Category Archives: Myths of Science

The House of Wisdom is a Myth

When I first got really interested in the history of science, the history of science of the Islamic empires was not something dealt with in any detail in general works on the topic. If you wanted to get to know anything much about what happened in the various areas of the world dominated by Islamic culture in the period between the seventh and sixteenth centuries then you had to find and read specialist literature produced by experts such as Edward Kennedy. Although our knowledge of that history still needs to be improved, the basic history has now reached the popular market and people can inform themselves about major figures writing in Arabic on various areas of science between the demise of classical antiquity and the European Renaissance such as the mathematician Muḥammad ibn Mūsā al-Khwārizmī, the alchemist Abū Mūsā Jābir ibn Hayyān, the optician, Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham or the physician Abū Bakr Muhammad ibn Zakariyyā al-Rāzī. These and a handful of other ‘greats’ are not as well known as their later European counterparts but knowledge of them, usually under their popular names, so al-Khwarizmi, Jabir, al-Haytham and al-Razi, is these days quite widespread amongst well educated and well read people. There is even a flourishing popular book market for titles about Islamic science.

Amongst those non-professionals, who interest themselves for the topic, particularly well known is the so-called House of Wisdom, a reputed major centre for scientific translation and research in Baghdad under the Abbasid Caliphs. This reputed academic institution even provided the title for two of the biggest selling popular books on Islamic science Jim al-Khalili’s The House of Wisdom: How Arabic Science Saved Ancient Knowledge and Gave Us the Renaissance and Jonathan Lyons’ The House of Wisdom: How the Arabs Transformed Western Civilisation. Neither Jim al-Khalili nor Jonathan Lyons is a historian of science, let alone Islamic science; al-Khalili is a physicist and broadcaster and Lyons is a journalist and herein lies the rub. Real historians of Islamic science say that the House of Wisdom never existed, at least not in any form remotely resembling the institution presented by al-Khalili, Lyons and other popular sources including, unfortunately Wikipedia, where the article is largely based on Lyons’ pop book.

The picture painted by al-Khalili and Lyons, and to be fair they didn’t create it but copied it from other fantasts, is of a special academic research institution set up by the early Abbasid Caliphs, staffed with leading scientific scholars, who carried out a sponsored programme of translating Greek scientific texts, which they them analysed, commented and developed further. Here academic exchanges, discussions, conferences took place amongst the leading scientific scholars in the Abbasid Empire.

The reality looks very different.[1]To quote Gutas (page 54):

It is in this light that the very scanty reliable reports about the bayt al-hikmashould be evaluated. Much ink has been used unnecessarily on description of the bayt al-hikma, mostly in fanciful and sometimes wishful projections of modern institutions and research projects back into the eighth century. The fact is that we have exceedingly little historical [emphasis in original] information about the bayt al-hikma. This in tself would indicate that it was not something grandiose or significant, and hence a minimalist interpretation would fit the historical record better.

The bayt al-hikma, to give it its correct name, which doesn’t really translate as house of wisdom, was the palace archive and library or repository, a practice taken over by the Abbasid Caliphs from the earlier Sassanian rulers along with much other royal court procedure to make their reign more acceptable to their Persian subjects. The wisdom referred to in the translation refers to poetic accounts of Iranian history, warfare, and romance. The Abbasid Caliphs appear to have maintained this practice now translating Persian historical texts from Persian into Arabic. There is absolutely no evidence of Greek texts, scientific or otherwise, being translated in the bayt al-hikma.

Much is made of supposed leading Islamic scientific scholars working in the bayt al-hikmaby the al-Khalili’s, Lyons et al. In fact the first librarian under the Abbasids was a well-known Persian astrologer, again a Sassanian practice taken over by the Abbasids. Later al-Khwarizmi and Yahya ibn Abi Mansur both noted astronomers but equally noted astrologers served in the bayt al-hikmaunder the Abbasid Caliph al-Ma’mun.

We will give Gutas the final word on the subject (page 59):

The bayt al-hikmawas certainly also not an “academy” for teaching the “ancient” sciences as they were being translated; such a preposterous idea did not even occur to the authors of the spurious reports about the transmission of the teaching of these sciences that we do have. Finally it is not a “conference centre for the meeting of scholars even under al-Ma’mun’s sponsorship. Al-Ma’mun, of course (and all the early Abbasid caliphs), did host scholarly conferences or rather gatherings, but not in the library; such gauche social behaviour on the part of the caliph would have been inconceivable. Sessions (magalis) were held in the residences of the caliphs, when the caliphs were present, or in private residences otherwise, as the numerous descriptions of them that we have indicate.

As a final comment we have the quite extraordinary statement made by Jim al-Khalili on the BBC Radio 4 In Our Time discussion on Maths in the Early Islamic World:

In answer to Melvyn Braggs question, “What did they mean by the House of Wisdom and what sort of house was it? It is supposed to have lasted for 400 years, it is contested”

Jim al-Khalili: “It is contested and I’ll probably get into hot water with historians but let’s say what I think of it. There was certainly potentially something called the house of wisdom a bit like the Library of Alexandria many centuries earlier, which was a place where books were stored it may have also been a translation house. It was in Baghdad this was in the time of al-Ma’mun, it may have existed in some form or other in his father’s palace…”

Bragg: “Was it a research centre, was it a place where people went to be paid by the caliphs to get on with the work that you do in mathematics?”

Al-Khalili: “I believe it very well could have been…” He goes on spinning a fable, drawing parallels with the Library of Alexandria

History is not about what you choose to believe but is a fact-based discipline. Immediately after al-Khalili’s fairy story Peter Pormann, Professor of Classics & Graeco-Arabic Studies at the University of Manchester chimes in and pricks the bubble.

Pormann: “There’s the myth of the House of Wisdom as this research school, academy and so on and so forth, basically there is very little evidence…”

Listen for yourselves!

I find Bragg’s choice of words, repeated by al-Khalili, “it is contested” highly provocative and extremely contentious. It is not contested; there is absolutely no evidence to support the House of Wisdom myth as presented by Lyons, al-Khalili et al. What we have here is another glaring example of unqualified pop historians propagating a myth and blatantly ignoring the historical facts, which they find boring.

[1]The facts in the following are taken from Dimitri Gutas, Greek Thought, Arabic Culture: The Graeco-Arabic Translation Movement in Baghdad and Early Abbasid Society (2nd–4th/8th–10th centuries), Routledge, Oxford, ppb. 1998 pp. 53-60 and Lutz Richter-Bernburg, Potemkin in Baghdad: The Abbasid “House of Wisdom” as Constructed by 1001 inventions In Sonja Brentjes–Taner Edis­–Lutz Richter-Bernburg eds., 1001 Distortions: How (Not) to Narrate History of Science, Medicine, and Technology in Non-Western Science, Biblioteca Academica Orientalistik, Band 25, Ergon Verlag, Würzburg, 2016 pp. 121-129


Filed under History of Islamic Science, History of science, Myths of Science

Unsound History of the Sound of Space

Those readers, who have been around for a number of years, will know that from time to time the Renaissance Mathematicus has hosted guest posts. One thing that we are very proud of is the very high standard of the authors, who have delivered up, at our invitation, those literary #histSTM highpoints. We only host the best! Todays guest post continues this tradition with a real star of the world of science, science writing and #histSTM, Tom McLeish FRS. Tom was Professor of Physics at Durham University, where he was one of the initiators and chief investigators of the on going Ordered Universe international research project: Interdisciplinary Readings of Medieval Science: Robert Grosseteste (c.1170–1253).


!4th Century portrait of Robert Grosseteste, Bishop of Lincoln Source: Wikimedia Commons

Tom is now Professor of Natural Philosophy in the Department of Physics at the University of York (I think he’s doing a slow tour of the beautiful cathedral cities of England). His most recent, in fact very recent, publication is a book that you all should read The Poetry and Music of Science: Comparing Creativity in Science and Art (OUP, 2019).

Recently he tweeted some truly horrendous #histSTM errors in a BBC publication, I’ll let him explain further, and I immediately thought that would be something for the HIST_SCI HULKTMbut then thought it would be nice if Tom wrote a guest post about it himself. I asked, he said yes and so I give you the HIST_SCI HULK’s mild mannered, but very erudite cousin Tom McLeish.

For some years now I have been treating myself to the weekly delight and lifelong education in the history of science that is Thony Christie’s ‘Renaissance Mathematicus’ blog. To be invited to write a guest instalment is therefore a great surprise and joy. But I’ll rapidly wrap up my imposter syndrome in a few tight twists of context before getting on with the main task of joining the host author in calling out bad and sloppy history of science – and calling for getting it right – for both writers and readers of this blog know that getting history right matters.

As much as I look forward to the weekly arrival of the R-mathematicus email alert, I also anticipate the annual publication of the BBC Proms guide. Science and music are equal passions for me, and as far as I am concerned, music doesn’t get more exciting than the best classical music festival in the world – the London Promenade series of summer concerts at the Royal Albert Hall. Although the science I do professionally turns around the physics of soft materials and biophysics, astronomy was my childhood gateway to the study of nature, and is still my own amateur scientific passion. So when I discovered that a chosen theme of this year’s Prom concerts was space, responding to the 50thanniversary of the first human moon landing, I became understandably excited. Sure enough, the usually well-researched and written Proms Guide contained a promising article by Neil Brand, The Sound of Space.

The first page takes the reader on a musical pathway through the scores for science fiction films – an area of expertise for Brand, and a good read. But his thesis that the cosmos and music have been linked for centuries requires some history of science. This is where, as is sadly so often the case, the source-checking (frankly even encyclopaedia checking) runs out. A first indication that trouble is afoot appears in the categorisation of Cicero’s Dream of Scipioas a ‘philosophical treatise’. This marvellous dream-discourse is just the closing portion of the 6thbook of Cicero’s De res publica– the whole work really a political treatise, though highly expansive. It is very significant for the imaginative tradition of viewing the Earth from Space, as I have noted elsewhere , but does indeed mention the ‘music of the spheres’, the author’s point. So we read on for now.


The Universe, the Earth in the centre, surrounded by the seven planets within the zodiacal signs Images from a 12th-century manuscript of Macrobius’ Commentarii in Somnium Scipionis Source: Copenhagen, Det Kongelige Bibliotek, ms. NKS 218 4° via Wikimedia Commons

Enter Johannes Kepler (1571-1630), one of my personal Renaissance/Early-Modern astronomical heroes. I ceaselessly find it impressive that Kepler was able to deduce the three propositions concerning planetary motion that we now refer to as ‘Kepler’s Laws’, including the discovery of the elliptical orbit of Mars (and the other planets) from naked eye observations. He could not have done this, however, without the equally heroic contribution of Danish astronomer Tycho Brahe, who improved the accuracy of stellar positional measurements over his predecessors by two orders of magnitude – and this without a telescope. It was Tycho’s observations that enabled Kepler to deduce the elliptical planetary motion, work begun around 1601 but first published in his Astronomia Nova of 1609. Given that the first telescopic astronomical observations were not made until Thomas Harriot and then Galileo Galilei turned their primitive telescopes skyward in 1609, it is strange that Brand is able to assure us that Kepler used ‘observation through early telescope lenses’ to establish his laws of motion.

A decade’s error may perhaps be forgivable (though not the silence on Tycho Brahe), but errors of, several centuries and more stretches all generosity on my part. For Brand then attempts to link Kepler casually to the adoption of music within the ‘quadrivium’ of mathematical subjects taught in medieval universities.

It is elementary educational history that the structure of the ‘Liberal Arts’, for which the quadrivium formed the second year of study, was conceived by the time the late Roman commentator Macrobius wrote about them (interestingly in a lengthy commentary on the Dream of Scipio, see above!) around 430 AD. There is strong corroboration for this early adoption two centuries later from Isidore of Seville in his compendious Etymologies. Music remained a mathematical art from late antiquity, through the cathedral schools and early universities of the high middle ages to Kepler’s own time.

Brand’s final science-history sin is an even stranger one. For in the next section he introduces us to William Herschel, a Hanoverian, who emigrated to England in 1757. Herschel is a fascinating figure, most famous for his discovery of the first new planet since antiquity – Uranus, in 1781.


William Herschel 1785 portrait by Lemuel Francis Abbott Source: Wikimedia Commons

But in an astonishingly dense sweep of double confusion, Brand tells us that Herschel managed this feat ‘through careful calculation with superb new and enormously large optical telescopes.’ The discovery was actually made by observing the tiny greenish disk of Uranus move over several nights against the background of stars, and through a relatively small reflecting telescope[1]. Herschel’s massive 40’ reflector was not operational before 1789, and no more than a twinkle in its designer’s eye in 1781. Brand’s other confusion is, of course, with the discovery of Neptune. This was indeed effected by calculation (simultaneously by Le Verrier in France and Adams in England), following perturbations noticed in the orbit of Uranus. Le Verrier’s theoretical predictions of the whereabouts of the planet that accounted for Uranus’ wanderings lead to the 1846 observational discovery of Neptune in Berlin by Johan Galle.

The reason that the mangling of Herschel’s history is strange, especially in a BBC Proms Guide, is that he was first a musician, not an astronomer. Composer, singer and oboist, his first position in England was as director of the military band in Durham. His later moves to Birmingham and then Bath were also to musical posts, and only in the last did his astronomical interests begin to dominate. His famous sister Carolyn accompanied him, also as a singer, and in parallel career development became an astronomer in her own right, discovering several comets, and recording their observations meticulously. But in the musical phase of his career, William himself composed 24 symphonies and three remarkable oboe concertos among other pieces. It is perhaps the greatest pity of all that, in a year dedicated to music and astronomy, none has found a place at any of the 2019 Prom performances, where they might have embodied a beautiful and historical sound of space.

[1]If you are ever in the area, the Herschel Museum of Astronomy  in Bath, situated in Herschel’s old place of residence, is a delight and you can go out into the back garden where he made his discovery of Uranus.


Filed under History of Astronomy, Myths of Science

Hagiography without context – how not to celebrate a historical figure

This is not so much a blog post as a brief comment. Today marks the five hundredth anniversary of the death of the Renaissance artist-engineer Leonardo da Vinci. This of course has led to a massive bun fight in the form celebrations not just today but throughout the entire year–exhibitions, articles, blog posts, etc., etc. The one thing that has been missing in almost all of the articles, posts, broadcasts and so on that I have come across up till now has been context. We get told that Leonardo was unique, a genius, one of a kind, a visionary, an amazing polymath, a man of the future and all of the verbal hyperbole that you can think of but in almost all cases there is absolutely no context presented for his life and work.


Francesco Melzi – Portrait of Leonardo Source: Wikimedia Commons

As I said above, and also in an earlier blog post, Leonardo was a Renaissance artist-engineer and his whole life and the wide spread of activities are actually characteristic for the carrier profile of a typical artist-engineer. He was not as unique in that sense as these hagiographic portraits without context present him. He is one of a crowd, a man of his times not some sort of freak or anomaly beamed back from the future into the fifteenth century. There are plenty of other polymath Renaissance artist-engineers, who were his predecessors and role models, as well as his contemporaries. To quote Leonardo da Vinci: The Man Behind the Myth on Google Arts & Culture, one of the better articles:

The way that Renaissance knowledge brought together many different disciplines and studies cannot be applied to modern times. In the Renaissance, Leonardo was one of many polymaths – perhaps the best, together with humanists like Filippo Brunelleschi, Leon Battista Alberti and Francesco di Giorgio Martini. 

Saying this does not diminish his stature. Whilst one of many Leonardo was primus inter pars, a man whose undeniably immense talents let him delve deeper, develop further and express better than any other of the Renaissance artist-engineers. However, if you really wish to understand and appreciate Leonard you can only really do so if you view him embedded in the historical context in which he lived and worked.

A good example of this is the notorious Vitruvian Man drawing by Leonardo, which at least two sources that I have read in the last few days claimed originated with Leonardo.


In fact, as I demonstrated in an earlier post, Vitruvian Man was an iconic image of the Renaissance artist-engineer milieu well before Leonardo produced his version of it. However, his version is superior to all the others.

An exception to the hagiographic posturing being presented on Leonardo is today’s essay on Thinking 3D about Leonardo’s anatomical drawings by Monica Azzolini, Leonardo Inside Out, which embeds his efforts in the medical history of the time. Do yourself a favour and read how to do it properly. Also readable is the Max Planck Institute for the History of Science essay Leonardo da Vinci’s Intellectual Cosmos: Exhibitions with Museo Galileo and Staatsbibliothek zu Berlin, which features a reconstruction of Leonardo’s library and so his rich and diverse sources.


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Filed under Myths of Science, Renaissance Science

You shouldn’t believe everything you read

One of the things that I have been reading recently is a very interesting paper by John N. Crossley, the Anglo-Australian logician and historian of mathematics, about the reception and adoption of the Hindu-Arabic numbers in medieval Europe.[1]Here I came across this wonderful footnote:[2]


It is interesting to note that Richard Lemay in his entry “Arabic Numerals,” in Joseph Reese Strayer, ed., Dictionary of the Middle Ages(New York, 1982–89) 1:382–98, at 398 reports that in the University of Padua in the mid-fifteenth century, prices of books should be marked “non per cifras sed per literas claras.” He gives a reference to George Gibson Neill Wright, The Writing of Arabic Numerals(London, 1952), 126. Neill Wright in turn gives a reference to a footnote of Susan Cunnigton, The Story of Arithmetic: A Short History of Its Origin and Development(London, 1904), 42, n. 2. She refers to Rouse Ball’s Short History of Mathematics, in fact this work is: Walter William Rouse Ball, A Short Account of the History of Mathematics, 3rded. (London, 1901), and there one finds on p. 192: “…in 1348 the authorities of the university of Padua directed that a list should be kept of books for sale with the prices marked ‘non per cifras sed per literas claras’ [not by cyphers but by clear letters].” I am yet to find an exact reference for this prohibition. (There is none in Rouse Ball.) Chrisomalis Numerical Notations, p. 124, cites J. Lennart Berggren, “Medieval Arithmetic: Arabic Texts and European Motivations,” in Word, Image, Number: Communication in the Middle Ages, ed. John J. Contreni and Santa Casciani (Florence, 2002), 351–65, at 361, who does not give a reference.

Here we have Crossley the historian following a trail of quotes, references and footnotes; his hunt doesn’t so much terminate in a dead-end as fizzle out in the void, leaving the reader unsure whether the university of Padua really did insist on its book prices being written in Roman numerals rather than Hindu-Arabic ones or not. What we have here is a succession of authors writing up something from a secondary, tertiary, quaternary source with out bothering to check if the claim it makes is actually true or correct by looking for and going back to the original source, which in this case would have been difficult as the trail peters out by Rouse Ball, who doesn’t give a source at all.

This habit of writing up without checking original sources is unfortunately not confined to this wonderful example investigated by John Crossley but is seemingly a widespread bad habit under historians and others who write historical texts.

I have often commented that I served my apprenticeship as a historian of science in a DFG[3]financed research project on Case Studies into a Social History of Formal Logic under the direction of Professor Christian Thiel. Christian Thiel was inspired to launch this research project by a similar story to the one described by Crossley above.

Christian Thiel’s doctoral thesis was Sinn und Bedeutung in der Logik Gottlob Freges(Sense and Reference in Gottlob Frege’s Logic); a work that lifted him into the elite circle of Frege experts and led him to devote his academic life largely to the study of logic and its history. One of those who corresponded with Frege, and thus attracted Thiel interest, was the German meta-logician Leopold Löwenheim, known to students of logic and meta-logic through the Löwenheim-Skolem theorem or paradox. (Don’t ask!) Being a thorough German scholar, one might even say being pedantic, Thiel wished to know Löwenheim’s dates of birth and death. His date of birth was no problem but his date of death turned out to be less simple. In an encyclopaedia article Thiel came across a reference to c.1940; the assumption being that Löwenheim, being a quarter Jewish and as a result having been dismissed from his position as a school teacher in 1933, had somehow perished during the holocaust. In another encyclopaedia article obviously copied from the first the ‘circa 1940’ had become a ‘died 1940’.

Thiel, being the man he is, was not satisfied with this uncertainty and invested a lot of effort in trying to get more precise details of the cause and date of Löwenheim’s death. The Red Cross information service set up after the Second World War in Germany to help trace people who had died or gone missing during the war proved to be a dead end with no information on Löwenheim. Thiel, however, kept on digging and was very surprised when he finally discovered that Löwenheim had not perished in the holocaust after all but had survived the war and had even gone back to teaching in Berlin in the 1950s, where he died 5. May 1957 almost eighty years old. Thiel then did the same as Crossley, tracing back who had written up from whom and was able to show that Löwenheim’s death had already been assumed to have fallen during WWII, as he was still alive and kicking in Berlin in the early 1950s!

This episode convinced Thiel to set up his research project Case Studies into a Social History of Formal Logic in order, in the first instance to provide solid, verified biographical information on all of the logicians listed in Church’s bibliography of logic volume of the Journal of Symbolic Logic, which we then proceeded to do; a lot of very hard work in the pre-Internet age. Our project, however, was not confined to this biographical work, we also undertook other research into the history of formal logic.

As I said above this habit of writing ‘facts’ up from non-primary sources is unfortunately very widespread in #histSTM, particularly in popular books, which of course sell much better and are much more widely read than academic volumes, although academics are themselves not immune to this bad habit. This is, of course, the primary reason for the continued propagation of the myths of science that notoriously bring out the HISTSCI_HULK in yours truly. For example I’ve lost count of the number of times I’ve read that Galileo’s telescopic discoveries proved the truth of Copernicus’ heliocentric hypothesis. People are basically to lazy to do the legwork and check their claims and facts and are much too prepared to follow the maxim: if X said it and it’s in print, then it must be true!

[1]John N. Crossley, Old-fashioned versus newfangled: Reading and writing numbers, 1200–1500, Studies in medieval and Renaissance History, Vol. 10, 2013, pp.79–109

[2]Crossley p. 92 n. 42

[3]DFG = Deutsche Forschungsgemeinschaft = German Research Foundation



Filed under History of Logic, History of Mathematics, Myths of Science

Hypatia – What do we really know?

The fourth century Alexandrian mathematician and philosopher Hypatia has become a feminist icon. She is probably the second most well known woman in #histSTM after Marie Curie. Unfortunately, down the centuries she has been presented more as a legend or a myth intended to fulfil the teller’s purposes rather than a real human being. As Alan Cameron puts it in his excellent essay, Hypatia: Life, Death, and Works:[1]

A pagan in the Christian city of Alexandria, she is one of those figures whose tragic death inspired a legend which could take almost any form because so few facts are known. As a pagan martyr, she has always been a stick to beat Christians with, a symbol in the continuing struggle between science and revealed religion. The memorable account in Gibbon begins wickedly “On a fatal day in the holy season of lent.” As a woman she can be seen as a feminist as well as a pagan martyr. Her name has been a feminist symbol down the centuries more recently a potent name in lesbian and gay circles. As an Egyptian, she has also been claimed as a black woman martyr. There is an asteroid named after her, a crater on the moon, and a journal of feminist studies. As early as 1886, the women of Wichita Kansas, familiar from the movies of our youth as a lawless western cattle town, formed a literary society called the Hypatia Club. Lake Hypatia in Alabama is a retreat for freethinkers and atheists. Rather less in tune with her scholarly activity, there is Hypatia Capital, a merchant bank whose strategy focuses on the top female executives in the Fortune 1000.

A few minutes’ googling will produce countless eulogies of Hypatia as a uniquely gifted philosopher, mathematician and scientist, the second female scientist after Marie Curie, the only woman in antiquity appointed to a university chair, a theorist who anticipated Copernicus with the heliocentric hypothesis. The 2009 movie Agora goes even further in this direction. A millennium before Kepler, Hypatia discovered that earth and its sister planets not only go round the sun but do so in ellipses, not circles. She remained unmarried, and could therefore be seen as a model of pagan virginity. Alternatively, since the monks are said to have killed her because of her influence on the prefect of Egypt, she could be seen as a slut. It is fascinating to observe how down the centuries she served as a lay figure for the prejudices of successive generations.

So what do we know about the real Hypatia? The answer is almost nothing. We know that she was the daughter of Theon (c.335–c.405) an Alexandrian mathematician and philosopher, most well known for his edition of The Elements of Euclid. We don’t know her birth date with estimates ranging from 350 to 370 CE. Absolutely nothing is known about her mother to whom no references whatsoever exist. It is assumed that she was educated by her father but once again, whilst highly plausible, no real evidence exists for this assumption. If we take a brief looked at the available sources for her biography the reason for all of this uncertainty becomes very clear.

The only source we have from somebody who actually knew Hypatia is Synesius of Cyrene (c.373–probably 413), who was one of her Christian students around 393 CE. In 410 CE he was appointed Bishop of Ptolemais. There was an edition of his letters, which contains seven letters to Hypatia and some to others that mention her. Unfortunately his letters tell us nothing about her death as he predeceased her. His last letter to her was written from his deathbed in 413 CE. Two of his letters, however, request her assistance for acquaintances in civil matters, which indicates that she exercised influence with the civil authorities.

Our second major source is Socrates of Constantinople (c.380–died after 439) a Christian church historian, who was a contemporary but who did not know her personally. He mention her and her death in his Historia Ecclesiastica:

There was a woman at Alexandria named Hypatia, daughter of the philosopher Theon, who made such attainments in literature and science, as to far surpass all the philosophers of her own time. Having succeeded to the school of Plato and Plotinus, she explained the principles of philosophy to her auditors, many of whom came from a distance to receive her instructions. On account of the self-possession and ease of manner which she had acquired in consequence of the cultivation of her mind, she not infrequently appeared in public in the presence of the magistrates. Neither did she feel abashed in going to an assembly of men. For all men on account of her extraordinary dignity and virtue admired her the more.

The third principle source is Damascius (c.458–after 538) a pagan philosopher, who studied in Alexandria but then moved to Athens where he succeeded his teacher Isidore of Alexandria (c.450–c.520) as head of the School of Athens. He mentions Hypatia in his Life of Isidore, which has in fact been lost but which survives as a fragment that has been reconstructed.

We also have the somewhat bizarre account of the Egyptian Coptic Bishop John of Nikiû (fl. 680–690):

And in those days there appeared in Alexandria a female philosopher, a pagan named Hypatia, and she was devoted at all times to magic, astrolabes and instruments of music, and she beguiled many people through her Satanic wiles. And the governor of the city honoured her exceedingly; for she had beguiled him through her magic. And he ceased attending church as had been his custom… And he not only did this, but he drew many believers to her, and he himself received the unbelievers at his house.

It is often claimed that she was head of The Neo-Platonic School of philosophy in Alexandria. This is simply false. There was no The Neo-Platonic School in Alexandria. She inherited the leadership of her father’s school, one of the prominent schools of mathematics and philosophy in Alexandria. She however taught a form of Neo-Platonic philosophy based mainly on Plotonius, whereas the predominant Neo-Platonic philosophy in Alexandria at the time was that of Iamblichus.

If we turn to her work we immediately have problems. There are no known texts that can be directly attributed to her. The Suda, a tenth-century Byzantine encyclopaedia of the ancient Mediterranean world list three mathematical works for her, which it states have all been lost. The Suda credits her with commentaries on the Conic Sections of the third-century BCE Apollonius of Perga, the “Astronomical Table” and the Arithemica of the second- and third-century CE Diophantus of Alexandria.

Alan Cameron, however, argues convincingly that she in fact edited the surviving text of Ptolemaeus’ Handy Tables, (the second item on the Suda list) normally attributed to her father Theon as well as a large part of the text of the Almagest her father used for his commentary.  Only six of the thirteen books of Apollonius’ Conic Sections exist in Greek; historians argue that the additional four books that exist in Arabic are from Hypatia, a plausible assumption.

All of this means that she produced no original mathematics but like her father only edited texts and wrote commentaries. In the history of mathematics Theon is general dismissed as a minor figure, who is only important for preserving texts by major figures. If one is honest one has to pass the same judgement on his daughter.

Although the sources acknowledge Hypatia as an important and respected teacher of moral philosophy there are no known philosophical texts that can be attributed to her and no sources that mention any texts from her that might have been lost.

Of course the most well known episode concerning Hypatia is her brutal murder during Lent in 414 CE. There are various accounts of this event and the further from her death they are the more exaggerated and gruesome they become. A rational analysis of the reports allows the following plausible reconstruction of what took place.

An aggressive mob descended on Hypatia’s residence probably with the intention of intimidating rather than harming her. Unfortunately, they met her on the open street and things got out of hand. She was hauled from her carriage and dragged through to the streets to the Caesareum church on the Alexandrian waterfront. Here she was stripped and her body torn apart using roof tiles. Her remains were then taken to a place called Cinaron and burnt.

Viewed from a modern standpoint this bizarre sequence requires some historical comments. Apparently raging mobs and pitched battles between opposing mobs were a common feature on the streets of fourth-century Alexandria. Her murder also followed an established script for the symbolic purification of the city, which dates back to the third-century. There was even a case of a pagan statue of Separis being subjected to the same fate. There is actually academic literature on the use of street tiles in street warfare[2]. What is more puzzling is the motive for the attack.

The exact composition of the mob is not known beyond the fact that it was Christian. There is of course the possibility that she was attacked simply because she was a woman. However, she was not the only woman philosopher in Alexandria and she enjoyed a good reputation as a virtuous woman. It is also possible that she was attacked because she was a pagan. Once again there are some contradictory facts to this thesis. All of her known students were Christians and she had enjoyed good relations with Theophilus the Patriarch of Alexandria (384–412), who was responsible for establishing the Christian dominance in Alexandria. Theophilus was a mentor of Synesius. Also the Neoplatonic philosophy that she taught was not in conflict with the current Christian doctrine, as opposed to the Iamblichan Neoplatonism. The most probably motive was Hypatia’s perceived influence on Orestes (fl. 415) the Roman Prefect of Egypt who was involved in a major conflict with Cyril of Alexandria (c.376–444), Theophilis’ nephew and successor as Patriarch of Alexandria. This would make Hypatia collateral damage in modern American military jargon. In the end it was probably a combination of all three factors that led to Hypatia’s gruesome demise.

Hypatia’s murder has been exploited over the centuries by those wishing to bash the Catholic Church but also by those wishing to defend Cyril, who characterise her as an evil woman. Hypatia was an interesting fourth-century philosopher and mathematician, who deserves to acknowledged and remembered for herself and not for the images projected on her and her fate down the centuries.

[1]Alan Cameron, Hypatia: Life, Death, and Works, in Wandering Poets and Other Essays on Late Greek Literature and Philosophy, OUP, 2016 pp. 185–203 Quote pp. 185–186

[2]You can read all of this in much more detail in Edward J. Watts’ biography of Hypatia, Hypatia: The Life and Legend of an Ancient Philosopher, OUP, 2017, which I recommend with some reservations.


Filed under History of Mathematics, History of science, Ladies of Science, Myths of Science

Galileo’s the 12th most influential person in Western History – Really?

Somebody, who will remain nameless, drew my attention to a post on the Presidential Politics for America blog shortly before Christmas in order to provoke me. Anybody who knows me and my blogging will instantly recognise why I should feel provoked if they just read the opening paragraph.

Despite the paradigm-shifting idea of our #28 Nicolaus Copernicus, for nearly a century afterward his heliocentric theory twisted in the solar wind. It took another man to confirm Copernicus’s daring theory. That alone would make this other man an all-time great contributor to Western science, but he gifted us so much more than merely confirming someone else’s idea. He had a series of inventions, discoveries, and theories that helped modernize science. His accomplishments in mechanics were without precedent. His telescope observed what was once unobservable. Perhaps most importantly, he embodied, furthered, and inspired a growing sentiment that truth is a slave to science and facts, not authority and dogma.

This man was Galileo Galilei, and he’s the 12thmost influential person in Western History.

Before I start on my usually HistSci_Hulk demolition job to welcome the New Year I should point out that this crap was written by somebody claiming to be a history teacher; I feel for his student.

This post is part of a long-term series on The Top 30 Most Influential Western European Figures in History; I kid you not! Sorry, but I’m not a fan of rankings in general and to attempt to rank the historical influence of Western Europeans is in my opinion foolhardy at best and totally bonkers at worst.

We turn our attention to his #11 Galileo Galilei. We start with the very obvious false claim, the very first one in fact, Galileo did not ‘confirm Copernicus’s daring theory.’ Next up we have the statement: ‘He had a series of inventions, discoveries, and theories that helped modernize science.’

Only in his teens, he identified the tautochronic curve that explains why the pendulum behaves as it does. This discovery laid the groundwork for Christian [sic] Huygens to create the world’s first pendulum clock, which became the most accurate method of keeping time into the twentieth century. 

It is Christiaan not Christian Huygens. Galileo discovered the isochronal principle of the pendulum but the earliest record of his researches on the pendulum is in a letter to his patron Guidobaldo del Monte dated 2 November 1602, when he was 38 years old. The story that he discovered the principle, as a teenager was first propagated posthumously by his first biographer Viviani and to be taken with a pinch of salt. He didn’t discover that the free circular pendulum swing is not isochronal but only the tautochrone curve is; this discovery was actually made by Huygens. There is no evidence that Galileo’s design of a never realised pendulum clock had any connections with or influence on Huygens’ eventually successfully constructed pendulum clock. That pendulum clocks remained the most accurate method of keeping time into the twentieth century is simply wrong.

The precocious Galileo also invented thethermoscope…

 It is not certain that Galileo invented the thermoscope; it is thought that his friend Santorio Santorio actually invented it; he was certainly the first during the Renaissance to publish a description of it. The invention was attributed to Galileo, Santorio, Robert Fludd and Cornelius Drebble. However, the principle on which it was based was used in the Hellenic period and described even earlier by Empedocles in book On Nature in 460 BCE. This is part of a general pattern in the Galileo hagiography, inventions and discoveries that were made by several researchers during his lifetime are attributed solely to Galileo even when he was not even the first to have made them.

At just 22, he published a book onhydrostatic balance, giving him his first bit of fame.

 This ‘book’, La Bilancetta or The Little Balance was actually a booklet or pamphlet and only exists in a few manuscripts so during his lifetime never printed. He used it together with another pamphlet on determining centres of gravity to impress and win patrons within the mathematical community such as Guidobaldo del Monte and Christoph Clavius; in this he was successful.

He attended medical school but, for financial reasons, he had to drop out and work as a tutor. Nevertheless, he eventually became chair of the mathematics department at theUniversity of Pisa.

He studied medicine at the University of Pisa because that was the career that his father had determined for him. He dropped out, not for financial reasons but because he wanted to become a mathematician and not a physician. He studied mathematics privately in Florence and having established his abilities with the pamphlets mentioned above was, with the assistance of his patrons, appointed to teach mathematics in Pisa. However, due to his innate ability to piss people off his contract was terminated after only three years. His patrons now helped him to move to the University of Padua.

He taught at Padua for nearly 20 years, and it’s there where he turned from reasonably well-known Galileo Galilei to Galileo[emphasis in original]. Like the great Italian artists of his age, he became so talented and renowned that soon just his first name sufficed.

This is simply rubbish. He remained virtually unknown outside of Padua until he made his telescopic discoveries in 1610. He turned those discoveries into his exit ticket and left Padua as soon as possible. As for his name, he is, for example, known in English as Galileo but in German as Galilei.

We now turn to mechanics the one field in which Galileo can really claim more than a modicum of originality. However, even here our author drops a major clangour.

Through experimentation, he determined that a feather falls slower than a rock not because of the contrasting weight but because of the extra friction caused by the displacement of Earth’s atmosphere on the flatter object. 

Through experimentation! Where and when did Galileo build his vacuum chamber? Our author missed an opportunity here. This was, of course, Galileo’s most famous thought experiment in which he argues rationally that without air resistance all objects would fall at the same rate. In fact Galileo’s famous use of thought experiments doesn’t make an appearance in this account at all.

Galileo built on this foundation a mathematical formula that showed the rate of acceleration for falling objects on Earth. Tying math to physics, he essentially laid the groundwork for later studies of inertia. These mechanical discoveries provided a firm launching point for Isaac Newton’s further modernization of the field.

It is time for the obligatory statement that the mean speed formula the basis of the mathematics of free fall was known to the Oxford Calculatores and the Paris Physicists in the fourteenth century and also the laws of free fall were already known to Giambattista Benedetti in the sixteenth century. As to inertia, Galileo famously got it wrong and Newton took the law of inertia from Descartes, who in turn had it from Isaac Beeckman and not Galileo. In the late sixteenth and early seventeenth centuries several researchers tied mathematics to physics, many of them before Galileo. See comment above about attributing the work of many solely to Galileo. We now turn to astronomy!

In the early 1600s, despite Copernicus’s elegant heliocentric model of the solar system having debuted more than a half-century earlier, skeptics remained. Indeed, there was an ongoing divide among astronomers; some favored the Copernican model while others clung to the traditional Ptolemaic premise adopted by the Catholic Church, which put the earth at the universe’s center. Even Tycho Brahe, a leading post-Copernican astronomer, favored geocentrism, though his Tychonic system did make some allowances for Copernicus’s less controversial ideas. Brahe’s position helped him avoid the fate of heliocentrist Giordano Bruno who was burned at the stake by the Catholic Inquisition in 1600. This heated astronomical climate awaited Galileo Galilei.

There is nothing particularly elegant about Copernicus’ heliocentric model of the solar system. In fact it’s rather clunky due to his insistence, after removing the equant point, of retaining the so-called Platonic axiom of uniform circular motion. His model was in fact more cluttered and less elegant than the prevailing geocentric model from Peuerbach. Sceptics didn’t remain, as our author puts it, implying in this and the following sentences that there was no reason other than (religious) prejudice for retaining a geocentric model. Unfortunately, as I never tire of repeating, Copernicus’ model suffered from a small blemish, a lack of proof. In fact the vast majority of available empirical evidence supported a geocentric system. You know proof is a fundamental element of all science, including astronomy. If I were playing mythology of science bingo I would now shout full house with the introduction of Giordano Bruno into the mix. No, Giordano was not immolated because he was a supporter of heliocentricity.

Like Bruno, Galileo knew Copernicus was right, and he set out to prove it. Early in the seventeenth century, he received word about a new invention created by the German-Dutch spectacle-makerHans Lippershey In 1608, Lippershey used his knowledge of lenses to make a refracting telescope, which used lenses, an eye piece, and angular strategies to bend light, allowing in more of it. More light could clarify and magnify a desired object, and Lippershey’s rudimentary design could make something appear about three times bigger. Galileo, though he never saw a telescope in person nor even designs of one, heard a basic description of it, checked the information against his brain’s enormous database, realized it could work, and built one of his own. A better one.

Comparing Bruno with Galileo is really something one should avoid doing. Our author’s description of how a refracting telescope works is, I admit, beyond my comprehension, as the function of a refracting telescope is apparently beyond his. The claim that Galileo never saw a telescope, which he made himself, has been undermined by the researches of Mario Biagioli, who argues convincingly that he probably had seen one. I love the expression “checked the information against his brain’s enormous database.” I would describe it not so much as hyperbole as hyperbollocks!

With his improved telescope he could magnify objects thirty times, and he immediately pointed it to the once unknowable heavens and transformed astronomy in numerous ways:

I will start with the general observation that Galileo was by no means the only person pointing a telescope at the heavens in the period between 1609 and 1613, which covers the discoveries described below. He wasn’t even the first that honour goes to Thomas Harriot. Also, all of the discoveries were made independently either at roughly the same time or even earlier than Galileo. If Galileo had never heard of the telescope it would have made virtually no difference to the history of astronomy. He had two things in his favour; he was in general a more accurate observer that his competitors and he published first. Although it should be noted that his principle publication, the Sidereus Nuncius, is more a press release that a scientific report. The first telescope Galileo presented to the world was a 9X magnification and although Galileo did build a 30X magnification telescope most of his discoveries were made with a 20X magnification model. The competitors were using very similar telescopes. “…the once unknowable heavens” we actually already knew quite a lot about the heavens through naked-eye observations.

  • It was assumed that the moon, like all the heavenly spheres, was perfectly smooth. Galileo observed craters and mountains. He inferred, accurately, that all celestial objects had blemishes of their own.

This was actually one of Galileo’s greatest coups. Thomas Harriot, who drew telescopic images of the moon well before Galileo did not realise what he was seeing. After seeing Galileo’s drawings of the moon in the Sidereus Nuncius, he immediately realised that Galileo was right and changed his own drawing immediately. One should, however, be aware of the fact that throughout history there were those who hypothesised that the shadows on the moon were signs of an uneven surface.

  • Though Jupiter had been observed since the ancient world, what Galileo was the first to discover was satellites orbiting around it — the Jovian System. In other words, a planet other than the Earth had stuff orbiting it. It was another brick in Copernicus’s “we’re not that important” wall.

And as I never tire of emphasising, Simon Marius made the same discovery one day later. I have no idea what Copernicus’s “we’re not that important” wall is supposed to be but the discovery of the moons of Jupiter is an invalidation of the principle in Aristotelian cosmology that states that all celestial bodies have a common centre of rotation; a principle that was already violated by the Ptolemaic epicycle-deferent model. It says nothing about the truth or lack of it of either a geocentric or heliocentric model of the cosmos.

  • Pointing his telescope at the sun, Galileo observed sunspots. Though the Chinese first discovered them in 800 BC, as Westerners did five hundred years later, no one had seen or sketched them as clearly as Galileo had. It was another argument against the perfect spheres in our sky.

Telescopic observations of sunspots were first made by Thomas Harriot. The first publication on the discovery was made by Johannes Fabricius. Galileo became embroiled in a meaningless pissing contest with the Jesuit astronomer, Christoph Scheiner, as to who first discovered them. The best sketches of the sunspots were made by Scheiner in his Rosa Ursina sive Sol (Bracciano, 1626–1630).

  • Galileo also discovered that Venus, like the moon, has phases (crescent/quarter/half, waxing/waning, etc.). This was a monumental step in confirming Copernicus’s theory, as Venusian phases require certain angles of sunlight that a geocentric model does not allow.

The phases of Venus were discovered independently by at least four observers, Thomas Harriot, Simon Marius, Galileo and the Jesuit astronomer Paolo Lembo. The astronomers of the Collegio Romano claimed that Lembo had discovered them before Galileo but dating the discoveries is almost impossible. In a geocentric model Venus would also have phases but they would be different to the ones observed, which confirmed that Venus, and by analogy Mercury, whose phases were only observed much later, orbits the Sun. Although this discovery refutes a pure geocentric system it is still compatible with a Capellan system, in which Venus and Mercury orbit the Sun in a geocentric model, which was very popular in the Middle ages and also with any of the Tychonic and semi-Tychonic models in circulation at the time so it doesn’t really confirm a heliocentric model

  • The observable hub of the Milky Way galaxy was assumed to be, just as it looks to us, a big, milky cloud. Galileo discovered it was not a cloud, but a huge cluster of stars. (We now know it numbers in the billions.)

Once again a multiple discovery made by everybody who pointed a telescope at the heavens beginning with Lipperhey.

Galileo not only confirmed Copernicus’s heliocentric theory, but he allowed the likes of Johannes Kepler to more accurately plot out the planets’ orbits, Isaac Newton to explain how it was happening, and Albert Einstein to explain why. It was such a colossal step forward for the observable universe that some people didn’t even believe what they were seeing in the telescope, electing to instead remain skeptical of Galileo’s “sorcery.”

Galileo did not in any way confirm Copernicus’ heliocentric theory. In fact heliocentricity wasn’t confirmed until the eighteenth century. First with Bradley’s discovery of stellar aberration in 1725 proving the annual orbit around the sun and then the determination of the earth’s shape in the middle of the century indirectly confirming diurnal rotation. The telescopic observations made by Galileo et al had absolutely nothing to do with Kepler’s determination of the planetary orbits. Newton’s work was based principally on Kepler’s elliptical system regarded as a competitor to Copernicus’ system, which Galileo rejected/ignored, and neither Galileo nor Copernicus played a significant role in it. How Albert got in here I have absolutely no idea. Given the very poor quality of the lenses used at the beginning of the seventeenth century and the number of optical artifacts that the early telescopes produced, people were more than justified in remaining skeptical about the things apparently seen in telescopes.

Ever the watchdog on sorcery, it was time for the Catholic Church to guard its territory. Protective of geocentrism and its right to teach us about the heavens, the Church had some suggestions about exactly where the astronomer could stick his telescope. In 1616, under the leadership of Pope Paul V, heliocentrism was deemed officially heretical, and Galileo was instructed “henceforth not to hold, teach, or defend it in any way.”

The wording of this paragraph clearly states the author’s prejudices without consideration of historical accuracy. Galileo got into trouble in 1615/16 for telling the Catholic Church how to interpret the Bible, a definitive mistake in the middle of the Counter Reformation. Heliocentrism was never deemed officially heretical. The injunction against Galileo referred only to heliocentrism as a doctrine i.e. a true theory. He and everybody else were free to discuss it as a hypothesis, which many astronomers preceded proceeded to do.

A few years later, a confusing stretch of papal leadership got Galileo into some trouble. In 1623,Pope Urban VIII took a shine to Galileo and encouraged his studies by lifting Pope Paul’s ban. A grateful Galileo resumed his observations and collected them into his largest work, 1632’s “Dialogue Concerning the Two Chief World Systems” In it, he sums up much of his observations and shows the superiority of the newer heliocentric model. The following year, almost as if a trap were set, the Catholic Inquisition responded with a formal condemnation and trial, charging him with violating the initial 1616 decree. Dialogue was placed on the Church’s Index of Prohibited Books.

Maffeo Barberini, Pope Urban VIII, had been a good friend of Galileo’s since he first emerged into the limelight in 1611 and after he was elected Pope did indeed show great favour to Galileo. He didn’t, however, lift Paul V’s ban. It appears that he gave Galileo permission to write a book presenting the geocentric and heliocentric systems, as long as he gave them equal weight. This he very obviously did not do; Galileo the master of polemic skewed his work very, very heavily in favour of the heliocentric system. He had badly overstepped the mark and got hammered for it.  He, by the way, didn’t resume his observations; the Dialogo is based entirely on earlier work. One is, by the way, condemn after being found guilty in a trial not before the trial takes place when one is charged or accused.

Galileo’s popularity, combined with a sheepish Pope Urban, limited his punishment to a public retraction and house arrest for his remaining days. At nearly 70, he didn’t have the strength to resist. Old, tired, and losing his vision after years of repeatedly pointing a telescope at the brightest object in the solar system, he accepted his sentence. Blind and condemned, his final years were mostly spent dictating “Two New Sciences,” which summarized his 30 years of studying physics.

Galileo’s popularity would not have helped him, exactly the opposite. People who were highly popular and angered the Church tended to get stamped on extra hard, as an example to the masses. Also, Urban was anything but sheepish. The public retraction was standard procedure for anyone found guilty by the Inquisition and the transmission of his sentence from life imprisonment to house arrest was an act of mercy to an old man by an old friend. Whether Galileo’s telescopic observations contributed to his blindness is disputed and he hadn’t really made many observations since about 1613. The work summarised in the Discorsi was mostly carried out in the middle period of his life between 1589 and 1616.

The author now veers off into a discussion, as to who is the father or founder of this or that and why one or other title belongs to Copernicus, Newton, Aristotle, Bacon etc. rather than Galileo. Given his belief that one can rank The Top 30 Most Influential Western European Figures in History, it doesn’t surprise me that he is a fan of founder and father of titles. They are, as regular readers will already know, in my opinion a load of old cobblers. Disciplines or sub-disciplines are founded or fathered over several generations by groups of researchers not individuals.

His article closes with a piece of hagiographical pathos:

Moreover, Galileo’s successes were symbolic of a cornerstone in modern science. His struggle against the Church embodied the argument that truth comes from experience, experiments, and the facts — not dogma. He showed us authority and knowledge are not interchangeable. Though the Inquisitors silenced him in 1633, his discoveries, works, and ideas outlived them. For centuries, he has stood as an inspiration for free thinkers wrestling against ignorant authority.

This is typical exaggerated presentation of the shabby little episode that is Galileo’s conflict with the Catholic Church. It wasn’t really like that you know. Here we have the heroic struggle of scientific truth versus religious dogma, a wonderful vision but basically pure bullshit. What actually took place was that a researcher with an oversized ego, Galileo, thought he could take the piss out of the Pope and the Catholic Church. As it turned out he was mistaken.

Being a history teacher I’m sure our author would want me to grade his endeavours. He has obviously put a lot of work into his piece so I will give him an E for effort. However, it is so strewn with errors and falsities that I can only give him a F for the content.

























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

Carl Sagan Skewered

I didn’t have time this week to write a proper blog post, so I thought I would pass on something I read recently. Not necessarily here on the blog but I tend to annoy people when I make rude comments about the American astrophysicist and science populariser Carl Sagan. Many people grew up watching his 1980s TV series Cosmos and regarded him as some sort of science saint. However, whatever his abilities to communicate science Sagan’s presentation of the history of science was terrible. Another thing that is likely to bring out the HIST_SCI HULK is mention of the biopic Agora, supposedly the life story of the ancient Greek mathematician Hypatia. Unfortunately the story line of Agora has more in common with a fairy tale than real history of science.

The medieval volume of the Cambridge History of Science[1]skewers both Sagan and Agora in just one paragraph and one footnote.

Many otherwise well-educated people have long taken this picture for granted. [Complete lack of science in the Middle Ages] No one has diffused it more widely than astronomer Carl Sagan (1934–1996), whose television series Cosmos drew an audience estimated at half a billion. In his 1980 book by the same name, a timeline of astronomy from Greek antiquity to the present left between the fifth and the late fifteenth centuries a familiar thousand-year blank labelled as a “poignant lost opportunity for mankind.” (a) The timeline reflected not the state of knowledge in 1980 but Sagan’s own “poignant lost opportunity” to consult the library of Cornell University, where he taught. In it, Sagan would have discovered large volumes devoted to the medieval history of his own field, some of them two hundred years old. He would also have learnt that the alleged medieval vacuum spawned the two institutions in which he spent his life: the observatory as a research institution (Islamic civilization) and the university (Latin Europe).

(a) Carl Sagan, Cosmos (New York: Random House, 1980), p. 335. Sagan’s outlook recently regained currency thanks to Alejandro Amenábar’s spectacular and spectacularly anachronistic film “Agor” (2009), which portrays Hypatia (d. 415) as on the verge of discovering the law of free fall and heliocentric planetary ellipses before she is murdered by fanatical monks.

[1]The Cambridge History of Science: Volume 2 Medieval Science, ed. David C. Lindberg & Michael H. Shank, CUP, New York, ppb. 2015 pp.9-10


Filed under Myths of Science, Uncategorized