Category Archives: History of Mathematics

The emergence of modern astronomy – a complex mosaic: Part XL

The event that would eventually lead to Isaac Newton writing and publishing his magnum opus, the Philosophiæ Naturalis Principia Mathematica (the Mathematical Principles of Natural Philosophy), took place in a London coffee house.

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Title page of ‘Principia’, first edition (1687). Source: Wikimedia Commons

This is not quite as strange as it might at first appear, shortly after their first appearance in England around 1650 coffee houses became the favourite meeting places of the English scientific intelligentsia, the astronomers, mathematicians and natural philosophers. Here, these savants would meet up to exchange ideas, discuss the latest scientific theories and pose challenges to each other. These institutions also earned the appellation Penny Universities, as some of those savants, such as William Whiston, Francis Hauksbee and Abraham de Moivre, bettered their incomes by holding lectures or demonstrating experiments to willing audiences, who paid the price of a cup of coffee, a penny, for their intellectual entertainment. Later, after he had become Europe’s most famous living natural philosopher, Isaac Newton would come to hold court in a coffee shop, surrounded by his acolytes, the original Newtonians, distributing words of wisdom and handing round his unpublished manuscripts for scrutiny. However, all that still lay in the future.

One day in January 1684 Christopher Wren, Robert Hooke and Edmond Halley were discussing the actual astronomical theories over a cup of coffee. Wren, today better known as one of England most famous architects, was a leading mathematician and astronomers, who had served both as Gresham and Savilian professor of astronomy. Newton would name him along with John Wallis and William Oughtred as one of the three leading English mathematicians of the seventeenth century.

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Wren, portrait c.1690 by John Closterman Source: Wikimedia Commons

Hooke was at the time considered to be the country’s leading experimental natural philosopher and Halley enjoyed an excellent reputation as a mathematician and astronomer.

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Portrait by Richard Phillips, before 1722 Source: Wikimedia Commons

The topic of discussion was Kepler’s elliptical, heliocentric astronomy and an inverse, squared law of gravity. All three men had arrived separately and independently at an inverse, squared law of gravity probably derived from Huygens’ formula for centrifugal force. Wren posed the question to the other two, whether they could demonstrate that such a law would lead to Kepler’s elliptical planetary orbits.

Hooke asserted that he already had such a demonstration but he would first reveal it to the others after they had admitted that they couldn’t solve the problem. Wren was sceptical of Hooke’s claim and offered a prize of a book worth forty shillings to the first to produce such a demonstration.  Hooke maintained his claim but didn’t deliver. It is worth noting that Hooke never did deliver such a demonstration. Halley, as already said no mean mathematician, tried and failed to solve the problem.

In August 1684 Halley was visiting Cambridge and went to see Newton in his chambers in Trinity College, who, as we know, he had met in 1682.

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Trinity College Cambridge, David Loggan’s print of 1690 Source: Wikimedia Commons

According the Newton’s account as told to Abraham DeMoivre, Halley asked Newton, “what he thought the Curve would be that would be described by the Planets supposing the force of attraction towards the Sun to be reciprocal to the square of the distance from it. Sir Isaac replied immediately that it would be an Ellipse…” Here was Newton claiming to know the answer to Wren’s question. Halley asked Newton how he knew it and he replied, “I have calculated it…” Newton acted out the charade of looking for the supposed solution but couldn’t find it. However he promised Halley that he would send him the solution.

In November Edward Paget, a fellow of Trinity College, brought Halley a nine page thesis entitled De motu corporum in gyrum (On the Motion of Bodies in an Orbit).

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Page of the De motu corporum in gyrum

When Halley read Newton’s little booklet he was immediately aware that he held something truly epoch making in the history of astronomy and physics in his hand. Newton had delivered up a mathematical proof that an elliptical orbit would be produced by an inverse square force situated at one of the foci of the ellipse, thus combining the inverse square law of gravity with Kepler’s first law. He went on to also derive Kepler’s second and third laws as well as laying down the beginnings of a mathematical theory of dynamics. Halley reported details of this extraordinary work to the Royal Society on 10 December 1684:

Mr Halley gave an account, that he had lately seen Mr. Newton at Cambridge, who had shewed him a curious treatise, De motu: which, upon Mr. Halley’s desire, was he said promised to be sent to the Society to be entered upon their register.

Mr. Halley was desired to put Mr. Newton in mind of his promise for securing his invention to himself till such time as he could be at leisure to publish it. Mr. Paget was desired to join with Mr. Halley.

The interest in and the demand to read Newton’s new production was very high but the author decided to improve and rewrite his first offering, triggering one of the most extraordinary episodes in his life.

Although he was Lucasian Professor and would turn forty-two on 25 December 1684, Newton remained a largely unknown figure in the intellectual world of the late seventeenth century. Following the minor debacle that resulted from the publication of his work in optics in the 1670s he had withdrawn into his shell, living in isolation within the walls of Cambridge University. He carried out his duties as Lucasian Professor but had almost no students to speak of and definitely no disciples. Thanks to the word of mouth propaganda of people like his predecessor as Lucasian Professor, Isaac Barrow, and above all the assiduous mathematics groupie, John Collins, it was rumoured that a mathematical monster slumbered in his chambers in Trinity College but he had done nothing to justify this bruited reputation. His chambers were littered with numerous unfinished scientific manuscripts, mostly mathematical but also natural philosophical and an even larger number of alchemical and theological manuscripts but none of them was in a fit state to publish and Newton showed no indication of putting them into a suitable state. Things now changed, Newton had found his vocation and his muse and the next two and a half years of his life were dedicated to creating the work that would make him into a history of science legend, the reworking of De motu into his Principia.

Over those two and a half years Newton turned his nine-page booklet into a major three-volume work of science. The modern English translation by I B Cohen runs to just over 560 large format pages, although this contains all the additions and alterations made in the second and third editions, so the original would have been somewhat shorter. Halley took over the editorship of the work, copyediting it and seeing it through the press. In 1685 the Royal Society had voted to take over the costs of printing and publishing Newton’s masterpiece, so everything seemed to be going smoothly and then disaster struck twice, firstly in the form of Robert Hooke and secondly in the form of a financial problem.

Hooke never slow to claim his priority in any matter of scientific discovery or invention stated that he alone had first discovered the inverse square law of gravity and that this fact should, indeed must, be acknowledged in full in the preface to Newton’s book. Halley, realising at once the potential danger of the situation, was the first to write to Newton outlining Hooke’s claim to priority, stating it, of course, as diplomatically as possible. Halley’s diplomacy did not work, Newton went ballistic. At first his reaction was comparatively mild, merely pointing out that he had had the inverse square law well before his exchanges with Hook in 1679 and had, in fact, discussed the matter with Wren in 1677, go ask him, Newton said. Then with more time to think about the matter and building up a head of steam, Newton wrote a new letter to Halley tearing into Hooke and his claim like a rabid dog. All of this ended with Newton declaring that he would no longer write volume three of his work. Halley didn’t know this at the time but this was in fact, as we shall see, the most important part of the entire work in which Newton presented his mathematical model of a Keplerian cosmos held together by the law of gravity. Halley remained calm and used all of his diplomatic skills to coax, flatter, persuade and cajole the prickly mathematician into delivering the book as finished. In the end Newton acquiesced and delivered but acknowledgements to Hooke were keep to a minimum and offered at the lowest level of civility.

The financial problem was of a completely different nature. In 1685 the Royal Society had taken over the cost of printing and publishing the deceased Francis Willughby’s Historia piscium as edited by John Ray.

This was an expensive project due to the large number plates that the book contained and the book was, at the time, a flop. This meant when it came time to print and publish Newton’s work the Royal Society was effectively bankrupt. One should note here that the popular ridicule poured out over Willughby’s volume, it having almost prevented Newton’s masterpiece appearing, is not justified. Historia piscium is an important volume in the history of zoology. Halley once again jumped into the breach and took over the costs of printing the volumes; on the 5 July 1687 Halley could write to Newton to inform him that the printing of his Philosophiæ Naturalis Principia Mathematica had been completed.

 

 

 

 

 

 

 

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The emergence of modern astronomy – a complex mosaic: Part XXXIX

The emergence of modern astronomy – a complex mosaic: Part XXXIX

One of the most often repeated false statements in the history of science is that Isaac Newton discovered gravity. Of course he didn’t discovery it, it’s all around us. You can observe gravity every time you drop something. Making the claim more precise, by saying Newton discovered the law of gravity, doesn’t really improve the situation much. What Newton did do was he proved the law of gravity and made the fairly rational assumption based on the available evidence that this law applies universally to all bodies in the cosmos. An assumption that is not written in stone and has been questioned in the present time for the general theory of relativity, the theory that replaced the Newtonian theory of universal gravity and of which the Newtonian theory of gravity is a very good approximation for local cases. However we don’t want to take the path to modern theories of cosmology and dark matter but want to stay firmly in the seventeenth century with Newton.

We can start with a brief survey of theories of gravity before Newton. Originally gravity was the Latin term applied to Aristotle’s explanation of why, when dropped, things fall to the ground. Aristotle thought that objects did so through a form of vital attraction, returning to their natural home, consisting predominantly of the elements earth and water. Fire and air rise up. This only applied to the Earth, as things beyond the Moon were made of a fifth element, aether, the quintessence, for which the natural form of motion was uniform circular motion.

This neat model wouldn’t work, however for Copernicus’ heliocentric model, which disrupted the division between the sublunar and supralunar worlds. To get around this problem Copernicus suggested that each planet had its own gravity, like the Earth. So we have terrestrial gravity, Saturnian gravity, Venusian gravity etc. This led Alexander von Humboldt, in the 19th century, to claim that Copernicus should be honoured as the true originator of the universal theory of gravity, although it is by no means clear that Copernicus thought that he planetary gravities were all one and the same phenomenon.

The whole concept became even more questionable when the early telescopic astronomers, above all Galileo, showed that the Moon was definitely Earth like and by analogy probably the other planets too. At the end of a long line of natural philosophers stretching back to John Philoponus in the sixth century CE, Galileo also showed that gravity, whatever it might actually be, was apparently not a vitalist attraction but a force subject to mathematical laws, even if he did get the value for the acceleration due to gravity ‘g’ wrong and although he didn’t possess a clear concept of force.. Throughout the seventeenth century other natural philosophers, took up the trail and experimented with pendulums and dropped objects. A pendulum is of course an object, whose fall is controlled. Most notable were the Jesuit, natural philosopher Giovanni Battista Riccioli (1598–1671) and the Dutch natural philosopher Christiaan Huygens (1629–1695). Riccioli conducted a whole series of experiments, dropping objects inside a high tower, making a direct confirmation of the laws of fall. Both Riccioli and Huygens, who independently of each other corrected Galileo’s false value for ‘g’, experimented extensively with pendulums in particular determining the length of the one-second pendulum, i.e. a pendulum whose swing in exactly one second. As we will see later, the second pendulum played a central roll in an indirect proof of diurnal rotation. Huygens, of course, built the first functioning pendulum clock.

Turning to England, it was not Isaac Newton, who in the 1670s and 80s turned his attention to gravity but Robert Hooke (1635–1703), who was Curator of Experiments for the newly founded Royal Society. Like Riccioli and Huygens Hooke experimented extensively with dropping objects and pendulums to try and determine the nature of gravity. However his experiments were not really as successful as his continental colleagues. However, he did develop the idea that it was the force of gravity that controlled the orbits of the planets and, having accepted that comets were real solid objects and not optical phenomena, also the flight paths of comets. Although largely speculative at this point Hooke presented a theory of universal gravity, whilst Newton was still largely confused on the subject. Hooke turned to Newton in a letter with his theory in order to ask his opinion, an act that was to lead to a very heated priority dispute.

Before we handle that correspondence we need to go back to the beginnings of the 1670s and an earlier bitter dispute between the two.  In 1672 Newton announced his arrival on the European natural philosophy scene with his first publication, a letter in the Philosophical Transactions of the Royal Society (1671/72), A New Theory of Light and Colours, which described the experimental programme that he had carried out to demonstrate that white light actually consisted of the colours of the spectrum.

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Newton’s original letter. Source: Royal Society

This brilliant piece of experimental optics did not receive the universal praise that, reading it today, we might have expected, in fact it was heavily criticised and attacked. Some critics were unable to reproduce Newton’s experimental results, probably because their prisms were of too poor quality. However, others, Hooke to the fore, criticised the content. Hooke and Huygens, the two current leaders in the field of optics both criticised Newton for interpreting his results within the framework of a particle theory of light, because they both propagated a wave theory of light. Newton actually wrote a paper that showed that his conclusions were just as valid under a wave theory of light, which, however, he didn’t publish. The harshest criticism came from Hooke alone, who dismissed the whole paper stating that he had already discovered anything of worth that it might contain . This did not make Newton very happy, who following this barrage of criticism announced his intention to resign from the Royal Society, to which he had only recently been elected.  Henry Oldenburg (c. 1619–1677), secretary of the Royal Society, offered to waive Newton’s membership fees if he would stay. Newton stayed but had little or nothing more to do with the society till after Hooke’s death in 1703. Newton did, however, write a very extensive paper on all of his optical work, which remained unpublished until 1704, when it formed a major part of his Opticks.

By  1679 tempers had cooled and Robert Hooke, now secretary of the Royal Society, wrote to Isaac Newton to enquire if he would be interested in reopening his dialogue with the Royal Society. In the same letter he asked Newton’s opinion on his own hypothesis that planetary motions are compounded of a tangential motion and “an attractive motion towards the centrall body…” Hooke is here referencing his Attempt to Prove the Motion of the Earth from Observations (1674, republished 1679),

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which contains the following fascinating paragraph:

This depends on three Suppositions. First, That all Coelestial Bodies whatsoever, have an attractive or gravitating power towards their own Centers, whereby they attract not only their own parts, and keep them from flying from the, as we observe the earth to do, [here Hooke is obviously channelling Copernicus] but that they do also attract all other Coelestial Bodies that are within the sphere of their activity … The second supposition is this, That all bodies whatsoever that are put into a direct and simple motion, will so continue to move forward in a streight line, till they are by some other effectual power deflected and bent into a Motion, describing a Circle, Ellipsis, or some other more compounded Curve Line. [the principle of inertia, as propounded by Descartes] The third supposition is, That these attractive powers are so much the more powerful in operating, by how much nearer the body wrought upon is to there own Centers. Now what these several degrees are I have not yet experimentally verified…

Whether or not this is truly a universal theory of gravity is a much-debated topic, but if not, it comes very close and was moving much more in that direction than anything Newton had produced at the time. As we shall see later this was to cause not a little trouble between the two rather prickly men.

Newton declined the offer of a regular exchange of ideas, claiming that he was moving away from (natural) philosophy to other areas of study. He also denied having read Hooke’s paper but referred to something else in it in a later letter to Flamsteed. However, in his reply he suggested an experiment to determine the existence of diurnal rotation involving the usually dropping of objects from high towers. Unfortunately for Newton, he made a fairly serious error in his descripting of the flight path of the falling object, which Hooke picked up on and pointed out to him, if unusually politely, in his reply. Newton of course took umbrage and ended the exchange but he did not forget it.

In our next episode we will deal with the events leading up to the writing and publication of Newton’s great masterpiece, Philosophiæ Naturalis Principia Mathematica (1687), which include the repercussions of this brief exchange between Hooke and its author.

 

 

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Filed under History of Astronomy, History of Mathematics, History of Optics, History of Physics, Renaissance Science

Mathematics and natural philosophy: Robert G socks it to GG

In my recent demolition of Mario Livio’s very pretentious Galileo and the Science Deniers I very strongly criticised Livio’s repeated claims, based on Galileo’s notorious Il Saggiatore quote on the two books, that Galileo was somehow revolutionary in introducing mathematics into the study of science. I pointed out that by the time Galileo wrote his book this had actually been normal practice for a long time and far from being revolutionary the quote was actually a common place.

Last night whilst reading my current bedtime volume, A Mark Smith’s excellent From Sight to Light: The Passage from Ancient to Modern Optics,(University of Chicago Press, 2015) I came across a wonderfully appropriate quote on the topic from Robert Grosseteste (c.1175–1253). For those that don’t know Grosseteste was an English cleric who taught at Oxford University and who became Bishop of Lincoln. He played an important and highly influential role in medieval science, particularly in helping to establish optics as a central subject in the medieval university curriculum.

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An early 14th-century portrait of Grosseteste Source: Wikimedia Commons

Of course, this is problematic for Livio, who firmly labelled the Catholic Church as anti-science and who doesn’t think there was any medieval science, remember that wonderfully wrong quote:

Galileo introduced the revolutionary departure from the medieval, ludicrous notion that everything worth knowing was already known.

If this were true then medieval science would be an oxymoron but unfortunately for Livio’s historical phantasy there was medieval science and Grosseteste was one of its major figure. If you want to know more about Grosseteste then I recommend the Ordered Universe website set up by the team from Durham University led by Giles Gasper, Hannah Smithson and  Tom McLeish

I already knew of Grosseteste’s attitude towards natural philosophy and mathematics but didn’t have a suitable quote to hand, so didn’t mention it in my review. Now I do have one. Let us first remind ourselves what Galileo actually said in Il Saggiatore:

Philosophy [i.e. natural philosophy] is written in this grand book — I mean the Universe — which stands continually open to our gaze, but it cannot be understood unless one first learns to comprehend the language and interpret the characters in which it is written. It is written in the language of mathematics, and its characters are triangles, circles, and other geometrical figures, without which it is humanly impossible to understand a single word of it; without these, one is wandering around in a dark labyrinth.

And now what Grosseteste wrote four hundred years earlier in his De lineis, angulis et figuris (On lines, angles and figures) between 1220 and 1235:

“…a consideration of lines, angles and fugures is of the greatest utility because it is impossible to gain a knowledge of natural philosophy without them…for all causes of natural effects must be expressed by means of lines, angles and figures”

Remarkably similar is it not!

 

 

 

 

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Filed under History of Mathematics, History of science, Mediaeval Science

How to create your own Galileo

Writing this book review caused me a great deal of of stress, even leading to sleepless night when I made the mistake of reading the offending piece of literature as bedtime reading. The review itself has become horrendously long and I must at times fight my instinct to add even more explanations, as to why this or that was wrong. It is in the words of that excellent history of science author, Matthew Cobb, ‘baggy and rambling’ and should actually be radically edited but I just can’t be arsed to do it, so I’m simply posting the whole monstrosity. For those, who don’t want to read the whole thing, and I wouldn’t blame you, the first three and the last five paragraphs offer a sort of synopsis of the whole thing.

Since I began writing book reviews on a more regular basis I have tried only to review books that I personally find good and which I think might be of interest to those who come here to read my weekly scribblings. I decided that on the whole it isn’t worth wasting time and energy writing about uninteresting, mediocre or simply bad books. However, occasionally a book come along that I feel duty bound, given my reputation as a #histSTM grouch, to debunk as a favour to my readers so that they don’t waste their time and energy reading it; today’s review is one such.

Some time back I wrote a post about the Alexandrian mathematician and philosopher Hypatia, which started with the fact that she has been used as a sort of blank slate onto which numerous people down the centuries have projected their images of what they would have wanted her to be. In the case of Hypatia this is fairly easy, as the rest of my post pointed out we know next to nothing about the lady. Another figure, who has been used extensively over the years as a silhouette, which people fill out according to their own wishes is Galileo Galilei; in his case this is more difficult as we actually know an awful lot about the Tuscan mathematician’s life and work. However, this has not prevented numerous authors from creating their own Galileos.

The latest author, who has decided to present the world with his Galileo, is the astrophysicist and very successful author of popular books on mathematics and science, Mario Livio with his Galileo and the Science Deniers.[1] I might not have bothered with this book but Livio is a very successful pop science book author, as is made very clear by the fact that the hardback and paperback were both issued simultaneously and at very low prices; the publishers expect it to sell well, so it will unfortunately have a big impact on uninformed peoples perceptions of Galileo. I say unfortunately, which, of course, gives readers of this review a very strong clue as to what I think of this book. Quite simply don’t bother, it brings nothing new to our knowledge of Galileo and in fact is full of, at times, quite serious historical errors, serious that is if you’re a historian, who takes getting the facts right seriously.

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The opening sentences starts with a couple of wonderful errors and also lays out Livio’s version of Galileo:

Being an astrophysicist myself, I have always been fascinated by Galileo. He was, after all, not only the founder of modern astronomy and astrophysics–the person who turned an ancient profession into the universe’s deepest secrets and awe-inspiring wonders–but also a symbol of the fight for intellectual freedom.

I think Copernicus, Tycho Brahe and Johannes Kepler might want a word with Livio about, who exactly is the founder of modern astronomy. Also, excuse the language, but what the fuck did Galileo ever do for astrophysics? The final half sentence tells us into which silhouette Livio has decided to pour his Galileo; Livio’s Galileo is the white knight of freedom of speech and freedom of thought, who has mounted his charger and taking up his lance sets off to kill the anti-science dragon of the Holy Roman Catholic Church. This is, of course not a new Galileo but a well-known old model, which historians of science have spent a lot of time and effort dismantling over the last fifty plus years.

Central to the problems with Livio’s book is that he completely ignores the historical context in which the Galileo story took place. His is totally a presentist view in which he applies the social rules and moral judgements of the twentieth-first century to the various occurrences he sketches in the early seventeenth century. This is quite simply very bad historiography. He compounds this error by trying to draw parallels between Galileo’s conflict with the Catholic Church and the current problems with science denialists in our times, hence the title of his book. To do this he simply denies Galileo’s critics any scientific basis for their criticism whatsoever, Galileo is science, his critics are anti-science. A rather simplistic and historically highly inaccurate presentation of the known facts.

Just to make clear what exactly the historical context was, there existed no freedom of speech or freedom of thought under any civil or religious authority anywhere in Europe at the beginning of the seventeenth century; such social concepts still lay in the future. There is a slight irony in the fact that the current wave of science denialists, against whom Livio’s book is directed, are in fact exercising their, protected by law, rights of freedom of thought and speech. More importantly the Holy Roman Catholic Church was not just a religion and a church but also a powerful political and judicial body with judicial rights over all within its dominion and this in an age of absolutism with the Pope as the most absolute of all absolute rulers. All authorities both civil and religious reserved for itself the right to determine what its subject were permitted to express in public, the Catholic Church was in no way unique in claiming and exercising this right.

Still in the preface to Livio’s book we find his first distortion of the historical scientific facts, he writes that Galileo’s telescopic discoveries, “All but destroyed the stability of the Earth-centered Ptolemaic universe.” Here Livio, and not only here, fails to differentiate between Aristotelian cosmology and Ptolemaic astronomy. All of the telescopic discoveries, with the exception of the phases of Venus, demolished aspects of Aristotelian cosmology but had no significance for Ptolemaic geocentric astronomy. The discovery of the phases of Venus, of course, refuted a pure geocentric system but was perfectly compatible with a Tychonic geo-heliocentric system, which then became the default alternative to a heliocentric system. With two notable exceptions that I will deal with later Livio makes no clear mention of the fact that the telescopic discoveries were made within the same approximately three year period not only by Galileo but simultaneous by others, so if Galileo had never used a telescope it would have made very little difference to the subsequent history of astronomy. This makes rather a mockery of Livio’s next dubious claim, “his [Galileo’s] ideas became the basis on which modern science has been erected.” This is much less true than Livio and other Galileo groupies would have us believe. Galileo made a contribution but others in the seventeenth century actually contributed significantly more.

One last comment from the preface, Livio writes:

He insisted on publishing many of his scientific findings in Italian [actually Tuscan not Italian] (rather than Latin), for the benefit of every educated rather than for a limited elite.

In the early seventeenth century almost every educated person would per definition have been able to read and write Latin; Latin was the default language of education.

Reading the opening chapter of Livio’s book, Rebel with a Cause, I constantly had the feeling that I had been transported back to the 1960s and 70s, when I first began to read books about the history of science in general and Galileo in particular. It as if the last fifty plus years of history of science research had never taken place, he even relies on Einstein and Bertrand Russell as his historical authorities, at times I shuddered. He goes so far as to tell us that the Renaissance happened because people discovered that they were individuals! I can’t remember when I last read this particular piece of inanity and I would be curious who actually put it into the world. The final page of this chapter contains all of the classic Galileo clichés.

Perhaps most important, Galileo was the pioneer and star of advancing the new art of experimental science. He realised that he could test or suggest theories by artificially manipulating various terrestrial phenomena. He as also the first scientist whose vision and scientific outlook incorporated methods and results that were applicable to all branches of science.

There is a long historical list of people who would disagree–Archimedes, Ptolemaeus, al-Haytham, Grosseteste, Roger Bacon, William Gilbert and a whole host of alchemists starting with Abū Mūsā Jābir ibn Hayyān (for Livio opinion on alchemy see below)–just to name the most prominent. Modern research has also conclusively shown that artisanal practice in the fifteenth and sixteenth centuries played a significant role in the development of empirical, experimental science. Livio’s last sentence here is also rather dubious, apart from some rather trivial aspects, there are no methods and results that are applicable to all branches of science.

…in four areas he revolutionised the field: astronomy and astrophysics; the laws of motion and mechanics; the astonishing relationship between mathematics and physical reality […]; and experimental science.

Despite everything, Galileo’s contributions to astronomy were rather minimal and he certainly didn’t revolutionise the field, others such as Kepler, whom he ignored, did. I am still trying to work out what his contributions to astrophysics could possibly be? His real major contribution was indeed to motion and mechanics but he was no means alone in this others such as Simon Stevin and Isaac Beeckman made substantial contributions to the new developments in these areas. The mathematics thing, to which Livio keeps returning, is baloney and I shall deal with it separately later. Galileo made contributions to the development of experimental science but he was by no means alone in this and to say he revolutionised it is hyperbole.

The only defense remaining to those obstinately refusing to accept the conclusions implied by the accumulating weight of empirical facts and scientific reasoning was to reject the results almost solely on the basis of religious or political ideology

Here Livio betrays his own tactic, put crudely, throughout the book he twists the historical facts in order to try and make out that there no legitimate scientific objections to Galileo’s claims, however there were.

The next chapter is the usual enthusiastic fan boy description of Galileo’s talents as an all round humanist and contains nothing particularly objectionable but does contain a strong indication of the superficiality of Livio’s historical knowledge. He writes, “First, at age twenty-two, Galileo, already had the chutzpah to challenge the great Aristotle on topics related to motion…” People had been consistently challenging the great Aristotle on topics related to motion since the sixth century CE and Galileo was merely joining a long tradition of such work. Livio also casually calls Aristotle’s theory of motion impetus! Impetus was, of course, a theory initially developed by John Philoponus in the sixth century CE when seriously challenging Aristotle’s theory of motion. On a side note Livio says that the tools to treat such variables such as velocity and acceleration, i.e. calculus, were first developed by Newton and Leibniz. Other seventeenth century mathematicians who contributed substantially to the development of the calculus such as Cavalieri, de Saint-Vincent, Fermat, Pascal, Descarte, John Wallis and Isaac Barrow would be very surprised to hear this. On the same page he repeats the myth that Christoph Clavius was “the senior mathematician on the commission that instituted the Gregorian calendar, he wasn’t, Ignazio Danti was.

Clavius turns up as one of the leading mathematicians, who the young Galileo turned to for mentorship when he was trying to establish a reputation as a mathematician and get support to find an appointment as professor of mathematics. Interestingly Galileo’s other mentor Guidobaldo del Monte (1545–1607) appears nowhere in Livio’s book. This is strange as it was del Monte, who acquired the professorship in Pisa for Galileo through his brother Cardinal Francesco Maria del Monte (1549–1627), who was the de ‘Medici cardinal and recommended Galileo to the Grand Duke. It was also del Monte, who devised the experiment that led Galileo to the parabola law, which Livio calls one of Galileo’s crowning achievements.

In the next chapter on Galileo’s work on the theory of fall Livio can’t help taking a sideswipe at alchemy and astrology:

It is certainly true that, at their inception, the sciences were not immune to false beliefs, since they are sometimes connected to fictitious fields such as alchemy and astrology. This was partly the reason why Galileo decided later to rely on mathematics, which appeared to provide a more secure foundation.

This off hand rejection ignores completely that astrology was the main driving force behind astronomy since its beginnings in antiquity down to the seventeenth century and that all the leading Renaissance astronomers, including Galileo, were practicing astrologers. The practice of astrology/astronomy, of course, requires a high level of mathematical ability. Alchemy developed virtually all of the experimental methods and the necessary equipment to carry out those experiments on which chemistry was built.

Now in Padua, where Galileo was also professor of mathematics, a position that he once again acquired with the assistance of del Monte, we get the story of Galileo’s three lectures on the nova of 1604. Livio informs us that “Christoph Clavius confirmed the null parallax determination–that is, no shift had been observed–but refused to accept its implications as compelling.”

This is once again Livio’s tactic of trying to discredit the Jesuits. The implications that he is talking about are that the heavens are not unchanging as claimed by Aristotle. Clavius observed the nova of 1572 and already in 1581 published a digression on the subject fully accepting that the nova was supralunar and that the heavens were not unchanging. He included this in his Sphaera in 1585, the most widely read astronomy textbook in the late sixteenth and early seventeenth centuries and he probably thus had the most influence in persuading others that change had occurred in the heavens. He also included the same results for the novae of 1600 and 1604, so what is Livio talking about? Clavius was unable to explain what these novae were but then again nobody else in the seventeenth century could either.

We now move on to Galileo, telescopic astronomy and the Sidereus Nuncius. Although he actually talks about other telescopic astronomers–Scheiner, Marius, Harriot, Fabricius–they are only offered bit parts in Livio’s screenplay, which follows the usual path of giving Galileo credit for everything. He attributes the discovery of Earthshine, the Moon illuminated by sunlight reflected by the Earth, to Galileo, whereas it was previously discovered by Leonardo, who didn’t publish, and Michael Mästlin, who did. He attributes the discovery of stars that can’t be seen without a telescope to Galileo, whereas this was already noted in the printed account of the first telescope demonstration in Den Hague, the source of Sarpi’s and thus Galileo’s first knowledge of the telescope. We then get one of the most bizarre claims made by Livio in the book:

Even more consequential for the future of astrophysics was Galileo’s discovery that stars varied enormously in brightness, with some being a few hundred times brighter than others.

Coming from a professional astrophysicist I find this statement mind boggling. The difference in brightness between celestial objects is obvious to anybody with reasonable eyesight, who simply looks up at the night sky in an area without light pollution. Astronomers even use a six-point scale to designate the different levels of brightness, which is termed magnitude; this was first introduced by Ptolemaeus around 150 CE!

We then get a very brief account of the star size argument as originated by Tycho, which Livio falsely claims Galileo dismissed by saying that the observed star discs are merely artefacts. They are in fact merely artefacts but Galileo didn’t say this. He accepts their existence and uses a completely different argument to try and dismiss the star size argument.

We now arrive at the Moons of Jupiter and Simon Marius. Livio mentions Marius several times in his book but insists on calling him Simon Mayr, his birth name, why? Marius issued all of his publications under the Latinised version of his name and so historian refer to him as Simon Marius. Livio doesn’t call Copernicus, Kopernik or Tycho, Tyge their birth names, so why does he call Marius, Mayr? What he writes about Marius and the Moons of Jupiter left me, as a Marius expert, totally flabbergasted:

What would have undoubtedly annoyed Galileo no end is that the Galilean satellites are known today by the names assigned to them by the German astronomer Simon Mayr rather than as the “Medici stars.” Mayr may have independently discovered the satellites before Galileo, but he failed to understand that the moons were orbiting the planet. [my emphasis]

First off, the names were suggested by Kepler not Marius, who however first published them specifically mentioning the fact that they were suggested by Kepler. Secondly Marius discovered the moons, famously, one day later than Galileo, any confusion about who discovered what when being produced by use of different calendars, Gregorian and Julian. Thirdly, the clause that I have emphasised above is pure and utter bullshit. Marius knew very well that the moons orbited Jupiter and he calculated the orbits, calculations that he published before Galileo. Marius’ calculations are also more accurate than those of Galileo. Should Livio doubt any of this I can send him scans of the relevant pages of Mundus Jovialis in the original Latin or in German and/or English translation. Livio now brings the story of Galileo hating Marius because he accused him of being behind Baldessar Capra’s plagiarism of Galileo’s proportional compass pamphlet in 1606. Marius had been Capra’s mathematics teacher earlier in Padua. Livio fails to mention that the accusations are provably false. Galileo in 1607 had himself cleared Marius of any involvement in the case and the whole episode took place a year after Marius had left Padua.

We now move on to the peculiar shape of Saturn and the discovery of the phases of Venus. In the later case we get absolutely no mention that the phases of Venus were discovered independently by Harriot, Marius, and the astronomers of the Collegio Romano, the latter almost certainly before Galileo. Livio notes correctly that the discovery of the phases definitively refutes the possibility of a pure geocentric system. However, it does not refute a geo-heliocentric Tychonic system. Livio admits this very grudgingly:

…but could not definitely dispose of Brahe’s geocentric-heliocentric compromise […]. This left a potential escape route for those Jesuit astronomers who were still determined to avoid Copernicanism.

Throughout his book Livio tries to imply that there is no real justification for supporting the Tychonic system, whereas it was not only the Jesuits, who did so but many other astronomers as well because the empirical evidence supported it more that a heliocentric one, of which more later. However, Livio consistently ignores this fact because it doesn’t fit his fairy-tale narrative.

Livio deals fairly conventionally with the telescopic discovery of sunspots and the discussion on their nature between Galileo and Christoph Scheiner and although he ends his account by noting the publication of Scheiner’s Rosa Ursina sive Sol (1626–1630) he makes no mention of the fact that the book is a masterpiece of astronomy, far better than anything Galileo published in the discipline. As should always be noted, due to the haste in which he wrote and published it, Sidereus Nuncius was closer to a press report than a scientific publication. He does however mention, what he calls “some further comments he made later in the book The Assayer, which the Jesuit astronomer took to be directed at him personally, did turn him into an unappeasable enemy.” Galileo actual vehemently and totally falsely accused Scheiner of plagiarism in The Assayer, which he later compounded by plagiarising Scheiner’s work in his own Dialogo. Scheiner’s antagonism is understandable. We now get the real reason why Livio keeps badmouthing the Jesuits; he sees them as behind Galileo’s trial in 1633. He writes, “This marked just the beginning of a conflict with the Jesuits, which would culminate in the punitive actions against Galileo in 1633.” This is an old myth and quite simply not true, the Jesuits did not come to Galileo defence but they were also not responsible for his trial.

We now come to objections to the telescopic discoveries:

How could anyone be sure that what Galileo was seeing was a genuine phenomenon and not a spurious artifact produced by the telescope itself?

Not only wasn’t there a convincing theory of optics a that could demonstrate that the telescope doesn’t deceive, they contended but also the validity of such a theory in itself based on mathematics, was questionable. [my emphasis]

 

Livio tries to imply that both objections are just anti-science nit picking but they are in fact very solid, very necessary scientific question that had to be asked and to be answered if people were going to accept the validity of the telescopic discovery. To the first general objection, although Galileo, an excellent observer, made none himself, there were numerous cases of published discoveries that turned out to be merely optical artefacts in the early years of telescopic astronomy. Not really surprising given the really poor quality of the instruments being used, Galileo’s included.

That an optical theory of the telescope didn’t exist was a very serious problem, as it would be with any new scientific instrument. If you can’t explain how the instrument works how do you expect people to accept the results? Kepler solved the problem with his Dioptrice published in 1611, which explained fully and scientifically how lenses and lens combinations function, describing various different types of telescope. Galileo dismissed and mocked, what is now regarded as a milestone in the history of geometrical optics. The last clause is, once again, Livio spouting total crap. Theories of optics had been geometrical, i.e. mathematical, since at least, in the fourth century BCE and even Aristotle classified optics as one of the mixed sciences, i.e. those such as astronomy that are dependent on mathematics for their proofs. Kepler’s book was accepted by all those qualified to pass judgement on the matter, with the notable exception of Galileo, who didn’t want to share the limelight with anybody, and together with Kepler’s earlier Pars Optica (1604) formed the foundations of modern scientific optics.

The reference to mathematics here is Livio’s attempt to create or propagate a myth that before Galileo, nobody conceived of a mathematics-based science. It is time to tackle that myth. Livio argues that Aristotle rejected mathematics in science and that Aristotelians regarded anything proof based on mathematics as not valid. He, of course, finds an obscure Aristotelian contemporary of Galileo’s to quote to prove this but does not quote any evidence to the contrary or even appear to think that some might exist. He is very wrong in this. Because, in Aristotle’s opinion, mathematics does no deal with the real world the results of mathematic are not episteme or scientia or as we would say knowledge. He however makes allowances for the so-called mixed sciences, astronomy, optics and statics. Livio acknowledges this status for astronomy but argues with the medieval Aristotelians that astronomical mathematical models are mere calculating devices and not models of reality; describing cosmological reality was the domain of the philosophers and not the mathematical astronomers. He also claims that this was still the situation in the second decade of the seventeenth century, it wasn’t. Beginning with Copernicus astronomers began to claim that their mathematical models were models of reality and by the time of Galileo’s first dispute with the Catholic Church this had become the generally accepted state of the discipline. The debate was which mathematical model describes the real cosmos?

It is a standard cliché in the history of science that one of the major factors that drove the so-called scientific revolution was the mathematization of science. Like many clichés there is more that a modicum of truth in this claim. Livio believes it is absolutely central and one of the major themes of his book is that Galileo was the first to mathematize science in his experiments on motion and the laws of fall. This is quite simply not true and Livio can only maintain his claim by steadfastly ignoring the history of mathematics in science prior to Galileo or did he even bother to look if there was any?

Starting with Galileo’s researches into motion and fall there is a three hundred year history of experimental and mathematical investigation into exactly this area starting with the Oxford Calculatores, who derived the mean speed theorem, which lies at the heart of the laws of fall and going down to Giambattista Benedetti (1530–1590), who produced all of the arguments and thought experiments on the subject for which Galileo is famous. There is much more, which I have already dealt with in an earlier post and won’t repeat here.Galileo knew of all of this work. The Archimedean renaissance in mathematics and the sciences, replacing the authority of Aristotle with that of Archimedes, in which Galileo is a major figure, does not start with Galileo but goes back at least to Regiomontanus (1436–1476).  The works of Archimedes were edited by Thomas Venatorius (1488–1551) and printed and published in a bilingual Greek and Latin edition in Basel in 1544. In general the sixteenth century saw a massive increase in the application of mathematics to a wide range of subjects, a development that was already well underway in the fifteenth century, including linear perspective in art, cartography, surveying, navigation, physics and astronomy. Galileo in no way started the mathematization but represents, together with several of his contemporaries such as Johannes Kepler, Simon Stevin, Christoph Clavius and Isaac Beeckman, a temporary high point in these developments. All four of those contemporaries were actually better mathematicians than Galileo.

On the question of the epistemological status of mathematical proofs, which Livio clearly states was still doubted in Galileo’s time, Christoph Clavius, who many people don’t realise was an excellent epistemologist, had already changed perceptions on this when Galileo was still a child. Clavius a Jesuit and thus by definition a Thomist Aristotelian used Aristotle’s own arguments to demonstrate that mathematical proofs have the same epistemological status as philosophical proofs. He even went to the extent of translating parts of the Elements of Euclid into Aristotelian syllogisms to show that mathematical proofs transport truth in the same way as philosophical, logical ones. Clavius’ influence was massive, he fought to get mathematics accepted as part of the educational reform programme of the Jesuits and then got the mathematical sciences established as a central part of the curriculum in Catholic schools, colleges and university also training the necessary teachers to carry out his programme. There is a reason why the young Galileo turned to Clavius, when seeking a mentor for his mathematical ambitions.

Taking all of this together the roll of mathematics and status of mathematical proofs in the sciences was very different in the early seventeenth century than the picture that Livio serves up. Far from being ground breaking Galileo’s (in)famous quote from The Assayer  “the book of nature is written in the language of mathematics” (which Livio offers up several times in his book) was actually stating a truth that had been generally accepted by many natural philosophers and mathematicians for many decades before Galileo put pen to paper.

Returning to Galileo’s telescope discoveries, Livio tells us that Kepler published his letter praising Galileo’s telescopic discoveries under the title Dissertio cum Nuncio Sidero (1610) then goes on to write: “Galileo was clearly pleased with its content, the letter was reprinted in Florence later in the year.” What Livio neglects to mention is that Galileo was responsible for that edition in Florence, which was a pirate edition published without Kepler’s knowledge and without his permission or consent. Livio makes it appear that the Jesuit astronomers of the Collegio Romano only reluctantly started to try and confirm Galileo’s discoveries and then only when ordered to do so. This is a complete distortion of what actually happened.

The astronomers in the Collegio Romano had their own telescopes and had been making astronomical telescopic observations well before Galileo published the Sidereus Nuncius. They immediately leapt on the pamphlet and set out to try and confirm or refute his observations. They had some difficulties constructing telescopes good enough to make the necessary observations and Christoph Grienberger (1561–1636), who was acting head of the school of mathematics due to Clavius’ advanced age, corresponded with Galileo, who provided copious advice and tips on observing and telescope construction. This was a work of friendly cooperation under fellow mathematicians. After some difficulties they succeeded in providing the necessary confirmation, which they made public and celebrated by throwing a banquet for Galileo when he visited Rome in 1611. As already stated above the Jesuit astronomers probably observed the phases of Venus before Galileo.

Livio then goes on to draw parallels with the fact that, “The current debate on global warming had to go […] through a similar painful [my emphasis] type of confirmation process.” I find this statement, quite frankly, bizarre coming from a scientist. All scientific discoveries have to be independently confirmed by other scientists, it is a central and highly important part of the whole scientific process. What the astronomers of the Collegio Romano did for Galileo was in no way “painful” but a necessary part of that scientific process for which Galileo was very thankful. I find it particularly bizarre given the very lively current debate on the significant number of scientific papers that have to be retracted because of failing confirmation. Reading Livio in the worst possible light, and not just here but at numerous other points in his narrative, he seems to be saying, if Galileo says it is so, then it must be true and anybody, who dares to criticise him, is in the wrong.

Of course, Livio cannot avoid the myth that, “First Copernicus and Galileo removed the Earth from its central position in the solar system.” Having previously quoted the “Copernicus principle”: the realisation that the Earth, and we human beings, are nothing special…” Also: “ What’s more the Copernican system was bound to be at odds with a worldview that had placed humans at the very center of creation, not only physically but also as a purpose and focus of for the universe’s existence.” Although geometrically central, the philosophers and astronomers in the Renaissance did not regard the Earth’s position as central in any special way. It was far more the bottom, the dregs of the universe. Trying to move the Earth into the heavens was moving it into an exalted place. At least Livio is honest enough to admit that Galileo remained blind to Kepler’s work, although Livio reduces it to just the discovery of elliptical orbits, whereas Kepler actually contributed more to modern astronomy than Copernicus and Galileo together.

Livio now moves on to Galileo’s entry into theology and his Letter to Castelli. As with all Galileo apologists, whist admitting that Galileo was trespassing in the territory of the theologians, he thinks that Galileo was right to do so and what he wrote was eminently sensible and should have been acknowledged and accepted. What Galileo did struck at the vey heart of the Reformation/Counter Reformation dispute that had been raging in Europe for one hundred years and just three years later would trigger the Thirty Years War, which devastated central Europe and resulted in the death of somewhere between one and two thirds of the entire population. The Catholic Church had always claimed that they and only they were permitted to interpret Holy Scripture. Luther claimed in opposition to this that every man should be allowed to interpret it for themselves. This led to schism and the Reformation. The Catholic Church confirmed, with emphasis, at the Council of Trent that only the Church’s own theologians were permitted to interpret the Bible. Now along comes a mere mathematicus, the lowest rang in the academic hierarchy, and cheerfully tells the theologians how to interpret the Holy Writ. The amazing thing is that they didn’t simply throw him into a foul dungeon and throw away the key.  I mentioned earlier that the Church was a judicial organ and the decisions of the Council of Trent were binding laws on all Catholics. Galileo knowingly and very provocatively broke that law and got mildly and unofficially admonished for doing so. Whatever a modern observer may think about the quality of Galileo’s theological arguments is completely irrelevant, it’s the fact that he made them at all that was the offence. However, in doing so he together with Foscarini provoked the Church into taking the heliocentric hypothesis under the microscope. He had been warned, as early as 1613, by various friends including Cardinal Maffeo Barberini, the future Pope Urban VIII not to do so.

Livio thinks that because he finds Galileo’s arguments in the Letter to Castelli reasonable and ‘because of science’ that the Catholic Church should have cut Galileo some slack and let him reinterpret the Bible. The Catholic Church should abandon their exclusive right to interpret Holy Writ, one of the fundaments of their entire religion, so that a nobody, and despite his celebrity status, in the grand scheme of things Galileo was a nobody, could promote an unproven astronomical hypothesis! This is the same exclusive right for which the same Church was prepared to engage in one of the most devastating wars in European history, just three years later. In his pseudo-historical narrative Livio has here completely lost touch with the historical context.  In fact Livio is not writing history at all but making presentist moral judgements with hindsight.

There is another bizarre statement by Livio where he writes:

All this notwithstanding, however, the Church might have still accommodated (albeit with difficulty) a hypotheticalsystem that would have made it easier for mathematicians to calculate orbits, positions, and appearances of planets and stars as long as such a system could be dismissed as not representing a true physical reality. The Copernican system could be accepted as a mere mathematical framework: a model invented so as to “save the appearances” of astronomical observations–that is, to fit the observed motion of the planets.

I am frankly baffled by this paragraph because that is exactly what the Church did in fact do. They fully accepted heliocentricity as a hypothesis, whilst rejecting it as a real physical description of the cosmos. This is shown very clearly by their treatment of Copernicus’ De revolutionibus, which unlike Kepler’s books, for example, was not placed on the Index of forbidden books but was only placed on it until corrected. This correction was carried out by 1620 and consisted only of changing or removing the comparatively few statement in the book claiming that heliocentricity was a real physical description of the cosmos. From 1621 Catholics were free to read the now purely hypothetical De revolutionibus. Livio relates all of this fairly accurately and then drops another clangour. He writes:

In reality, the modifications introduced by Cardinal Luigi Caetani and later by Cardinal Francesco Ingoli were indeed relatively minor and the publication of the revised version was approved in 1620. However, the new edition never reached the press, and so Copernicus’s book remained on the Index of Prohibited Books until 1835!

This is once again complete rubbish. The Catholic Church never intended to publish a new or revised edition of De revolutionibus. What they did was to issue the list of corrections deemed necessary and every Catholic owner of the book was expected to carry out the corrections in the own copies themselves. Quite a few obviously did and we have a number of surviving copies, including Galileo’s own private copy, with the corrections carried out according to the issued instructions. Interestingly almost all of the thus censored copies are in Italy or of Italian provenance, it seems that Catholics outside of Italy didn’t take much notice of the Vatican’s censorship order. De revolutionibuswas of course removed from the Index in 1620 having been corrected. Also, I know of no case of anyone being prosecuted for reading or owning an uncensored copy of the book.

Livio tries to counter the argument that I have presented above that Galileo was admonished because he meddled in theology by claiming that the motivation was one of anti-science. Livio. “[They] were trying only to convince Galileo not to meddle in theology, as a few modern scholars have concluded.” To counter this he brings statements from Grienberger and Bellarmino saying that elements of Copernicus theory contradict passages of Holy Writ. He writes:”[they] were quite intent on crushing the Copernican challenge as a representation of reality because, from their perspective, they were vindicating the authority of Scripture in determining truth.” Dear Dr Livio that is theology! As Bellarmino wrote in his letter to Foscarini, if a contradiction exists between Holy Writ and a proven scientific fact, the heliocentric hypothesis was of course at this point in time no where near being a proven scientific fact, then the theologians have to very carefully considered how to reinterpret Holy Writ; that is what theologians do!

This brings us to Roberto Bellarmino famous letter to Paolo Antonio Foscarini. Foscarini, a monk, had written a book defending heliocentricity and reinterpreting the Bible in a similar way to Galileo. Criticised, he sent his book to Roberto Bellarmino for his judgement; he hoped it would be favourable. The title contains the word Pythagorean, so Livio explains that the Pythagoreans thought Earth etc. orbited a central fire, therefore the comparison with Copernicus’ theory. Livio then writes, “Greek philosopher Heraclides of Pontus added, also in the fourth century BCE that the Earth rotated on its axis too…” As far as can be determined Heraclides proposed diurnal rotation in a geocentric system and not in a heliocentric or Pythagorean one.

Livio goes into a lot of detail about Foscarini’s text and Bellarmino’s letter but I will only mention two points. Livio quotes the paragraph that I have already paraphrased above, “…if there were a true demonstration that the sun is at the center of the world and the earth in the third heaven, and that the sun does not circle the earth but the earth circles the sun, then one would have to proceed with great care in explaining the Scriptures that appear contrary, and say rather that we do not understand them, than what is demonstrated is false.” Livio adds, “But I will not believe that there is such a demonstration, until it is shown me. Nor is it the same to demonstrate that by supposing the sun to be at the center and the earth in heaven one can save the appearances, and to demonstrate that in truth the sun is at the center and the earth in the heaven; for I believe the first demonstration may be available, but I have very great doubts about the second, and in case of doubt one must not abandon the Holy Scripture as interpreted by the Holy Fathers.”

This is of course eminently sensible and rational. If you want me to accept you scientific theory then show me the proof! Livio doesn’t accept this and goes of into a long diatribe, which demonstrates his own prejudices rather more than any faults in Bellarmino’s logic. He then comes with a totally spurious argument:

If two theories explain all the observed facts equally well, scientists would prefer to adopt, even if tentatively, the simpler one. Following Galileo’s discoveries, such a process would have definitely favoured the Copernican system over the Ptolemaic one, which was what Galileo had been championing all along. The requirement of simplicity would have also given an advantage to Copernicanism over Tycho Brahe’s hybrid geocentric-heliocentric model.

Ignoring the fact that the Ptolemaic system was dead in the water after the discovery of the phases of Venus and so the comparison is a waste of time, any alert reader will immediately spot the massive error in this argument. The two theories, Copernicus and Brahe, do not explain all the observed facts equally well. The Copernican system requires something very central that the Tychonic system does not, terrestrial motion. Livio adds this in a very off hand way, “Of course the ultimate test would have been to find direct proof for the Earth’s motion…” There was in fact absolutely no empirical proof of the Earth’s motion and wouldn’t be until Bradley discovered stellar aberration in 1725! To give the “advantage to Copernicanism over Tycho Brahe’s hybrid geocentric-heliocentric model” would be under the circumstances actually unscientific.

A little bit further on Livio delivers another highly spurious comment, he writes, “…but Bellarmino’s position was extremely rigid. He did not believe that a proof of Copernicanism could ever be found.” Livio is here putting words into Bellarmino’s mouth, who never said anything of the sort, rather he expressed doubt that that such a proof existed.  Livio finishes off his series of spurious attacks on Bellarmino by claiming to prove him theologically wrong. I find it slightly amusing that a twenty-first century astrophysicists claims that Bellarmino, who was universally regarded as the greatest living Catholic theologian and whose reputation as a theologian was such that at the end of his life he was both head of the Index and head of the Inquisition, was theologically wrong.

Things developed as they must and we now have Galileo rushing off to Rome to try and rescue the situation with his infamous theory of the tides. Livio explains the theory and its possible origins then he drops the following jewel:

Albeit wrong, Galileo’s commitment to mechanical easy-to-understand causation made his theory of tides at least plausible.

There is only one possible answer to this claim, bullshit! A theory that states there is only one high tide and one low tide at the same time every day, when there are in fact two of each of which the times travel around the clock over the lunar month (a strong indication of the correct theory of the tides) is anything but a plausible theory. It is as I said bullshit.

We now turn to the committee of consultors set up to examine the theological implications of heliocentricity. Livio of course has much to say against this. His first objection:

Ironically, the same office that had objected vehemently to scientists intruding into theology was now asking the theologians to judge on two purely scientific questions–two of the central tenets of he Copernican model.

Once again Livio appears to have no idea what theology is. The discipline of theology covers all forms of human activity in their entirety. There is absolutely nothing in human existence that doesn’t fall under the remit of theology. Secondly the function of the consultors in this case were being asked to examine the two central tenets of heliocentricity in relation to Catholic religious belief, not a scientific question at all.

Next up, Livio objects to the consultors themselves: “Not one was a professional astronomer or even an accomplished scientist in any discipline.” All of the consultors were highly educated, learned men, who would have had a solid instruction to Ptolemaic astronomy during there education and were more than capable of asking an expert for his advice if necessary.

Consultor: Is there any empirical evidence that the Earth moves and the Sun stands still?

Astronomer: No

Consultor: Is there any empirical evidence that the Sun and not the Earth is at the centre of the cosmos?

Astronomer: No

Simple wasn’t it.

 

The decisions of the consultors are well know:

On February 24 the Qualifiers delivered their unanimous report: the proposition that the Sun is stationary at the centre of the universe is “foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture”; the proposition that the Earth moves and is not at the centre of the universe “receives the same judgement in philosophy; and … in regard to theological truth it is at least erroneous in faith. (Wikipedia)

Foolish and absurd in philosophy is the scientific judgement and sounds somewhat harsh but can be simply translated as, is not supported by the available empirical evidence. Livio would disagree with both the judgement and my interpretation of it but it is historically fundamentally accurate. The second part of each judgement is of course the theological one. As is also well known the Pope commissioned Cardinal Bellarmino to inform Galileo of the decision and to instruct him not to hold or teach the heliocentric theory. Books, such as those of Kepler, claiming the physical reality of heliocentricity, were placed on the Index and De revolutionibus, as detailed above until corrected, which it was.

Bewilderingly Livio accuses Bellarmino and the Jesuits of failing to support Galileo against the Pope, which displays an incredible ignorance of the Catholic Church, the Pope and the Jesuit Order in the seventeenth century. As stated at the beginning the Catholic Church was a religious, political and judicial power in an age of absolutism and the Pope was an absolutist ruler. The Society of Jesus (Jesuits), and Bellarmino was also a Jesuit, is a religious order dedicated to and directly under the authority of the Pope. Livio’s accusations are totally insane.  He, of course, can’t resist making ahistorical and inaccurate comments about the decision, he writes:

The ruling made by officers of the Church for whom retaining authoritative power over areas totally outside their expertise took priority over open-minded critical thinking informed by scientific evidence.

Livio here continues to ignore/deny the simple fact that the scientific evidence in the early seventeenth century simply did not support an interpretation of heliocentricity as a physical reality and whilst it appears somewhat draconian the Church decision doesn’t actually say anything else.

Livio also launches the presentist moral outrage attack, “[some] argue that some of the responsibility for the prohibition of Copernicanism lies with Galileo himself, because he wouldn’t keep his mouth shut. Such claims are outrages.” Firstly the heliocentric hypothesis was never prohibited only the heliocentric theory, which given its scientific status at the time was in fact, although unnecessarily harsh, justifiable and secondly if Galileo had displayed somewhat more tact, instead of behaving like the proverbial bull in a china shop, things would never have taken the turn that they did.

We move on to the dispute over the nature of comets between the Jesuit astronomer Orazio Grassi and Galileo. Here Livio again displays his ignorance of the history of astronomy. He writes:

Grassi’s theory of comets deviated courageously from the Aristotelian view, which placed comets at about the distance of the Moon. Instead following Tycho Brahe, Grassi proposed that the comets were further out between the Moon and the Sun.

[…]

As to the actual nature of comets, many astronomers at the time were sill adopting Aristotle’s theory, which stated that these represented exhalations of the Earth that became visible above a certain height due to combustion, disappearing from view as soon as that inflammable material was exhausted. Grassi, however, again followed Brahe in suggesting that comets were some sort of “imitation planets.”

 

The modern debate on the nature of comets and whether they were sub- or supralunar began in the fifteenth century with Toscanelli (1397–1482), who tried to track the path of Comet Halley in 1456, as if it were a supralunar object. The debate continued in the work of Georg von Peuerbach (1423–1461), Toscanelli’s one time student, and Peuerbach’s student, Regiomontanus (1436–1476), who wrote a work on how to detect parallax in a moving comet. The debate continued in the 1530’s with many leading European astronomers taking part, including, Johannes Schöner (1477–1547), who published Regiomontanus’ work on comets, Peter Apian (1495–1552), after whom the law concerning comets’ tails in named, Copernicus (1473–1543), Gerolamo Cardano (1501–1576) and Jean Pena (1528–1558). The latter two both proposed a theory that comets were translucent, supralunar, bodies that focused the Sun’s rays like a lens creating the comets tail. Tycho’s comet, the great comet of 1577 was observed by astronomers all over Europe and Tycho, Michael Mästlin (1550-1631) and Thaddaeus Hagecius ab Hayek (1525–1600), three leading astronomers, all determined that comets were supralunar. Clavius accepted these results and included the fact that comets were supralunar in his Sphaera. This meant that the official view of the Catholic Church in general and the Jesuits in particular was that comets were supralunar. This view was confirmed again by astronomers throughout Europe observing Comet Halley in 1607. The was nothing courageous about Grassi’s theory of comets and in fact you would be hard put to it to find a serious European astronomer, apart from Galileo, who still adhered to Aristotelian cometary theory in 1618. In the same year Grassi’s Jesuit colleague Johann Baptist Cysat (c. 1587–1657), a student of Christoph Scheiner, became the first astronomer to observe a comet with a telescope giving the first ever description of a comet’s nucleus in his Mathemata astronomica de loco, motu, magnitudine et causis cometae qui sub finem anni 1618 et initium anni 1619 in coelo fulsit. Ingolstadt Ex Typographeo Ederiano 1619 (Ingolstadt, 1619). He followed Tycho Brahe in believing that comets orbited the sun. He also demonstrated the orbit was parabolic not circular.

Galileo, who due to ill health had not observed the comets of 1618, launched a vicious and insulting, unprovoked attack on Grassi’s publication, presenting a view of comets that was totally out of date, ignoring all of the accumulated scientific evidence from the last two centuries on the nature of comets just to put one over on the Jesuits and the supporters of Tycho’s theories. Livio does his best to defend Galileo’s disgusting behaviour but even he admits that Grassi was principally in the right and Galileo simply wrong. Livio goes as far as to claim that because comets has an elongated elliptical orbit (actually only some do) that Galileo’s claim that they travel in straight lines was more correct than Grassi’s claim that they orbit the Sun. In all other instances Livio goes out of his way to emphasise that hindsight shows that Galileo was right and his critics wrong so why the opposite tack here? Comets do orbit the Sun. Livio scrabbles around in the cesspit that is Galileo’s paper on comets looking for crumbs for which he can give Galileo credit.

Livio now criticises Grassi’s answer to Galileo’s attack because it contained sarcastic attacks on Galileo. Talk about pot calling the kettle black. He even brings up the obtuse suggestion that it was actually written by Christoph Scheiner because of his antagonism towards Galileo. This theory has a small problem; Scheiner only became antagonistic towards Galileo after Galileo had viciously insulted him in The Assayer, a publication that still lay in the future. Livio’s whole account of the affair is biased in Galileo’s favour so that it serves as a lead up to The Assayer, for the time being the last document in the dispute, because, as already mentioned, Livio sees it as the document in which Galileo established the place of mathematics in science. Livio’s account of The Assayer and its significance is more than somewhat outlandish.

With very little evidence to base this opinion upon, Galileo thought in 1623 that he knew the answer: the universe “is written in the language of mathematics.” It was this dedication to mathematics that raised Galileo above Grassi and the other scientist of his day, even when his specific arguments fell short of convincing–and even though he assigned to geometry a more important role than it seemed to deserve at the time. His opponents, he wrote, “failed to notice that to go against geometry is to deny truth in broad daylight.”

This whole paragraph contains so much that is wrong that it is difficult to know where to start.  I have already explained above that by the time Galileo wrote this infamous piece of purple prose it was widely accepted by both mathematician and natural philosophers that the future of science lay in an intensive mathematization. A process that was well under way when Galileo wrote something that was not new and sensational but a common place. A lot of contemporary scientists were dedicated to mathematics, such as Johannes Kepler, Simon Steven and Isaac Beeckman. In fact the last two both contributed at least as much to the development of mathematical physics in the seventeenth century as Galileo if not more. Unfortunately their achievements tend to get blended out on the popular level by the Galileo myth machine of which, Livio is just the latest in a long line of operators.

To raise Galileo above Grassi because of his dedication to mathematics is more than a joke; it’s grotesque. Earlier in his account of the dispute between Grassi and Galileo, Livio acknowledged that Grassi was an excellent optical physicist and an equally excellent architect both disciplines are fundamentally mathematical disciplines. He also points out that Grassi succeeded Grienberger as professor for mathematics at the Collegio Romano, who had succeeded Clavius. The chair for mathematics at the Collegio Romano was unique in European universities. Clavius had set up what we would now call an institute for advanced mathematics, a roll that both Grienberger and Grassi kept alive. This institute was dedicated to exemplifying, establishing and developing the roll of mathematics in the sciences. The Collegio Romano was quite simply the most advanced school for mathematics and its application anywhere in Europe. As far as geometry goes the standard textbook for geometry throughout most of the seventeenth century was Christoph Clavius’ Euclides Elementorum Libri XV, Rom 1574, note the date. This was not simply a new translation of Euclid’s classic but a modernised, simplified, streamlined textbook that was used extensively by both Catholic and Protestant educational establishments; the last edition was printed in 1717.

Shortly after the above passage on Galileo’s supposed revolutionary thoughts on mathematics we get the following throwaway line:

Galileo introduced the revolutionary departure from the medieval, ludicrous notion that everything worth knowing was already known.

When I read this I didn’t know whether to laugh, cry, rip my hair out (if I had any), or simply go out and throw myself off a high cliff in the face of such imbecilic drivel. I strongly suspect that any of my history of medieval science friends and colleagues will react similarly should they happen to read the above sentence. Starting at the very latest with the translation movement in the twelfth century medieval science was an evolving developing field with advances in a wide range of disciplines. The medieval scholars laid the foundations upon which Galileo built his own achievements. I would be quite happy to give Dr Livio a very long reading list of good books on medieval science to help him find a way out of his ignorance.

At the end of his chapter on The Assayer Livio warms up the old discovery of Pierto Redondi that Galileo was denounced to the Inquisition for the bits of primitive atomism contained in The Assayer. This was indeed true but the accusation was dismissed and nothing came of it, as Livio admits. Livio, however, now writes a whole paragraph about how important atomism, he actually means particle physics, is in modern physics, mentioning quarks, leptons, gage bosons etc., etc. I wonder how Livio would react if he knew that the principle source of atomism in the seventeenth century is now considered to be the German alchemist Daniel Sennert (1572–1637) reviving the theories of the thirteenth century alchemist Paul of Taranto. You remember alchemy one of those fictitious fields together with astrology that scientists sometime connected to.

Next up the Dialogo: Livio acknowledges that there were external political and social factors that affected the situation within the Vatican in the years leading up to the publication of the Dialogo. He starts with the astrological scandal. In 1630 an astrological prognostication predicting the Pope’s death was made and circulated by, to quote Livio, the abbot of Saint Praxedes in Rome. Livio then tells us, “some of Galileo’s adversaries tried to pin the blame on Galileo…” What Livio neglects to mention is that although Galileo was in this case innocent there were plausible ground for suspecting him, it was a case of guilt by association. Firstly, Galileo was known to be a practicing astrologer. Secondly, the abbot of Saint Praxedes, Orazio Morandi had been a good friend of Galileo’s since at least 1613. Thirdly, following an audience with the Pope concerning the forthcoming Dialogo in 1630, Galileo took part in a supper with Moriandi in Saint Praxedes together with Rafaello Visconti (Master of the Sacred Palace), another friend of Galileo’s, who read the manuscript of the Dialogo for Niccolò Ricardi the censor, who never actually read it, and an appraiser of the Inquisition. When Morandi was arrested for his horoscope and thrown into the Vatican’s dungeon, Visconti was also implicated and banished from the Vatican. That Galileo came under suspicion by association is hardly surprising. This was not a plot against Galileo as Livio claims.

We then have a wonderfully mangled piece of history from Livio, who write:

Unfortunately, this was not the end of the trials and tribulations Galileo had to endure for the publication of the Dialogo. Most significant of these was the sudden death on August 1, 1630, of Federico Cesi, the founder and sole source of funding for the Accademia dei Lincei. As a result the printing had to be done in Florence, outside of Riccardi’s jurisdiction. After some negotiations, it was agreed that Father Jacinto Stefani, a consultor of the Inquisition in Florence, would be in charge, but only after Riccardi approved the introduction and conclusion.

Although Cesi’s death was a serious blow to Galileo’s plans because he Cesi was supposed to finance the publication of the Dialogo, but this was not the reason why it was published in Florence and not in Rome. What actually happened is that after Galileo had returned to Florence from Rome with his manuscript the plague broke out in Florence. Restrictions on travel imposed by the authorities meant that Galileo could not return to Rome to oversee the printing and publication of his book. He requested permission from Riccardi to get the book published in Florence instead, but as already mentioned Riccardi hadn’t actually read the book intending to review the pages as they came of the printing press instead, having accepted Visconti’s recommendation. Riccardi was now in a pickle and wanted Galileo to send him a copy of the manuscript but due to the immense cost of producing such a copy, Galileo was very reluctant to do so.  Riccardi agreed to Galileo just sending the introduction and conclusion to Rome to be controlled and the rest being controlled in Florence by Stefani. Galileo and his circle of supporters now manipulated and even oppressed the two censors and played them against each other. The result was that the imprimatur was granted by Stefani under the impression that Ricarrdi had already cleared the manuscript for publication in Rome, he hadn’t, without actually controlling the text himself. Galileo had an imprimatur that had been obtained under false pretences, which meant that he didn’t actually have an imprimatur at all. All of this came out during the investigations following publication, which contributed to Galileo’s being prosecuted but did not play a role in the actual trial.

All of this, which Livio doesn’t mention at all, is important because when dealing with the trial Livio several times emphasises that the Church had given Galileo to publish the book as it was because he had not one but two imprimaturs, whereas in fact formally he didn’t have one at all.

Livio now tells us:

There is a certain sleight of hand in the title. [Dialogue Concerning the Two Chief Systems of the World, Ptolemaic and Copernican, Propounding Inconclusively in the Philosophical Reasons as Much for the One Side as for the Other] Even if one were to ignore the fact that the Aristotelian and the Ptolemaic systems were not identical, there was at least one other world system that in terms of agreement with observations was superior to the Ptolemaic: Tycho Brahe’s Hybrid system in which the planets revolved around the Sun, but the Sun itself revolved around the Earth. Galileo always regarded that system as unnecessarily complex and contrived, and he also thought that he’d found proof for the Earth’s motion through the phenomenon of the tides, so in striving to hand Copernicanism a clear victory (although formally the book was inconclusive) he probably didn’t want to confuse the issue with superfluous qualifications.

Once again so much to unpick. Livio obviously doesn’t understand that the system propagated by the Catholic Church before Copernicus was an uneasy mixture of Ptolemaic astronomy and Aristotelian cosmology, not Aristotelian astronomy, which is a whole different kettle of fish that had been revived by some in the sixteenth century and against which Clavius had fought tooth and nail. In fact he devotes much more space to refuting the Aristotelian homocentric astronomy in his Sphaera than he devotes to refuting Copernicus. The developments in astronomy since Copernicus published De revolutionibus had left Aristotelian cosmology in shreds and Clavius had been quite happy to also jettison that, so for Clavius, speak the Catholic Church, the world system was simply the Ptolemaic.

In fact Galileo’s whole title and thus his whole book is a complete sham By 1630 the two chief systems of the world were the Tychonic system and Johannes Kepler’s elliptical heliocentric system, which was regarded as separate from and as a competitor to Copernicus’ system. The Ptolemaic system had been killed off by the discovery of the phases of Venus and the plausible assumption that Mercury would also orbit the Sun as its general behaviour was identical to that of Venus; the phases of Mercury were first observed in 1639. Galileo just used Ptolemy as a fall guy for his sham Copernican victory. Copernicus’ heliocentric system had been rendered totally obsolete by Kepler’s discovery of the three laws of planetary motion, empirically based mathematical laws I would point out, which Galileo just completely ignored clinging to Copernicus’ ‘unnecessarily complex and contrived’ system of deferents and epicycles. Livio’s dismissal of the Tychonic system as ‘superfluous qualifications’ is put quite simply a joke, especially given that the Tychonic system was at the time the leading contender as the world system because of the failing evidence of terrestrial motion.

Livio without realising it now points out the central problem with the Dialogo:

The Dialogo is one of the most engaging science texts ever written. There are conflicts and drama, yes, but also philosophy, humor, cynicism, and poetic usage of language, so that the sum is much more than its parts.

All of the above is true except that as a piece of astronomy the sum is much less than its parts, which I will explain shortly. There is no doubt whatsoever that for all of his undeniably polymathic talents, Galileo’s greatest gift was as a polemicist. A friend of mine, who is a Galileo expert, calls him the first science publicist and this is a function that he carried out brilliantly. Yes, the Dialogo is a brilliant piece of literature, which is probably unequalled by any other scientific publication in the entire history of science. However, its literary brilliance appears to have blinded many of its readers to the fact that as a piece of astronomy it’s total crap.

As already mention, Galileo struts on to the stage to discuss what he calls the two chief world systems but actually delivers up is a sham battle between two obsolete and refuted systems. He clung stubbornly to his completely false theory that comets are mere optical illusions originating on the Earth against a mass of solid, empirical, scientific evidence that comets were in fact supralunar celestial objects that orbited the Sun. Something that Galileo was no prepared to accept because it was first proposed by Tycho, who saw it as supporting evidence for his system. He clung to Copernicus’ deferents and epicycles rather than acknowledge Kepler’s much simpler, empirically proven elliptical orbits. In fact, Galileo completely ignores Kepler’s three laws of planetary motion, by far and away, the best scientific supporting evidence for a heliocentric system because if he did acknowledge them he would have to hand the laurels for proving the superiority of the heliocentric system to Kepler instead of winning them for himself, his one and only aim in the whole story. Last but by no means least he structures his whole book and his argument around his totally ludicrous theory of the tides. One of the greatest mysteries in Galileo’s life is why he, an undeniably brilliant scientist, clung so tenaciously to such an obviously bankrupt theory.

Galileo’s masterwork sailed majestically past the actually astronomy debate in the 1630s and played little or no role in the ensuing astronomical discussion of the seventeenth century in which it was largely ignored being of no real relevance. It only became crowned as a classic in the late eighteenth and early nineteenth centuries when Galileo was declared to be a scientific martyr

Livio, like so many others, blinded by the radiance of Galileo’s rhetoric sees the matter somewhat differently. In a surprisingly short presentation of the book he praises Galileo’s achievements. There are a couple of minor points that I would like to pick up on, Livio delivers up once again the myth of heliocentricity removing the Earth from its central place in the cosmos:

More important, the act of removing humans from their central place in the cosmos was too brutal to be remedied by some philosophical pleasantries at the end of a debate from a very different tone.

The whole central place in the cosmos myth is one created in the late eighteenth century and I know of no seventeenth century use of it to criticise the heliocentric hypothesis. In a bit of waffle towards the end of this chapter Livio says the “He [Galileo] did his best…” If Galileo had truly done his best he would not have ignored the most compelling evidence for the heliocentric hypothesis, Kepler’s laws of planetary motion. He goes on to say that, “History has indeed proved that Galileo was right,” it hasn’t Galileo was wrong and Kepler was right.

Livio gives a fairly short and largely accurate account of Galileo’s trial by the Inquisition and the events leading up to following the publication of the book. The only major error being, as mentioned above, his insistence that the book had two imprimaturs. Livio acknowledges that the judgement of the three clerics, commissioned to read the book and determine whether Galileo taught or defended in anyway the heliocentric theory, that he had in fact done just that and thus broken the order from 1616 was correct. Although he can’t avoid a dig at Melchior Inchofer, the Jesuit under the three. This was the charge that was brought against Galileo and of which he was found guilty. He also can’t avoid turning up the emotional rhetoric, “What happened on the following day remains one of the most shameful events in our intellectual history.” Galileo deliberately and wilfully broke the law and received the standard punishment for having done so, which included abjuring. There is an old saying under criminals, if you can’t do the time don’t do the crime. Galileo was arrogant enough to think that he could put one over on the Catholic Church and get away scot-free, it turned out that he couldn’t.

We get a short, once again, rather gushing account of the Discorsi, Galileo real claim to fame but Livio rather spoils it by once again trying to claim that Galileo created modern science.

Through an ingenious combination of experimentation (for example, with inclined planes), abstraction (discovering mathematical laws), and rational generalisation (understanding that the same laws apply to all accelerated motions), Galileo established what has since become the modern approach to the study of all natural phenomena.

Although in the case of the studies presented by Galileo in the Discorsi he proved himself to be an excellent experimental scientist, all of these things had been done by others before Galileo and independently by others contemporaneously to Galileo. He was only one amongst other who helped to establish this methodology. Galileo was part of the evolution of a new scientific methodology that had started long before he was born and which he did not initiate. Like many others before him Livio also falsely attributes Newton’s first law, the principle of inertia, to Galileo. Whilst Galileo did indeed produce a version of the principle of inertia, Newton took his first law from the works of René Descartes, who in turn had taken it from Isaac Beeckman, who had formulated it independently of Galileo.

The next chapter of Livio’s book is an obtuse story of an account of the Galileo affair commissioned by the Vatican in the 1940s and then not published but then published under the name of a different author in the 1960s. The sole aim of this chapter is simply to take another gratuitous swing at the Catholic Church. The book closes with a fairly long digression on Einstein’s views on science and religion, which brings us to a major problem with the book, apart from the historical inaccuracies, it tries to be too many things at once.

One thing that I have mentioned in passing is Livio’s attempts to draw parallels between what happened to Galileo and the current crop of science deniers. The analogies simply don’t work because no matter how hard Livio tries to claim the opposite, Galileo’s critics in astronomy, especially the Jesuits, were not science deniers but just as much scientists as Galileo, who argued for an equally valid, in fact empirically more valid, system of astronomy, the Tychonic one, as Galileo’s heliocentric system. All the way through the book Livio keeps trying to disqualify the Tychonic system as unscientific but in the first half of the seventeenth century it was just as scientific as the heliocentric hypothesis. The only person practicing science denial here is Livio. He also wants to present the book as a discussion of the general relationship between science and religion but the whole time he argues from a presentist standpoint and refuses to view the relationship in Galileo’s time in its correct historical context. Lastly he actually wants to sell the book as a new biography of Galileo presented with the insights of a working astrophysicist, his own claim at the beginning of the book. Unfortunately it is here that he fails most.

He enters his story with a preconceived image of Galileo as a white knight on his mighty charger fighting for freedom of speech and freedom of thought in the sciences and as the originator and creator of modern experimental and mathematical science. With this image firmly in mind, from the start of his narrative, he fills out the picture with a classic case of confirmation bias. He completely ignores any real facts from the history of science that might force him to rethink his preconceived image of his hero. There is no mistaking the fact that is a strong element of hero worship in Livio’s vision of Galileo. Instead of describing the real state of science in the early seventeenth century, he present the reader with a comic book version of Aristotelian philosophy from the thirteenth century making it easier for him to present Galileo as some sort of superman, who dragged natural philosophy kicking and screaming into the modern world, whilst singlehandedly creating modern science. Edward Grant the eminent historian of medieval science (a discipline that Livio probably thinks doesn’t exist, because he seems to think that there was no medieval science), once very perceptively wrote that Aristotelian philosophy was not Aristotle’s philosophy and went on to point out that it is very difficult to define Aristotelian philosophy, as it kept on evolving and changing down the centuries. The Thomist philosophy of the Jesuits in the first third of the seventeenth century was a very different beast to the Aristotelian philosophy that Thomas Aquinas propagated in the thirteenth century. The historical distortions that Livio presents would be funny if they weren’t so grotesque.

On the question of Galileo being ‘a symbol of the fight for intellectual freedom, a lifetime of studying and thinking about Early Modern science has brought me to the conclusion that he wasn’t. In my opinion Galileo didn’t really care about such abstractions as freedom of thought, freedom of speech or intellectual freedom, all he cared about was his own vainglory. As Mario Biagioli clearly shows in his Galileo Courtier,[2] Galileo was a social climber. He was a relatively unknown, middle aged, professor of mathematics, who overnight became the most celebrated astronomer in Europe because of his telescopic discoveries. Alone the way he presented those discoveries shows his principle aim was to see what he could gain socially from them. Galileo loved his celebrity status and revelled in it. His engagement for heliocentricity was all motivated by the thought that if he could prove it true, then he would become even more famous and even more feted. To achieve this aim he lied, cheated and plagiarised. He attacked and viciously stomped on all those he regarded as competitors in his strivings for fame and adulations. He also deliberately ignored any evidence for heliocentricity presented by others (see Kepler’s laws of planetary motion) that might mean that they get the laurels and not he. Galileo might have been a great scientist but he was also a vain egoist. I think all of this might go someway to explaining his extraordinary blindness to the enormous inadequacies of his theory of the tides.

Reading this book made me very angry. The only positive thing I can say about it is that Livio is an excellent writer and the book is very well written and easy to read, but in the end even this must be viewed negatively. Mario Livio is a prominent scientist and the very successful author of popular books on mathematics and science. Because of his reputation non-specialist journals will have glowing reviews of his book, mostly written by people, who are neither Galileo experts and nor historians of science. If it follows the normal pattern for such books, specialist journals and professional historians of science will decline to review it, because it’s a pop book. The book will almost certainly become a genre bestseller and another generation of readers will acquire a mythical image of Galileo Galilei and a totally false impression of Renaissance science, something I have battled against in the eleven years that I have been writing this blog.

[1] Mario Livio, Galileo and the Science Deniers, Simon & Schuster paperbacks, New York, London, Toronto, Sydney, New Delhi, 2020

[2] Mario Biagioli, Galileo Courtier: The Practice of Science in the Culture of Absolutism, University of Chicago Press, Chicago & London, ppb. 1994

23 Comments

May 27, 2020 · 8:35 am

The emergence of modern astronomy – a complex mosaic: Part XXXV

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The seventeenth century is commonly called the scientific revolution principally for the emergence of two branches of science, although much more was actually going on. Firstly, the subject of this series, astronomy, and secondly the branch of science we now know as physics. The name physics had a significantly different meaning in the medieval Aristotelian philosophy. As we know astronomy and physics are intimately connected, in fact, intertwined with each other and this connection came into being during the seventeenth century. We have already seen in an earlier episode how the modern concepts of motion began to emerge from Aristotelian philosophy in the sixth century reaching a temporary high point in the early seventeenth century in the works of Galileo and Beeckman.

Galileo is often regarded as the initiator, founder of these developments and lauded with titles such as the father of physics, which is just so much irrelevant verbiage. In fact as we saw in the case of the laws of fall he was just following developments that had long preceded him. On a more general level the situation is no different. Kepler was apparently the first to use the concept of a physical force rather than a vitalist anima. Simon Stevin (1548–1620) resolved the forces acting on an object on an inclined plane, effectively using the parallelogram of forces to do so. In hydrostatics he also discovered the so-called hydrostatic paradox i.e. that the pressure in a liquid is independent of the shape of the vessel and the area of the base, but depends solely on its depth. Thomas Harriot (c. 1560–1621) actually developed a more advanced mechanics than Galileo but as usually didn’t publish, so his work had no impact. However, it clearly shows that Galileo was by no means the only person considering the problems. All of these early discoveries, including Galileo’s, suffered from a problem of vagueness. Nobody really knew what force was and the definitions of almost all the basic concepts–speed, velocity, acceleration etc.–were defective or simply wrong. The century saw the gradual development of a vocabulary of correctly defined terms for the emerging new physics and a series of important discoveries in different areas, mechanics, statics, hydrostatics, optics etc.

I’m not going to give a blow-by-blow history of physics in the seventeenth century, I would need a whole book for that, but I would like to sketch an aspect that in popular accounts often gets overlooked. The popular accounts tend to go Galileo–Descartes–Newton, as if they were a three-man relay team passing the baton of knowledge down the century. In reality there were a much larger community of European mathematicians and proto-physicists, who were involved, exchanging ideas, challenging discovery claims, refining definitions and contributing bits and pieces to big pictures. Each of them building on the work of others and educating the next generation. What emerged was a pan European multidimensional cooperative effort that laid the foundations of what has become known as classical or Newtonian physics, although we won’t be dealing with Newton yet. Once again I won’t be able to give all the nodes in the network but I hope I can at least evoke something of the nature of the cooperative effort involved.

I will start of with Simon Stevin, a man, who few people think of when doing a quick survey of seventeenth century physics but who had a massive influence on developments in the Netherlands and thus, through connections, in France and further afield. Basically an engineer, who also produced mathematics and physics, Stevin motivated Maurits of Nassau, Stadholder of the young Dutch Republic to establish engineering and the mathematical sciences on the new Dutch universities. Stevin’s work influenced both the Snels, Rudolph (1546–1613) and his son Willebrord (1580–1626), the latter translated Stevin’s work into French and Latin from the Dutch, making it available to a much wider audience.

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Source: Wikimedia Commons

Stevin set up a school for engineering at the University of Leiden with Ludolph van Ceulen as the first professor of mathematics teaching from textbooks written by Stevin. Van Ceulen (1540–1610), who was Willebrord Snel’s teacher, was succeeded by his pupil Frans van Schooten the elder (1581–1646), whose pupils included his own son, Frans van Schooten the younger (1615–1660), Jan de Witt (1625–1672), Johann Hudde (1628–1704), Hendrick van Heuraet (1633–1660?), René-François de Sluse ((1622–1685) and Christiaan Huygens (1629–1695), all of whom would continue their mathematical development under van Schooten junior and go on to make important contributions to the mathematical sciences. An outlier in the Netherlands was Isaac Beeckman (1588–1637), a largely self taught natural philosopher, who made a point of seeking out and studying Stevin’s work. This group would actively interact with the French mathematicians in the middle of the century.

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Portrait of Frans van Schooten the younger by Rembrandt Source: Wikimedia Commons

On the French side with have a much more mixed bunch coming from varying backgrounds although Descartes and Mersenne were both educated by the Jesuits at the College of La Flèche. Nicolas-Claude Fabri de Peiresc (1580–1637), the already mentioned René Descartes (1596–1650) and Marin Mersenne (1588–1648), Pierre de Fermat (1607–1665), Pierre Gassendi (1592–1655), Ismaël Boulliau (1605–1694) and Blaise Pascal (1623–1662) are just some of the more prominent members of the seventeenth century French mathematical community.

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Pierre de Fermat artist unknown Source: Wikimedia Commons

René Descartes made several journeys to the Netherlands, the first as a soldier in 1618 when he studied the military engineering of Simon Stevin. He also got to know Isaac Beeckman, with whom he studied a wide range of areas in physics and from who he got both the all important law of inertia and the mechanical philosophy, borrowings that he would later deny, claiming that he had discovered them independently. Descarte and Beeckman believed firmly on the necessity to combine mathematics and physics. Beeckman also met and corresponded with both Gassendi and Mersenne stimulating their own thoughts on both mathematics and physics.

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René Descartes at work Source: Wikimedia Commons

On a later journey to the Netherlands Descartes met with Frans van Schooten the younger, who read the then still unpublished La Géometrié. This led van Schooten to travel to Paris where he studied the new mathematics of both living, Pierre Fermat, and dead, François Viète (1540–1603), French mathematicians before returning to the Netherlands to take over his father’s professorship and his group of star pupils. Descartes was also a close friend of Constantijn Huygens (1596–1687), Christiaan’s father.

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Source: Wikimedia Commons

Peiresc and Mersenne were both scholars now referred to as post offices. They both corresponded extensively with mathematicians, astronomers and physicists all over Europe passing on the information they got from one scholar to the others in their networks; basically they fulfilled the function now serviced by academic journals. Both had contacts to Galileo in Italy and Mersenne in particular expended a lot of effort trying to persuade people to read Galileo’s works on mechanics, even translating them into Latin from Galileo’s Tuscan to make them available to others. Mersenne’s endeavours would suggest that Galileo’s work was not as widely known or appreciated as is often claimed.

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Nicolas-Claude Fabri de Peiresc by Louis Finson Source: Wikimedia Commons

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Marin Mersenne Source: Wikimedia Commons

Galileo was, of course, by no means the only mathematician/physicist active in seventeenth century Italy. The main activist can be roughly divided in two groups the disciples of Galileo and the Jesuits, whereby the Jesuits, as we will see, by no means rejected Galileo’s physics. The disciples of Galileo include Bonaventura Francesco Cavalieri (1598–1647) a pupil of Benedetto Castelli (1578­–1643) a direct pupil of Galileo, Evangelista Torricelli (1608–­1647) another direct pupil of Galileo and Giovanni Alfonso Borelli (1608-1679) like Cavalieri a pupil of Castelli.

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Benedetto Castelli artist unknown Source: Wikimedia Commons

On the Jesuit side we have Giuseppe Biancani (1565–1624) his pupil Giovanni Battista Riccioli (1598–1671) and his one time pupil and later partner Francesco Maria Grimaldi (1618–1663) and their star pupil Giovanni Domenico Cassini (1625–1712), who as we have already seen was one of the most important telescopic astronomers in the seventeenth century. Also of interest is Athanasius Kircher (1602–1680), professor at the Jesuit University, the Collegio Romano, who like Peiresc and Mersenne was an intellectual post office, collecting scientific communications from Jesuit researchers all over the world and redistributing them to scholars throughout Europe.

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Athanasius Kircher Source: Wikimedia Commons

Looking first at the Jesuits, Riccioli carried out extensive empirical research into falling bodies and pendulums. He confirmed Galileo’s laws of fall, actually using falling balls rather than inclined planes, and determined an accurate figure for the acceleration due to gravity; Galileo’s figure had been way off. He was also the first to develop a second pendulum, a device that would later prove essential in determining variation in the Earth’s gravity and thus the globes shape.

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Riccioli as portrayed in the 1742 Atlas Coelestis (plate 3) of Johann Gabriel Doppelmayer. Source: Wikimedia Commons

Grimaldi was the first to investigate diffraction in optics even giving the phenomenon its name. Many of the people I have listed also did significant work in optics beginning with Kepler and the discovery of more and more mathematical laws in optics helped to convince the researchers that the search for mathematical laws of nature was the right route to take.

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Francesco Maria Grimaldi Source: Wikimedia Commons

As we saw earlier Borelli followed Kepler’s lead in trying to determine the forces governing the planetary orbits but he also created the field of biomechanics, applying the newly developed approaches to studies of muscles and bones.

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Giovanni Alfonso Borelli Source: Wikimedia Commons

Torricelli is, of course, famous for having invented the barometer, a device for measuring air pressure, of which more in a moment, he was trying to answer the question why a simple air pump cannot pump water to more than a height of approximately ten metres. However, most importantly his experiments suggested that in the space above the mercury column in his barometer there existed a vacuum. This was a major contradiction to traditional Aristotelian physics, which claimed that a vacuum could not exist.

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Evangelista Torricelli by Lorenzo Lippi (c. 1647) Source: Wikimedia Commons

Torricelli’s invention of the barometer was put to good use in France by Blaise Pascal, who sent his brother in law, Périer, up the Puy de Dôme, a volcano in the Massif Central, carrying a primitive barometer. This experiment demonstrated that the level of the barometer’s column of mercury varied according to the altitude thus ‘proving’ that the atmosphere had weight that lessened the higher one climbed above the earth’s surface. This was the first empirical proof that air is a material substance that has weight. One person, who was upset by Torricelli’s and Pascal’s claims that the barometer demonstrates the existence of a vacuum, was René Descartes to whom we now turn.

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Painting of Blaise Pascal made by François II Quesnel for Gérard Edelinck in 1691 Source: Wikimedia Commons

Descartes, who is usually credited with being one of, if not the, founders of modern science and philosophy, was surprisingly Aristotelian in his approach to physics. Adopting Beeckman’s mechanical philosophy he thought that things could only move if acted upon by another object by direct contact; action at a distance was definitely not acceptable. Aristotle’s problem of projectile motion, what keeps the projectile moving when the contact with the projector breaks was solved by the principle of inertia, which reverses the problem. It is not longer the question of what keeps the projectile moving but rather what stops it moving. He also, like Aristotle, adamantly rejected the possibility of a vacuum. His solution here was to assume that all space was filled by very fine particles of matter. Where this theory of all invasive particles, usually called corpusculariansim, comes from would takes us too far afield but it became widely accepted in the second half of the seventeenth century, although not all of its adherents rejected the possibility of a vacuum.

Descartes set up laws of motion that are actually laws of collision or more formally impact. He starts with three laws of nature; the first two are basically the principle of inertia and the third is a general principle of collision. From these three laws of nature Descartes deduces seven rules of impact of perfectly elastic (i.e. solid) bodies. Imagine the rules for what happens when you play snooker or billiards.  The details of Descartes rules of impact needn’t bother us here; in fact his rules were all wrong; more important is that he set up a formal physical system of motion and impact. Studying and correcting Descartes rules of impact was Newton’s introduction to mechanics.

Turning to another Frenchman, we have Ismaël Boulliau, who was a convinced Keplerian. Kepler had hypothesised that there was a force emanating from the Sun that swept the planets around their orbits, which diminished inversely with increasing distance from the Sun. Boulliau didn’t think that such a force existed but if it did then it would be an inversed square force in analogy to Kepler’s law for the propagation of light; a candidate for the first modern mathematical law of physics. The foundations of the new physics were slowly coming together.

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Ismaël Boulliau portrait by Pieter van Schuppen Source: Wikimedia Commons

Our last link between the Dutch and French mathematicians is Christiaan Huygens. Huygens initially took up correspondence with Mersenne around 1648; a correspondence that covered a wide range of mathematics and physics. In 1655 he visited Paris and was introduced to Boulliau and a year later began correspondence with Pierre Fermat. Frans van Schooten the younger continued to act as his mathematical mentor.

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Christiaan Huygens by Caspar Netscher, 1671, Museum Boerhaave, Leiden Source: Wikimedia Commons

Huygens absorbed the work of all the leading European mathematician and physicists and as an avowed Cartesian became acknowledged as Europe’s leading natural philosopher. He realised that Descartes rules of impacts were wrong and corrected them. Huygens was also the first to derive and state what is now know as Newton’s second law of motion and derived the law of centripetal force, important steps on the route to a clear understanding of forces and how they operate. Huygens also created the first functioning pendulum clock in the process of which he derived the correct formula for the period of an ideal mathematical pendulum. It is very easy to underestimate Huygens contributions to the development of modern physics; he tends to get squeezed out between Descartes and Newton.

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Spring-driven pendulum clock, designed by Huygens, built by instrument maker Salomon Coster (1657), and a copy of the Horologium Oscillatorium. Museum Boerhaave, Leiden Source: Wikimedia Commons

All the way through I have talked about the men, who developed the new physics as mathematicians and this is highly relevant. The so-called scientific revolution has been referred to as the mathematization of science, an accurate description of what was taking place. The seventeenth century is also known as the golden age of mathematics because the men who created the new physics were also at the same time creating the new mathematical tools needed to create that physics. An algebra based analytical mathematics came to replace the geometric synthetic mathematics inherited from the Greeks.

Algebra first entered Europe in the twelfth century with Robert of Chester’s translation of Muḥammad ibn Mūsā al-Khwārizmī’s ninth century Al-kitāb al-mukhtaṣar fī ḥisāb al-ğabr wa’l-muqābala (The Compendious Book on Calculation by Completion and Balancing), the word algebra coming from the Arabic al-ğabr, meaning completion or setting together (in Spanish an algebraist is a bone setter). This introduction had little impact. It was reintroduced in the thirteenth century by Leonardo of Pisa, this time as commercial arithmetic, where it, especially with the introduction of double entry bookkeeping, had a major impact but still remained outside of academia.

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Leonardo of Pisa Liber Abaci

It was first in the sixteenth century that algebra found its way into academia through the work of Scipione del Ferro (1465–1526), Niccolò Fontana known as Tartaglia (c.1499–1557)and above all Gerolamo Cardano (1501–1576), whose Artis Magnæ, Sive de Regulis Algebraicis Liber Unus (Book number one about The Great Art, or The Rules of Algebra) published by Johannes Petreius (c. 1496–1550) in Nürnberg in 1545 is regarded as the first modern algebra textbook or even the beginning of modern mathematics (which, as should be obvious to regular readers, is a view that I don’t share).

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Source: Wikimedia Commons

Modern readers would find it extremely strange as all of the formulas and theorems are written in words or abbreviations of words and there are no symbols in sight. The status of algebra was further established by the work of the Italian mathematician Rafael Bombelli (1526–1572),

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Source: Wikimedia Commons

(1572)

Another school of algebra was the German Cos school represented by the work of the

German mathematician Michael Stifel (1487–1567), Arithmetica integra (1544),

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Source: Wikimedia Commons

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Michael Stifel’s Arithmetica Integra (1544)

Simon Stevin in the Netherlands L’arithmétique (1585)

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and Robert Recorde (c. 1512–1558) in Britain with his The Whetstone of Witte (1557).

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The passage in The Whetstone of Witte introducing the equals sign Source: Wikimedia Commons

Algebra took a new direction with the French mathematician François Viète (1540–1603),

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François Viète Source: Wikimedia Commons

who wrote an algebra text based on the work of Cardano and the late classical work of Diophantus of Alexandria (2nd century CE) In artem analyticam isagoge (1591) replacing many of the words and abbreviations with symbols.

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Algebra was very much on the advance. Of interest here is that Galileo, who is always presented as the innovator, rejected the analytical mathematics, whereas the leading Jesuit mathematician Christoph Clavius (1538–1612), the last of the staunch defenders of Ptolemaic astronomy, wrote a textbook on Viète’s algebra for the Jesuit schools and colleges.  Two further important publications on symbolic algebra in the seventeenth century were the English mathematician, William Oughtred’s Clavis Mathematicae (1631),

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which went through several editions and was read all over Europe and Thomas Harriot’s unnamed (1631), the only one of his scientific works ever published and that only posthumously.

The development of the then new analytical mathematics reach a high point with the independent invention by Pierre Fermat and René Descartes of analytical geometry, which enabled the geometrical presentation of algebraic functions or the algebraic presentation of geometrical forms; a very powerful tool in the armoury of the mathematical physicists in the seventeenth century. Fermat’s pioneering work in analytical geometry (Methodus ad disquirendam maximam et minimam et de tangentibus linearum curvarum) was circulated in manuscript form in 1636 (based on results achieved in 1629) This manuscript was published posthumously in 1679 in Varia opera mathematica, as Ad Locos Planos et Solidos Isagoge (Introduction to Plane and Solid Loci).

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Descartes more famous work was published as La Géometrié, originally as an appendix to his Discours de la méthode (1637). However, much more important for the dissemination of Descartes version of the analytical geometry was the expanded Latin translation produced by Frans van Schooten the younger with much additional material from van Schooten himself, published in 1649 and the second edition, with extra material from his group of special students mentioned above, in two volumes 1659 and 1661. Van Schooten was the first to introduce the nowadays, ubiquitous orthogonal Cartesian coordinates and to extend the system to three dimensions in his Exercises (1657).

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The other branch of analytical mathematics that was developed in the seventeenth century was what we now know as infinitesimal calculus, the mathematics that is necessary to deal with rates of change, for example for analysing motion. There is a prehistory, particularly of integral calculus but it doesn’t need to interest us here. Kepler used a form of proto-integration to prove his second law of planetary motion and a more sophisticated version to calculate the volume of barrels in a fascinating but often neglected pamphlet. The Galilean mathematician Cavalieri developed a better system of integration, his indivisibles, which he published in his Geometria indivisibilibus continuorum nova quadam ratione promota, (Geometry, developed by a new method through the indivisibles of the continua) (1635) but actually written in 1627, demonstrated on the area of a parabola. This work was developed further by Torricelli, who extended it to other functions.

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The other branch of calculus the calculating of tangents and thus derivatives was worked on by a wide range of mathematicians. Significant contributions were made by Blaise Pascal, Pierre de Fermat, René Descarte, Gregoire de Saint-Vincent, John Wallis and Isaac Barrow. Fermat’s work was the most advanced and included contributions to both integral and deferential calculus, including a general method for determining tangents that is still taught in schools. The Scottish mathematician, James Gregory (1638–1675), inspired by Fermat’s work developed the second fundamental theory of calculus, which states that the integral of a function f over some interval can be computed by using any one, say F, of its infinitely many anti-derivatives. Isaac Barrow (1630–1677) was the first to provide a full proof of the fundamental theorem of calculus, which is a theorem that links the concept of differentiating a function with the concept of integrating a function. Fermat’s work and John Wallis’ Arithmetica Infinitorum (1656) would be an important jumping off point for both Leibniz and Newton in the future.

Wallis_Arithmetica_Infinitorum

Source: Wikimedia Commons

By about 1670, the mathematicians of Europe, who knew of and built on each other’s work had made major advances in the development of both modern mathematics and physics laying the foundations for the next major development in the emergence of modern astronomy. However, before we reach that development there will be a couple of other factors that we have to consider first.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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May 6, 2020 · 8:33 am

Annus mythologicus

Almost inevitably Newton’s so-called Annus mirabilis has become a social media meme during the current pandemic and the resulting quarantine. Not surprisingly Neil deGrasse Tyson has once again led the charge with the following on Twitter:

When Isaac Newton stayed at home to avoid the 1665 plague, he discovered the laws of gravity, optics, and he invented calculus.

Unfortunately for NdGT and all the others, who have followed his lead in posting variants, both positive and negative, the Annus mirabilis is actually a myth. So let us briefly examine what actually took place and what Isaac actually achieved in the 1660s.

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Portrait of Newton at 46 by Godfrey Kneller, 1689 Source: Wikimedia Commons

We will start with the calculus, which he didn’t actually invent at all, neither in the 1660s nor at any other time. Calculus has a more than two thousand year history stretching back to fourth century BCE. The development of calculus accelerated in the seventeenth century beginning with Kepler and Cavalieri and, previous to Newton, reaching a high point in the work of John Wallis. What Newton, like Leibniz, did was to collate, order and expand the work that others had already produced. Let us take a closer look at what Newton actually achieved in the 1660s.

But before we start, one point that various people have made on the Internet is that during this time Newton was a completely free agent with no commitments, obligations or burdens, a bachelor without children. In college his chambers were cleaned by servants and his meals were prepared by others. At home in Woolsthorpe all of his needs were also met by servants. He could and did devote himself to studying without any interruptions.

Newton, who entered Trinity College Cambridge in June 1661, was an indifferent student apparently bored by the traditional curriculum he was supposed to learn. In April 1664 he was due to take a scholarship exam, which would make him financially independent. The general opinion was not positive, however he did pass as he also passed his BA in the following year, when the prognosis was equally negative. Westfall suggests that he had a patron, who recommended that Cambridge retain him.

Freed by the scholarship, Newton now discovered his love and aptitude for the modern mathematics and set off on a two-year intensive study of the subject, almost to the exclusion of everything else, using the books of the leading mathematicians of the period, Descartes (but in the expanded, improved Latin edition of van Schooten), Viète and Wallis. In October 1666 Newton’s total immersion in mathematics stopped as suddenly as it had begun when he wrote a manuscript summarising all that he had internalised. He had thoroughly learnt all of the work available on the modern analytical mathematics, extended it and systematised it. This was an extraordinary achievement by any standards and, although nobody knew about it at the time, established Newton as one of the leading mathematicians in Europe. Although quite amazing, the manuscript from 1666 is still a long way from being the calculus that we know today or even the calculus that was known, say in 1700.

It should be noted that this intense burst of mathematical activity by the young Newton had absolutely nothing to do with the plague or his being quarantined/isolated because of it. It is an amusing fact that Newton was stimulated to investigate and learn mathematics, according to his own account, because he bought a book on astrology at Sturbridge Fair and couldn’t understand it. Unlike many of his contemporaries, Newton does not appear to have believed in astrology but he learnt his astronomy from the books of Vincent Wing (1619–1668) and Thomas Street (1621–1689) both of whom were practicing astrologers.

I said above that Newton devoted himself to mathematics almost to the exclusion of everything else in this period. However, at the beginning he started a notebook in which he listed topics in natural philosophy that he would be interested in investigating further in the future. Having abandoned mathematics he now turned to one of those topics, motion and space. Once again he was guided in his studies by the leaders in the field, once again Descartes, then Christiaan Huygens and also Galileo in the English translation by Thomas Salusbury, which appeared in 1665. Newton’s early work in this field was largely based on the principle of inertia that he took from Descartes and Descartes’ theories of impact. Once again Newton made very good progress, correcting Descartes errors and demonstrating that Galileo’s value for ‘g’ the force of acceleration due to gravity was seriously wrong. He also made his first attempt to show that the force that causes an object to fall to the ground, possibly the legendary apple, and the force that prevents the Moon from shooting off at a tangent, as the principle of inertia says it should, were one and the same. This attempt sort of failed because the data available to Newton at the time was not accurate enough. Newton abandoned this line of thinking and only returned to it almost twenty years later.

Once again, the progress that the young Newton made in this area were quite impressive but his efforts were very distant from his proof of the law of gravity and its consequences that he would deliver in the Principia, twenty year later. For the record Newton didn’t discover the law of gravity he proved it, there is an important difference between the two. Of note in this early work on mechanics is that Newton’s concepts of mass and motions were both defective. Also of note is that to carry out his gravity comparison Newton used Kepler’s third law of planetary motion to determine the force holding the Moon in its orbit and not the law of gravity. The key result presented in Principia is Newton’s brilliant proof that Kepler’s third law and the law of gravity are in fact mathematically equivalent.

The third area to which Newton invested significant time and effort in the 1660s was optics. I must confess that I have absolutely no idea what Neil deGrasse Tyson means when he writes that Newton discovered the laws of optics. By the time Newton entered the field, the science of optics was already two thousand years old and various researchers including Euclid, Ptolemaeus, Ibn al-Haytham, Kepler, Snel, and Descartes had all contributed substantially to its laws. In the 1660s Newton entered a highly developed field of scientific investigation. He stated quite correctly that he investigated the phenomenon of colour. Once again his starting point was the work of others, who were the leaders in the field, most notably Descartes and Hooke. It should be clear by now that in his early development Newton’s debt to the works of Descartes was immense, something he tried to deny in later life. What we have here is the programme of experiments into light that Newton carried out and which formed the basis of his very first scientific paper published in 1672. This paper famously established that white light is made up of coloured light. Also of significance Newton was the first to discover chromatic aberration, the fact that spherical lenses don’t sharply focus light to a single point but break it up into a spectrum, which means the images have coloured fringes. This discovery led Newton to develop his reflecting telescope, which avoids the problem of chromatic aberration.

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Newton’s sketch of his crucial experiment. Source: Royal Society

Here trying to establish a time line of when and where he carried out these experiments is very difficult, not alone because Newton’s own statements on the subject are contradictory and some of them are provably false. For example he talks about acquiring a second prism from Sturbridge Fair in a year when one didn’t take place. Also Newton’s source of light was sunlight let into a darkened room through small hole in the shutters. This was only possible at certain times of year and certain times of day when the sun is in the right position respective the window. Newton claims experiments made at times where these conditions weren’t met. That not all the experiments were made in Woolsthorpe Manor is clear, as many of them required two operators, which means that they were made when Newton was back in his chambers in Trinity College. The best guestimate is that this programme of experiments took place over the period 1660 to 1670, so once again not in Newton’s year of quarantine.

Another thing that keeps getting mentioned in connection with this story is that during his experiments on light Newton, shock-horror, stuck a pin in his eye! He didn’t. What he did was to insert a bodkin, a flat, blunt, threading needle, into his eye-socket between his skull and his eyeball in order to apply pressure to the back of his eyeball. Nasty enough, but somewhat different to sticking a pin in his eye.

All in all the developments that the young Newton achieved in mathematics and physics in the 1660s were actually spread out over a period of six years. They were also not as extensive or revolutionary as implied in Neil deGrasse Tyson brief tweeted claim. In fact a period of six intensive years of study would be quite normal for a talented student to acquire the basics of mathematics and physics. And I think we can all agree that Newton was very talented. His achievements were remarkable but not sensational.

It is justified to ask where then does the myth of the Annus Mirabilis actually come from? The answer is Newton himself. In later life he claimed that he had done all these things in that one-year, the fictional ones rather than the real achievements. So why did he claim this? One reason, a charitable interpretation, is that of an old man just telescoping the memories of his youth. However, there is a less charitable but probably more truthful explanation. Newton became in his life embroiled in several priority disputes with other natural philosophers over his discoveries, with Leibniz over the calculus, with Hooke over gravity and with Hook and Huygens over optics. By pushing back into the distant past some of his major discoveries he can, at least to his own satisfaction, firmly establish his priority.

The whole thing is best summarised by Westfall in his Newton biography Never at Rest at the end of his chapter on the topic, interestingly entitled Anni mirabiles, amazing years, not Annus mirabilis the amazing year, on which the brief summary above is largely based. It is worth quoting Westfall’s summary in full:

On close examination, the anni mirabiles turn out to be less miraculous than the annus mirabilis of Newtonian myth. When 1660 closed, Newton was not in command of the results that have made his reputation deathless, not in mathematics, not in mechanics, not in optics. What he had done in all three was to lay foundations, some more extensive than others, on which he could build with assurance, but nothing was complete at the end of 1666, and most were not even close to complete. Far from diminishing Newton’s stature, such a judgement enhances it by treating his achievements as a human drama of toil and struggle rather than a tale of divine revelation. “I keep the subject constantly before me, “ he said, “and wait ‘till the first dawnings open slowly, by little and little, into full and clear light.” In 1666 by dint of keeping subjects constantly before him, he saw the first dawnings open slowly. Years of thinking on them continuously had yet to pass before he gazed on a full and clear light.[1]

Neil deGrasse Tyson has form when it comes to making grand false statements about #histSTM, this is by no means the first time that he has spread the myth of Newton’s Annus mirabilis. What is perhaps even worse is that when historians point out, with evidence, that he is spouting crap he doesn’t accept that he is wrong but invents new crap to justify his original crap. Once he tweeted the classic piece of fake history that people in the Middle Ages believed the world was flat. As a whole series of historians pointed out to him that European culture had known since antiquity that that the world was a sphere, he invented a completely new piece of fake history and said, yes the people in antiquity had known it but it had been forgotten in the Middle Ages. He is simply never prepared to admit that he is wrong. I could bring other examples such as my exchange with him on the superstition of wishing on a star that you can read here but this post is long enough already.

Bizarrely Neil deGrasse Tyson has the correct answer to his behaviour when it comes to #histSTM, of which he is so ignorant. He offers an online course on the scientific method, always ready and willing to turn his notoriety into a chance to make a quick buck, and has an advertising video on Youtube for it that begins thus:

One of the great challenges in this world is knowing enough about a subject to think you’re right but not enough about the subject to know you’re wrong.

This perfectly encapsulates Neil deGrasse Tyson position on #histSTM!

If you want a shorter, better written, more succinct version of the same story then Tom Levenson has one for you in The New Yorker 

[1] Ricard S. Westfall, Never at Rest: A Biography of Isaac Newton, CUP; Cambridge, ppb. 1983, p. 174.

 

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Filed under History of Astronomy, History of Mathematics, History of Optics, Myths of Science, Newton

How Renaissance Nürnberg became the Scientific Instrument Capital of Europe

This is a writen version of the lecture that I was due to hold at the Science and the City conference in London on 7 April 2020. The conference has for obvious reasons been cancelled and will now take place on the Internet. You can view the revised conference program here.

The title of my piece is, of course, somewhat hyperbolic, as far as I know nobody has ever done a statistical analysis of the manufacture of and trade in scientific instruments in the sixteenth century. However, it is certain that in the period 1450-1550 Nürnberg was one of the leading European centres both for the manufacture of and the trade in scientific instruments. Instruments made in Nürnberg in this period can be found in every major collection of historical instruments, ranging from luxury items, usually made for rich patrons, like the column sundial by Christian Heyden (1526–1576) from Hessen-Kassel

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Column Sundial by Christian Heyden Source: Museumslandschaft Hessen-Kassel

to cheap everyday instruments like this rare (rare because they seldom survive) paper astrolabe by Georg Hartman (1489–1564) from the MHS in Oxford.

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Paper and Wood Astrolabe Hartmann Source: MHS Oxford

I shall be looking at the reasons why and how Nürnberg became such a major centre for scientific instruments around 1500, which surprisingly have very little to do with science and a lot to do with geography, politics and economics.

Like many medieval settlements Nürnberg began simply as a fortification of a prominent rock outcrop overlooking an important crossroads. The first historical mention of that fortification is 1050 CE and there is circumstantial evidence that it was not more than twenty or thirty years old. It seems to have been built in order to set something against the growing power of the Prince Bishopric of Bamberg to the north. As is normal a settlement developed on the downhill slopes from the fortification of people supplying services to it.

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A fairly accurate depiction of Nürnberg from the Nuremberg Chronicle from 1493. The castles (by then 3) at the top with the city spreading down the hill. Large parts of the inner city still look like this today

Initially the inhabitants were under the authority of the owner of the fortification a Burggraf or castellan. With time as the settlement grew the inhabitants began to struggle for independence to govern themselves.

In 1200 the inhabitants received a town charter and in 1219 Friedrich II granted the town of Nürnberg a charter as a Free Imperial City. This meant that Nürnberg was an independent city-state, which only owed allegiance to the king or emperor. The charter also stated that because Nürnberg did not possess a navigable river or any natural resources it was granted special tax privileges and customs unions with a number of southern German town and cities. Nürnberg became a trading city. This is where the geography comes into play, remember that important crossroads. If we look at the map below, Nürnberg is the comparatively small red patch in the middle of the Holy Roman Empire at the beginning of the sixteenth century. If your draw a line from Paris to Prague, both big important medieval cities, and a second line from the border with Denmark in Northern Germany down to Venice, Nürnberg sits where the lines cross almost literally in the centre of Europe. Nürnberg also sits in the middle of what was known in the Middle Ages as the Golden Road, the road that connected Prague and Frankfurt, two important imperial cities.

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You can also very clearly see Nürnberg’s central position in Europe on Erhard Etzlaub’s  (c. 1460–c. 1531) pilgrimage map of Europe created for the Holy Year of 1500. Nürnberg, Etzlaub’s hometown, is the yellow patch in the middle. Careful, south is at the top.

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Over the following decades and centuries the merchant traders of Nürnberg systematically expanded their activities forming more and more customs unions, with the support of various German Emperors, with towns, cities and regions throughout the whole of Europe north of Italy. Nürnberg which traded extensively with the North Italian cities, bringing spices, silk and other eastern wares, up from the Italian trading cities to distribute throughout Europe, had an agreement not to trade with the Mediterranean states in exchange for the Italians not trading north of their northern border.

As Nürnberg grew and became more prosperous, so its political status and position within the German Empire changed and developed. In the beginning, in 1219, the Emperor appointed a civil servant (Schultheis), who was the legal authority in the city and its judge, especially in capital cases. The earliest mention of a town council is 1256 but it can be assumed it started forming earlier. In 1356 the Emperor, Karl IV, issued the Golden Bull at the Imperial Diet in Nürnberg. This was effectively a constitution for the Holy Roman Empire that regulated how the Emperor was to be elected and, who was to be appointed as the Seven Prince-electors, three archbishops and four secular rulers. It also stipulated that the first Imperial Diet of a newly elected Emperor was to be held in Nürnberg. This stipulation reflects Nürnberg’s status in the middle of the fourteenth century.

The event is celebrated by the mechanical clock ordered by the town council to be constructed for the Frauenkirche, on the market place in 1506 on the 150th anniversary of the Golden Bull, which at twelve noon displays the seven Prince-electors circling the Emperor.

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Mechanical clock on the Frauenkirche overlooking the market place in Nürnberg. Ordered by the city council in 1506 to celebrate the 150th anniversary of the issuing of the Golden Bull at the Imperial Diet in 1356

Over time the city council had taken more and more power from the Schultheis and in 1385 they formally bought the office, integrating it into the councils authority, for 8,000 gulden, a small fortune. In 1424 Emperor, Sigismund appointed Nürnberg the permanent residence of the Reichskleinodien (the Imperial Regalia–crown, orb, sceptre, etc.).

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The Imperial Regalia

This raised Nürnberg in the Imperial hierarchy on a level with Frankfurt, where the Emperor was elected, and Aachen, where he was crowned. In 1427, the Hohenzollern family, current holders of the Burggraf title, sold the castle, which was actually a ruin at that time having been burnt to the ground by the Bavarian army, to the town council for 120,000 gulden, a very large fortune. From this point onwards Nürnberg, in the style of Venice, called itself a republic up to 1806 when it was integrated into Bavaria.

In 1500 Nürnberg was the second biggest city in Germany, after Köln, with a population of approximately 40,000, about half of which lived inside the impressive city walls and the other half in the territory surrounding the city, which belonged to it.

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Map of the city-state of Nürnberg by Abraham Ortelius 1590. the city itself is to the left just under the middle of the map. Large parts of the forest still exists and I live on the northern edge of it, Dormitz is a neighbouring village to the one where I live.

Small in comparison to the major Italian cities of the period but even today Germany is much more decentralised with its population more evenly distributed than other European countries. It was also one of the richest cities in the whole of Europe.

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Nürnberg, Plan by Paul Pfinzing, 1594 Castles in the top left hand corner

Nürnberg’s wealth was based on two factors, trading, in 1500 at least 27 major trade routes ran through Nürnberg, which had over 90 customs unions with cities and regions throughout Europe, and secondly the manufacture of trading goods. It is now time to turn to this second branch of Nürnberg’s wealth but before doing so it is important to note that whereas in other trading centres in Europe individual traders competed with each other, Nürnberg function like a single giant corporation, with the city council as the board of directors, the merchant traders cooperating with each other on all levels for the general good of the city.

In 1363 Nürnberg had more than 1200 trades and crafts masters working in the city. About 14% worked in the food industry, bakers, butchers, etc. About 16% in the textile industry and another 27% working leather. Those working in wood or the building branch make up another 14% but the largest segment with 353 masters consisted of those working in metal, including 16 gold and silver smiths. By 1500 it is estimated that Nürnberg had between 2,000 and 3,000 trades and crafts master that is between 10 and 15 per cent of those living in the city with the metal workers still the biggest segment. The metal workers of Nürnberg produced literally anything that could be made of metal from sewing needles and nails to suits of armour. Nürnberg’s reputation as a producer rested on the quality of its metal wares, which they sold all over Europe and beyond. According to the Venetian accounts books, Nürnberg metal wares were the leading export goods to the orient. To give an idea of the scale of production at the beginning of the 16th century the knife makers and the sword blade makers (two separate crafts) had a potential production capacity of 80,000 blades a week. The Nürnberger armourers filled an order for armour for 5,000 soldiers for the Holy Roman Emperor, Karl V (1500–1558).

The Nürnberger craftsmen did not only produce goods made of metal but the merchant traders, full blood capitalists, bought into and bought up the metal ore mining industry–iron, copper, zinc, gold and silver–of Middle Europe, and beyond, (in the 16th century they even owned copper mines in Cuba) both to trade in ore and to smelt ore and trade in metal as well as to ensure adequate supplies for the home production. The council invested heavily in the industry, for example, providing funds for the research and development of the world’s first mechanical wire-pulling mill, which entered production in 1368.

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The wirepulling mills of Nürnberg by Albrecht Dürer

Wire was required in large quantities to make chainmail amongst other things. Around 1500 Nürnberg had monopolies in the production of copper ore, and in the trade with steel and iron.  Scientific instruments are also largely made of metal so the Nürnberger gold, silver and copper smiths, and toolmakers also began to manufacture them for the export trade. There was large scale production of compasses, sundials (in particular portable sundials), astronomical quadrants, horary quadrants, torquetum, and astrolabes as well as metal drawing and measuring instruments such as dividers, compasses etc.

The city corporation of Nürnberg had a couple of peculiarities in terms of its governance and the city council that exercised that governance. Firstly the city council was made up exclusively of members of the so-called Patrizier. These were 43 families, who were regarded as founding families of the city all of them were merchant traders. There was a larger body that elected the council but they only gave the nod to a list of the members of the council that was presented to them. Secondly Nürnberg had no trades and crafts guilds, the trades and crafts were controlled by the city council. There was a tight control on what could be produced and an equally tight quality control on everything produced to ensure the high quality of goods that were traded. What would have motivated the council to enter the scientific instrument market, was there a demand here to be filled?

It is difficult to establish why the Nürnberg city corporation entered the scientific instrument market before 1400 but by the middle of the 15th century they were established in that market. In 1444 the Catholic philosopher, theologian and astronomer Nicolaus Cusanus (1401–1464) bought a copper celestial globe, a torquetum and an astrolabe at the Imperial Diet in Nürnberg. These instruments are still preserved in the Cusanus museum in his birthplace, Kues on the Mosel.

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The Cusanus Museum in Kue

In fact the demand for scientific instrument rose sharply in the 15th & 16th centuries for the following reasons. In 1406 Jacopo d’Angelo produced the first Latin translation of Ptolemy’s Geographia in Florence, reintroducing mathematical cartography into Renaissance Europe. One can trace the spread of the ‘new’ cartography from Florence up through Austria and into Southern Germany during the 15th century. In the early 16th century Nürnberg was a major centre for cartography and the production of both terrestrial and celestial globes. One historian of cartography refers to a Viennese-Nürnberger school of mathematical cartography in this period. The availability of the Geographia was also one trigger of a 15th century renaissance in astronomy one sign of which was the so-called 1st Viennese School of Mathematics, Georg von Peuerbach (1423–1461) and Regiomontanus (1436–176), in the middle of the century. Regiomontanus moved to Nürnberg in 1471, following a decade wandering around Europe, to carry out his reform of astronomy, according to his own account, because Nürnberg made the best astronomical instruments and had the best communications network. The latter a product of the city’s trading activities. When in Nürnberg, Regiomontanus set up the world’s first scientific publishing house, the production of which was curtailed by his early death.

Another source for the rise in demand for instruments was the rise in interest in astrology. Dedicated chairs for mathematics, which were actually chairs for astrology, were established in the humanist universities of Northern Italy and Krakow in Poland early in the 15th century and then around 1470 in Ingolstadt. There were close connections between Nürnberg and the Universities of Ingolstadt and Vienna. A number of important early 16th century astrologers lived and worked in Nürnberg.

The second half of the 15th century saw the start of the so-called age of exploration with ships venturing out of the Iberian peninsular into the Atlantic and down the coast of Africa, a process that peaked with Columbus’ first voyage to America in 1492 and Vasco da Gama’s first voyage to India (1497–199). Martin Behaim(1459–1507), son of a Nürnberger cloth trading family and creator of the oldest surviving terrestrial globe, sat on the Portuguese board of navigation, probably, according to David Waters, to attract traders from Nürnberg to invest in the Portuguese voyages of exploration.  This massively increased the demand for navigational instruments.

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The Erdapfel–the Behaim terrestial globe Germanische National Museum

Changes in the conduct of wars and in the ownership of land led to a demand for better, more accurate maps and the more accurate determination of boundaries. Both requiring surveying and the instruments needed for surveying. In 1524 Peter Apian (1495–1552) a product of the 2nd Viennese school of mathematics published his Cosmographia in Ingolstadt, a textbook for astronomy, astrology, cartography and surveying.

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The Cosmographia went through more than 30 expanded, updated editions, but all of which, apart from the first, were edited and published by Gemma Frisius (1508–1555) in Louvain. In 1533 in the third edition Gemma Frisius added an appendix Libellus de locorum describendum ratione, the first complete description of triangulation, the central method of cartography and surveying down to the present, which, of course in dependent on scientific instruments.

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In 1533 Apian’s Instrumentum Primi Mobilis 

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was published in Nürnberg by Johannes Petreius (c. 1497–1550) the leading scientific publisher in Europe, who would go on ten years later to publish, Copernicus’ De revolutionibus, which was a high point in the astronomical revival.

All of this constitutes a clear indication of the steep rise in the demand for scientific instruments in the hundred years between 1450 and 1550; a demand that the metal workers of Nürnberg were more than happy to fill. In the period between Regiomontanus and the middle of the 16th century Nürnberg also became a home for some of the leading mathematici of the period, mathematicians, astronomers, astrologers, cartographers, instrument makers and globe makers almost certainly, like Regiomontanus, at least partially attracted to the city by the quality and availability of the scientific instruments.  Some of them are well known to historians of Renaissance science, Erhard Etzlaub, Johannes Werner, Johannes Stabius (not a resident but a frequent visitor), Georg Hartmann, Johannes Neudörffer and Johannes Schöner.**

There is no doubt that around 1500, Nürnberg was one of the major producers and exporters of scientific instruments and I hope that I have shown above, in what is little more than a sketch of a fairly complex process, that this owed very little to science but much to the general geo-political and economic developments of the first 500 years of the city’s existence.

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One of the most beautiful sets on instruments manufactured in Nürnberg late 16th century. Designed by Johannes Pretorius (1537–1616), professor for astronomy at the Nürnberger University of Altdorf and manufactured by the goldsmith Hans Epischofer (c. 1530–1585) Germanische National Museum

 

**for an extensive list of those working in astronomy, mathematics, instrument making in Nürnberg (542 entries) see the history section of the Astronomie in Nürnberg website, created by Dr Hans Gaab.

 

 

 

 

 

 

 

 

 

 

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Filed under Early Scientific Publishing, History of Astronomy, History of Cartography, History of Mathematics, History of Navigation, History of science, History of Technology, Renaissance Science

3 into 2 does go!

It would of course be totally unethical for me to review a book of which I am one of the authors. However, as my contribution is only six of two-hundred pages, of which three are illustrations, and the book is one that could/would/should interest some (many) of my readers, I’m going to be unethical and review it anyway.

Thinking 3D is an intellectual idea, it is a website, it is exhibitions and other events, it is a book but above all it is two people, whose idea it is: Daryl Green, who was Fellow Librarian of Magdalen College, Oxford and is now Special Collections Librarian of the University of Edinburg and Laura Moretti, who is Senior Lecturer in Art History at the University of St Andrews. The Thinking 3D idea is the historical investigation of the representation of the three-dimensional world on the two-dimensional page particular, but not exclusively, in print.

The Thinking 3D website explains in great detail what it is all about and contains a full description of the activities that have been carried out. For those quarantined there is a fairly large collection of essays on various topics from the project.

In 2019 Thinking 3D launched a major exhibition with The Bodleian Libraries Oxford as part of the commemorations of the 500th anniversary of Leonardo da Vinci’s death, Thinking 3D From Leonardo to the Present, which ran from March 2019 to February 2020 and which I have been told was quite exceptional.

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As an extension and permanent record of that exhibition Bodleian Libraries published a book, Thinking 3D: Books, Images and Ideas from Leonardo to the Present[1], which appeared in autumn 2019. This is both a coffee table book but also, at the same time, a piece of serious academic literature.

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The book opens with a long essay by Green and Moretti, The history of thinking 3D in forty books, which delivers exactly what the title says. This is an excellent survey of the topic and it is worth reading the book just for this. However, it does contain one historical error that I, in my alter ego of the HIST_SCI HULK, simply cannot ignore, at least not if I want to maintain my hard won reputation. Having introduced the topic of Copernicus’ De revolutionibus the authors write:

As mentioned above, the oft-published heliocentric diagram, and its theoretical propositions, are what launched this book into infamy (the book was immediately put on the Catholic Church’s Index of Prohibited Books [my emphasis]), but the execution of this relational illustration is simple and reductive.

De revolutionibus was published in 1543 but was first placed on the Index sixty-three years later in 1616 and more importantly, as I wrote very recently, not for the first time, it was placed on the Index until corrected. These corrections, which were fairly minimal, were carried out surprisingly quickly and the book became available to be studied by Catholics already in 1621.

Other than this I noticed no other errors in the highly informative introductory essay, which is followed by an essay from Matthew Landrus, Leonardo da Vinci, 500 years on, which examines Leonardo’s three-dimensional perception of the world and everything in it. It was for me an interesting addition to my previous readings on the Tuscan polymath.

The main body of the book is taken up by sixteen fairly short essays in four categories: Geometry, Astronomy, Architecture and Anatomy.

Geometry starts off with Ken Saito’s presentation of a ninth century manuscript of The Elements of Euclid, where he demonstrates very clearly that the author has no real consistent, methodology for presenting a 3D space on a 2D page.   This is followed by Renzo Baldasso’s essay on Luca Pacioli’s De divina proportione (1509). Here the three dimensional solids are presented perfectly by Pacioli’s friend, colleague and one time pupil Leonardo. We return to Euclid for Yelda Nasifoglu’s investigation of the English translation of The Elements by Henry Billingsley in 1570. This volume is totally fascinating as three-dimensional figures are present as pop-up figure like those that we all know from our children’s books. The geometry section closes with a book that I didn’t know, Max Brückner’s Vielecke und Vielflache (1900) presented by George Hart. This is a vast collection of photographs of paper models of three-dimensional figures, which I learnt also influenced M. C. Escher a master of the third dimension.

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Luca Pacioli De divina proportione

 

Karl Galle, Renaissance Mathematicus friend and guest blogger, kicks of the astronomy section with Johannes Kepler’s wonderfully bizarre presentation of the planetary orbits embedded in the five regular Platonic solids from his Mysterium Cosmographicum (1596). Yours truly is up next with an account of Galileo’s Sidereus Nuncius (1610) and it’s famous washes of the Moon displaying three-dimension features. Also covered are the later pirate editions that screwed up those illustrations. Stephanie O’Rourke presents one of the most extraordinary nineteenth century astronomy books James Nasmyth’s and James Carpenter’s The Moon: Considered as a Planet, a World, and a Satellite(1874). This contains stunningly realistic photographic plates of the Moon’s surface but which are not actually real. The two Jameses constructed plaster models that they then lit and photographed to achieve the desired effect. We close the astronomy section with Thinking 3D’s co-chef, Daryl Green, taking on a survey of the surface of Mars with the United Stated Geological Survey, Geological Map of Mars (1978).

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Johannes Kepler Mysterium Cosmographicum

Turning our attention to architecture, we travel back to the twelfth century, with Karl Kinsella as our guide, to Richard of St Victor’s In visionen Ezekielis; a wonderfully modern in its presentation but somewhat unique medieval architectural manuscript. The other half of the Thinking 3D team, Laura Moretti now takes us up to the sixteenth century and Sebastiano Serlio’s catalogue of the buildings of Rome (1544), which has an impossibly long Italian title that I’m not going to repeat here. We remain in the sixteenth century for Jacques Androuet du Cerceau’s Le premier [et second] volume des plus excellent bastiment de France (1576–9), where our guide is Frédérique Lemerle. Moving forward a century we close out the architecture section with Francesco Marcorin introducing us to Hans Vredeman de Vries’s absolutely stunning Perspective (1604–5).

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Hans Vredeman de Vries Perspective

It would not be too difficult to guess that the anatomy section opens with one of the greatest medical books of all time, Andreas Vesalius’ De fabrica but not with the full version but the shorter (cheaper?) De humani corporis fabrica libroum epitome, like the full version published in 1543 in Basel. Our guide to Vesalius’ masterpiece is Mark Samos. Camilla Røstvik introduces us to William Hunter’s The Anatomy of the Human Gravid Uterus (1774), as she makes very clear a milestone in the study of women’s bodies with its revolutionary and controversial study of the pregnant body. For me this essay was a high point in a collection of truly excellent essays. We stay in the eighteenth century for Jacques Fabien Gautier D’Agoty’s Exposition anatomique des organes des sens (1775). Dániel Margócsy present a fascinating guide to the controversial work of this pioneer of colour printing. Anatomy, and the book as a whole, closes with Denis Pellerin’s essay on Arthur Thomson’s Anatomy of the Human Eye (1912). Thomson’s book was accompanied by a collection of stereoscopic images of the anatomy of the eye together with a stereoscope with which to view the 3D images thus created; a nineteenth century technology that was already dying out when Thomson published his work.

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William Hunter The Anatomy of the Human Gravid Uterus

The book closes with a bibliography of five books for further reading for each essay, brief biography of each of the authors, a glossary of technical terms and a good general index. All sixteen of the essays are short, informative, light to read, easily accessible introductions to the volumes that they present and maintain a high academic quality throughout the entire book.

I said at the outset that this is also a coffee table book and that was not meant negatively. It measures 24X26 cm and is printed on environmentally friendly, high gloss paper. The typeface is attractive and light on the eyes and the illustrations are, as is to be expected for a book about the history of book illustration, spectacularly beautiful. The publishing team of the Bodleian Libraries are to be congratulated on an excellent publication. If you leave this on your coffee table then your visitors will soon be leafing though it admiring the pictures, whether they are interested in book history or not. I don’t usually mention the price of books that I review but at £35 this beautifully presented and wonderfully informative volume is very good value for money.

[1] Thinking 3D: Books, Images and Ideas from Leonardo to the Present, edited by Daryl Green and Laura Moretti, Bodleian Library, Oxford, 2019.

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Filed under Book Reviews, Early Scientific Publishing, History of Astronomy, History of Mathematics, History of medicine

War, politics, religion and scientia

There is a strong tendency to view the history of science and the people who produced it in a sort of vacuum, outside of everyday society–Copernicus published this, Kepler published that, Newton synthesised it all… In fact the so-called scientific revolution took place in one of the most troubled times in European history, the age of the religious wars, the main one of which the Thirty Years War is thought to have been responsible directly and indirectly for the death of between one third and two thirds of the entire population of middle Europe. Far from being isolated from this turbulence the figures, who created modern science, were right in the middle of it and oft deeply involved and affected by it.

The idea for this blog post sort of crept into my brain as I was writing my review, two weeks ago, of two books about female spies during the English Revolution and Interregnum that is the 1640s to the 1660s. Isaac Newton was born during this period and grew up during it and, as I will now sketch, was personally involved in the political turbulence that followed on from it.

Born on Christmas Day in 1642 (os) shortly after the outbreak of the first of the three wars between the King and Parliament, Britain’s religious wars, he was just nine years old when Charles I was executed at the end of the second war.

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Portrait of Newton by Godfrey Kneller, 1689 Source: Wikimedia Commons

Newton was too young to be personally involved in the wars but others whose work would be important to his own later developments were. The Keplerian astronomer William Gascoigne (1612-1644), who invented the telescope micrometer, an important development in the history of the telescope, died serving in the royalist forces at the battle of Marston Moor. The mathematician John Wallis (1616–1703), whose Arithmetica Infinitorum (1656) strongly influenced Newton’s own work on infinite series and calculus, worked as a code breaker for Cromwelland later for Charles II after the restoration.

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John Wallis by Sir Godfrey Kneller

Newton first went up to university after the restoration but others of an earlier generation suffered loss of university position for being on the wrong side at the wrong time. John Wilkins (1614–1672), a parliamentarian and Cromwell’s brother-in-law, was appointed Master of Trinity College Cambridge, Newton’s college, in 1659 and removed from this position at the restoration. Wilkins’ Mathematical Magick (1648) had been a favourite of Newton’s in his youth.

Greenhill, John, c.1649-1676; John Wilkins (1614-1672), Warden (1648-1659)

Greenhill, John; John Wilkins (1614-1672), Warden (1648-1659); Wadham College, University of Oxford;

Newton’s political career began in 1689 following the so-called Glorious Revolution, when James II was chased out of Britain by William of Orange, his son-in-law, invited in by the parliament out of fear that James could reintroduce Catholicism into Britain. Newton sat in the House of Commons as MP for the University of Cambridge in the parliament of 1689, which passed the Bill of Rights, effectively a new constitution for England. Newton was not very active politically but he identified as a Whig, the party of his student Charles Montagu (1661–1715), who would go on to become one of the most powerful politicians of the age. It was Montagu, who had Newton appointed to lead the Royal Mint and it was also Montagu, who had Newton knighted in 1705in an attempt to get him re-elected to parliament.

In the standard version of story Newton represents the end of the scientific revolution and Copernicus (1473–1543) the beginning. Religion, politics and war all played a significant role in Copernicus’ life.

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Copernicus, the “Torun portrait” (anonymous, c. 1580), kept in Toruń town hall, Poland.

Copernicus spent the majority of his life living in the autonomous prince-bishopric of Warmia, where as a canon of the cathedral he was effectively a member of the government. Warmia was a Catholic enclave under the protection of the Catholic Crown of Poland but as the same time was geographically part of Royal Prussia ruled over by Duke Albrecht of Prussia (1490–1568), who had converted to Lutheran Protestantism in 1552. Ironically he was converted by Andreas Osiander (1498–1552), who would go on the author the controversial ad lectorum in Copernicus’ De revolutionibus. Relations between Poland and Royal Prussia were strained at best and sometimes spilled over into armed conflict. Between 1519 and 1521 there was a war between Poland and Royal Prussia, which took place mostly in Warmia. The Prussians besieged Frombork burning down the town, but not the cathedral, forcing Copernicus to move to Allenstein (Olsztyn), where he was put in charge of organising the defences during a siege from January to February 1521.  Military commander in a religious war in not a role usually associated with Copernicus. It is an interesting historical conundrum that, during this time of religious strife, De revolutionibus, the book of a Catholic cathedral canon, was published by a Protestant printer in a strongly Protestant city-state, Nürnberg.

The leading figure of the scientific revolution most affected by the religious wars of the age must be Johannes Kepler. A Lutheran Protestant he studied and graduated at Tübingen, one of the leading Protestant universities. However, he was despatched by the university authorities to become the mathematics teacher at the Protestant school in Graz in Styria, a deeply Catholic area in Austria in 1594. He was also appointed district mathematicus.

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Johannes Kepler Source: Wikimedia Commons

In 1598, Archduke Ferdinand, who became ruler of Styria in 1596, expelled all Protestant teachers and pastors from the province. Kepler was initially granted an exception because he had proved his worth as district mathematicus but in a second wave of expulsion, he too had to go. After failing to find employment elsewhere, he landed in Prague as an assistant to Tycho Brahe, the Imperial Mathematicus.

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Tycho Brahe Source: Wikimedia Commons

Once again he, like Tycho, was a Protestant in a Catholic city serving a Catholic Emperor, Rudolf II. Here he soon inherited Tycho’s position as Imperial Mathematicus. However, Rudolf was tolerant, more interested in Kepler’s abilities as an astrologer than in his religious beliefs. Apart from a substantial problem in getting paid in the permanently broke imperial court, Kepler now enjoyed a fairly quiet live for the next twelve years, then everything turned pear shaped once more.

In 1612, Rudolf’s younger brother Archduke Matthias deposed him and although Kepler was allowed to keep his title of Imperial Mathematicus, and theoretically at least, his salary but he was forced to leave Prague and become district mathematicus in Linz. In Linz Kepler, who openly propagated ecumenical ideas towards other Protestant communities, most notably the Calvinists, ran into conflict with the local Lutheran pastor. The pastor demanded that Kepler sign the Formula of Concord, basically a commitment to Lutheran theology and a rejection of all other theologies. Kepler refused and was barred from Holy Communion, a severe blow for the deeply religious astronomer. He appealed to the authorities in Tübingen but they up held the ban.

In 1618 the Thirty Years War broke out and in 1620 Linz was occupied by the Catholic army of Duke Maximilian of Bavaria, which caused problems for Kepler as a Lutheran. At the same time he was fighting for the freedom of his mother, Katharina, who had been accused of witchcraft. Although he won the court case against his mother, she died shortly after regaining her freedom. In 1625, the Counterreformation reach Linz and the Protestants living there were once again persecuted. Once more Kepler was granted an exception because of his status as Imperial Mathematicus but his library was confiscated making it almost impossible for him to work, so he left Linz.

Strangely, after two years of homeless wandering Kepler moved to Sagen in Silesia in 1628, the home of Albrecht von Wallenstein the commander of the Catholic forces in the war and for whom Kepler had interpreted a horoscope much earlier in life. Kepler never found peace or stability again in his life and died in Ulm in 1630. Given the turbulence in his life and the various forced moves, which took years rather than weeks, it is fairly amazing that he managed to publish eighty-three books and pamphlets between 1596 and his death in 1630.

A younger colleague of Kepler’s who also suffered during the Thirty Years’ War was Wilhelm Schickard, who Kepler had got to know during his time in Württemberg defending his mother. Schickard would go on to produce the illustrations both Kepler’s Epitome Astronomiae Copernicanae and his Harmonice Mundi, as well as inventing a calculating machine to help Kepler with his astronomical calculations. In 1632 Württemberg was invaded by the Catholic army, who brought the plague with them, by 1635 Schickard, his wife and his four living children, his sister and her three daughters had all died of the plague.

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Wilhelm Schickard, artist unknown Source: Wikimedia Commons

As I have pointed out on numerous occasions Galileo’s initial problems in 1615-16 had less to do with his scientific views than with his attempts to tell the theologians how to interpret the Bible, not an intelligent move at the height of the Counterreformation. Also in 1632 his problems were very definitely compounded by the fact that he was perceived to be on the Spanish side in the conflict between the Spanish and French Catholic authorities to influence, control the Pope, Urban VIII.

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Galileo Portrait by Ottavio Leoni Source: Wikimedia Commons

I will just mention in passing that René Descartes served as a soldier in the first two years of the Thirty Year’s War, at first in the Protestant Dutch States Army under Maurice of Nassau and then under the Catholic Duke of Bavaria, Maximilian. In 1620 he took part in the Battle of the White Mountain near Prague, which marked the end of Elector Palatine Frederick V’s reign as King of Bohemia. During his time in the Netherlands Descartes trained as a military engineer, which was his introduction to the works of Simon Stevin and Isaac Beeckman.

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René Descartes Portrait after Frans Hals Source: Wikimedia Commons

We have now gone full circle and are almost back to Isaac Newton. One interesting aspect of these troubled times is that although the problems caused by the wars, the religious disputes and the associated politics caused major problems in the lives of the astronomers and mathematicians, who were forced to live through them, and certainly affected their ability to carry on with their work, I can’t somehow imagine Copernicus working on De revolutionibus during the siege of Allenstein, the scholars themselves communicated quite happily across the religious divide.

Rheticus was treated as an honoured guest in Catholic Warmia although he was a professor at the University of Wittenberg, home to both Luther and Melanchthon. Copernicus himself was personal physician to both the Catholic Bishop of Frombork and the Protestant Duke of Royal Prussia. As we have seen, Kepler spent a large part of his life, although a devoted Protestant, serving high-ranking Catholic employers. The Jesuits, who knew Kepler from Prague, even invited him to take the chair for mathematics at the Catholic University of Bologna following the death of Giovanni Antonio Magini in 1617, assuring him that he did not need to convert. Although it was a very prestigious university Kepler, I think wisely, declined the invitation. The leading mathematicians of the time all communicated with each other, either directly or through intermediaries, irrespective of their religious beliefs. Athanasius Kircher, professor for mathematics and astronomy at the Jesuit Collegio Romano, collected astronomical data from Jesuits all over the world, which he then distributed to astronomers all over Europe, Catholic and Protestant, including for example the Lutheran Leibniz. Christiaan Huygens, a Dutch Calvinist, spent much of his life working as an honoured guest in Catholic Paris, where he met and influenced the Lutheran Leibniz.

When we consider the lives of scientists we should always bear in mind that they are first and foremost human beings, who live and work, like all other human beings, in the real world with all of its social, political and religious problems and that their lives are just as affected by those problems as everybody else.

 

 

 

 

 

 

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The emergence of modern astronomy – a complex mosaic: Part XXX

As stated earlier the predominant medieval view of the cosmos was an uneasy bundle of Aristotle’s cosmology, Ptolemaic astronomy, Aristotelian terrestrial mechanics, which was not Aristotle’s but had evolved out of it, and Aristotle’s celestial mechanics, which we will look at in a moment. As also pointed out earlier this was not a static view but one that was constantly being challenged from various other models. In the early seventeenth century the central problem was, having demolished nearly all of Aristotle’s cosmology and shown Ptolemaic astronomy to be defective, without however yet having found a totally convincing successor, to now find replacements for the terrestrial and celestial mechanics. We have looked at the development of the foundations for a new terrestrial mechanics and it is now time to turn to the problem of a new celestial mechanics. The first question we need to answer is what did Aristotle’s celestial mechanics look like and why was it no longer viable?

The homocentric astronomy in which everything in the heavens revolve around a single central point, the earth, in spheres was created by the mathematician and astronomer Eudoxus of Cnidus (c. 390–c. 337 BCE), a contemporary and student of Plato (c. 428/27–348/47 BCE), who assigned a total of twenty-seven spheres to his system. Callippus (c. 370–c. 300 BCE) a student of Eudoxus added another seven spheres. Aristotle (384–322 BCE) took this model and added another twenty-two spheres. Whereas Eudoxus and Callippus both probably viewed this model as a purely mathematical construction to help determine planetary position, Aristotle seems to have viewed it as reality. To explain the movement of the planets Aristotle thought of his system being driven by friction. The outermost sphere, that of the fixed stars drove the outer most sphere of Saturn, which in turn drove the next sphere down in the system and so on all the way down to the Moon. According to Aristotle the outermost sphere was set in motion by the unmoved mover. This last aspect was what most appealed to the churchmen of the medieval universities, who identified the unmoved mover with the Christian God.

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During the Middle Ages an aspect of vitalism was added to this model, with some believing that the planets had souls, which animated them. Another theory claimed that each planet had its own angel, who pushed it round its orbit. Not exactly my idea of heaven, pushing a planet around its orbit for all of eternity. Aristotelian cosmology said that the spheres were real and made of crystal. When, in the sixteenth century astronomers came to accept that comets were supralunar celestial phenomena, and not as Aristotle had thought sublunar meteorological ones, it effectively killed off Aristotle’s crystalline spheres, as a supralunar comet would crash right through them. If fact, the existence or non-existence of the crystalline spheres was a major cosmological debate in the sixteenth century. By the early seventeenth century almost nobody still believed in them.

An alternative theory that had its origins in the Middle Ages but, which was revived in the sixteenth century was that the heavens were fluid and the planets swam through them like a fish or flew threw them like a bird. This theory, of course, has again a strong element of vitalism. However, with the definitive collapse of the crystalline spheres it became quite popular and was subscribed to be some important and influential thinkers at the end of the sixteenth beginning of the seventeenth centuries, for example Roberto Bellarmino (1542–1621) the most important Jesuit theologian, who had lectured on astronomy at the University of Leuven in his younger days.

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Robert Bellarmine artist unknown Source: Wikimedia Commons

It should come as no surprise that the first astronomer to suggest a halfway scientific explanation for the motion of the planets was Johannes Kepler. In fact he devoted quite a lot of space to his theories in his Astronomia nova (1609).

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Astronomia Nova title page Source: Wikimedia Commons

That the periods between the equinoxes and the solstices were of unequal length had been known to astronomers since at least the time of Hipparchus in the second century BCE. This seemed to imply that the speed of either the Sun orbiting the Earth, in a geocentric model, or the Earth orbiting the Sun, in a heliocentric model, varied through out the year. Kepler calculated a table for his elliptical, heliocentric model of the distances of the Sun from the Earth and deduced from this that the Earth moved fastest when it was closest to the Sun and slowest when it was furthest away. From this he deduced or rather speculated that the Sun controlled the motion of the Earth and by analogy of all the planets. The thirty-third chapter of Astronomia nova is headed, The power that moves the planets resides in the body of the sun.

His next question is, of course, what is this power and how does it operate? He found his answer in William Gilbert’s (1544–1603) De Magnete, which had been published in 1600.

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William Gilbert Source: Wikimedia Commons

Kepler speculated that the Sun was in fact a magnet, as Gilbert had demonstrated the Earth to be, and that it rotated on its axis in the same way that Gilbert believed, falsely, that a freely suspended terrella (a globe shaped magnet) did. Gilbert had used this false belief to explain the Earth’s diurnal rotation.

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It should be pointed out that Kepler was hypothesising a diurnal rotation for the Sun in 1609 that is a couple of years before Galileo had demonstrated the Sun’s rotation in his dispute over the nature of sunspots with Christoph Scheiner (c. 1574–1650). He then argues that there is power that goes out from the rotating Sun that drives the planets around there orbits. This power diminishes with its distance from the Sun, which explains why the speed of the planetary orbits also diminishes the further the respective planets are from the Sun. In different sections of the Astronomia nova Kepler argues both for and against this power being magnetic in nature. It should also be noted that although Kepler is moving in the right direction with his convoluted and at times opaque ideas on planetary motion there is still an element of vitalism present in his thoughts.

Kepler conceived the relationship between his planetary motive force and distance as a simple inverse ratio but it inspired the idea of an inverse squared force. The French mathematician and astronomer Ismaël Boulliau (1605–1694) was a convinced Keplerian and played a central roll in spreading Kepler’s ideas throughout Europe.

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Ismaël Boulliau portrait by Pieter van Schuppen Source: Wikimedia Commons

His most important and influential work was his Astronomia philolaica (1645). In this work Boulliau hypothesised by analogy to Kepler’s own law on the propagation of light that if a force existed going out from the Sun driving the planets then it would decrease in inverse squared ratio and not a simple one as hypothesised by Kepler. Interestingly Boulliau himself did not believe that such a motive force for the planet existed.

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Another mathematician and astronomer, who looked for a scientific explanation of planetary motion was the Italian, Giovanni Alfonso Borelli (1608–1697) a student of Benedetto Castelli (1578–1643) and thus a second-generation student of Galileo.

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Giovanni Alfonso Borelli Source: Wikimedia Commons

Borelli developed a force-based theory of planetary motion in his Theoricae Mediceorum Planatarum ex Causius Physicis Deductae (Theory [of the motion] of the Medicean planets [i.e. moons of Jupiter] deduced from physical causes) published in 1666. He hypothesised three forces that acted on a planet. Firstly a natural attraction of the planet towards the sun, secondly a force emanating from the rotating Sun that swept the planet sideway and kept it in its orbit and thirdly the same force emanating from the sun pushed the planet outwards balancing the inwards attraction.

The ideas of both Kepler and Borelli laid the foundations for a celestial mechanics that would eventually in the work of Isaac Newton, who knew of both theories, produced a purely force-based mathematical explanation of planetary motion.

 

 

 

 

 

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