason, extends further into space. "

Nevertheless, for the philosophers of Newton's time, the separation of the two philosophies is not necessarily obvious, and they can even be conceived as complementary. Richard Westfall argues that it is perhaps the possibilities of universal description offered by mechanism and alchemy that prompted Newton not to close either of the two ways of working. Newton's interest in alchemy would lie in a “rebellion” against the restrictive limits imposed by mechanistic philosophy as well as by the desire to go beyond the mechanism of René Descartes.

In a work entitled De la gravitation et de la balance des fluid (dated at the earliest from 1668), he notably criticizes Descartes for an "atheism" arising from the strict separation of body and soul and the assumption according to which the material mechanistic world has no dependence on God. For BJT Dobbs, the first period of alchemical studies, which ended in 1675, and all the rest of his scientific research aimed at integrating mechanics and alchemy in a synthesis reconciling the corpuscular and neutral vision of the matter of on the one hand and long-distance interactions (or “affinities”) on the other, which he will ultimately achieve thanks to the introduction of the concept of force. 

The concept of force, and in particular of the force of gravitational attraction, although currently considered as the very foundation of mechanics was indeed considered at the time by mechanists as a resurgence of occultism and provoked strong reactions like that of Christiaan Huygens who wrote in 1687 a few days after the release of Principia: “I wish to see Newton's book. I do not mind that he is not Cartesian as long as he does not make assumptions like that of attraction. "

Research and alchemical studies 

By the extent of his work in this field, Newton can be considered as an outstanding alchemist in Europe. From 1668 to 1675, Isaac Newton practiced alchemy. In 1669, his accounts indicated an important acquisition of laboratory equipment related to his work in alchemy: a furnace, a mixer, various chemicals, and a compilation of alchemy treatises.

Some consider that alchemy is present to varying degrees in all his scientific work and that it allows us to understand its genesis and even unity. For his work, he will be based on an abundant bibliography, including the following books:

• the great alchemical collection of Theatrum Chemicum
• Zosime of Panopolis
• the pseudo-Geber (Latin name of the Arab alchemist Jabir Ibn Hayyan )
• Eyrénée Philalète (pseudonym of George Starkey ), The Open Entrance to the King's Closed Palace
• Michael Maier, Artifex Chymicus
• Basil Valentin, The Triumphal Chariot of Antimony
• the Cosmopolitan (pseudonym of Michael Sendivogius ), The New Chemical Light
• Jean d'Espagnet, Arcanum hermeticum

He established a synthesis which, applied to astronomy, made him draw the following conclusions: “The best water is attracted by the power of our Sulfur which lies hidden in the antimony. Because antimony was called Aries [Aries] by the Ancients. Because Aries is the first sign of the zodiac in which the Sun begins to be exalted and gold is especially exalted in antimony. Air begets the Chalybs or magnet, and this makes air appear. So his father is the Sun (gold) and his mother the Moon (silver). This is what the wind carries in its belly”. Later, he thinks he has discovered philosophical mercury and gives the precise modality of operation.

He founds "hypothesis 3": "Anybody can be transformed into any other body, and successively take all the degrees of qualities".

Issac Newton: Posterity 

Diffusion Newton's ideas 

The spread of Newton's ideas was slow enough but quite profound in the long run. The first edition of Newton's most famous work, the Principia, also written in Latin, had only been printed in 250 copies. The second edition of 750 copies in 1713 accelerated this distribution.

The first French scientist who learned about Newton's work was Maupertuis, who during his stay in England in 1728, belonged to the Royal Society of London. Maupertuis was a member of the Academy of Sciences in France. Back in Paris, Maupertuis decided to have his peers recognize Newton's theories: he published a text On the Laws of Attraction in the Mémoires de l'Académie in 1732, then a Discourse on the figure of the stars. On this occasion, Maupertuis established a friendship with Voltaire. Maupertuis's work on Newton revived the debates between supporters and opponents of the latter.

Paradoxically, it was a man of letters, a French philosopher moreover, who propagated Newton's ideas: Voltaire stayed in England between 1726 and 1728 and was very impressed by Newton's national funeral which he attended in April 1727. During his stay, among the many high-level contacts, he was able to have, Voltaire maintained relations with Samuel Clarke, a friend of Newton. He did not cease, thereafter, to spread the new ideas in a France which was still acquired with the theory of the vortices of Descartes. Voltaire wrote two essays on Newton: the epistle on Newtonian 1736, and Newton's Elements of Philosophy in 1738.

The Encyclopédie de Diderot et d'Alembert will also contribute to spreading Newton's theories, through astronomical articles whose writing has been taken care of mainly by d'Alembert, mathematician, and philosopher, who salutes the genius of Newton in the Preliminary Discourse of the Encyclopedia, and of course, devotes an article.

In the 19th  century, the influence of Newton was so deep that Claude Henri de Rouvroy Saint-Simon took universal gravitation as a fundamental principle of his philosophical system.

In the 20th  century, the historian and philosopher of science Thomas Kuhn believes that Newton is the origin of one of the greatest scientific revolutions in history.

Newton in the literature and the arts 

On Newton, Alexander Pope wrote a famous epitaph :

“Nature and its laws lay in the night.

So God said, "Let Newton be!" And the light was. "

William Blake made Newton the subject of one of his prints in 1795.

Isaac Newton is one of the regular characters in Gotlib's Rubric-à-brac. He appears there in a recurring gag featuring the apple which, falling on his head, leads him to conceive of the theory of gravitation. The apple is replaced, in many gags, by objects of all kinds, generally incongruous.

Isaac Newton appears in the animated Vision of Escaflowne, although he is never referred to except as “Isaac”. Transported to another world, Gaia, he will bring his science to a poor and arid nation to make it the most powerful industrial empire on the planet. Re-baptized Dornkirk, he then pursued research there on fate, fatality and luck, convinced that events and individuals are subject to forces of attraction similar to gravity.

In the series Star Trek: The Next Generation, Data regularly plays poker in his holodeck with Isaac Newton as well as Albert Einstein and Stephen Hawking.

Newtonian mechanics today 

Some phenomena that remained unresolved in the context of Newtonian mechanics as the precession of the perihelion of Mercury, now find an explanation to the theory of general relativity of Einstein. Note also that Newton's law is not able to apply to black holes, nor to the deviation of light by gravity. The philosopher of science Thomas Kuhn argues that Einstein's theory can only be accepted if Newton's theory is held to be false. In addition, Einstein rather defines gravitation by the twists of space-time. This is a new scientific revolution, which is accompanied by.

Issac Newton: Works 

• Scientific works
  • Method of Fluxions and Infinite series: a work of differential calculus, completed in 1671, posthumous publication in 1736.
  • De motu corporum in gyrum (From the movement of bodies on orbit), a work sent to Edmond Halley in 1684. In French: Du mouvement des corps , Gallimard, coll. "Tel", Paris, 1995 ( ISBN  2-07-072560-X )
  • Of gravitatione and equipondio fluidorum . In French: De la gravitation , Gallimard, coll. "Tel", Paris, 1995 ( ISBN  2-07-072560-X )
  • Philosophiæ Naturalis Principia Mathematica, London, 1687, 2nd ed. 1713, 3 ed. 1726.
  • Opticks, London, 1704. It is a major work in the history of science, dealing with light and its composition. In French: Optique, Christian Bourgois editor, Paris, 1989.
  • Arithmetica Universalis, published in 1707 brings together notations on various mathematical concepts.
  • Lectiones opticae , published posthumously in 1728.
• Other works, published posthumously
  • A treatise of the system of the world published posthumously in 1728.
  • The chronology of ancient kingdoms amended, published posthumously in 1728.
  • Observations upon the prophecies of Daniel and the apocalypse of St John published posthumously in 1733.
  • Two letters of Sir Isaac Newton to M. Leclerc… containing a Dissertation upon the Reading of the Greek Text, published posthumously in 1754.
• Unpublished works
  • Of Natures Obvious Laws & Processes in Vegetation (1671–75), unpublished work on alchemy.
• Works gathering Newton's writings
  • Writings on religion, Gallimard, Paris, 1996, 263 p. ( ISBN  2-07-073814-0 )

Issac Newton: Museums 

• Woolsthorpe Manor, the birthplace of Isaac Newton and Museum of Science, Woolsthorpe-by-Colsterworth, in the county of Lincolnshire