Having lots of letters after your name doesn’t protect you from spouting rubbish

The eloquently excellent Elegant Fowl (aka Pete Langman @elegantfowl) just drew my attention to a piece of high-grade seventeenth-century history of science rubbish on the website of my favourite newspaper The Guardian. In the books section a certain Ian Mortimer has an article entitled The 10 greatest changes of the past 1,000 years. I must to my shame admit that I’d never heard of Ian Mortimer and had no idea who he is. However I quick trip to Wikipedia informed that I have to do with Dr Ian James Forrester Mortimer (BA, PhD, DLitt, Exeter MA, UCL) and author of an impressive list of books and that the article on the Guardian website is a promotion exercise for his latest tome Centuries of Change. Apparent collecting lots of letter after your name and being a hyper prolific scribbler doesn’t prevent you from spouting rubbish when it comes writing about the history of science. Shall we take a peek at what the highly eminent Mr Mortimer has to say about the seventeenth-century that attracted the attention of the Elegant Fowl and have now provoked the ire of the Renaissance Mathematicus.

17th century: The scientific revolution

One thing that few people fully appreciate about the witchcraft craze that swept Europe in the late 16th and early 17th centuries is that it was not just a superstition. If someone you did not like died, and you were accused of their murder by witchcraft, it would have been of no use claiming that witchcraft does not exist, or that you did not believe in it. Witchcraft was recognised as existing in law – and to a greater or lesser extent, so were many superstitions. The 17th century saw many of these replaced by scientific theories. The old idea that the sun revolved around the Earth was finally disproved by Galileo. People facing life-threatening illnesses, who in 1600 had simply prayed to God for health, now chose to see a doctor. But the most important thing is that there was a widespread confidence in science. Only a handful of people could possibly have understood books such as Isaac Newton’s Philosophiae Naturalis Principia Mathematica, when it was published in 1687. But by 1700 people had a confidence that the foremost scientists did understand the world, even if they themselves did not, and that it was unnecessary to resort to superstitions to explain seemingly mysterious things.

Regular readers of this blog will be aware that I’m a gradualist and don’t actually believe in the scientific revolution but for the purposes of this post we will just assume that there was a scientific revolution and that it did take place in the seventeenth century, although most of those who do believe in it think it started in the middle of the sixteenth-century.

I find it mildly bizarre to devote nearly half of this paragraph to a rather primitive description of the witchcraft craze and to suggest that the scientific revolution did away with belief in witchcraft, given that several prominent propagators of the new science wrote extensively defending the existence of witches. I recommend Joseph Glanvill’s Saducismus triumphatus (1681) and Philosophical Considerations Touching the Being of Witches and Witchcraft (1666). Apart from witchcraft I can’t think of any superstition that was replaced by a scientific theory in the seventeenth-century. However it is the next brief sentence that cries out for my attention.

The old idea that the sun revolved around the Earth was finally disproved by Galileo.

By a strange coincidence I spent yesterday evening listening to a lecture by one of Germany’s leading historians of astronomy, Dr Jürgen Hamel (who has written almost as many books as Ian Mortimer) on why it was perfectly reasonable to reject the heliocentric theory of Copernicus in the first hundred years or more after it was published. He of course also explained that Galileo did not succeed in either disproving geocentricity or proving heliocentricity. Now anybody who has regularly visited this blog will know that I have already written quite a lot on this topic and I don’t intend to repeat myself here but I recommend my on going series on the transition to heliocentricity (the next instalment is in the pipeline) in particular the post on the Sidereus Nuncius and the one on the Phases of Venus. Put very, very simply for those who have not been listening: GALILEO DID NOT DISPROVE THE OLD IDEA THAT THE SUN REVOLVED AROUND THE EARTH. I apologise for shouting but sometimes I just can’t help myself.

Quite frankly I find the next sentence totally mindboggling:

People facing life-threatening illnesses, who in 1600 had simply prayed to God for health, now chose to see a doctor.

Even more baffling, it appears that Ian Mortimer has written prize-winning essay defending this thesis, “The Triumph of the Doctors” was awarded the 2004 Alexander Prize by the Royal Historical Society. In this essay he demonstrated that ill and injured people close to death shifted their hopes of physical salvation from an exclusively religious source of healing power (God, or Christ) to a predominantly human one (physicians and surgeons) over the period 1615–70, and argued that this shift of outlook was among the most profound changes western society has ever experienced. (Wikipedia) I haven’t read this masterpiece but colour me extremely sceptical.

We close out with a generalisation that simply doesn’t hold water:

[…] by 1700 people had a confidence that the foremost scientists did understand the world, even if they themselves did not, and that it was unnecessary to resort to superstitions to explain seemingly mysterious things.

They did? I really don’t think so. By 1700 hundred the number of people who had “confidence that the foremost scientists did understand the world” was with certainty so minimal that one would have a great deal of difficulty expressing it as a percentage.

Mortimer’s handful of sentences on the 17th century and the scientific revolution has to be amongst the worst paragraphs on the evolution of science in this period that I have ever read.


Filed under History of Astronomy, History of medicine, History of science, Myths of Science

Copernicus and the calendar

A recent blog post on Yovisto repeats a very widespread myth concerning Copernicus, his De revolutionibus and the calendar reform of 1582. This particular myth is so prevalent that I have no illusions about stamping it out but as a bone fide history of science myth buster I thought I could at least put the record straight in my little corner of the Internet.

Astronomers and mathematicians had been aware that all was not well with the Julian calendar since at least the time of the Venerable Bead Bede in the ninth-century eight-century CE. The average length of the solar year produced by this calendar, with a leap year every four years, was about eleven minutes too long producing a slippage of the calendar against the natural year of one day every one hundred and twenty-eight years. This might not seem like an awful lot but over the centuries it accumulates. As the Gregorian calendar reform was introduced in 1582 the calendar had already slipped ten days against the natural solar year since the fourth-century CE. The Catholic Church was particularly concerned about this slippage because of their desire to celebrate Easter on the appointed day, a moving date dependent on the vernal equinox and the phases of the moon.

Over the centuries the Church made various attempts to start the process of investigating the cause of this slippage and finding a lasting solution but none of them came to fruition. It’s worth pausing to ask why? The answer is to be found in the very strange power structure of the Catholic Church. The papacy is an elected absolute monarchy. This bizarre and probably unique structure means that there is little or no continuity in new policies from one papacy to the next. If one pope sets about wanting to reform the calendar and then dies his successor doesn’t automatically carry on where he left off but everything goes back to zero, with calendar reform somewhere down the to-do list. This factor combined with the fact that most popes only get elected when fairly old, and thus are not very long in office, meant that the many attempts to reform the calendar set in motion over the centuries all stalled before they could make any real headway. Things changed, however in the sixteenth century.

During the Fifth Lateran Council Pope Leo X invited Paul of Middelburg, Bishop of Fossombrone, an astronomer and avid advocate of calendar reform, to advise him on the possibilities of bring the calendar into line with the natural solar year. Paul had already been considering the problem for a couple of decades and in 1514 he persuaded the Pope to send out letters to all the European monarchs requesting them to consult their astronomers on the subject. Enter Nicolaus Copernicus Warmienis. We know that Copernicus was one of the astronomers consulted because Paul tells us so, unfortunately we don’t know the exact nature of his reply because it no longer exists. However the topic does get mentioned by Copernicus himself in De revolutionibus, published, effectively posthumously, in 1543. He writes:

For not so long ago under Leo X the Lateran Council considered the problem of reforming the ecclesiastical calendar. The issue remained undecided then only because the lengths of the year and month and the motions of the sun and moon were regarded as not yet adequately measured. From that time on, at the suggestion of that most distinguished man, Paul, bishop of Fossombrone, who was then in charge of the matter, I have directed my attention to a more precise study of these topics.

Copernicus’ involvement tells us that he was already considered to be an astronomical authority in 1514. His claim, made here, for the failure of this particular calendar reform is, however, not historically accurate. In reality Leo X became involved in an altercation with the French who invaded Italy in 1515 and calendar reform got put onto the back burner once again. Of historical interest is Galileo’s totally erroneous claim that Copernicus actually took part in the calendar reform deliberations at the Lateran Council, he didn’t. This is by no means the only spurious claim made by Galileo concerning Copernicus.

This time however Gregory XIII, who became Pope in 1572, took up the reform where it had been broken off and lived long enough to see it through to its conclusion in 1582. I don’t intend to go into all the gory details in this post, but only to address the question of Copernicus’ supposed involvement in this successful reform of the calendar. As stated at the beginning of this post, Yovisto repeated a common myth about this supposed involvement. In quoting it here I have no desire to put the good folks at Yovisto in the stocks, as one can find this claim made in numerous places including in several Wikipedia articles. They write:

Both Reinhold’s Prutenic Tables and Copernicus’ studies were the foundation for the Calendar Reform by Pope Gregory XIII in 1582.

Here Yovisto exaggerates a little, as the usual claim is that Copernicus’ determination of the length of the tropical year, as addressed by him in the passage quoted above, was used in the new improved Gregorian calendar. This claim is bogus.

Luigi LIlio  artist unknown

Luigi LIlio
artist unknown

The mathematical model on which the Gregorian calendar reform was based was produced by the Italian physician and astronomer, Luigi Lilio, who very definitely used the length of the tropical year, as determined by the Alfonsine Tables and neither Copernicus’ from De revolutionibus nor Reinhold’s from the Prutenic Tables, they differ. The historical confusion exists because in his writings, after the event, to justify and defend the new calendar against its critics, Christoph Clavius does in fact discuss Copernicus determinations of the length of the tropical year showing it to be in agreement with the figure used in the calendar reform. If the three sources under discussion all have differing lengths for the tropical year, and they do, and if Lilio used the Alfonsine length, which he did, how then can Copernicus’ figure be in agreement? If you convert the three differing lengths into days expressed in sexagesimal fractions (that’s base sixty!), as was general astronomical practice at the time, they all begin 356; 14, 33 differing only the third sexagesimal fraction. All three sources therefore agree if rounded off to 365; 14, 33 days as was done for the Gregorian calendar.


This might seem like a trivial point, and in some senses it is, but the supposed superiority of Copernicus’ determination of the length of tropical solar year, shown by its use in the epoch defining Gregorian calendar reform, is quoted as a historical proof of the general superiority of Copernicus’ work and used as an argument against those, ignoramuses, who were too blind to recognise that superiority and immediately adopt his system.


Filed under History of Astronomy, Renaissance Science

Little things matter – for want of a semicolon.

The Prof is back. A couple of years back Professor Christopher M. Graney, known to his friends as Chris, wrote a highly informative guest post for The Renaissance Mathematicus defending the honour of Tyco Brahe against his ignorant modern critics. In the mean time The Renaissance Mathematics was able to lure him into coming all the way to Middle Franconia, from the depths of Kentucky, to entertain the locals with a couple of lectures on Early Modern telescope images, Airy discs and how this all applies to Galileo Galilei’s and Simon Marius’ interpretations of the stars that they saw through their telescopes in 1609-10, stirring stuff I can tell you. You can read all about it in his forthcoming book, Setting Aside All Authority: Giovanni Battista Riccioli and the Science against Copernicus in the Age of Galileo (forthcoming March 2015). While he was here he made some videos of The Renaissance Mathematicus waving his arms about and scratching his fleas that you can view on Youtube, if that sort of thing turns you on. In exchange for this act of personal humiliation The Renaissance Mathematics demanded that he provide the readers of this blog with a new guest post and here it is. This time The Prof explains why it is important when during historical research to actually look at the original documents and not to rely on secondary sources. 


You have probably heard the expression “Don’t sweat the small stuff.” Sometimes the small stuff matters. Consider one of the more infamous statements from the history of science: the one, made on 24 February 1616 by a team of consultants for the Roman Inquisition, which declared the Copernican theory to be —


foolish and absurd in philosophy and formally heretical, because it expressly contradicts the doctrine of the Holy Scripture in many passages


— unless, that is, it was —


philosophically and scientifically untenable; and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture.


The first quote is from the noted scholar Albert Van Helden in the book Planetary Astronomy from the Renaissance to the Rise of Astrophysics, published by Cambridge University Press in 1989. That is certainly a first-rate source. The second is, more or less, from Maurice Finocchiaro, another very accomplished scholar, in his book The Galileo Affair: A Documentary History, published by the University of California Press, also in 1989. It is also a first-rate source.


I say, “more or less,” because Finocchiaro actually gives the translation as —


foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture.


But elsewhere in the book he substitutes “philosophically and scientifically untenable” for “foolish and absurd in philosophy” — “philosophy” in the seventeenth century included that which we would call “science” today. And still elsewhere he notes that the original document in the Vatican, in Latin, has a semicolon after the word “philosophia.”


Is Finocchiaro correct? After all, Van Helden’s translation conveys the impression that biblical contradiction is being given as a reason for ascribing both philosophical-scientific falsehood and theological heresy. But Finocchiaro’s translation conveys a different impression: that biblical contradiction is being given as a reason for ascribing theological heresy to a philosophically-scientifically false theory (I’m borrowing Finocchiaro’s phrasing here). I would say Van Helden’s translation, not Finocchiaro’s, is what people usually think of when they think of the infamous condemnation. But Finocchiaro’s made sense to me, based on my reading of anti-Copernican writers from that time.


I wanted to know if Finocchiaro is correct. But looking at sources that give the “original Latin” provided no answers. A review of different sources revealed a remarkable variety of punctuations. A few nineteenth-century sources show Finocchiaro’s semicolon after “philosophia.” One of these is Galileo Galilei und die romische Curie by Karl von Gebler, published in Stuttgart in 1877. Yet Galileo Galilei and the Roman Curia, by Karl von Gebler, published in London in 1879, shows no semicolon. Two editions of I documenti del processo di Galileo Galilei, edited by S. M. Pagano and published in Vatican City in 1984 and 2009, both disagree with Finocchiaro. That might seem to settle the matter — Finocchiaro must be wrong, since the Vatican would know what its documents say — except that the two editions also disagree with each other. The 1984 edition has no punctuation after “philosophia” (note Van Helden’s translation); the 2009 edition has a comma.


I contacted Finocchiaro. Was he certain about the semicolon? Yes — he had seen it himself. Did he have a copy of the original 1616 document? No.


I could find no published image of the original. That left one option: get a copy from the Vatican. How does one get a copy of an important historical document stored in the Vatican Secret Archives? Send the VSA an e-mail. For less than the cost of a cheap pizza, I had a super-high-resolution image of the infamous 24 February 1616 document condemning the Copernican system.


High-resolution images of this document are available here, on page 17-19.

And yes, Finocchiaro is correct! But follow the link above to the high-resolution image, and you will find that it is understandable that the semicolon could be overlooked when casually studying the document. I had expected the document to be a bumptious masterpiece of calligraphy, with an imposing appearance of formality suitable for an Important Proclamation. In fact, it appears much like hastily scrawled meeting minutes. The writer of the document often dots his “i” letters well to the right of the letters themselves. When these fall over commas, they give the appearance of semicolons where none exist. Furthermore, the real semicolon after “philosophia” has a very elongated dot. But, study the chicken-scratch handwriting more closely, and it is clear that “philosophia” is followed by a real semicolon.

If you think it not so clear, there is a second reason to be sure that the “philosophia” semicolon is indeed a semicolon. Here is the original Latin, taken from the document, with my translation (I kept as close as possible to the original):

Sol est centrum mundi, et omnino immobilis motu locali. The sun is the center of the world, and entirely immobile insofar as location movement [i.e. movement from place to place; no comment here on rotation movement].
Censura: Omnes dixerunt dictam propositionem esse stultam et absurdam in Philosophia; et formaliter haereticam, quatenus contradicit expresse sententiis sacrae scripturae in multis locis, secundum proprietatem verborum, et secundum communem expositionem, et sensum, Sanctorum Patrum et Theologorum doctorum. Appraisal: All have said the stated proposition to be foolish and absurd in Philosophy; and formally heretical, since it expressly contradicts the sense of sacred scripture in many places, according to the quality of the words, and according to the common exposition, and understanding, of the Holy Fathers and the learned Theologians.
Terra non est centrum mundi, nec immobilis, sed secundum se Totam, movetur, etiam motu diurno. The earth is not the center of the world, and not immobile, but is moved along Whole itself, and also by diurnal motion.
Censura: Omnes dixerunt, hanc propositionem recipere eandem censuram in Philosophia; et spectando veritatem Theologicam, adminus esse in fide erroneam. Appraisal: All have said, this proposition to receive the same appraisal in Philosophy; and regarding Theological truth, at least to be erroneous in faith.

Note the parallel structure used here. There is a statement, and then an assessment of the statement; a second statement, and then an assessment of that statement. Each assessment first has a comment regarding philosophy, and then a comment regarding religion. The second assessment statement clearly has a semicolon after “philosophia” and before “et spectando” (plenty of secondary sources show this second semicolon). Parallel structure suggests that there should also be a semicolon in the first assessment statement, after “philosophia” and before “et formaliter.”

Now, two questions.

The first question is why secondary sources have almost always gotten the punctuation wrong. I will provide a speculative answer to this.

The consultants’ statement was issued as the Inquisition investigated a complaint filed against Galileo in 1615. Galileo had been exonerated, but the Inquisition decided to consult its experts for an opinion on the status of Copernicanism. Despite the consultants’ statement, the Inquisition issued no formal condemnation of the Copernican system. (However, the Congregation of the Index, the arm of the Vatican in charge of book censorship, issued a decree on 5 March 1616 declaring the Copernican system to be “false” and “altogether contrary to the Holy Scripture,” and censoring books that presented the Copernican system as being more than a hypothesis.) The consultants’ statement was filed away in the Inquisition archives. Two decades later, a paraphrase of the statement was made public. This was because, following the trial of Galileo, copies of the 22 June 1633 sentence against him were sent to papal nuncios and to inquisitors around Europe. The sentence, which was written in Italian rather than Latin, noted the opinion of the consultant team and included a paraphrase of their statement from 1616. Still later, Giovanni Battista Riccioli included in his 1651 Almagestum Novum a Latin translation of Galileo’s sentence. Riccioli’s translation was widely referenced for centuries, and it reads as though biblical contradiction is the reason for ascribing both philosophical-scientific falsehood and theological heresy. But it was a Latin translation of an Italian paraphrase of a Latin original. Translations into modern languages of Riccioli’s Latin version simply added a fourth layer of translation.

The original statement itself was not published until the middle of the nineteenth century. Now to speculate: I imagine that at that time scholars were both used to the Riccioli version and sure that science was firmly on the side of Copernicus. The original statement, with its semicolon, assesses first that the proposition is philosophically-scientifically untenable, and then that it is formally heretical since it contradicts Scripture. Indeed, I have found that in Latin from this time semicolons are often used much as we use periods, so it would not be completely out of line to render the consultants’ statement as —

[The Copernican theory is] philosophically and scientifically untenable. It is also formally heretical since it explicitly contradicts in many places the sense of Holy Scripture.

This makes little sense under the assumption that the Copernican system had the weight of scientific evidence behind it. I imagine this to be the reason why the statement has consistently been presented with altered punctuation — so that it reads in a manner that conforms to what modern readers believe to have been the case. If we know science was on the side of Copernicus, then the consultants must be saying that Copernicanism is untenable because it contradicts scripture. The chicken-scratch handwriting makes it easy to overlook the semicolon.

Today it is clear that in February 1616 science was not so firmly on the side of Copernicus. As Dennis Danielson and I discussed in the January issue of Scientific American (the article is available in French in Pour la Science and in German in Spektrum der Wissenschaft), and as I have written in a previous guest blog for the Renaissance Mathematicus, Tycho Brahe had formulated a potent anti-Copernican scientific argument. The argument was based on the fact that the Copernican theory seemed to imply that every star in a heliocentric universe, even the smallest, would be vastly larger than the sun. By contrast, Tycho found that in a geocentric universe the stars would have sizes consistent with the sun and larger planets. Moreover, Copernicans responded to this argument by appealing to God’s Power, saying that an infinite Creator could make giant stars. Tycho had said in print that all this was “absurd.” Indeed, most scientists today would probably classify as absurd a theory that creates a new class of giant bodies, and chalks them up to the power of God. This star size problem was definitely “in play” immediately prior to the 1616 condemnation. Simon Marius mentions it in his 1614 Mundus Jovialis. Georg Locher cites it as one of the main reasons to reject Copernicanism in his 1614 Disquisitiones Mathematicae. And Monsignor Francesco Ingoli brings it up in an essay he wrote to Galileo just prior to the condemnation (Galileo believed Ingoli to be influential in the rejection of the Copernican theory). No, these writers did not reject telescopic discoveries. They simply endorsed the Tychonic geocentric theory, which was compatible with those discoveries. Marius, for example, cites telescopic observations of the sizes of stars as supporting a Tychonic universe. Locher illustrates telescopic discoveries like the Jovian system and the phases of Venus, and endorses the Tychonic theory.

In light of this, the statement that the Copernican theory was “foolish and absurd in philosophy” (“philosophically and scientifically untenable”) makes a little more sense on its own. It essentially echoes Tycho Brahe, the most prominent astronomer of that time.

The second question is why, even granted all this, anyone should really care about a semicolon. Yes, readers of the Renaissance Mathematicus care because they love history of astronomy. Why should anyone else care? This is an important question. Indeed, in September I was in Germany, talking quite a bit with the Mathematicus, and in one conversation he mentioned how academic historians of science that he knows are facing real pressure at their institutions to justify their existence. Because, well, why should anyone care?

Here is the answer to that: In the United States, at least, science is increasingly burdened by the problem of “science deniers.” This was brought home to me yet again this semester. I was giving my students an assignment to make a video illustrating the phases of the moon and Venus by means of a ball and a light source. I went to YouTube to find an example of such a video, and quickly discovered that a “Bill Nye the Science Guy” video on moon phases will be accompanied by several links to videos demanding that NASA reveal the “truth” about the Apollo landings, as seen in this example:


No wonder so many of my students and so many of our visitors at my college’s observatory ask about whether the Apollo landings actually took place!

Whether they be the “Apollo deniers” I found on YouTube, or “9-11 Truthers,” or “vaccine deniers,” or those who assert science to support the universe being 6000 years old, all such deniers build their claims on the premise that in science, powerful forces conspire to cover up scientific truths. Science deniers see themselves as brave Copernicans, standing against the power of an Inquisition that is determined to hide scientific truth because it contradicts some Holy Writ.

The story of the Inquisition’s semicolon undermines an important narrative for science denial — the narrative that, at the beginning of the history of modern science, powerful forces indeed did conspire to suppress a scientific idea, declaring it to be “foolish and absurd” only because it was religiously inconvenient. Thus the semicolon story should undermine the entire idea of conspiracy and cover-up that is behind the science denial phenomenon. That’s a reason to care, a reason why we need good history of science, and a reason why some times we need to sweat the small stuff.

For a more academic treatment of this subject, with full references, images of different secondary sources and their different punctuations, etc., see “The Inquisition’s Semicolon: Punctuation, Translation, and Science in the 1616 Condemnation of the Copernican System.” An article on this work is also available on EsMateria.com.


Filed under History of Astronomy, Myths of Science, Renaissance Science

The Queen of Science – The woman who tamed Laplace.

In a footnote to my recent post on the mythologizing of Ibn al-Haytham I briefly noted the inadequacy of the terms Arabic science and Islamic science, pointing out that there were scholars included in these categories who were not Muslims and ones who were not Arabic. In the comments Renaissance Mathematicus friend, the blogger theofloinn, asked, Who were the non-muslim “muslim” scientists? And (aside from Persians) who were the non-Arab “arab” scientists? And then in a follow up comment wrote, I knew about Hunayn ibn Ishaq and the House of Wisdom, but I was not thinking of translation as “doing science.” From the standpoint of the historian of science this second comment is very interesting and reflects a common problem in the historiography of science. On the whole most people regard science as being that which scientists do and when describing its history they tend to concentrate on the big name scientists.

This attitude is a highly mistaken one that creates a falsified picture of scientific endeavour. Science is a collective enterprise in which the ‘scientists’ are only one part of a collective consisting of scientists, technicians, instrument designers and makers, and other supportive workers without whom the scientist could not carry out his or her work. This often includes such ignored people as the secretaries, or in earlier times amanuenses, who wrote up the scientific reports or life partners who, invisible in the background, often carried out much of the drudgery of scientific investigation. My favourite example being William Herschel’s sister and housekeeper, Caroline (a successful astronomer in her own right), who sieved the horse manure on which he bedded his self cast telescope mirrors to polish them.

Translators very definitely belong to the long list of so-called helpers without whom the scientific endeavour would grind to a halt. It was translators who made the Babylonian astronomy and astrology accessible to their Greek heirs thus making possible the work of Eudoxus, Hipparchus, Ptolemaeus and many others. It was translators who set the ball rolling for those Islamic, or if you prefer Arabic, scholars when they translated the treasures of Greek science into Arabic. It was again translators who kicked off the various scientific Renaissances in the twelfth and thirteenth-centuries and again in the fifteenth-century, thereby making the so-called European scientific revolution possible. All of these translators were also more or less scientists in their own right as without a working knowledge of the subject matter that they were translating they would not have been able to render the texts from one language into another. In fact there are many instances in the history of the transmission of scientific knowledge where an inadequate knowledge of the subject at hand led to an inaccurate or even false translation causing major problems for the scholars who tried to understand the texts in the new language. Translators have always been and continue to be an important part of the scientific endeavour.

The two most important works on celestial mechanics produced in Europe in the long eighteenth-century were Isaac Newton’s Philosophiæ Naturalis Principia Mathematica and Pierre-Simon, marquis de Laplace’s Mécanique céleste. The former was originally published in Latin, with an English translation being published shortly after the author’s death, and the latter in French. This meant that these works were only accessible to those who mastered the respective language. It is a fascinating quirk of history that the former was rendered into French and that latter into English in each case by a women; Gabrielle-Émilie Le Tonnelier de Breteuil, Marquise du Châtelet translated Newton’s masterpiece into French and Mary Somerville translated Laplace’s pièce de résistance into English. I have blogged about Émilie de Châtelet before but who was Mary Somerville? (1)


Mary Somerville by Thomas Phillips

Mary Somerville by Thomas Phillips

She was born Mary Fairfax, the daughter of William Fairfax, a naval officer, and Mary Charters at Jedburgh in the Scottish boarders on 26 December 1780. Her parents very definitely didn’t believe in education for women and she spent her childhood wandering through the Scottish countryside developing a lifelong love of nature. At the age of ten, still semi-illiterate, she was sent to Miss Primrose’s boarding school at Musselburgh in Midlothian for one year; the only formal schooling she would ever receive. As a young lady she received lessons in dancing, music, painting and cookery. At the age of fifteen she came across a mathematical puzzle in a ladies magazine (mathematical recreation columns were quite common in ladies magazines in the 18th and 19th-centuries!) whilst visiting friends. Fascinated by the symbols that she didn’t understand, she was informed that it was algebra, a word that meant nothing to her. Later her painting teacher revealed that she could learn geometry from Euclid’s Elements whilst discussing the topic of perspective. With the assistance of her brother’s tutor, young ladies could not buy maths-books, she acquired a copy of the Euclid as well as one of Bonnycastle’s Algebra and began to teach herself mathematics in the secrecy of her bedroom. When her parents discovered this they were mortified her father saying to her mother, “Peg, we must put a stop to this, or we shall have Mary in a strait jacket one of these days. There is X., who went raving mad about the longitude.” They forbid her studies, but she persisted rising before at dawn to study until breakfast time. Her mother eventually allowed her to take some lessons on the terrestrial and celestial globes with the village schoolmaster.

In 1804 she was married off to a distant cousin, Samuel Grieg, like her father a naval officer but in the Russian Navy. He, like her parents, disapproved of her mathematical studies and she seemed condemned to the life of wife and mother. She bore two sons in her first marriage, David who died in infancy and Woronzow, who would later write a biography of Ada Lovelace. One could say fortunately, for the young Mary, her husband died after only three years of marriage in 1807 leaving her well enough off that she could now devote herself to her studies, which she duly did. Under the tutorship of John Wallace, later professor of mathematics in Edinburgh, she started on a course of mathematical study, of mostly French books but covering a wide range of mathematical topic, even tacking Newton’s Principia, which she found very difficult. She was by now already twenty-eight years old. During the next years she became a fixture in the highest intellectual circles of Edinburgh.

In 1812 she married for a second time, another cousin, William Somerville and thus acquired the name under which she would become famous throughout Europe. Unlike her parents and Samuel Grieg, William vigorously encouraged and supported her scientific interests. In 1816 the family moved to London. Due to her Scottish connections Mary soon became a member of the London intellectual scene and was on friendly terms with such luminaries as Thomas Young, Charles Babbage, John Herschel and many, many others; all of whom treated Mary as an equal in their wide ranging scientific discussions. In 1817 the Somervilles went to Paris where Mary became acquainted with the cream of the French scientists, including Biot, Arago, Cuvier, Guy-Lussac, Laplace, Poisson and many more.

In 1824 William was appointed Physician to Chelsea Hospital where Mary began a series of scientific experiments on light and magnetism, which resulted in a first scientific paper published in the Philosophical Transactions of the Royal Society in 1826. In 1836, a second piece of Mary’s original research was presented to the Académie des Sciences by Arago. The third and last of her own researches appeared in the Philosophical Transactions in 1845. However it was not as a researcher that Mary Somerville made her mark but as a translator and populariser.

In 1827 Henry Lord Brougham and Vaux requested Mary to translate Laplace’s Mécanique céleste into English for the Society for the Diffusion of Useful Knowledge. Initially hesitant she finally agreed but only on the condition that the project remained secret and it would only be published if judged fit for purpose, otherwise the manuscript should be burnt. She had met Laplace in 1817 and had maintained a scientific correspondence with him until his death in 1827. The translation took four years and was published as The Mechanism of the Heavens, with a dedication to Lord Brougham, in 1831. The manuscript had been refereed by John Herschel, Britain’s leading astronomer and a brilliant mathematician, who was thoroughly cognisant with the original, he found the translation much, much more than fit for the purpose. Laplace’s original text was written in a style that made it inaccessible for all but the best mathematicians, Mary Somerville did not just translate the text but made it accessible for all with a modicum of mathematics, simplifying and elucidating as she went. This wasn’t just a translation but a masterpiece. The text proved too vast for Brougham’s Library of Useful Knowledge but on the recommendation of Herschel, the publisher John Murray published the book at his own cost and risk promising the author two thirds of the profits. The book was a smash hit the first edition of 750 selling out almost instantly following glowing reviews by Herschel and others. In honour of the success the Royal Society commissioned a bust of Mrs Somerville to be placed in their Great Hall, she couldn’t of course become a member!

At the age of fifty-one Mary Somerville’s career as a science writer had started with a bang. Her Laplace translation was used as a textbook in English schools and universities for many years and went through many editions. Her elucidatory preface was extracted and published separately and also became a best seller. If she had never written another word she would still be hailed as a great translator and science writer but she didn’t stop here. Over the next forty years Mary Somerville wrote three major works of semi-popular science On the Connection of the Physical Sciences (1st ed. 1834), Physical Geography (1st ed. 1848), (she was now sixty-eight years old!) and at the age of seventy-nine, On Molecular and Microscopic Science (1st ed. 1859). The first two were major successes, which went through many editions each one extended, brought up to date, and improved. The third, which she later regretted having published, wasn’t as successful as her other books. Famously, in the history of science, William Whewell in his anonymous 1834 review of On the Connection of the Physical Sciences first used the term scientist, which he had coined a year earlier, in print but not, as is oft erroneously claimed, in reference to Mary Somerville.

Following the publication of On the Connection of the Physical Sciences Mary Somerville was awarded a state pension of £200 per annum, which was later raised to £300. Together with Caroline Herschel, Mary Somerville became the first female honorary member of the Royal Astronomical Society just one of many memberships and honorary memberships of learned societies throughout Europe and America. Somerville College Oxford, founded seven years after her death, was also named in her honour. She died on 28 November 1872, at the age of ninety-one, the obituary which appeared in the Morning Post on 2 December said, “Whatever difficulty we might experience in the middle of the nineteenth century in choosing a king of science, there could be no question whatever as to the queen of science.” The Times of the same date, “spoke of the high regard in which her services to science were held both by men of science and by the nation”.

As this is my contribution to Ada Lovelace day celebrating the role of women in the history of science, medicine, engineering, mathematics and technology I will close by mentioning the role that Mary Somerville played in the life of Ada. A friend of Ada’s mother, the older women became a scientific mentor and occasional mathematics tutor to the young Miss Byron. As her various attempts to make something of herself in science or mathematics all came to nought Ada decided to take a leaf out of her mentor’s book and to turn to scientific translating. At the suggestion of Charles Wheatstone she chose to translate Luigi Menabrea’s essay on Babbage’s Analytical Engine, at Babbage’s suggestion elucidating the original text as her mentor had elucidated Laplace and the rest is, as they say, history. I personally would wish that the founders of Ada Lovelace Day had chosen Mary Somerville instead, as their galleon figure, as she contributed much, much more to the history of science than her feted protégée.

(1) What follows is largely a very condensed version of Elizabeth  C. Patterson’s excellent Somerville biography Mary Somerville, The British Journal for the History of Science, Vol. 4, 1969, pp. 311-339



Filed under History of Astronomy, History of Mathematics, History of Physics, History of science, Ladies of Science

Polluting Youtube once again!

Professor Christopher M Graney, Renaissance Mathematicus friend and guest blogger, has posted another of his holiday videos on Youtube, documenting parts of his visit to Nürnberg and Bamberg for the Astronomy in Franconia Conferences. In his new video “Nürnberg and Bamberg” you can see the Behaim Globe (Martin Behaim celebrates his 555th birthday today!), the Frauenkirche Clock (1509) doing its thing, and yours truly wittering on about Johannes Petreius and Copernicus’ De revolutionibus (4.11–6.56)

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Filed under Early Scientific Publishing, History of Astronomy, History of science, Renaissance Science

The unfortunate backlash in the historiography of Islamic science

Anybody with a basic knowledge of the history of Western science will know that there is a standard narrative of its development that goes something like this. Its roots are firmly planted in the cultures of ancient Egypt and Babylon and it bloomed for the first time in ancient Greece, reaching a peak in the work of Ptolemaeus in astronomy and Galen in medicine in the second-century CE. It then goes into decline along with the Roman Empire effectively disappearing from Europe by the fifth-century CE. It began to re-emerge in the Islamic Empire[1] in the eight-century CE from whence it was brought back into Europe beginning in the twelfth-century CE. In Europe it began to bloom again in the Renaissance transforming into modern science in the so-called Scientific Revolution in the seventeenth-century. There is much that is questionable in this broad narrative but that is not the subject of this post.

In earlier versions of this narrative, its European propagators claimed that the Islamic scholars who appropriated Greek knowledge in the eighth-century and then passed it back to their European successors, beginning in the twelfth-century, only conserved that knowledge, effectively doing nothing with it and not increasing it. For these narrators their heroes of science were either ancient Greeks or Early Modern Europeans; Islamic scholars definitely did not belong to the pantheon. However, a later generation of historians of science began to research the work of those Islamic scholars, reading, transcribing, translating and analysing their work and showing that they had in fact made substantial contributions to many areas of science and mathematics, contributions that had flowed into modern European science along with the earlier Greek, Babylonian and Egyptian contributions. Also Islamic scholars such as al-Biruni, al-Kindi, al-Haytham, Ibn Sina, al-Khwarizmi and many others were on a level with such heroes of science as Archimedes, Ptolemaeus, Galen or Kepler, Galileo and Newton. Although this work redressed the balance there is still much work to be done on the breadth and deep of Islamic science.

Unfortunately the hagiographic, amateur, wannabe pop historians of science now entered the field keen to atone for the sins of the earlier Eurocentric historical narrative and began to exaggerate the achievements of the Islamic scholars to show how superior they were to the puny Europeans who stole their ideas, like the colonial bullies who stole their lands. There came into being a type of hagiographical popular history of Islamic science that owes more to the Thousand and One Nights than it does to any form of serious historical scholarship. I came across an example of this last week during the Gravity Fields Festival, an annual shindig put on in Grantham to celebrate the life and work of one Isaac Newton, late of that parish.

On Twitter Ammār ibn Aziz Ahmed (@Ammar_Ibn_AA) tweeted the following:

I’m sorry to let you know that Isaac Newton learned about gravity from the books of Ibn al-Haytham

I naturally responded in my usual graceless style that this statement was total rubbish to which Ammār ibn Aziz Ahmed responded with a link to his ‘source

I answered this time somewhat more moderately that a very large part of that article is quite simply wrong. One of my Internet friends, a maths librarian (@MathsBooks) told me I was being unfair and that I should explain what was wrong with his source, so here I am.

The article in question is one of many potted biographies of al-Haytham that you can find dotted all other the Internet and which are mostly virtual clones of each other. They all contain the same collection of legends, half-truths, myths and straightforward lies usually without sources, or, as in this case, quoting bad popular books written by a non-historian as their source. It is fairly obvious that they all plagiarise each other without bothering to consult original sources or the work done by real historian of science on the life and work of al-Haytham.

The biography of al-Haytham is, like that of most medieval Islamic scholars, badly documented and very patchy at best. Like most popular accounts this article starts with the legend of al-Haytham’s feigned madness and ten-year incarceration. This legend is not mentioned in all the biographical sources and should be viewed with extreme scepticism by anybody seriously interested in the man and his work. The article then moves on to the most pernicious modern myth concerning al-Haytham that he was the ‘first real scientist’.

This claim is based on a misrepresentation of what al-Haytham did. He did not as the article claims introduce the scientific method, whatever that might be. For a limited part of his work al-Haytham used experiments to prove points, for the majority of it he reasoned in exactly the same way as the Greek philosophers whose heir he was. Even where he used the experimental method he was doing nothing that could not be found in the work of Archimedes or Ptolemaeus. There is also an interesting discussion outlined in Peter Dear’s Discipline and Experience (1995) as to whether al-Haytham used or understood experiments in the same ways as researchers in the seventeenth-century; Dear concludes that he doesn’t. (pp. 51-53) It is, however, interesting to sketch how this ‘misunderstanding’ came about.

The original narrative of the development of Western science not only denied the contribution of the Islamic Empire but also claimed that the Middle Ages totally rejected science, modern science only emerging after the Renaissance had reclaimed the Greek scientific inheritance. The nineteenth-century French physicist and historian of science, Pierre Duhem, was the first to challenge this fairy tale claiming instead, based on his own researches, that the Scientific Revolution didn’t take place in the seventeenth–century but in the High Middle Ages, “the mechanics and physics of which modern times are justifiably proud to proceed, by an uninterrupted series of scarcely perceptible improvements, from doctrines professed in the heart of the medieval schools.” After the Second World War Duhem’s thesis was modernised by the Australian historian of science, Alistair C. Crombie, whose studies on medieval science in general and Robert Grosseteste in particular set a new high water mark in the history of science. Crombie attributed the origins of modern science and the scientific method to Grosseteste and Roger Bacon in the twelfth and thirteenth-centuries. A view that has been somewhat modified and watered down by more recent historians, such as David Lindberg. Enter Matthias Schramm.

Matthias Schramm was a German historian of science who wrote his doctoral thesis on al-Haytham. A fan of Crombie’s work Schramm argued that the principle scientific work of Grosseteste and Bacon in physical optics was based on the work of al-Haytham, correct for Bacon not so for Grosseteste, and so he should be viewed as the originator of the scientific method and not they. He makes this claim in the introduction to his Ibn al-Haythams Weg zur Physik (1964), but doesn’t really substantiate it in the book itself. (And yes, I have read it!) Al-Haytham’s use of experiment is very limited and to credit him with being the inventor of the scientific method is a step too far. However since Schramm made his claims they have been expanded, exaggerated and repeated ad nauseam by the al-Haytham hagiographers.

We now move on to what is without doubt al-Haytham’s greatest achievement his Book of Optics, the most important work on physical optics written between Ptolemaeus in the second-century CE and Kepler in the seventeenth-century. Our author writes:

In his book, The Book of Optics, he was the first to disprove the ancient Greek idea that light comes out of the eye, bounces off objects, and comes back to the eye. He delved further into the way the eye itself works. Using dissections and the knowledge of previous scholars, he was able to begin to explain how light enters the eye, is focused, and is projected to the back of the eye.

Here our author demonstrates very clearly that he really has no idea what he is talking about. It should be very easy to write a clear and correct synopsis of al-Haytham’s achievements, as there is a considerable amount of very good literature on his Book of Optics, but our author gets it wrong[2].

Al-Haytham didn’t prove or disprove anything he rationally argued for a plausible hypothesis concerning light and vision, which was later proved to be, to a large extent, correct by others. The idea that vision consists of rays (not light) coming out of the eyes (extramission) is only one of several ideas used to explain vision by Greek thinkers. That vision is the product of light entering the eyes (intromission) also originates with the Greeks. The idea that light bounces off every point of an object in every direction comes from al-Haytham’s Islamic predecessor al-Kindi. Al-Haytham’s great achievement was to combine an intromission theory of vision with the geometrical optics of Euclid, Heron and Ptolemaeus (who had supported an extramission theory) integrating al-Kindi’s punctiform theory of light reflection. In its essence, this theory is fundamentally correct. The second part of the paragraph quoted above, on the structure and function of the eye, is pure fantasy and bears no relation to al-Haytham’s work. His views on the subject were largely borrowed from Galen and were substantially wrong.

Next up we have the pinhole camera or better camera obscura, although al-Haytham was probably the first to systematically investigate the camera obscura its basic principle was already known to the Chinese philosopher Mo-Ti in the fifth-century BCE and Aristotle in the fourth-century BCE. The claims for al-Haytham’s studies of atmospheric refraction are also hopelessly exaggerated.

We the have an interesting statement on the impact of al-Haytham’s optics, the author writes:

The translation of The Book of Optics had a huge impact on Europe. From it, later European scholars were able to build the same devices as he did, and understand the way light works. From this, such important things as eyeglasses, magnifying glasses, telescopes, and cameras were developed.

The Book of Optics did indeed have a massive impact on European optics in Latin translation from the work of Bacon in the thirteenth-century up to Kepler in the seventeenth-century and this is the principle reason why he counts as one of the very important figures in the history of science, however I wonder what devices the author is referring to here, I know of none. Interesting in this context is that The Book of Optics appears to have had very little impact on the development of physical optics in the Islamic Empire. One of the anomalies in the history of science and technology is the fact that as far was we know the developments in optical physics made by al-Haytham, Bacon, Witelo, Kepler et al had no influence on the invention of optical instruments, glasses, magnifying glasses, the telescope, which were developed along a parallel but totally separate path.

Moving out of optics we get told about al-Haytham’s work in astronomy. It is true that he like many other Islamic astronomers criticised Ptolemaeus and suggested changes in his system but his influence was small in comparison to other Islamic astronomers. What follows is a collection of total rubbish.

He had a great influence on Isaac Newton, who was aware of Ibn al-Haytham’s works.

He was not an influence on Newton. Newton would have been aware of al-Haytham’s work in optics but by the time Newton did his own work in this field al-Haytham’s work had been superseded by that of Kepler, Scheiner, Descartes and Gregory amongst others.

He studied the basis of calculus, which would later lead to the engineering formulas and methods used today.

Al-Haytham did not study the basis of calculus!

He also wrote about the laws governing the movement of bodies (later known as Newton’s 3 laws of motion)

Like many others before and after him al-Haytham did discuss motion but he did not come anywhere near formulating Newton’s laws of motion, this claim is just pure bullshit.

and the attraction between two bodies – gravity. It was not, in fact, the apple that fell from the tree that told Newton about gravity, but the books of Ibn al-Haytham.

We’re back in bullshit territory again!

If anybody thinks I should give a more detailed refutation of these claims and not just dismiss them as bullshit, I can’t because al-Haytham never ever did the things being claimed. If you think he did then please show me where he did so then I will be prepared to discuss the matter, till then I’ll stick to my bullshit!

I shall examine one more claim from this ghastly piece of hagiography. Our author writes the following:

When his books were translated into Latin as the Spanish conquered Muslim lands in the Iberian Peninsula, he was not referred to by his name, but rather as “Alhazen”. The practice of changing the names of great Muslim scholars to more European sounding names was common in the European Renaissance, as a means to discredit Muslims and erase their contributions to Christian Europe.

Alhazen is merely the attempt by the unknown Latin translator of The Book of Optics to transliterate the Arabic name al-Haytham there was no discrimination intended or attempted.

Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham is without any doubt an important figure in the history of science whose contribution, particularly those in physical optics, should be known to anybody taking a serious interest in the subject, but he is not well served by inaccurate, factually false, hagiographic crap like that presented in the article I have briefly discussed here.






[1] Throughout this post I will refer to Islamic science an inadequate but conventional term. An alternative would be Arabic science, which is equally problematic. Both terms refer to the science produced within the Islamic Empire, which was mostly written in Arabic, as European science in the Middle Ages was mostly written in Latin. The terms do not intend to imply that all of the authors were Muslims, many of them were not, or Arabs, again many of them were not.

[2] For a good account of the history of optics including a detailed analysis of al-Haytham’s contributions read David C. Lindberg’s Theories of Vision: From al-Kindi to Kepler, University of Chicago Press, 1976.


Filed under History of Optics, History of Physics, Mediaeval Science, Myths of Science, Renaissance Science

The horror, the horror!

For those readers who might have wondered what The Renaissance Mathematicus looks and sounds like, you need wonder no more. There is now a video on Youtube in which I stumble and stutter my way through a very impromptu, not quite fifteen minute, lecture on the relationship between astronomy, astrology and medicine in the Early Modern Period. During which I indulge in a lot of arm waving and from time to time scratch my fleas. This video was filmed in the kitchen of the Remeis Observatory in Bamberg during a coffee break at the Astronomy in Franconia Conference last Monday, complete with the sounds of somebody loading the dishwasher.

The cameraman, who also puts some questions during this solo performance, was Chris Graney who requested my golden words for his students back in Louisville, the poor sods.

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Filed under Autobiographical, History of Astrology, History of Astronomy, History of medicine