Introduction
1. From 1582, most countries in Europe used the Gregorian calendar that was introduced that year (and is still used today). In England, however, people could only bring themselves to use it in 1752. (Unless otherwise stated, the dates in this book refer to the Gregorian calendar used today, such as the date of Newton's birth, January 4, 1643.)
2. I therefore deliberately decided to forgo a chronological presentation of Newton's life, and instead jump back and forth in time, in order to look at what I consider to be the interesting episodes in his life and work from the specific angle of this book.
3. See “Newton's Notebooks,” Newton Project, http://www.newtonproject.ox.ac.uk/texts/notebooks.
4. Unless you're a religious fundamentalist.
Chapter 1. At All Costs: Newton, Ruthless in the Extreme
1. Letter from Humphrey Newton to John Conduitt, January 17, 1727/28. See “Two Letters from Humphrey Newton to John Conduitt,” Newton Project, http://www.newtonproject.ox.ac.uk/view/texts/normalized/THEM00033.
2. Ibid.
3. See “Newton's Notebooks,” Newton Project, http://www.newtonproject.ox.ac.uk/texts/notebooks.
4. See “An Extract of a Letter Not Long since Written from Rome, Rectifying the Relation of Salamanders Living in Fire,” Philosophical Transactions 1 (1667): 377–78, http://rstl.royalsocietypublishing.org/content/1/21/377.1.short. The seventeenth century was certainly not a time of brief, concise titles. Today, the title of the text would probably be something like “He threw the salamander into the fire—you won't believe what happened next!”
5. “An Extract of M. Dela Quintiny's Letter, Written to the Publisher in French Sometime Agoe, Concerning His Way of Ordering Melons; Now Communicated in English for the Satisfaction of Several Curious Melonists in England,” Philosophical Transactions 4(1669): 901.
6. The pressure of an ideal gas is inversely proportional to the volume, if the temperature remains the same.
7. The French words thé, caffé, and chocolat had just begun to be used in the German language at the time; the dog wasn't bilingual, therefore, merely very well-informed about the latest culinary developments.
8. But honestly—please don't look directly at the sun! It really is dangerous, even using sunglasses, thermal blankets, colored bits of glass, or other supposedly safe methods. Get hold of a pair of eclipse glasses, ideally NOW and not merely a day before the next major astronomical event. Or observe the eclipse in an observatory: the people there will know their stuff and will have prepared appropriate means of seeing the eclipse. You should only look directly at the sun if you have already seen everything else there is to see and have no need to see any more. Or if you are Isaac Newton.
9. Although, in view of his extensive alchemistic experiments (see chapter 6), it would certainly be tempting to invent a suitable fictional biography, in which a failed experiment turns the puritanical scientist into a musclebound comic-book superhero.
10. It is likely that Newton had health problems at the time. Whether it was full-blown depression, overwork, or something else cannot be said for sure today. But he was certainly in the mood for a change of circumstances.
11. Newton's contemporary, the French philosopher Voltaire, remarked, “Fluxions and gravitation would have been of no use without a pretty niece.”
12. A groat was a small silver coin worth four pence.
13. Guzman Redivivus. A Short View of the Life of Will. Chaloner, the Notorious Coyner, Who Was Executed at Tyburn on Wednesday the 22d of March, 1698/9 (London: J. Hayns, 1699).
14. See Thomas Levenson, Newton and the Counterfeiter: The Unknown Detective Career of the World's Greatest Scientist (London: Faber and Faber, 2009).
15. See Levenson, Newton and the Counterfeiter, and “William Chaloner's Letter to Isaac Newton,” Newton Project, http://www.newtonproject.ox.ac.uk/view/texts/normalized/MINT00918.
16. This is what we call the search for external sources of funding, e.g., from foundations, research funding organizations, or business enterprises.
Chapter 2. Principia First: Newton the Egoist
1. See David Clark and Stephen Clark, Newton's Tyranny (New York: W. H. Freeman, 2000).
2. The Royal Observatory in Greenwich, which still exists today, though it is no longer used as a scientific observatory.
3. The measurements were of course still relatively imprecise. If you really want to know exactly where you are, you need to take many different factors into account about which much too little was known back then: that the earth is not a perfect globe, for example, and actually has an irregular form, or that the earth's axis sways to and fro a little thanks to the influence of the moon.
4. Although, to be precise, that actually depends on what the rotation is in relation to. In relation to the starry sky (if we assume that this remains unchanged), the earth only takes 23 hours, 56 minutes, and 4.099 seconds for one full rotation.
5. See Newton and Flamsteed. Remarks on an Article in Number CIX of the Quarterly Review (Cambridge and London: 1836), and Clark and Clark, Newton's Tyranny.
6. See Clark and Clark, Newton's Tyranny.
7. Richard S. Westfall, Never at Rest: A Biography of Isaac Newton (Cambridge: Cambridge University Press, 1980).
8. Richard S. Westfall, The Life of Isaac Newton (Cambridge: Cambridge University Press, 1993).
9. And Flamsteed received a second humiliation: Newton's friend, the astronomer Edmond Halley, received a fee of 150 pounds for the processing of Flamsteed's data.
10. Richard S. Westfall, The Life of Isaac Newton (Cambridge: Cambridge University Press, 2015).
11. Flamsteed later makes explicit reference to being called a “puppy” by Newton. What Newton's aim was in calling him this is not clear, but that's probably what really bad insults were like in those circles back then.
12. Stealing the data from its originators like Newton did, however, is something to be avoided.
Chapter 3. False Modesty and Easily Offended: Newton the Shrinking Violet
1. Astrology was of course just as much nonsense then as it is now. But if you wanted to practice astrology, you had to work everything out for yourself, since the computer programs that allow anybody to put together their own horoscope today didn't exist at the time. In order to understand astrology in Newton's day, therefore, you needed to have a command of mathematics.
2. One example is the so-called geometric series: 1 + ½ +¼ + ⅛ + etc. Although an infinite number of figures is added here, the result is simply 2, since the figures get smaller and smaller.
3. René Descartes, Principles of Philosophy, XXVI.
4. Isaac Newton to John Collins, Trinity College, Cambridge, January 19, 1669, in Correspondence of Scientific Men of the Seventeenth Century, Including Letters of Barrow, Flamsteed, Wallis, and Newton, Printed from the Originals in the Collection of the Earl of Macclesfield (Oxford: Oxford University Press, 1841), p. 286.
5. And a ray of light that was “another green” would probably be just as much “another green” as before.
6. Such mirrors have little to do with the glass mirrors we know from our bathrooms, however. They were made of metal that was covered with a reflective layer.
7. The magnification is not, however, such an important feature of a telescope – at least not in modern astronomy. The stars and galaxies are much too far away for us to get a significantly larger image of them, regardless how strong the magnification is. The important thing in astronomers’ telescopes is for them to collect more light than the human eye can, in order to be able to detect objects shining more and more weakly.
8. Isaac Newton to Henry Oldenburg, Cambridge, January 6, 1671, in Correspondence of Scientific Men, p. 311.
9. It was also Hooke who gave the word “cell” its biological meaning. When observing bits of plants, he noticed the small, separate sections, which reminded him of the narrow rooms occupied by monks in a monastery, and so called them “cells.”
10. Probably “green,” “another green,” and “a light green.”
11. What modern color theory calls “complementary colors.”
12. Incidentally, the reviewers are not paid for their work. The authors also don't get any money for publishing their results in a journal (indeed, they themselves often have to pay the publishers for this). That is a slightly absurd state of affairs and creates a whole new set of problems.
13. Thanks to my colleague's criticism, I did have to rewrite large chunks of my work and redo many things. Finally, however, I was able to produce a much better article than before, and also got it published (“Planets of Beta Pictoris revisited,” Astronomy & Astrophysics 466 [2007]—in case anybody is interested).
14. Albert Einstein, in a letter to Physical Review, July 27, 1936, in Daniel Kennefick, “Einstein Versus the Physical Review,” Physics Today 58, no. 9 (September 2005): 43.
15. Both Einstein and the reviewer (the American mathematician and physicist Howard Robertson) were proved right in February 2016, when the LIGO collaboration announced the first direct evidence of gravitational waves.
Chapter 4. Gravity without the Apple: Newton's Pugnacious Side
1. The buoyant force acting on an object in a medium is equal to the weight of the medium displaced by the object.
2. Isaac Newton, Questiones quædam Philosophiæ, in Newton Project, http://www.newtonproject.ox.ac.uk/view/texts/normalized/THEM00092.
3. For Newton, on the other hand, it was precisely the “second” that was an unusual term. Measurements accurate to the second were remarkable then, since there were scarcely any clocks that could measure time so accurately. Galileo himself used a pendulum to measure time.
4. Wilhelm Foerster, Die Erforschung des Weltalls, in Hans Kraemer, Weltall und Menschheit (Berlin and Leipzig: Band III, Verlag Bong and Company, 1903).
5. A comet would later be named after him: the famous Halley's Comet, which will next appear and be visible on Earth in 2061. Unless the world comes to an end before then, of course—see chapter 6.
6. It has to travel a greater distance in the same time. A point on the earth's surface describes a circle in one day that is exactly equal to the distance around the earth. The top of the tower is higher, and so the circle it describes has a larger diameter.
7. An astronomer and founding member of the Royal Society, who became famous above all as an architect. His most famous building is St. Paul's Cathedral in London.
8. A then unpublished work of Willughby's still in existence today concerns games in the seventeenth century. Here, there is the first use of the word “goal.” According to Willughby, football is played on “a close that has a gate at either end. The gates are called goals.” He also gave thought to the rules, since the players “often break one another's shins when two meet and strike both together against the ball, and therefore there is a law that they must not strike higher than the ball.”
9. De historia piscium libri quatuor (1686).
10. Today, however, Willughby's book is a highly-prized collector's item, and each copy is worth several thousand dollars.
11. And later a further twenty copies, as a kind of bonus. You can just imagine how Halley's wife (to whom he had been married for four years at the time) reacted when her husband brought home another pile of books about fish instead of money.
12. At least back then.
13. This is the logical fallacy of the so-called Galileo gambit, which asserts that, since Galileo Galilei was ridiculed and criticized by everyone because he claimed that the earth revolved around the sun, although he was a genius and was absolutely right, then if I am ridiculed and criticized by everyone, then I must also be right.
Chapter 5. The Silent Revolutionary: Newton the Mystery-Monger
1. See Stephen Hawking and Werner Israel, eds., 300 Years of Gravitation (Cambridge: Cambridge University Press, 1996).
2. See Colin Pask, Magnificent Principia: Exploring Isaac Newton's Masterpiece (Amherst, NY: Prometheus Books, 2013), pp. 124–26.
3. Although that is only a short version, to be precise. Newton's formulation is more general: force is the temporal change of momentum. Momentum is the product of mass and velocity and, therefore, changes in both velocity and mass must be taken into account in its temporal change. In the vast majority of cases, the mass of an object doesn't change, and then the well-known formula “Force is mass times acceleration (i.e., change in velocity)” does hold true. But sometimes—for example with rockets being launched, which burn large quantities of fuel within a short time and thus lose mass—Newton's more general formulation must be used.
4. In addition to these three axioms, Newton also came up with what is known today as the superposition theory, which explains how several forces acting on an object can be put together to make one single force.
5. Not for nothing is weightlessness in space also referred to as “free fall”: an astronaut is not at rest, but rather falls constantly around the earth, like the moon.
6. A unit of length used by Isaac Newton that corresponds to approximately 32.48 cm. There was no uniform system of units at the time.
7. In mathematics, the branch of mathematics developed by Newton is also called “mathematical analysis.”
8. The Mediterranean is not large enough for this, and the form of the coastline, unlike in the North Sea, for example, does not allow the water to mount up very much at high tide.
9. A precise explanation of the tides is extremely complicated and Newton too was not in a position to explain all the details. This was only done by the physicists and mathematicians who followed him. Today, while we have managed to understand the tides, it is still incredibly difficult to give a clear explanation. Even in many textbooks, you find explanations that are wrong or so simplified that they give a distorted impression of the facts.
10. Not to be confused with the word “precision,” which means something completely different. “Precession” is a specialist term that originates in the Latin word for “advance.”
11. Contrary to widespread belief, there was never a notable number of scholars who thought the earth was a disk. This is a myth that developed relatively late. Even in the (supposed) “dark” Middle Ages, people knew about the earth's spherical shape.
12. The values as measured today are 6,378.137 km to the equator and 6,356.752 km to the poles.
13. Here, too, we can assume that Newton fiddled with the figures a little. With all the simplifications of his models and the quality of the observation data, it would be a huge coincidence if the theoretical calculations and observations tallied so precisely.
Chapter 6. In Search of the Philosopher's Stone: Newton's Esoteric Side
1. The full quote from a lecture by Keynes in 1942: “Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind that looked out on the visible and intellectual world with the same eyes as those who began to build our intellectual inheritance rather less than 10,000 years ago.”
2. Newton didn't have to resign after all; the king passed an exemption that allowed him to remain at the university even without joining the clergy.
3. Yahuda MS 7.3, Jewish National and University Library, Jerusalem.
4. Although “Jehova Sanctus Unus” or rather “Ieoua Sanctus Unus” is actually an anagram of the Latin form of Newton's name: Isaacus Neuutonus.
5. “Quicksilver” or “mercury” was not only the name of the corresponding chemical element, but could also refer quite generally to substances with special qualities.
6. “Praxis,” Ms. 420, The Babson College Grace K. Babson Collection of the Works of Sir Isaac Newton, Huntington Library, San Marino, California, USA.
7. The story that the fire was caused by Newton's dog “Diamond” knocking over a candle is definitely a later invention, however. Newton didn't have a dog. Nor did he have a cat, which is why the widespread story that he was the inventor of the cat flap is also nonsense (Newton is even supposed to have been stupid enough to make a large flap for his cat and an extra-small one for its young).
8. Pantokrator, from the Greek for “ruler of the world,” is often used in the Greek Septuagint Bible and the New Testament as a synonym for “God.”
9. M-J Liu, C-H Xiong, L Xiong, and X-L Huang, “Biomechanical Characteristics of Hand Coordination in Grasping Activities of Daily Living,” PLOS ONE 11, 1 (2016): e0146193. doi:10.1371/journal.pone.0146193.
10. From “Newton and Alchemy” by Richard Westfall in Occult & Scientific Mentalities in the Renaissance, edited by Brian Vickers (Cambridge: Cambridge University Press, 1984), p. 316.
Chapter 7. Rivalry beyond Death: Newton and His Intrigues
1. Diogenes Laertius, DL IX 72.
2. Today, we know that the solution of Zeno's paradoxes is to be found precisely in this new understanding of infinity. The paradoxes only vanished when, thanks to Leibniz and Newton, it was possible to deal mathematically and correctly with infinite additions, such as in the case of the race between Achilles and the tortoise. An infinite series need not necessarily be infinitely large, as Zeno thought it did.
3. But I certainly did move—my sweaty running gear is proof of that.
4. Erhard Weigel was not only an outstanding teacher at the university in my hometown of Jena—he was also an astronomer. While he didn't discover anything of note, he did think constantly about how best to pass on knowledge in a sensible and understandable way. When I was looking for a title for the internet blog I was planning to write, back in 2008, I therefore based my thinking on Weigel, since it was also my goal to make astronomy and science as clearly understandable as possible. One of Weigel's many inventions is a small instrument that simplifies orientation in the sky and with which you can show people where any stars can be found. This “simple star-pointer” or “Astrodicticum Simplex” became the name of my blog, in which I still try today to live up to Weigel's example (http://scienceblogs.de/astrodicticum-simplex/).
5. And today, the University of Leipzig is certainly terribly annoyed that they let such a prominent alumnus slip through their fingers.
6. See Eike Christian Hirsch, Der berühmte Herr Leibniz (Munich: C. H. Beck, 2017).
7. Before that, however, he sought contact with alchemists in Nuremberg, but unlike Newton, he had no particular enthusiasm for this. In order to be accepted by them, he had to prove himself to be worthy in his knowledge. He achieved this by simply writing a long text full of invented alchemistic nonsense, and nobody seemed to realize what he had done. He later wrote, in 1691, about his experiences: “Nuremberg first initiated me into chemical studies, and I do not regret having learned in my youth what makes me cautious as a man…I saw how…those well-known to me were shipwrecked, though they believed themselves to be sailing with the favorable winds of their alchemistic dreams.”
8. A triangular number is a number which represents the sum of all numbers from 1 up to a certain upper limit. The first triangular number is 1. The second is then 1 + 2 = 3, the next is 1 +2 + 3 = 6, followed by 1 + 2 + 3 + 4 = 10, and so on. Leibniz was therefore asked to calculate the sum of 1 + 1/3 + 1/6 + 1/10 +….
9. Naturally, Flamsteed immediately took advantage of the situation and sent a long list of Newton's mistakes and offenses to Leibniz.
10. “An Account of the Book Entitled Commercium Epistolicum,” Philosophical Transactions 29 (1714/15).
11. For example, the integral symbol ∫, which Leibniz first used in a paper dated October 29, 1675.
12. Leibniz was not only a diplomat, lawyer, and mathematician. He was a historian, and practiced geology, logic, linguistics, philology, and biology. He drew plans for an underwater boat, improved mining techniques, explored how to measure fever, and investigated all manner of other topics. Above all, though, he was also one of the most important philosophers of the modern era. It would go far beyond the limits of this book to present his philosophical works. But he was in any case superior to Newton in this field.
13. A dramatic case is described in the book Plastic Fantastic by Eugenie Reich, which looks at the faked research results of the German physicist Jan Hendrik Schön, who nevertheless managed to have thirteen papers published in highly respected journals before his misdemeanors were noticed.
14. The pressure to publish more and more quickly is accompanied by a whole new set of problems, of course, but that is a different story altogether.