Christmas Day (by the Julian calendar in use in England at the time), is the birthday (1642) of Sir Isaac Newton PRS, who is widely regarded as one of the most influential scientists of all time, and as a key figure in the 17th century scientific revolution. His book Philosophiæ Naturalis Principia Mathematica (“Mathematical Principles of Natural Philosophy”), first published in 1687, laid the foundations for classical mechanics. Newton made seminal contributions to optics, and he shares credit with Gottfried Leibniz for the development of calculus.
Newton’s Principia formulated the laws of motion and universal gravitation, which dominated scientists’ view of the physical universe for the next three centuries. By deriving Kepler’s laws of planetary motion from his mathematical description of gravity, and then using the same principles to account for the trajectories of comets, the tides, the precession of the equinoxes, and other phenomena, Newton removed the last doubts about the validity of the heliocentric model of the solar system. This work also demonstrated that the motion of objects on Earth and of celestial bodies could be described by the same principles. His prediction that Earth should be shaped as an oblate spheroid was later vindicated by the measurements of Maupertuis, La Condamine, and others, which helped convince most Continental European scientists of the superiority of Newtonian mechanics over the earlier system of Descartes.
Newton built the first practical reflecting telescope and developed a theory of color based on the observation that a prism decomposes white light into the many colors of the visible spectrum. He formulated an empirical law of cooling, studied the speed of sound, and introduced the notion of a Newtonian fluid. In addition to his work on calculus, as a mathematician Newton contributed to the study of power series, generalized the binomial theorem to non-integer exponents, developed a method for approximating the roots of a function, and classified most of the cubic plane curves.
Newton was a fellow of Trinity College and the second Lucasian Professor of Mathematics at the University of Cambridge. He was a devout but unorthodox Christian and, unusually for a member of the Cambridge faculty of the day, he refused to take holy orders in the Church of England, perhaps because he privately rejected the doctrine of the Trinity. I repeat: He was a devout, but unorthodox, Christian. Beyond his work on the mathematical sciences, Newton dedicated much of his time to the study of biblical chronology and alchemy, but most of his work in those areas remained unpublished until long after his death. In his later life, Newton became president of the Royal Society. Newton also served the British government as Warden and Master of the Royal Mint.
I am going to assume that you are either familiar with Newton’s work in physics and mathematics, or don’t want a lesson from me. Instead I’ll focus on a few lesser known aspects of his life and work. First , here are two well-known quotes that I think adequately display his humility:
If I have seen further than others, it is by standing upon the shoulders of giants.
I was like a boy playing on the sea-shore, and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
These are less well known:
We build too many walls and not enough bridges.
Genius is patience.
Plato is my friend; Aristotle is my friend, but my greatest friend is truth.
I can calculate the motion of heavenly bodies, but not the madness of people.
We could use him around today. As many of my readers know, I do not use superlatives such as “best” in relation to the greats of the world or their works. But I certainly stand in absolute awe and wonder at what Newton accomplished. Here’s a few tidbits from his life.
Although born into an Anglican family, by his thirties Newton held a Christian faith that would not have been considered orthodox by contemporary Christianity, and, in consequence, he did not make his fundamental beliefs public. By 1672 he had started to record his theological researches in notebooks which he showed to no one and which have only recently been examined. They demonstrate an extensive knowledge of early church writings and show that in the conflict between Athanasius and Arius, which spawned the Nicene Creed, he took the side of Arius, the loser, who rejected the conventional view of the Trinity. Newton saw Christ as a divine mediator between God and humans, who was subordinate to the Father who created him. He wrote, “the great apostasy is trinitarianism.” Newton tried unsuccessfully to obtain one of the two fellowships that exempted the holder from the ordination requirement. At the last moment in 1675 he received a dispensation from the government that excused him and all future holders of the Lucasian chair from being ordained.
Newton was not a deist, in the conventional way, however. Rejecting trinitarianism did not mean rejecting Christianity. Although the laws of motion and universal gravitation became Newton’s best-known discoveries, he warned against using them to view the universe as a mere machine, as if akin to a great clock. He said, “Gravity explains the motions of the planets, but it cannot explain who set the planets in motion. God governs all things and knows all that is or can be done.”
Newton wrote works on Biblical textual criticism, most notably An Historical Account of Two Notable Corruptions of Scripture. He placed the crucifixion of Jesus Christ at 3 April, AD 33, which is now one of several dates accepted by some scholars. He believed in a rationally immanent world, but he rejected the hylozoism (matter is living) implicit in Leibniz and Baruch Spinoza. The ordered and dynamically informed universe could be understood, and must be understood, as directed by active reason. In his correspondence, Newton claimed that in writing the Principia “I had an eye upon such Principles as might work with considering men for the belief of a Deity”. He saw evidence of design in the system of the world: “Such a wonderful uniformity in the planetary system must be allowed the effect of choice”. But Newton insisted that divine intervention would eventually be required to reform the system, due to the slow growth of instabilities. For this, Leibniz lampooned him: “God Almighty wants to wind up his watch from time to time: otherwise it would cease to move. He had not, it seems, sufficient foresight to make it a perpetual motion machine.”
Newton and Robert Boyle’s approach to a mechanical philosophy was promoted by rationalist pamphleteers as a viable alternative to the pantheists and enthusiasts, and was accepted hesitantly by orthodox preachers as well as some dissidents. The clarity and simplicity of science was seen as a way to combat the emotional and metaphysical superlatives of both superstitious enthusiasm and the threat of atheism, and at the same time, the second wave of English deists used Newton’s discoveries to demonstrate the possibility of a “Natural Religion”.
In a manuscript Newton wrote in 1704, in which he describes his attempts to extract scientific information from the Bible, he estimated that the world would end no earlier than 2060. In predicting this he said, “This I mention not to assert when the time of the end shall be, but to put a stop to the rash conjectures of fanciful men who are frequently predicting the time of the end, and by doing so bring the sacred prophesies into discredit as often as their predictions fail.”
It is now just beginning to be recognized in the wider intellectual world that Newton spent over 30 years studying and writing about alchemy. John Maynard Keynes, who acquired many of Newton’s writings on alchemy, asserted 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. In Newton’s day there was no clear distinction between alchemy and science. Had he not relied on the occult idea of action at a distance, across a vacuum, he might not have developed his theory of gravity. Newton’s writings suggest that one of the goals of his alchemy was the discovery of The Philosopher’s Stone (a material believed to turn base metals into gold), and perhaps to a lesser extent, the discovery of the highly coveted Elixir of Life. Some practices of alchemy were banned in England during Newton’s lifetime, due in part to unscrupulous practitioners who would often promise wealthy benefactors unrealistic results in an attempt to swindle them. The English Crown, also fearing the potential devaluation of gold, should The Philosopher’s Stone actually be discovered, made penalties for alchemy very severe, including execution.
The story of Newton and the apple has sometimes been debunked as legend, and often popularly altered to claim that the apple struck him on the head. In fact, Newton himself often told the story that he was inspired to formulate his theory of gravitation by watching the fall of an apple from a tree. Acquaintances of Newton (such as William Stukeley, whose manuscript account of 1752 has been made available by the Royal Society) do in fact confirm the incident. Stukeley recorded in his Memoirs of Sir Isaac Newton’s Life a conversation with Newton in Kensington on 15 April 1726:
we went into the garden, & drank tea under the shade of some appletrees; only he, & my self. amidst other discourse, he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind. “why should that apple always descend perpendicularly to the ground,” thought he to himself; occasion’d by the fall of an apple, as he sat in a contemplative mood. “why should it not go sideways, or upwards? but constantly to the earths center? assuredly, the reason is, that the earth draws it. there must be a drawing power in matter. & the sum of the drawing power in the matter of the earth must be in the earths center, not in any side of the earth. therefore dos this apple fall perpendicularly, or toward the center. if matter thus draws matter; it must be in proportion of its quantity. therefore the apple draws the earth, as well as the earth draws the apple.
John Conduitt, Newton’s assistant at the Royal Mint and husband of Newton’s niece, also described the event when he wrote about Newton’s life:
In the year 1666 he retired again from Cambridge to his mother in Lincolnshire. Whilst he was pensively meandering in a garden it came into his thought that the power of gravity (which brought an apple from a tree to the ground) was not limited to a certain distance from earth, but that this power must extend much further than was usually thought. Why not as high as the Moon said he to himself & if so, that must influence her motion & perhaps retain her in her orbit, whereupon he fell a calculating what would be the effect of that supposition.
It is known from his notebooks that Newton was grappling in the late 1660s with the idea that terrestrial gravity extends, in an inverse-square proportion, to the Moon; however it took him two decades to develop the full-fledged theory. The question was not whether gravity existed, but whether it extended so far from Earth that it could also be the force holding the Moon to its orbit. Newton showed that if the force decreased as the inverse square of the distance, one could indeed calculate the Moon’s orbital period, and get good agreement. He guessed the same force was responsible for other orbital motions, and hence named it “universal gravitation”.
Various trees are claimed to be “the” apple tree which Newton describes. The King’s School, Grantham, claims that the tree was purchased by the school, uprooted and transported to the headmaster’s garden some years later. The staff of the [now] National Trust-owned Woolsthorpe Manor dispute this, and claim that a tree present in their gardens is the one described by Newton. A descendant of the original tree can be seen growing outside the main gate of Trinity College, Cambridge, below the room Newton lived in when he studied there. The National Fruit Collection at Brogdale can supply grafts from their tree, which appears identical to Flower of Kent, a coarse-fleshed cooking variety.
To honor Newton I’ve culled several apple recipes from 17th century cookbooks. The first, entitled “To fry Applepies” comes from A True Gentlewomans Delight, 1653. These are like fruit empanadas or empanaditas. You need to peel the apples and chop them very fine, otherwise they will not cook when you fry the pastries. You could parboil the apples in a little sugar syrup before filling the pastry if you wish.
To fry Applepies.
Take Apples and pare them, and chop them very small, beat in a little Cinnamon, a little Ginger, and some Sugar, a little Rosewater, take your paste, roul it thin, and make them up as big Pasties as you please, to hold a spoonful or a little lesse of your Apples; and so stir them with Butter not to hastily least they be burned.
Here’s apples in wine sauce and cream from Archimagirus Anglo-Gallicus; Or, Excellent & Approved Receipts and Experiments in Cookery, 1658. The herb and spice combinations are well worth a try.
Apples in wine sauce & cream
Boil six Pippins pared, (doe not cut the cores apieces) in Claret wine, a little more than will cover them, put in of sugar a good quantity, then boil a quart of good cream, with a little rosemary and thyme, sweeten it with sugar, one spoonful of sack, when they be cold put them together, lay your Apples like Eggs: Remember to boil in your Apples some ginger, lemmon pils very thin sliced.
Finally a refreshing alternative to cider from The Closet Of the Eminently Learned Sir Kenelme Digby Kt. Opened, 1677, where, again, rosemary is the flavoring of choice.
Apple-Drink with Sugar, Honey, &c..
A very pleasant drink is made of Apples, thus: Boil sliced Apples in water, to make the water strong of Apples, as when you make to drink it for coolness and pleasure. Sweeten it with Sugar to your taste, such a quantity of sliced Apples, as would make so much water strong enough of Apples; and then bottle it up close for three or four months. There will come a thick mother at the top, which being taken off, all the rest will be very clear, and quick and pleasant to the taste, beyond any Cider. It will be the better to most tastes, if you put a very little Rosemary into the liquor when you boil it, and a little Limon-peel into each bottle when you bottle it up.
Merry Newtonian Christmas !!!