NEWTON (Newton) Isaac (January 4, 1643, Woolsthorpe, near Grantham, Lincolnshire, England - March 31, 1727, London; buried in Westminster Abbey), one of the founders of modern physics, formulated the basic laws of mechanics and was the actual creator of a unified physical program for describing all physical phenomena based on mechanics; discovered the law of universal gravitation, explained the movement of the planets around the Sun and Moon around the Earth, as well as tides in the oceans, laid the foundations of continuum mechanics, acoustics and physical optics.
Childhood years
Isaac Newton was born in a small village in the family of a small farmer who died three months before the birth of his son.
The baby was premature; there is a legend that he was so small that he was placed in a sheepskin glove lying on a bench, from which he once fell out and hit his head hard on the floor.
When the child was three years old, his mother remarried and left, leaving him in the care of his grandmother.
Newton grew up sickly and unsociable, prone to daydreaming.
He was attracted to poetry and painting, he, far from his peers, made kites, invented a windmill, a water clock, a pedal cart.
The beginning of school life was difficult for Newton.
He studied poorly, was a weak boy, and once his classmates beat him until he lost consciousness.
To endure such a humiliating situation was unbearable for the proud Newton, and there was only one thing left: to stand out with academic success.
Through hard work, he achieved that he took first place in the class.
His interest in technology made Newton think about the phenomena of nature; he also studied mathematics in depth.
Jean Baptiste Biot later wrote about this: "One of his uncles, finding him one day under a hedge with a book in his hands, immersed in deep thought, took the book from him and found that he was busy solving a mathematical problem.
Struck by such a serious and active direction of such a young man, he persuaded his mother not to further resist the desire of her son and send him to continue his studies."
After serious training, Newton entered Cambridge in 1660 as a Subsizzfr (the so called poor students who were obliged to serve the members of the college, which could not but burden Newton).
The beginning of creativity.
Optics
In six years, Newton completed all the degrees of the college and prepared all his further great discoveries.
In 1665, Newton became a Master of Arts.
In the same year, when the plague was raging in England, he decided to temporarily settle in Woolsthorpe.
It was there that he began to actively engage in optics; the search for ways to eliminate chromatic aberration in lens telescopes led Newton to research what is now called dispersion, i.e. the dependence of the refractive index on frequency.
Many of his experiments (and there are more than a thousand of them) have become classic and are repeated today in schools and institutes.
The leitmotif of all research was the desire to understand the physical nature of light.
At first, Newton was inclined to the idea that light is waves in the all pervading ether, but later he abandoned this idea, deciding that the resistance from the ether should noticeably slow down the movement of celestial bodies.
These arguments led Newton to the idea that light is a stream of special particles, corpuscles, flying out of a source and moving in a straight line until they meet obstacles.
The corpuscular model explained not only the straightness of light propagation, but also the law of reflection (elastic reflection), and - true, not without additional assumption - the law of refraction.
This assumption was that light corpuscles, flying up to the surface of water, for example, should be attracted by it and therefore experience acceleration.
According to this theory, the speed of light in water should be greater than in air (which contradicted later experimental data).
Laws of mechanics
The formation of corpuscular ideas about light was clearly influenced by the fact that at this time, the work that was destined to become the main great result of Newton's works was already completed - the creation of a unified physical picture of the world based on the laws of mechanics formulated by him.
This picture was based on the idea of material points - physically infinitesimal particles of matter and the laws governing their movement.
It was the clear formulation of these laws that gave Newton's mechanics completeness and completeness.
The first of these laws was, in fact, the definition of inertial reference systems: it is in such systems that material points that do not experience any effects move uniformly and rectilinearly.
The second law of mechanics plays a central role.
It says that the change in quantity, motion (the product of mass by speed) per unit of time is equal to the force acting on a material point.
The mass of each of these points is an unchangeable quantity; in general, all these points "do not wear out", according to Newton's expression, each of them is eternal, i.e. it can neither arise nor be destroyed.
Material points interact, and the quantitative measure of the impact on each of them is the force.
The problem of finding out what these forces are is the root problem of mechanics.
Finally, the third law the law of "equality of action and reaction" explained why the total impulse of any body that does not experience external influences remains unchanged, no matter how its component parts interact with each other.
The law of universal gravitation
Having posed the problem of studying various forces, Newton himself gave the first brilliant example of its solution, formulating the law of universal gravitation: the force of gravitational attraction between bodies whose dimensions are much smaller than the distance between them is directly proportional to their masses, inversely proportional to the square of the distance between them and is directed along the straight line connecting them.
The law of universal gravitation allowed Newton to give a quantitative explanation of the movement of the planets around the Sun and the Moon around the Earth, to understand the nature of sea tides.
This could not but make a huge impression on the minds of researchers.
The program of a single mechanical description of all natural phenomena - both "terrestrial" and "celestial" - has been established in physics for many years.
Moreover, for many physicists for two centuries, the very question of the limits of the applicability of Newton's laws seemed unjustified.
The Lukas Chair at Cambridge
In 1668, Newton returned to Cambridge and soon he received the Lucas Chair of Mathematics.
This chair was occupied before him by his teacher I. Barrow, who gave up the chair to his favorite student in order to provide him financially.
By that time, Newton was already the author of the binomial and the creator (simultaneously with Leibniz, but independently of him) of the fluxion method - what is now called differential and integral calculus.
In fact, it was the most fruitful period in Newton's work: for seven years, from 1660 to 1667, his main ideas were formed, including the idea of the law of universal gravitation.
Not limited to theoretical research alone, in the same years he designed and began to create a reflector telescope (reflective).
This work led to the discovery of what was later called interference "lines of equal thickness".
(Newton, realizing that here there is a "light quenching by light" that did not fit into the corpuscular model, tried to overcome the difficulties that arose here by introducing the assumption that corpuscles in light move in waves - "tides").
The second of the manufactured telescopes (improved) served as an occasion for introducing Newton to the membership of the Royal Society of London.
When Newton refused membership, citing the lack of funds to pay membership fees, it was considered possible, given his scientific achievements, to make an exception for him, exempting him from paying them.
Being by nature a very cautious (not to say timid) person, Newton, despite his will, sometimes found himself involved in painful discussions and conflicts for him.
Thus, his theory of light and colors, set forth in 1675, caused such attacks that Newton decided not to publish anything on optics while Hooke, his most bitter opponent, was alive.
Newton had to take part in political events as well.
He was a member of Parliament from 1688 to 1694.
By that time, in 1687, his main work "Mathematical Principles of Natural Philosophy" was published - the basis of the mechanics of all physical phenomena, from the movement of celestial bodies to the propagation of sound.
For several centuries ahead, this program determined the development of physics, and its significance has not been exhausted to this day.
Newton's Disease
Constant great nervous and mental stress led to the fact that in 1692 Newton fell ill with a mental disorder.
The immediate impetus for this was a fire, in which all the manuscripts he was preparing were destroyed.
Only by 1694, according to Huygens, he "... already begins to understand his book "Beginnings"".
The constant oppressive feeling of material insecurity was undoubtedly one of the causes of Newton's illness.
Therefore, the position of caretaker of the Mint with the preservation of a professorship at Cambridge was important for him.
Zealously starting work and quickly achieving notable success, he was appointed director in 1699.
It was impossible to combine this with teaching, and Newton moved to London.
At the end of 1703, he was elected president of the Royal Society.
By that time, Newton had reached the pinnacle of fame.
In 1705, he was elevated to knighthood, but, having a large apartment, having six servants and a rich departure, he remains as lonely as before.
The time of active creativity is over, and Newton is limited to preparing an edition of "Optics", a reissue of "Beginnings" and an interpretation of the Holy Scripture (he owns the interpretation of the Apocalypse, an essay about the prophet Daniel).
Newton was buried in Westminster Abbey.
The inscription on his grave ends with the words: "Let mortals rejoice that such an ornament of the human race lived in their midst."
