Ранние годы и научные открытия Исаака Ньютона

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The following article is part of a biography of Sir Isaac Newton, the English mathematician and scientist, author of the Principia. It portrays the years after Newton's birth in 1642, his education, as well as his early scientific contributions, before the writing of his main work, the Principia Mathematica, in 1685.

Sir Isaac Newton is known for many scientific findings. Some of these discoveries include the laws of motion, the theory of gravity, and basic calculus. Although Newton was predominantly known for his discoveries in mathematics and physics, he also put much effort and study into chemistry, biblical history, and optics. One of Newton's most famous writings was the Principia where he described some of his major findings of time, physics, mathematics, and calculus. Although his theories soon became universal, he faced much opposition to some of his early theories. Specifically, his theory of gravity faced criticism from leading scientists such as Christiaan Huygens and Leibniz. After a few years of debate, Newton's concept of gravity became universally accepted as he became the dominant figure in the European continent.

In January 1665 Newton took the degree of Bachelor of Arts. The persons appointed (in conjunction with the proctors, John Slade of Catharine Hall, Cambridge, and Benjamin Pulleyn of Trinity College, Newton's tutor) to examine the questionists were John Eachard of Catharine Hall and Thomas Gipps of Trinity University. It is a curious accident that we have no information about the respective merits of the candidates for a degree in this year since the "ordo senioritis" of the Bachelors of Arts for the year is omitted in the "Grace Book". It is supposed that it was in 1665 that the method of fluxións (his term for calculus of variations) first occurred to Newton's mind. There are several papers in Newton's handwriting bearing dates 1665 and 1666 in which the method is described, in some of which dotted or dashed letters are used to represent fluxions (i. e. derivatives), and in some of which the method is explained without the use of dotted letters. Both in 1665 and 1666 Trinity College was dismissed on account of the Great Plague of London. On each occasion it was agreed, as shown by entries in the "Conclusion Book" of the college, dated 7 August 1665, and 22 June 1666, and signed by the master of the college, Dr Pearson, that all fellows and scholars who were dismissed on account of the pestilence be allowed one month's commons. Newton must have left college before August 1665, as his name does not appear in the list of those who received extra commons on that occasion, and he tells us himself in the extract from his commonplace book already quoted that he was "forced from Cambridge by the plague" in the summer of that year. He was elected a fellow of his college on 5 October 1667. There were nine vacancies, one caused by the death of Abraham Cowley the previous summer, and the nine successful candidates were all of the same academic standings. A few weeks after his election to a fellowship Newton went to Lincolnshire and did not return to Cambridge until the following February. In March 1668, he took his M. A. degree. During the years 1666 to 1669 Newton's studies were very diverse. He bought prisms and lenses on two or three occasions, and also chemicals and a furnace, apparently for chemical experiments; but he also employed part of his time on the theory of fluxions and other branches of pure mathematics. He wrote a paper, De Analysi per Aequationes Numero Terminorum Infinitas, which he put, probably in June 1669, into the hands of Isaac Barrow (then Lucasian Professor of Mathematics), at the same time permitting him to communicate its contents to their common friend John Collins (1624–1683), a mathematician of no mean order. Barrow did so on 31 July 1669, but kept the name of the author a secret, and merely told Collins that he was a friend staying at Cambridge, who had a powerful genius for such matters. In a subsequent letter on 20 August, Barrow expressed his pleasure at hearing the favourable opinion which Collins had formed of the paper, and added, "the name of the author is Newton, a fellow of our college, and a young man, who is only in his second year since he took the degree of Master of Arts, and who, with an unparalleled genius (examine quo est acumen), has made very great progress in this branch of mathematics". Shortly afterward, Barrow resigned his chair and was instrumental in securing Newton's election as his successor. Newton was elected Lucasian professor on 29 October 1670. It was his duty as professor to lecture at least once a week in term time on some portion of geometry, arithmetic, astronomy, geography, optics, statics, or some other mathematical subject, and also for two hours in the week to allow an audience to any student who might come to consult with the professor on any difficulties he had encountered. The subject which Newton chose for his lectures was optics. These lectures did little to expand his reputation, as they were remarkably sparsely attended; frequently leaving Newton to lecture at the walls of the classroom. An account of their content was presented to the Royal Society in the spring of 1672. During the year 1684, Edmund Halley visited the home of Newton. While on his visit, Halley noted the remarkable development Newton had conducted regarding the path of objects in space such as stars and planets. Newton was convinced to step forward and introduce his findings to the general public which soon became publicized. The publication, "Mathematical Principles of Natural Philosophy" introduced the three laws that Newton became famous for: law of inertia, summation of forces equals mass multiplied by acceleration and every action has an equal and opposite reaction. Prior to Newton, there were several other philosophers who proposed ideas to describe the motion of celestial bodies. Kepler and Galileo Galilei often studied the way objects fell in order to gain an understanding of the motion of the planets. However, by putting his theories into laws, it was Newton who achieved the most success. Students learn these concepts in grade school, being applicable to every conceivable aspect of life. In the year 1688, Newton was elected to the convention parliament at Cambridge University where he remained on board for two years. During his time at Cambridge, he was able to meet several famous people like John Locke and Nicolas Fatio de Duillier. Newton was able to form life long bonds with these two figures in the matter of two years. Christiaan Huygens also came into the picture as Newton and him had disagreements in the past about gravity. The two figures had several extended arguments about their debate and were able to reach accord. Soon after, Newton entered a period of life where writing became his priority. He began by editing his book, Principia. Despite the adjustments he made, the new version of Principia was abandoned by the year 1693 due to Newton's mental state. He decaled himself as having a mental breakdown which eradicated the adjustments he made to his famous writing. Newton had a different novel that he worked on during the same time period called Praxis. This text consists of five drafts of literature written by Newton having to do with chemistry. During this period, Newton studied several areas of work including religion, calculus and chemistry. According to Alfred Rupert Hall the first practical reflecting telescope was built by Newton in 1668. Later on, such a prototype for its design came to be called a Newtonian telescope or Newton's reflector. On 21 December 1671 he was proposed as a candidate for admission to the Royal Society by Dr. Seth Ward, bishop of Salisbury, and on 11 January 1672, he was elected a fellow of the Society. At the meeting at which Newton was elected, he read a description of a reflecting telescope which he had invented, and "it was ordered that a letter should be written by the secretary to Mr. Newton to acquaint him of his election into the Society, and to thank him for the communication of his telescope, and to assure him that the Society would take care that all right should be done him concerning this invention." In his reply to the secretary on 18 January 1672, Newton writes: "I desire that in your next letter you would inform me for what time the society continue their weekly meetings; because, if they continue them for any time, I am purposing them to be considered of and examined an account of a philosophical discovery, which induced me to the making of the said telescope, and which I doubt not but will prove much more grateful than the communication of that instrument being in my judgment the oddest if not the most considerable detection which hath hitherto been made into the operations of nature." This promise was fulfilled in communication which Newton addressed to Henry Oldenburg, the secretary of the Royal Society, on 6 February 1672, and which was read before the society two days afterward. The whole is printed in No. 80 of the Philosophical Transactions. Newton's "philosophical discovery" was the realisation that white light is composed of a spectrum of colours. He realised that objects are coloured only because they absorb some of these colours more than others. After he explained this to the Society, he proceeded: "When I understood this, I left off my aforesaid glassworks; for I saw, that the perfection of telescopes was hitherto limited, not so much for want of glasses truly figured according to the prescriptions of Optics Authors (which all men have hitherto imagined), as because that light itself is a heterogeneous mixture of differently refrangible rays. So that was a glass so exactly figured as to collect any one sort of rays into one point, it could not collect those also into the same point, which has the same incidence upon the same medium are apt to suffer a different refraction. Nay, I wondered, that seeing the difference of refrangibility was so great, as I found it, telescopes should arrive at that perfection they are now at." This "difference in refrangibility" is now known as dispersion. He then points out why "the object glass of any telescope cannot collect all the rays which come from one point of an object, to make them convene at its focus in less room than in a circular space, whose diameter is the 50th part of the diameter of its aperture: which is an irregularity some hundreds of times greater, than a circularly figured lens, of so small a section as the object glasses of long telescopes are, would cause by the unfitness of its figure, were light uniform." He adds: "This made me take reflections into consideration, and finding them regular so that the Angle of Reflection of all sorts of Rays was equal to their Angle of Incidence; I understood, that by their mediation optic instruments might be brought to any degree of perfection imaginable, provided a reflecting substance could be found, which would polish as finely as glass, and reflect as much light, as glass transmits, and the art of communicating to it a parabolic figure be also attained. But these seemed very great difficulties, and I have almost thought them insuperable, when I further considered, that every irregularity in a reflecting superficies makes the rays stray 5 or 6 times more out of their due course, than the like irregularities in a refracting one; so that a much greater curiosity would be here requisite, than in figuring glasses for refraction. "Amidst these thoughts, I was forced from Cambridge by the intervening Plague, and it was more than two years before I proceeded further. But then having thought on a tender way of polishing, proper for metal, whereby, as I imagined, the figure also would be corrected to the last; I began to try, what might be affected in this kind, and by degrees so far perfected an instrument (in the essential parts of it like that I sent to London), by which I could discern Jupiter's 4 Concomitants, and showed them diverse times to two others of my acquaintance. I could also discern the Moon like phase of Venus, but not very distinctly, nor without some niceness in disposing of the instrument. "From that time I was interrupted until this last autumn when I made the other. And as that was sensibly better than the first (especially for day objects), so I doubt not, but they will be still brought to much greater perfection by their endeavours, who, as you inform me, are taking care of it at London."

The publication of these discoveries led to a series of controversies which lasted for several years, in which Newton had to contend with the eminent English physicist Robert Hooke, Anthony Lucas (mathematical professor at the University of Liège), Franciscus Linus (a physician in Liège), and many others. Some of his opponents denied the truth of his experiments, refusing to believe in the existence of the spectrum. Others criticised the experiments, saying that the length of the spectrum was never more than three and a half times the breadth, whereas Newton found it to be five times the breadth. It appears that Newton made the mistake of supposing that all prisms would give a spectrum of the same length; the objections of his opponents led him to measure carefully the lengths of spectra formed by prisms of different angles and different refractive indices, but he was not led thereby to the discovery of the different dispersive powers of different refractive substances. Newton carried on the discussion with the objectors with great courtesy and patience, but the pain which these long discussions gave to his sensitive mind may be estimated from his letter of 18 November 1676 to Oldenburg: "I promised to send you an answer to Mr. Lucas this next Tuesday, but I find I shall scarce finish what I have designed, to get a copy taken of it by that time, and therefore I beg your patience a week longer. I see I have made myself a slave to philosophy, but if I get free of Mr. Lucas's business, I will resolutely bid adieu to it eternally, excepting what I do for my private satisfaction, or leave to come out after me; for I see a man must either resolve to put out nothing new or to become a slave to defend it." It was fortunate that these disputes did not damp Newton's ardour as much as he feared. He later published many papers in the Philosophical Transactions on various aspects of optics, and, although some of his views are erroneous, and are now almost universally rejected, his investigations led to discoveries which are of permanent value. He succeeded in explaining the colour of thin and of thick plates (diffraction), and the inflexion of light, and he wrote on double refraction, light polarisation and binocular vision. He also invented a reflecting quadrant for observing the angles between the Moon and the fixed stars— the same in every essential as the historically important navigational instrument more commonly known as Hadley's quadrant. This discovery was communicated by him to Edmund Halley in 1700 but was not published, or communicated to the Royal Society, until after Newton's death, when a description of it was found among his papers.

In March 1673 Newton took a prominent part in a dispute in the university. The public oratorship fell vacant, and a contest arose between the heads of the colleges and the members of the Senate as to the mode of electing to the office. The heads claimed the right of nominating two persons, one of whom was to be elected by the senate. The senate insisted that the proper mode was by an open election. George Villiers, 2nd Duke of Buckingham, who was the chancellor of the university, endeavoured to effect a compromise which, he says, "I hope may for the present satisfy both sides. I propose that the heads may for this time nominate and the body comply, yet interposing (if they think fit) a protestation concerning their plea that this election may not hereafter pass for a decisive precedent in prejudice of their claim", and, "whereas I understand that the whole university has chiefly consideration for Dr Henry Paman of St John's College and Mr. Craven of Trinity College, I do recommend them both to be nominated." The heads, however, nominated Drs Paman and Ralph Sanderson (of St John's); the next day 121 members of the senate recorded their votes for Craven and ninety eight for Paman. On the morning of the election, a protest in which Newton's name appeared was read and entered in the Regent House. But the vice chancellor admitted Paman the same morning, and so ended the first contest of a non scientific character in which Newton took part.

On 8 March 1673 Newton wrote to Oldenburg, the secretary of the Royal Society:"Sir, I desire that you will procure that I may be put out from being any longer Fellow of the Royal Society: for though I honour that body, yet since I see I shall neither profit them nor (because of this distance) can partake of the advantage of their assemblies, I desire to withdraw." Oldenburg replied to this with an offer to apply to the Society to excuse Newton the weekly payments, as in a letter of Newton's to Oldenburg, dated 23 June 1673, he says, "For your proffer about my quarterly payments, I thank you, but I would not have you trouble yourself to get them excused if you have not done it already." Nothing further seems to have been done in the matter until 28 January 1675, when Oldenburg informed the Society that "Mr. Newton is now in such circumstances that he desires to be excused from the weekly payments." Upon this "it was agreed to by the council that he be dispensed with, as several others are." On 18 February 1675 Newton was formally accepted into the Society. The most probable reason why Newton wished to be excused from these payments is that, as he was not in holy orders, his fellowship at Trinity College would lapse in autumn 1675, with a consequent reduction in his income. But he received a patent from the Crown in April 1675, allowing him as Lucasian professor to retain his fellowship without being required to take holy orders. This must have relieved Newton's financial worries since in November 1676 he donated £40 towards the building of the new library of Trinity College.