>What did Isaac Newton discover?
Isaac Newton's discoveries– laws and physics from one of the greatest geniuses. Study the law of universal gravitation, the three laws of motion, gravity, the shape of the Earth.
Isaac Newton(1642-1727) is remembered by us as a philosopher, scientist and mathematician. He did a lot for his time and actively participated in the scientific revolution. Interestingly, his views, Newton's laws and physics would prevail for another 300 years after his death. In fact, we have before us the creator of classical physics.
Subsequently, the word “Newtonian” will be inserted into all statements related to his theories. Isaac Newton is considered one of the greatest geniuses and most influential scientists, whose work spanned many scientific fields. But what do we owe to him and what discoveries did he make?
Three laws of motion
Let's start with his famous work “Mathematical Principles of Natural Philosophy” (1687), which revealed the foundations of classical mechanics. We are talking about three laws of motion, derived from the laws of planetary motion put forward by Johannes Kepler.
The first law is inertia: an object at rest will remain at rest unless acted upon by a force that is unbalanced. A body in motion will continue to move at its original speed and in the same direction unless it encounters an unbalanced force.
Second: acceleration occurs when force affects mass. The greater the mass, the more force required.
Third: for every action there is an equal and opposite reaction.
Universal gravity
Newton is to be thanked for the law of universal gravitation. He deduced that each point of mass attracts another by a force directed along a line intersecting both points (F = G frac(m_1 m_2)(r^2)).
These three postulates of gravity will help him measure the trajectories of comets, tides, equinoxes and other phenomena. His arguments crushed the last doubts regarding the heliocentric model and the scientific world accepted the fact that the Earth does not act as the universal center.
Everyone knows that Newton came to his conclusions about gravity thanks to the incident of an apple falling on his head. Many people think that this is just a comic retelling, and the scientist developed the formula gradually. But the entries in Newton’s diary and the retellings of his contemporaries speak in favor of the apple breakthrough.
Shape of the Earth
Isaac Newton believed that our planet Earth formed as an oblate spheroid. Later the guess would be confirmed, but in his time it was important information that helped transfer most of the scientific world from the Cartesian system to Newtonian mechanics.
In the mathematical field, he generalized the binomial theorem, studied power series, developed his own method for approximating the roots of a function, and divided most curved cubic planes into classes. He also shared his developments with Gottfried Leibniz.
His discoveries were breakthroughs in physics, mathematics and astronomy, helping to understand the structure of space using formulas.
Optics
In 1666, he delved deeper into optics. It all started with studying the properties of light, which he measured through a prism. In 1670-1672. studied the refraction of light, showing how a multi-colored spectrum is rearranged into a single white light using a lens and a second prism.
As a result, Newton realized that color is formed due to the interaction of objects that were originally colored. In addition, I noticed that the lens of any instrument suffers from light scattering (chromatic aberration). He managed to solve the problems using a telescope with a mirror. His invention is considered the first model of a reflecting telescope.
Besides…
He is also credited with formulating the empirical law of cooling and studying the speed of sound. From his suggestion, the term “Newtonian fluid” appeared - a description of any fluid where viscous stresses are linearly proportional to the rate of its transformation.
Newton devoted a large amount of time to researching not only scientific postulates, but also biblical chronology and introduced himself into alchemy. However, many works appeared only after the death of the scientist. So Isaac Newton is remembered not only as a talented physicist, but also as a philosopher.
What do we owe to Isaac Newton? His ideas were breakthrough not only for that time, but also served as starting points for all subsequent scientists. It prepared fertile ground for new discoveries and inspired exploration of this world. It is not surprising that Isaac Newton had followers who developed his ideas and theories. If you are interested in learning more, the site has a biography of Isaac Newton, which presents the date of birth and death (according to the new and old style), the most important discoveries, as well as interesting facts about the greatest physicist.
There is probably not a single person in the world who does not know who Isaac Newton is. One of the world's most outstanding scientists, who made discoveries in several fields of science at once, giving rise to scientific directions in mathematics, optics, astronomy, one of the founding fathers classical physics. So, who is Isaac Newton? Today his short biography and his discoveries are widely known.
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The story of a scientist and explorer
One could say about him in the words of the poet Nikolai Tikhonov: “I should make nails out of these people. There couldn’t be any stronger nails in the world.” Born before his due date, very small and weak, he lived 84 years in perfect health, until a ripe old age, devoting wholeheartedly to the development of science and engaging in government affairs. Throughout his life, the scientist adhered to strong moral principles, was a model of honesty, and did not strive for publicity and fame. Even the will of King James II did not break him.
Childhood
The scientist considered his birth on the eve of Catholic Christmas to be a special sign of providence. After all, he managed to make his greatest discoveries. Like a new star of Bethlehem, he illuminated many directions in which science subsequently developed. Many discoveries have been made thanks to the planned they are on their way.
Newton's father, who seemed an eccentric and strange man to his contemporaries, never found out about the birth of his son. A successful farmer and good owner, who lived only a few months before the birth of his son, left the family a significant farm and money.
From his youth, having had a tender affection for his mother all his life, Isaac could not forgive her decision to leave him in the care of his grandparents after she married for the second time. The autobiography, compiled by him as a teenager, tells of outbursts of despair and children's plans for revenge against his mother and stepfather. He could only trust paper with the story of his emotional experiences; in life, the famous scientist was closed, didn't have close friends and was never married.
At the age of 12 he was sent to Grantham School. His closed and unsociable disposition, as well as his internal focus, turned his peers against him. From childhood, the future scientist preferred studying the natural sciences to boyish pranks. He read a lot, was interested in designing mechanical toys, and solving mathematical problems. A conflict situation with classmates prompted the proud Newton to become best student at school.
Studying at Cambridge
Having been widowed, Newton's mother really hoped that her 16-year-old son would begin to help her with farming. But through the joint efforts of the school teacher, the boy's uncle and especially Humphrey Babington, a member of Trinity College, she was able to convince her of the need for further education. In 1661, Newton took an exam in Latin and enters Trinity College at the University of Cambridge. It was in this institution that for 30 years he studied science, conducted experiments and made world discoveries.
Instead of paying for his studies at the college, where the young man first lived as a student-sizer, he had to carry out some errands for richer students and other economic work around the university. Just 3 years later, in 1664, Newton passed the exams with honors and received an advanced student category, as well as the right not only to free education, but also to a scholarship.
His studies fascinated and inspired him so much that, according to the recollections of his classmates, he could forget about sleep and food. Still engaged in mechanics and designed various things and tools, was interested in mathematical calculations, astronomical observations, research in optics, philosophy, even music theory and history.
Deciding to devote his years of life to science, he gives up love and plans to start a family. The young pupil of the pharmacist Clark, with whom he lived during his school years, also did not marry and retained a tender memory of Newton throughout her life.
First steps in scientific activity
The year 1664 was an inspiring year for the young scientist. He compiles a “Questionnaire” of 45 scientific problems and sets himself the goal of solving them all.
Thanks to the lectures of the famous mathematician I. Barrow, Newton made his first discovery of the binomial expansion, which allowed him to subsequently develop the method of differential calculus, which is used today in higher mathematics. He passes the exam successfully and receives a bachelor's degree.
Even the plague epidemic of 1665 - 1667 could not stop this inquisitive mind and force him to sit idle. During the rampant illness, Newton went home, where he continued to engage in scientific activities. Here, in the privacy of home, he does most of his great discoveries:
- establishes basic methods of types of calculus - integral and differential;
- deduces the theory of color and gives rise to the development of optical science;
- finds a method for finding roots of quadratic equations;
- derives a formula for the expansion of an arbitrary natural power of a binomial.
Important! The famous apple tree, the observations of which helped in the discovery, was preserved as a memorial bench for the scientist.
Major discoveries
Isaac Newton a brief description of his activities. He was not just a genius, a famous scientist, but a person with diverse interests in many areas of science and technology. What is he famous for and what did he discover? A keen mathematician and physicist, he was equally well versed in both the exact sciences and the humanities. Economics, alchemy, philosophy, music and history - in all these areas the genius of his talent worked. Here is just a brief description of the great discoveries of Isaac Newton:
- developed a theory of the movement of celestial bodies - determined that the planets revolve around;
- formulated three important laws of mechanics;
- developed the theory of light and color shades;
- built the world's first mirror;
- discovered the Law of Gravity, thanks to which he became famous.
According to existing legend, Newton discovered the famous law while observing apples falling from an apple tree in his garden. Biographer of the famous scientist William Stukeley describes this moment in a book dedicated to the memories of Newton, which was published in 1752. According to Stukeley, it was an apple falling from a tree that gave him the idea of attraction of cosmic bodies and gravity.
“Why do apples fall perpendicular to the ground?” - thought Newton and, reflecting, deduced a new law. In the garden of the University of Cambridge, students revere and carefully care for a tree considered to be a descendant of the same “Newton’s apple tree”.
The falling of the apple served only as an impetus for the famous discovery. Newton went to him for many years, studying the works Galileo, Bullialda, Hooke, other astronomers and physicists. The scientist considered Keller’s Third Law to be another impulse. True, he composed the modern interpretation of the Law of Universal Gravitation somewhat later, when he studied the laws of mechanics.
Other scientific developments
The basis of classical mechanics is Newton’s Laws, the most important in the field of mechanics, which were formulated in a scientific work on mathematics and the principles of philosophy, published in 1687:
- the first Law of uniform motion in a straight line if no other forces act on the body;
- the second Law is , which in differential form describes the influence of acting forces on acceleration;
- the third Law is about the force of interaction between two bodies at a certain distance.
Currently these Newton's laws are an axiom.
Astronomy
At the end of 1669, the scientist received one of the most prestigious positions in the world at Trinity College, the named Lucasian professor of mathematics and optics. In addition to a £100 salary, bonuses and scholarships, there is the opportunity to devote more time own scientific research activities. Doing experiments in optics and the theory of light, Newton creates his first reflecting telescope.
Important! The improved telescope became the main instrument for astronomers and navigators of the time. With its help, the planet Uranus was discovered and other galaxies were discovered.
Studying the celestial bodies through his reflector, the scientist developed a theory of celestial bodies and determined the movement of planets around the Sun. Using the calculations of my reflector and applying a scientific approach to Bible study, I made my own message about the end of the world. According to his calculations, this event will take place in 2060.
Government activities
1696 The great scientist holds the position of keeper of the Mint and moved to London, where he lived until 1726. Having carried out financial accounting and established order in the documentation, he becomes Montagu's co-author on carrying out monetary reform.
During the period of his activity, a branch network of the Mint was created, and the production of silver coins increased several times. Newton introduces technology, allowing you to get rid of counterfeiters.
1699 Becomes manager of the Mint. In this post he continues to fight counterfeiters. His actions as manager were as brilliant as during his scientific career. Thanks to the reforms carried out in England economic crisis was averted.
1698 A report on Newton's economic reform was presented. While in England, Tsar Peter met with the famous professor three times. In 1700, a monetary reform similar to the English one was carried out in Russia.
1689 -1690. He was a representative of Cambridge University in the country's parliament. From 1703 to 1725 he served as President of the Royal Society.
Attention! In 1705, Queen Anne of Great Britain knighted Isaac Newton. This was the only time in English history that knighthood was awarded for scientific achievements.
Biography of Newton, his discoveries
The life of the great scientist Isaac Newton
Completion of life's journey
The last months of his life the professor lived in Kensington. The great scientist died on March 20, 1727. He died in his sleep and was buried on the grounds of Westminster Abbey in the tomb of the kings and most prominent people of England. All the townspeople came to say goodbye to their famous contemporary. The funeral procession was led by the Lord Chancellor himself, followed in the funeral procession by British ministers.
The complete picture of the world created by the great English scientist Isaac Newton still amazes scientists. Newton's merit is that both huge celestial bodies and the smallest grains of sand driven by the wind obey the laws he discovered.
Isaac Newton was born in England on January 4, 1643. At the age of 26 he became a professor of mathematics and physics and taught for 27 years. In the first years of his scientific activity, he became interested in optics, where he made many discoveries. He personally made the first reflecting telescope, which magnified 40 times (a considerable amount at that time).
Since 1676, Newton began studying mechanics. The scientist outlined the main discoveries in this area in the monumental work “Mathematical Principles of Natural Philosophy.” “Principles” described everything that was known about the simplest forms of motion of matter. Newton's teachings about space, mass and force were of great importance for the further development of physics. Only the discoveries of the 20th century, especially Einstein, showed the limitations of the laws on which Newton's theory of classical mechanics was built. But despite this, classical mechanics has not lost its practical significance.
Isaac Newton laid down the law of universal gravitation and the three laws of mechanics, which became the basis of classical mechanics. He gave a theory of the movement of celestial bodies, creating the foundations of celestial mechanics. He developed differential and integral calculus, made many discoveries in the science of optics and color theory, and developed a number of other mathematical and physical theories. Newton's scientific works were far ahead of the general scientific level of his time, and therefore many of them were poorly understood by his contemporaries. Many of his hypotheses and predictions turned out to be prophetic, for example, the deflection of light in the gravitational field, the phenomenon of polarization of light, the interconversion of light and matter, the hypothesis about the oblateness of the Earth at the poles, etc.
The following words are carved on the grave of the great scientist:
"Here lies
Sir Isaac Newton
Who with the almost divine power of his mind
First explained
Using your own mathematical method
Movements and shapes of the planets,
The paths of comets, the ebb and flow of the ocean.
He was the first to explore the variety of light rays
And the resulting characteristics of colors,
Which until that time no one even suspected.
Diligent, insightful and faithful interpreter
Nature, antiquities and scripture,
He glorified the Almighty Creator in his teaching.
He proved the simplicity required by the Gospel with his life.
Let mortals rejoice that in their midst
Once upon a time there lived such an ornament of the human race.
The great English physicist, mathematician and astronomer. The author of the fundamental work “Mathematical Principles of Natural Philosophy” (lat. Philosophiae Naturalis Principia Mathematica), in which he described the law of universal gravitation and the so-called Newton’s Laws, which laid the foundations of classical mechanics. He developed differential and integral calculus, color theory and many other mathematical and physical theories.
Isaac Newton, the son of a small but prosperous farmer, was born in the village of Woolsthorpe (Lincolnshire), in the year of Galileo's death and on the eve of the Civil War. Newton's father did not live to see his son born. The boy was born sickly, prematurely, but still survived and lived for 84 years. Newton considered the fact of being born on Christmas a special sign of fate.
The boy's patron was his maternal uncle, William Ayscough. After graduating from school (1661), Newton entered Trinity College (College of the Holy Trinity) at the University of Cambridge. Even then, his powerful character took shape - scientific meticulousness, the desire to get to the bottom of things, intolerance to deception and oppression, indifference to public fame. As a child, Newton, according to contemporaries, was withdrawn and isolated, loved to read and make technical toys: a clock, a mill, etc.
Apparently, the scientific support and inspiration for Newton’s work were largely the physicists: Galileo, Descartes and Kepler. Newton completed their work by combining them into a universal system of the world. Other mathematicians and physicists had a lesser but significant influence: Euclid, Fermat, Huygens, Mercator, Wallis. Of course, the enormous influence of his immediate teacher Barrow cannot be underestimated.
It seems that Newton made a significant part of his mathematical discoveries while still a student, during the “plague years” of 1664-1666. At the age of 23, he was already fluent in the methods of differential and integral calculus, including series expansion of functions and what was later called the Newton-Leibniz formula. At the same time, according to him, he discovered the law of universal gravitation, or rather, he became convinced that this law follows from Kepler’s third law. In addition, during these years Newton proved that white color is a mixture of colors, derived the formula of “Newton’s binomial” for an arbitrary rational exponent (including negative ones), etc.
1667: The plague subsides and Newton returns to Cambridge. Elected a fellow of Trinity College, and in 1668 he became a master.
In 1669, Newton was elected professor of mathematics, Barrow's successor. Barrow forwarded to London Newton's "Analysis by Equations of Infinite Number of Terms," which contained a condensed summary of some of his most important discoveries in analysis. It gained some fame in England and abroad. Newton is preparing a complete version of this work, but is still unable to find a publisher. It was published only in 1711.
Experiments in optics and color theory continue. Newton studies spherical and chromatic aberration. To reduce them to a minimum, he builds a mixed reflecting telescope (lens and concave spherical mirror, which he polishes himself). He is seriously interested in alchemy and conducts a lot of chemical experiments.
1672: Demonstration of the reflector in London - universally rave reviews. Newton becomes famous and is elected a member of the Royal Society (British Academy of Sciences). Later, improved reflectors of this design became the main tools of astronomers, with their help other galaxies, red shifts, etc. were discovered.
A controversy breaks out over the nature of light with Hooke, Huygens and others. Newton makes a vow for the future: not to get involved in scientific disputes.
1680: Newton receives a letter from Hooke with the formulation of the law of universal gravitation, which, according to the former, served as the reason for his work on determining planetary motions (though then postponed for some time), which formed the subject of the Principia. Subsequently, Newton, for some reason, perhaps suspecting Hooke of illegally borrowing some earlier results of Newton himself, does not want to recognize any of Hooke’s merits here, but then agrees to do so, although rather reluctantly and not completely.
1684-1686: work on “Mathematical principles of natural philosophy” (the entire three-volume work was published in 1687). The Cartesians gained worldwide fame and fierce criticism: the law of universal gravitation introduces long-range action that is incompatible with the principles of Descartes.
1696: By royal decree, Newton was appointed Warden of the Mint (from 1699 - Director). He vigorously pursues monetary reform, restoring confidence in the British monetary system, which had been thoroughly neglected by his predecessors.
1699: the beginning of an open priority dispute with Leibniz, in which even the reigning persons were involved. This absurd quarrel between two geniuses cost science dearly - the English mathematical school soon withered for a whole century, and the European school ignored many of Newton’s outstanding ideas, rediscovering them much later. On the continent, Newton was accused of stealing the results of Hooke, Leibniz and the astronomer Flamsteed, as well as of heresy. Even the death of Leibniz (1716) did not extinguish the conflict.
1703: Newton is elected president of the Royal Society, which he rules for twenty years.
1705: Queen Anne knights Newton. From now on he is Sir Isaac Newton. For the first time in English history, the title of knight was awarded for scientific merit.
Newton devoted the last years of his life to writing the Chronology of Ancient Kingdoms, which he worked on for about 40 years, and preparing the third edition of the Elements.
In 1725, Newton's health began to deteriorate noticeably (stone disease), and he moved to Kensington near London, where he died at night, in his sleep, on March 20 (31), 1727.
The inscription on his grave reads:
Here lies Sir Isaac Newton, the nobleman who, with an almost divine mind, was the first to prove with the torch of mathematics the motion of the planets, the paths of comets, and the tides of the oceans.
He investigated the difference in light rays and the various properties of colors that appeared at the same time, which no one had previously suspected. A diligent, wise and faithful interpreter of nature, antiquity and Holy Scripture, he affirmed with his philosophy the greatness of Almighty God, and with his disposition he expressed evangelical simplicity.
Let mortals rejoice that such an adornment of the human race existed.
Named after Newton:
craters on the Moon and Mars;
SI unit of force.
The statue erected to Newton in 1755 at Trinity College bears the following verses from Lucretius:
Qui genus humanum ingenio superavit (He was superior to the human race in intelligence)
Scientific activity
A new era in physics and mathematics is associated with Newton's work. Powerful analytical methods appear in mathematics, and there is a breakthrough in the development of analysis and mathematical physics. In physics, the main method of studying nature is the construction of adequate mathematical models of natural processes and intensive research of these models with the systematic use of the full power of the new mathematical apparatus. Subsequent centuries have proven the exceptional fruitfulness of this approach.
According to A. Einstein, “Newton was the first who tried to formulate elementary laws that determine the time course of a wide class of processes in nature with a high degree of completeness and accuracy” and “... had with his works a deep and strong influence on the entire worldview as a whole.”
Mathematical analysis
Newton developed differential and integral calculus simultaneously with G. Leibniz (a little earlier) and independently of him.
Before Newton, operations with infinitesimals were not linked into a single theory and had the character of isolated ingenious techniques (see Method of indivisibles), at least there was no published systematic formulation and the power of analytical techniques for solving such complex problems as the problems of celestial mechanics in their entirety. The creation of mathematical analysis reduces the solution of relevant problems, to a large extent, to a technical level. A complex of concepts, operations and symbols appeared, which became the starting point for the further development of mathematics. The next century, the 18th century, was a century of rapid and extremely successful development of analytical methods.
Apparently, Newton came to the idea of analysis through difference methods, which he studied extensively and deeply. True, in his “Principles” Newton almost did not use infinitesimals, adhering to ancient (geometric) methods of proof, but in other works he used them freely.
The starting point for differential and integral calculus were the works of Cavalieri and especially Fermat, who already knew how (for algebraic curves) to draw tangents, find extrema, inflection points and curvature of a curve, and calculate the area of its segment. Among other predecessors, Newton himself named Wallis, Barrow and the Scottish astronomer James Gregory. There was no concept of a function yet; he interpreted all curves kinematically as trajectories of a moving point.
Already as a student, Newton realized that differentiation and integration are mutually inverse operations (apparently, the first published work containing this result in the form of a detailed analysis of the duality of the area problem and the tangent problem belongs to Newton's teacher Barrow).
For almost 30 years Newton did not bother to publish his version of the analysis, although in letters (in particular to Leibniz) he willingly shared much of what he had achieved. Meanwhile, Leibniz's version had been spreading widely and openly throughout Europe since 1676. Only in 1693 did the first presentation of Newton's version appear - in the form of an appendix to Wallis's Treatise on Algebra. We have to admit that Newton’s terminology and symbolism are rather clumsy in comparison with Leibniz’s: fluxion (derivative), fluenta (antiderivative), moment of magnitude (differential), etc. Only Newton’s notation “o” for an infinitesimal dt has been preserved in mathematics (however , this letter was used earlier by Gregory in the same sense), and even a dot above the letter as a symbol of the derivative with respect to time.
Newton published a fairly complete statement of the principles of analysis only in the work “On the Quadrature of Curves” (1704), an appendix to his monograph “Optics”. Almost all of the material presented was ready back in the 1670-1680s, but only now Gregory and Halley persuaded Newton to publish the work, which, 40 years late, became Newton’s first printed work on analysis. Here, Newton introduced derivatives of higher orders, found the values of the integrals of various rational and irrational functions, and gave examples of solving 1st order differential equations.
1711: "Analysis by Equations with an Infinite Number of Terms" is finally published, after 40 years. Newton explores both algebraic and “mechanical” curves (cycloid, quadratrix) with equal ease. Partial derivatives appear, but for some reason there is no rule for differentiating a fraction and a complex function, although Newton knew them; however, Leibniz had already published them at that time.
In the same year, “The Method of Differences” was published, where Newton proposed an interpolation formula for drawing through (n + 1) given points with equally spaced or unequally spaced abscissas of a parabolic curve of the nth order. This is a difference analogue of Taylor's formula.
1736: The final work, “The Method of Fluxions and Infinite Series,” is published posthumously, significantly advanced compared to “Analysis by Equations.” Numerous examples are given of finding extrema, tangents and normals, calculating radii and centers of curvature in Cartesian and polar coordinates, finding inflection points, etc. In the same work, quadratures and straightenings of various curves were performed.
It should be noted that Newton not only developed the analysis quite fully, but also made an attempt to strictly substantiate its principles. If Leibniz was inclined to the idea of actual infinitesimals, then Newton proposed (in the Principia) a general theory of passage to limits, which he somewhat floridly called the “method of first and last relations.” The modern term “limes” is used, although there is no clear description of the essence of this term, implying an intuitive understanding.
The theory of limits is set out in 11 lemmas in Book I of the Elements; one lemma is also in book II. There is no arithmetic of limits, there is no proof of the uniqueness of the limit, and its connection with infinitesimals has not been revealed. However, Newton rightly points out the greater rigor of this approach compared to the “rough” method of indivisibles.
Nevertheless, in Book II, by introducing moments (differentials), Newton again confuses the matter, in fact considering them as actual infinitesimals.
Other mathematical achievements
Newton made his first mathematical discoveries back in his student years: the classification of algebraic curves of the 3rd order (curves of the 2nd order were studied by Fermat) and the binomial expansion of an arbitrary (not necessarily integer) degree, from which Newton’s theory of infinite series began - a new and powerful tool of analysis . Newton considered series expansion to be the main and general method of analyzing functions, and in this matter he reached the heights of mastery. He used series to calculate tables, solve equations (including differential ones), and study the behavior of functions. Newton was able to obtain expansions for all the functions that were standard at that time.
In 1707, the book “Universal Arithmetic” was published. It presents a variety of numerical methods.
Newton always paid great attention to the approximate solution of equations. Newton's famous method made it possible to find the roots of equations with previously unimaginable speed and accuracy (published in Wallis' Algebra, 1685). Newton's iterative method was given its modern form by Joseph Raphson (1690).
It is noteworthy that Newton was not at all interested in number theory. Apparently, physics was much closer to mathematics to him.
Theory of gravity
The very idea of the universal force of gravity was repeatedly expressed before Newton. Previously, Epicurus, Kepler, Descartes, Huygens, Hooke and others thought about it. Kepler believed that gravity is inversely proportional to the distance to the Sun and extends only in the ecliptic plane; Descartes considered it the result of vortices in the ether. There were, however, guesses with the correct formula (Bulliald, Wren, Hooke), and even quite seriously substantiated (using the correlation of Huygens' formula for centrifugal force and Kepler's third law for circular orbits). But before Newton, no one was able to clearly and mathematically conclusively connect the law of gravity (a force inversely proportional to the square of the distance) and the laws of planetary motion (Kepler's laws).
It is important to note that Newton did not simply publish a proposed formula for the law of universal gravitation, but actually proposed a complete mathematical model in the context of a well-developed, complete, explicit and systematic approach to mechanics:
law of gravitation;
law of motion (Newton's 2nd law);
system of methods for mathematical research (mathematical analysis).
Taken together, this triad is sufficient for a complete study of the most complex movements of celestial bodies, thereby creating the foundations of celestial mechanics. Before Einstein, no fundamental amendments to this model were needed, although the mathematical apparatus was very significantly developed.
Newton's theory of gravity caused many years of debate and criticism of the concept of long-range action.
The first argument in favor of the Newtonian model was the rigorous derivation of Kepler's empirical laws on its basis. The next step was the theory of the movement of comets and the Moon, set out in the “Principles”. Later, with the help of Newtonian gravity, all observed movements of celestial bodies were explained with high accuracy; This is a great merit of Clairaut and Laplace.
The first observable corrections to Newton's theory in astronomy (explained by general relativity) were discovered only more than 200 years later (shift of the perihelion of Mercury). However, they are also very small within the solar system.
Newton also discovered the cause of tides: the gravity of the Moon (even Galileo considered tides to be a centrifugal effect). Moreover, having processed many years of data on the height of tides, he calculated the mass of the Moon with good accuracy.
Another consequence of gravity was the precession of the earth's axis. Newton found out that due to the oblateness of the Earth at the poles, the earth's axis undergoes a constant slow displacement with a period of 26,000 years under the influence of the attraction of the Moon and the Sun. Thus, the ancient problem of “anticipation of the equinoxes” (first noted by Hipparchus) found a scientific explanation.
Optics and theory of light
Newton made fundamental discoveries in optics. He built the first mirror telescope (reflector), in which, unlike purely lens telescopes, there was no chromatic aberration. He also discovered the dispersion of light, showed that white light is decomposed into the colors of the rainbow due to the different refraction of rays of different colors when passing through a prism, and laid the foundations of the correct theory of colors.
During this period there were many speculative theories of light and color; Basically, they fought between the points of view of Aristotle (“different colors are a mixture of light and darkness in different proportions”) and Descartes (“different colors are created when light particles rotate at different speeds”). Hooke, in his Micrographia (1665), proposed a variant of Aristotelian views. Many believed that color is an attribute not of light, but of an illuminated object. The general discord was aggravated by a cascade of discoveries in the 17th century: diffraction (1665, Grimaldi), interference (1665, Hooke), double refraction (1670, Erasmus Bartholin, studied by Huygens), estimation of the speed of light (1675, Roemer), significant improvements in telescopes. There was no theory of light compatible with all these facts.
In his speech to the Royal Society, Newton refuted both Aristotle and Descartes, and convincingly proved that white light is not primary, but consists of colored components with different angles of refraction. These components are primary - Newton could not change their color with any tricks. Thus, the subjective sensation of color received a solid objective basis - the refractive index.
Newton created the mathematical theory of interference rings discovered by Hooke, which have since been called “Newton’s Rings.”
In 1689, Newton stopped research in the field of optics - according to a widespread legend, he vowed not to publish anything in this area during the life of Hooke, who constantly pestered Newton with criticism that was painful for the latter. In any case, in 1704, the next year after Hooke’s death, the monograph “Optics” was published. During the author’s lifetime, “Optics,” like “Principles,” went through three editions and many translations.
Book one of the monograph contained the principles of geometric optics, the doctrine of light dispersion and the composition of white color with various applications.
Book two: interference of light in thin plates.
Book three: diffraction and polarization of light. Newton explained polarization during birefringence closer to the truth than Huygens (a supporter of the wave nature of light), although the explanation of the phenomenon itself was unsuccessful, in the spirit of the emission theory of light.
Newton is often considered a proponent of the corpuscular theory of light; in fact, as usual, he “did not invent hypotheses” and readily admitted that light could also be associated with waves in the ether. In his monograph, Newton described in detail the mathematical model of light phenomena, leaving aside the question of the physical carrier of light.
Other works in physics
Newton was the first to derive the speed of sound in a gas, based on the Boyle-Mariotte law.
He predicted the oblateness of the Earth at the poles, approximately 1:230. At the same time, Newton used a homogeneous fluid model to describe the Earth, applied the law of universal gravitation and took into account centrifugal force. At the same time, Huygens performed similar calculations on similar grounds; he considered gravity as if its source was in the center of the planet, since, apparently, he did not believe in the universal nature of the force of gravity, that is, ultimately he did not take into account the gravity of the deformed surface layer of the planet. Accordingly, Huygens predicted a compression less than half that of Newton, 1:576. Moreover, Cassini and other Cartesians argued that the Earth is not compressed, but bulged at the poles like a lemon. Subsequently, although not immediately (the first measurements were inaccurate), direct measurements (Clerot, 1743) confirmed Newton’s correctness; actual compression is 1:298. The reason this value differs from that proposed by Newton in favor of Huygens’s is that the model of a homogeneous liquid is still not entirely accurate (density increases noticeably with depth). A more accurate theory, explicitly taking into account the dependence of density on depth, was developed only in the 19th century.
Other works
In parallel with the research that laid the foundation of the current scientific (physical and mathematical) tradition, Newton devoted a lot of time to alchemy, as well as theology. He did not publish any works on alchemy, and the only known result of this long-term hobby was the serious poisoning of Newton in 1691.
It is paradoxical that Newton, who worked for many years at the College of the Holy Trinity, apparently himself did not believe in the Trinity. Researchers of his theological works, such as L. More, believe that Newton's religious views were close to Arianism.
Newton proposed his own version of biblical chronology, leaving behind a significant number of manuscripts on these issues. In addition, he wrote a commentary on the Apocalypse. Newton's theological manuscripts are now kept in Jerusalem, in the National Library.
The Secret Works of Isaac Newton
As is known, shortly before the end of his life, Isaac refuted all the theories put forward by himself and burned the documents that contained the secret of their refutation: some had no doubt that everything was exactly like that, while others believe that such actions would be simply absurd and claim that the archive complete with documents, but only belongs to a select few...
Great personality
The lives of epoch-making personalities and their progressive role have been meticulously studied over many centuries. They gradually build up in the eyes of descendants from event to event, overgrown with details recreated from documents and all sorts of idle inventions. So is Isaac Newton. A brief biography of this man, who lived in the distant 17th century, can only be contained in a book volume the size of a brick.
So, let's begin. Isaac Newton - English (now substitute “great” for each word) astronomer, mathematician, physicist, mechanic. In 1672 he became a scientist of the Royal Society of London, and in 1703 - its president. Creator of theoretical mechanics, founder of all modern physics. Described all physical phenomena based on mechanics; discovered the law of universal gravitation, which explained cosmic phenomena and the dependence of earthly realities on them; tied the causes of tides in the oceans to the movement of the Moon around the Earth; described the laws of our entire solar system. It was he who first began to study the mechanics of continuous media, physical optics and acoustics. Independently of Leibniz, Isaac Newton developed differential and integral equations, discovered the dispersion of light, chromatic aberration, tied mathematics to philosophy, wrote works on interference and diffraction, worked on the corpuscular theory of light, theories of space and time. It was he who designed the reflecting telescope and organized the coin business in England. In addition to mathematics and physics, Isaac Newton studied alchemy, the chronology of ancient kingdoms, and wrote theological works. The genius of the famous scientist was so far ahead of the entire scientific level of the seventeenth century that his contemporaries remembered him to a greater extent as an exceptionally good person: non-covetous, generous, extremely modest and friendly, always ready to help his neighbor.
Childhood
The great Isaac Newton was born into the family of a small farmer who died three months ago in a small village. His biography began on January 4, 1643 with the fact that a very small premature baby was placed in a sheepskin mitten on a bench, from which he fell, hitting him hard. The child grew up sickly and therefore unsociable; he could not keep up with his peers in fast games and became addicted to books. Relatives noticed this and sent little Isaac to school, where he graduated as the first student. Later, seeing his zeal for learning, they allowed him to continue studying. Isaac entered Cambridge. Since there was not enough money for training, his role as a student would have been very humiliating if he had not been lucky with his mentor.
Youth
At that time, poor students could only study as servants from their teachers. This is the fate that befell the future brilliant scientist. There are all sorts of legends, some of them ugly, about this period in Newton’s life and creative path. The mentor whom Isaac served was an influential Freemason who traveled not only throughout Europe, but also throughout Asia, including the Middle East, the Far East, and the Southeast. On one of his trips, as the legend says, he was entrusted with ancient manuscripts of Arab scientists, whose mathematical calculations we still use today. According to legend, Newton had access to these manuscripts, and they inspired many of his discoveries.
The science
Over six years of study and service, Isaac Newton went through all the stages of college and became a Master of Arts.
During the plague epidemic, he had to leave his alma mater, but he did not waste time: he studied the physical nature of light, built the laws of mechanics. In 1668, Isaac Newton returned to Cambridge and soon received the Lucasian chair of mathematics. He got it from his teacher, I. Barrow, that same Mason. Newton quickly became his favorite student, and in order to financially provide for his brilliant protégé, Barrow abandoned the chair in his favor. By that time, Newton was already the author of the binomial. And this is only the beginning of the biography of the great scientist. What followed was a life full of titanic mental labor. Newton was always modest and even shy. For example, he did not publish his discoveries for a long time and was constantly planning to destroy one or another chapter of his amazing “Principles.” He believed that he owed everything to those giants on whose shoulders he stood, meaning, probably, his predecessor scientists. Although who could precede Newton if he literally said the very first and most weighty word about everything in the world.