Isaac Newton, beyond doubt the greatest scientist in history, was born on this day, more or less, in 1642. Though Newton was a key figure in the scientific revolution, he was arguably more the last of the mystics than the first of the scientists.
I say more or less because Newton lived during the time that England made the shift from the Julian to the Gregorian calendars. Newton was born "an hour or two after midnight" on December 25 Julian, which was in force at the time. When the calendar changed, that day became January 4 Gregorian. So you pay your money and you take your pick.
Newton was born prematurely, and his mother, Hannah Ayscough, said he could have fit inside a quart mug. His father had died three months before. When Newton was three, his mother remarried and left her son to be raised by his maternal grandmother.
In June 1661, he was admitted to Trinity College, Cambridge, on the recommendation of his uncle Rev William Ayscough, who had studied there. He started as a subsizar—paying his way by performing valet's duties—until he was awarded a scholarship in 1664, guaranteeing him four more years until he could get his MA.[16] At that time, the college's teachings were based on those of Aristotle, whom Newton supplemented with modern philosophers such as Descartes, and astronomers such as Galileo and Thomas Street, through whom he learned of Kepler's work. He set down in his notebook a series of "Quaestiones" about mechanical philosophy as he found it. In 1665, he discovered the generalised binomial theorem and began to develop a mathematical theory that later became calculus.
In August, 1665, the university closed due to the Great Plague and Newton retreated to the countryside for two years. While there, he invented calculus, the laws of motion, the law of universal gravitation, figured out the orbits of the planets from that law, and did extensive work in optics. In APril 1667, he returned to Cambridge and was elected fellow.
Fellows were required to become ordained priests, which was potentially a serious problem for Newton as he was already developing some seriously deviationary religious ideas. In the restoration years, however, a simple assertion of conformity was sufficient. In 1669, only one year after receiving his MA, he succeed Isaac Barrow as Lucasian Professor of Mathematics. Newton was clearly on a fast track.
Newton later became involved in a dispute with Leibniz over priority in the development of calculus. Most modern historians believe that Newton and Leibniz developed calculus independently, although with very different mathematical notations. Occasionally it has been suggested that Newton published almost nothing about it until 1693, and did not give a full account until 1704, while Leibniz began publishing a full account of his methods in 1684.
Curiously, today we use Newton's conceptual formulation and Leibniz's notation. Leibniz' notation is very intuitive, but his conceptual foundation, in terms of infinitesimals, numbers that are greater than zero but smaller than every positive number, was quite iffy and only really became rigorous in the 20th century in something called nonstandard analysis. Newton's conceptual foundation, in terms of slopes and areas, is very intuitive but his notation, such as it is, is extremely opaque.
Newton published the Principia Mathematica on 5 July 1687, and all of modern science descends from it. In this work, Newton stated the three universal laws of motion. Together, these laws describe the relationship between any object, the forces acting upon it and the resulting motion, laying the foundation for classical mechanics. They contributed to many advances during the Industrial Revolution which soon followed and were not improved upon for more than 200 years. Many of these advancements continue to be the underpinnings of non-relativistic technologies in the modern world. He used the Latin word gravitas (weight) for the effect that would become known as gravity, and defined the law of universal gravitation.
In the same work, Newton presented a calculus-like method of geometrical analysis using 'first and last ratios', gave the first analytical determination (based on Boyle's law) of the speed of sound in air, inferred the oblateness of Earth's spheroidal figure, accounted for the precession of the equinoxes as a result of the Moon's gravitational attraction on the Earth's oblateness, initiated the gravitational study of the irregularities in the motion of the Moon, provided a theory for the determination of the orbits of comets, and much more.
In 1666, Newton observed that the spectrum of colours exiting a prism in the position of minimum deviation is oblong, even when the light ray entering the prism is circular, which is to say, the prism refracts different colours by different angles.[41][42] This led him to conclude that colour is a property intrinsic to light – a point which had, until then, been a matter of debate.
From 1670 to 1672, Newton lectured on optics. During this period he investigated the refraction of light, demonstrating that the multicoloured spectrum produced by a prism could be recomposed into white light by a lens and a second prism. Modern scholarship has revealed that Newton's analysis and resynthesis of white light owes a debt to corpuscular alchemy.
He showed that coloured light does not change its properties by separating out a coloured beam and shining it on various objects, and that regardless of whether reflected, scattered, or transmitted, the light remains the same colour. Thus, he observed that colour is the result of objects interacting with already-coloured light rather than objects generating the colour themselves. This is known as Newton's theory of colour.
From this work, he concluded that the lens of any refracting telescope would suffer from the dispersion of light into colours (chromatic aberration). As a proof of the concept, he constructed a telescope using reflective mirrors instead of lenses as the objective to bypass that problem. Building the design, the first known functional reflecting telescope, today known as a Newtonian telescope, involved solving the problem of a suitable mirror material and shaping technique. Newton ground his own mirrors out of a custom composition of highly reflective speculum metal, using Newton's rings (a thin film interference phenomenon) to judge the quality of the optics for his telescopes.
In his Hypothesis of Light of 1675, Newton posited the existence of the ether to transmit forces between particles. The contact with the Cambridge Platonist philosopher Henry More revived his interest in alchemy. He replaced the ether with occult forces based on Hermetic ideas of attraction and repulsion between particles. John Maynard Keynes, who acquired many of Newton's writings on alchemy, stated that "Newton was not the first of the age of reason: He was the last of the magicians." Newton's interest in alchemy cannot be isolated from his contributions to science. This was at a time when there was no clear distinction between alchemy and science.
In 1704, Newton published Opticks, in which he expounded his corpuscular theory of light. He considered light to be made up of extremely subtle corpuscles, that ordinary matter was made of grosser corpuscles and speculated that through a kind of alchemical transmutation "Are not gross Bodies and Light convertible into one another, ... and may not Bodies receive much of their Activity from the Particles of Light which enter their Composition? Newton also constructed a primitive form of a frictional electrostatic generator, using a glass globe.
In Opticks, Newton was the first to show a diagram using a prism as a beam expander, and also the use of multiple-prism arrays. Some 278 years after Newton's discussion, multiple-prism beam expanders became central to the development of narrow-linewidth tunable lasers.
Subsequent to Newton, much has been amended. Young and Fresnel combined Newton's particle theory with Huygens' wave theory to show that colour is the visible manifestation of light's wavelength. Science also slowly came to realise the difference between perception of colour and mathematisable optics. Newton had committed himself to the doctrine that refraction without colour was impossible. He, therefore, thought that the object-glasses of telescopes must forever remain imperfect, achromatism and refraction being incompatible. This inference was proved by Dollond to be wrong.
For the last half of his life, 30 years, Newton was warden of the Royal Mint as well as Master of the Mint. Newton got his appointment because of his renown as a scientist and because he supported the winning side in the Glorious Revolution. Charles Montagu, after being appointed Chancellor of the Exchequer in 1694, had previously consulted Newton upon the subject of the recoinage, and took the opportunity to appoint Newton to the post of warden of the Royal Mint in 1696.
Although the post was intended to be a sinecure, Newton took it seriously. By the time of his appointment the currency had been seriously weakened by an increase in clipping and counterfeiting during the Nine Years' War to the extent that it had been decided to recall and replace all hammered silver coinage in circulation. The exercise came close to disaster due to fraud and mismanagement, but was salvaged by Newton's personal intervention. Newton's chemical and mathematical knowledge proved of great use in carrying out this Great Recoinage of 1696, a process that was completed in about two years. Newton was subsequently given the post of Master of the Mint in 1699, a post worth between £1,200 and £1,500 per annum. Due to his income from the Mint Newton became very wealthy, although he lost a substantial sum in the collapse of the South Sea Bubble.
Despite counterfeiting being considered high treason, punishable by hanging, drawing and quartering, convicting even the most flagrant criminals could be extremely difficult. Undaunted, Newton conducted more than 100 cross-examinations of witnesses, informers, and suspects between June 1698 and Christmas 1699. He himself gathered much of the evidence he needed to successfully prosecute 28 coiners.
In June 1696 Johann Bernoulli addressed a letter to the mathematicians of Europe challenging them to solve two problems:
to determine the brachistochrone curve between two given points not in the same vertical line
to determine a curve such that, if a straight line drawn through a fixed point A meet it in two points P1, P2, then mAP1 + mAP2 will be constant.
This challenge was first made in the Ada Lipsiensia for June 1696.
Six months were allowed by Bernoulli for the solution of the problem, and in the event of none being sent to him he promised to publish his own. The six months elapsed without any solution being produced; but he received a letter from Leibniz, stating that he had "cut the knot of the most beautiful of these problems", and requesting that the period for their solution should be extended to Christmas next; that the French and Italian mathematicians might have no reason to complain of the shortness of the period. Bernoulli adopted the suggestion, and publicly announced the postponement for the information of those who might not see the Ada Lipsiensia.
On 29 January 1697 Newton returned at 4pm from working at the Royal Mint and found in his post the problems that Bernoulli had sent to him directly; two copies of the printed paper containing the problems. Newton stayed up to 4am before arriving at the solutions; on the following day he sent a solution of them to Montague, then president of the Royal Society for anonymous publication. He announced that the curve required in the first problem must be a cycloid, and he gave a method of determining it. He also solved the second problem, and in so doing showed that by the same method other curves might be found which cut off three or more segments having similar properties.
Newton had largely been out of mathematics due to his duties at the Mint but, though the solutions were submitted anonymously, Bernoulli remarked that he could "recognize the lion by the print of his paw."
In January 1725 Nwton was seized with violent cough and inflammation of the lungs which induced him to move to Kensington. In the next month he had a case of gout and then had an improvement of health. His duties from the mint were terminated and thus he seldom left home. On 28 February 1727 he went to London to preside at a meeting of the Royal Society but his health forced him to return to Kensington on 4 March when it was determined he had a gallstone. On 18 March, around 6 PM, he became delirious and stayed in that state until Monday 20 March 1727 when he died between one and two in the morning.
His body was taken to London and on Tuesday, 28 March it lay in state in the Jerusalem Chamber in Westminster Abbey, and then was moved to his burial location in the Abbey. Voltaire was present at his funeral and praised the British for honoring a scientist of heretical religious beliefs with burial there.
The image below is a copperplate engraving depicting Newton and made by William Blake.
And from my pillow, looking forth by light
Of moon or favouring stars, I could behold
The antechapel where the statue stood
Of Newton with his prism and silent face,
The marble index of a mind for ever
Voyaging through strange seas of Thought, alone.
-- William Wordsworth
The Prelude
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