Seven

VWNUM7

 

Seven is the largest single digit prime number and a Mersenne prime. It is the number of planets in ancient Greek astronomy and the number of days in the astrological week, named after those planets. Isaac Newton decided to give the rainbow seven colours to match the seven notes of the major scale. Albrecht Dürer included a construction of a seven-sided polygon, the heptagon, in his maths book, which was criticised by Kepler as being only an approximation. Rome was built on seven hills. There are seven deadly sins, of which I have committed all seven more than once in my life, and seven heavenly virtues, of which I possess none. Two of my favourite films are Akira Kurosawa’s The Seven Samurai and John Sturges’ glorious Hollywood rendition of it, The Magnificent Seven. Snow White had seven dwarfs and there were seven brides for those seven brothers. David Fincher’s neo-noir psychological thriller was simply called Seven. Seven is a number that turns up in a multitude of historical, mythical, literary, musical, artistic, mathematical and scientific contexts and today is the seventh birthday of the Renaissance Mathematicus.

I came comparatively late to computers. There are no Ataris, Sinclairs or C64s collecting dust in my cellar and I didn’t spend my youth painfully learning to programme in Fortran, BASIC or Pascal. I also came comparatively late to the Internet. I was not one of those who cobbled together a dial up modem and spent a fortune on telephone fees to gain online contact to a fellow enthusiast on the other side of the world. However when I did take the plunge the world of blogging was still very young and when I first discovered them a blog that was seven years old definitely belonged to the pioneer founder generation and was venerated as a Methuselah amongst its peers. Given the short lived and oft fickle nature of blogs, over the years seven continued to remain a sort of bench mark for a successful, mature, established blog. This being the case I regard today as the day that The Renaissance Mathematicus has become part of the cyberspace establishment.

When I started this blog I never imagined, even in my wildest dreams, that I would be sitting here typing a post to mark or celebrate my seventh anniversary. Over the last seven years the content and the aims of this blog have remained constant but the style of the blog posts has developed (degenerated!) and matured (gone stale!). I very rarely look at blog statistics, as doing so makes me too aware of the fact that people are reading the rubbish that I write and I start to worry about pleasing/insulting them and that impedes my ability to write freely. I do however know that, for a moderately hard-core history of science blog, a surprisingly large number of people read my regular outpourings. A thought that both frightens and humbles me. I would like to mark this milestone by issuing some thanks.

Thanks to all the people who, for whatever reason, read what I present here on a regular basis. Thanks to those highly knowledgeable and critical souls, who brave my wrath and comment on my posts, particularly on the more provocative or contentious ones. Thanks to all those who tweet or retweet links to my posts on Twitter or share them on Facebook. And a very special thanks to all the members of the Internet history of science community for letting me, a bungling amateur, be part of your world. I hope that at least some of you will stick around for the next seven years.

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How do we kill off myths of science zombies?

The Internet is a sort of cyberspace limbo where myths in the history of science, which have been debunked a long time ago, keep popping up on social media as #histsci zombies, the history of science undead. One such that has popped up to haunt me several times in recent weeks is the claim that Johannes Kepler murdered Tycho Brahe. This claim was at best ludicrous and, having been thoroughly debunked, is now just pathetic but continues to ghost through cyberspace as a #histsci zombie. Where does it come from, who put it into the world and did it ever have any validity?

Portrait of Kepler by an unknown artist, 1610 Source: Wikimedia Commons

Portrait of Kepler by an unknown artist, 1610
Source: Wikimedia Commons

After protracted negotiations and a return to Graz to fetch his family Johannes Kepler began to work with Tycho Brahe in Prague as his assistant in late 1600, not as his student as is often falsely stated. In September 1601, Tycho managed to negotiate an official position for Kepler at the Imperial Court of the German Emperor Rudolph II. Their partnership was however short lived, as Tycho died 24 October 1601. According to Kepler’s account Tycho had retained his urine during a banquet eleven days earlier, so as not to breach etiquette by leaving the table. Upon returning home he was unable to urinate, fell ill and falling into delirium died, apparently of some sort of urinary infection. This was the state of play in 1601 and remained unchanged until 1901.

Tycho Brahe Source: Wikimedia Commons

Tycho Brahe
Source: Wikimedia Commons

In 1901 Tycho’s body was exhumed and an autopsy carried out that failed to establish a cause of death. However when the corpse was reburied a sample of his beard hair was retained. In 1990 this hair sample was analysed and found to contain abnormally high levels of mercury, which led to the speculation that Tycho had died of mercury poisoning. At this point there was no real suspicion of murder but more speculation about an accidental mercury poisoning. Tycho was a Paracelsian pharmacist, who along with his observatory on Hven ran a pharmacy that produced various medical remedies. The speculation was that he had either poisoned himself whilst working with mercury, a not uncommon problem amongst pharmacists in the Early Modern period when mercury was used extensively in medicines, or that he had poisoned himself by taking one of his own mercury containing remedies.

The first real accusations that Tycho had been murdered, that is poisoned by another person, came with the publication in 2004 of Joshua & Anne-Lee Gilder’s book Heavenly Intrigue: Johannes Kepler, Tycho Brahe, and the Murder Behind One of History’s Greatest Scientific Discoveries. Put simply the Gilders claimed that Kepler had poisoned Tycho to gain access to his astronomical data. The first part of their book, in which they outline the lives of Tycho and Kepler is actually well researched and well written but it’s when they come to the cause of Tycho’s death the book goes of the rails.

The Gilder’s build a chain of speculative, unsubstantiated, circumstantial evidence leading to their conclusions that Tycho was murdered and Johannes Kepler did the evil deed. Any able defence lawyer or competent historian of science could dismantle the Gilder’s rickety and highly dubious chain of evidence without too much effort leading to a full acquittal of the accused. Unfortunately most book reviewers are neither lawyers nor historians of science and the popular press reviewers jumped on the book and swallowed the Gilder’s arguments hook, line and sinker. The result was that Kepler went from being a hero of the scientific revolution to being a perfidious murderer, almost overnight.

Fascinatingly, the furore created by the popular press led to an international team of experts being granted permission to exhume Tycho’s corpse and to carry out yet another autopsy. The noble Dane would not be allowed to rest in peace. This was duly done in 2010 and the corpse, or what was left of it, was subjected to a battery of scientific tests. All of this activity led to the popular science press publishing a cart load of articles, many of them on the Internet, asking if Kepler had indeed poisoned Tycho most of them skewing their articles strongly in the direction of a guilty verdict.

The international team of archaeologists, forensic anthropologists, pathologists and whoever took their time but in 2012 they finally published their results. There was not enough mercury present in the samples to have caused mercury poisoning and there were no other poison found in any quantities whatsoever. Tycho was not poisoned by Johannes Kepler or anybody else for that matter. A second independent team re-analysed the beard hairs taken from the corpse in 1901 and confirmed that there was not enough mercury present to have caused mercury poisoning.

The press outlets both popular and scientific that had trumpeted the Gilder’s highly dubious claims out into the world did not apply the same enthusiasm to reporting the negative results of the autopsy. Those lengthy articles in the Internet claiming, implying, insinuating or suggesting that Kepler had done for his employer were not updated, amended or corrected to reflect the truth and the Gilder’s book was not withdrawn from the market or consigned to the wastepaper basket, where it very definitely belongs. Below is part of the sales pitch for that book taken just a couple of hours ago from Amazon.com:

But that is only half the story. Based on recent forensic evidence (analyzed here for the first time) and original research into medieval and Renaissance alchemy—all buttressed by in-depth interviews with leading historians, scientists, and medical specialists—the authors have put together shocking and compelling evidence that Tycho Brahe did not die of natural causes, as has been believed for four hundred years. He was systematically poisoned—most likely by his assistant, Johannes Kepler.

An epic tale of murder and scientific discovery, Heavenly Intrigue reveals the dark side of one of history’s most brilliant minds and tells the story of court politics, personal intrigue, and superstition that surrounded the protean invention of two great astronomers and their quest to find truth and beauty in the heavens above.

The result of all this is that historian of astronomy of the Early Modern period are forced to indulge in a game of historical Whac-A-Mole every time that somebody stumbles across one of those articles in the Internet and starts broadcasting on Twitter, Facebook or wherever that Johannes Kepler murdered Tycho Brahe.

 

 

 

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How Chemistry came to its first journal – and a small-town professor to lasting prominence

Being fundamentally a lazy sod I am always very pleased to welcome a guest blogger to the Renaissance Mathematicus, because it means I don’t have to write anything to entertain the mob. Another reason why I am pleased to welcome my guest bloggers is because they are all better educated, better read and much more knowledgeable than I, as well as writing much better than I ever could, meaning I get princely entertained and educated by them. Todays new guest blogger, Anna Gielas, maintains the high standards of the Renaissance Mathematicus guests. Anna, who’s a German studying in Scotland whereas I’m an English man living in Germany, helps me to put together Whewell’s Gazette the #histSTM weekly links list. I’ll let her tell you somewhat more about herself.

 I’m a doctoral candidate at the University of St Andrews (Dr Aileen Fyfe and Prof Frank James from the Royal Institution of Great Britain are my supervisors) and I study the editorship and the establishment of early scientific journals in Britain and the German lands. I focus on the decades between 1760 and 1840 because this was the time when commercial (as opposed to society-based) science periodicals took off and became a central means of scientific communication and knowledge production

 As you can see Anna is an expert for the history of scientific journals and her post honours the 200th anniversary of the death Lorenz Crell, 7 June 1816, who edited and published the world’s first commercial journal devoted exclusively to chemistry. Read and enjoy.

 


 

 

In early February 1777, the famous Swiss physiologist Albrecht von Haller received a letter from an obscure small-town professor named Lorenz Crell. Crell had studied medicine, travelled Europe and returned to his hometown, where he succeeded his former professor of medicine at the local university.

The young professor asked Haller for feedback on a few essays he had submitted anonymously. Haller’s favourable comments encouraged Crell not only to reveal his name but also his risky plan: “I have a chemical journal in the works”, Crell announced to Haller in February 1777.

Lorenz Crell Source: Wikimedia Commons

Lorenz Crell
Source: Wikimedia Commons

The thirty-three year old professor had hardly any experiences with publishing, let alone with editing a learned journal. Yet his periodical would go on to become the first scientific journal devoted solely to chemical research—and would influence the course of chemical research throughout the German speaking lands.

In February of 1777—roughly one year before the inaugural issue of his Chemisches Journal appeared—things looked rather dire for Crell. At this time, there were essentially two professional groups in the German speaking lands devoted to chemical endeavours: university professors and apothecaries. The core of professorial work—and the task they were paid for—was teaching. And chemistry was taught as part of the medical curriculum. Apothecaries, in turn, focused mainly on producing remedies. Neither profession was based on chemical research. Experimentation would remain secondary until the nineteenth century.

So whom did Crell expect to pick up his periodical? He hoped to garner the attention of the eminent Andreas Sigismund Marggraf and his peers. Marggraf was the first salaried chemist at the Royal Prussian Academy of Sciences in Berlin. Like most of the leading chemical researchers, Marggraf was an apprenticed apothecary. He had audited lectures and seminars at the University of Halle, an epicentre of the Enlightenment, but he never graduated. Before taking on his post at the Academy, Marggraf earned his living through the apothecary shop that he had inherited from his father, the “Apotheke zum Bären” (Bear’s Pharmacy) on Spandauer Straße in Berlin.

Hoping that renowned chemical experimenters like Marggraf would pick up Crell’s journal was one thing—catching their attention and actually persuading them to contribute to the periodical a very different one. But Crell, it appears, had a plan. Later in 1777 he contacted Friedrich Nicolai, a famous publisher and bookseller of the German Enlightenment, and asked for the honour of reviewing a few chemical books for Nicolai’s Allgemeine deutsche Bibliothek (ADB). Crell picked a good moment to do so: in 1777, the ADB experienced record sales. But the editor-to-be approached Nicolai without any letter of introduction, which according to the mores of his times, the Prussian Aufklärer could have easily interpreted as impudence. Nicolai apparently saw moxie where others might have seen brazenness: the publisher commissioned reviews from Crell within days of receiving his letter. Within roughly two months, from November 1777 until mid-January 1778, Crell submitted no less than eleven pieces for Nicolai’s famous periodical. “I still owe you five reviews which shall follow quickly”, he wrote to the Prussian publisher in January. Nicolai received them by February.

Title page from the Chemisches Journal for 1778 Source: Wikimedia Commons

Title page from the Chemisches Journal for 1778
Source: Wikimedia Commons

Crell was aware that Nicolai had close ties to leading chemical investigators. The publisher was about to become an extraordinary member of the Prussian Academy of Sciences and chemical researchers such as Johann Christian Wiegleb and Johann Friedrich Gmelin contributed to the ADB. Wiegleb was a pharmacist who expanded his laboratory in Langensalza to teach chemistry. Wiegleb’s students lived, learned, and—most importantly—researched at his Privat-Institut. Johann Friedrich Göttling was one of Wiegleb’s pupils—as was the English industrialist Matthew Boulton.

Crell tried to tap into this network when he first contacted Nicolai. Maybe he even hoped to recruit the renowned chemical researchers for the inaugural issue of his Chemisches Journal. But the editor had to pace himself: the first issue of his periodical was almost entirely authored by himself and Johann Christian Dehne, a close friend and physician from a neighbouring village.

Ultimately, Crell’s concerted efforts as a regular contributor to the ADB and the editor of the Chemisches Journal paid off: all three—Wiegleb, Gmelin and Göttling—submitted articles for the second issue of Crell’s novel journal. Throughout the years many other joined them, including the Irish chemist Richard Kirwan, the Scottish researcher Joseph Black and the German Martin Heinrich Klaproth, the first professor of chemistry at the University of Berlin. Andreas Sigismund Marggraf, however, never published in Crell’s journal, maybe due to health issues following a stroke.

Crell devoted decades of his life to his journals. Within nearly 27 years he published nine periodicals, the longest-running and most famous of which is the Chemische Annalen (1784-1804). It was here that the German chemists debated (and death-bedded) phlogiston. During a busier year, such as 1785, Crell published over 2,000 pages of chemical facts, findings and flapdoodle.

Today, some scientists and historians belittle his role in chemistry, arguing that Crell did not contribute anything crucial to science. To judge Crell by what he did not achieve in his laboratory is to present science as a solitary undertaking, tucked away in labs. But if we acknowledge that science is a joint endeavour, based on communication, on-going exchange and discussions, Crell’s contribution appears vital.

According to the Berkeley-historian Karl Hufbauer, Crell’s Chemische Annalen was crucial in the formation of the German chemical community. Even more, Crell provided German and European researchers with an instrument for the production of chemical knowledge.

Today is the 200th anniversary of his death. Let’s use the date to commemorate all the editors throughout the centuries who spent countless hours at their desks—and contributed to the giant’s shoulders on which we stand today.

 

 

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Filed under Early Scientific Publishing, History of Chemistry, History of science

The Earth was definitely not flat in the Middle Ages

Gossuin de Metz L'image du monde

Gossuin de Metz L’image du monde

 

One of my most recent posts concerned the myth that people in the Middle Ages believed the world to be flat. Tim O’Neill, friend of the Renaissance Mathematicus, guest poster and frequent commentator, also added interesting comments to that post. Now he has gone one better and written an extensive blog post of his own on the subject on his History for Atheists website, The New Atheists Bad History Guide 1: The Medieval Flat Earth. Much more wide ranging and informative than my own brief rant it is definitely worth reading, so get on over there and do just that.

 

 

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Galileo Super Star – Galileo Galilei to get Hollywood biopic

My attention was drawn recently to a Hollywood gossip website that announced that a movie is to be made of a play by Richard Goodwin about Galileo, The Hinge of the World. I must admit that my curiosity was piqued, not least because I had never heard of either Mr Goodwin or his play and I naturally wondered what his line on the Tuscan mathematicus would be. It turns out that Richard Goodwin is a former high power Washington political advisor and speechwriter who served Presidents Kennedy and Johnson as well as JFK’s brother Robert, not exactly the best qualifications for the author of a play about the history of science. My doubts about this particular production were only heightened upon reading the full original title of the play, The Hinge of the World: In Which Professor Galileo Galilei, Chief Mathematician and Philosopher to His Serene Highness the Grand Duke of Tuscany, and His Holiness Urban VIII, Bishop of Rome, Battle for the Soul of the World. This title does not bode well for a historically accurate account of Galileo’s clash with the Catholic Church. However I will reserve judgement, because as I say, I do not know the play. I have however ordered a second hand copy that is at this very moment wending its way from some distant land to my humble abode and when it arrives and I have perused it with due diligence, I will report back with a critical assessment.

A scene from the stage production of The Hinge of the World

A scene from the stage production of The Hinge of the World

The website report does however offer a précis of the contents of the soon to be film and this is possibly the most confused and inaccurate presentation of the affair and the events leading up to it that I have read in a very long time:

The film will stay true to the spirit of the play in that it will revolve around the one-time friends whose vehement disagreements led to the Church calling Galileo out for heresy when science started to challenge long-held beliefs.

Science had been challenging long held beliefs long before Galileo came along. Apart from anything else Galileo was tried for defending the truth of Copernicus’ heliocentric hypothesis and Copernicus had died twenty-one years before Galileo was born. Just for the record Copernicus was also by no means the first person to present science that challenged the Church’s long-held beliefs.

Just to be a little bit pedantic, the one-time friends, Galileo and Maffeo Barberini (Pope Urban VIII) only had one vehement disagreement.

During that time, around 1610, the Church was never questioned,…

Somebody really ought to have consulted a historian of the Catholic Church. People both inside and outside of the Church questioned it continuous, some with impunity, for example Galileo’s friend Paolo Sarpi, and some with dire consequences, such as Giordano Bruno.

…yet Galileo who had a passion, curiosity and a telescope started to question everything after logging what he was learning through his scientific research. He published much of his findings in a book that were disavowed by Pope Urban VIII and the Catholic Church. Despite delving into dangerous territory, Galileo continued his research into comets, tide movements until he was ultimately ordered by the Church to stop teaching his ideas.

 The above is just a historical train wreck. The book of Galileo’s disavowed by Urban VII and the Church was the Dialogue Concerning the Two Chief World Systems, published in 1632, which led directly to his trail and imprisonment in 1633. However, he was told to stop teaching the truth of the heliocentric hypothesis and only that, the rest of his ideas were not the subject of Church condemnation, in 1616 following the semi-public distribution of the so-called Letter to Castelli, much later published in expanded form, as the Letter to the Grand Duchess Christina. Also in 1616 Paul V was Pope and Maffeo Barberini was a mere Cardinal and still a good friend of Galileo’s.

 The brilliant scientist, engineer, physicist and mathematician who helped discover the law of the pendulum (which became the basis for modern-day clocks), who pushed scientists to conduct experiments to prove theorems, who continued the work of Nicolaus Copernicus to help understand our own universe and laid the groundwork for modern astronomy eventually lost his battle with the powerful Roman Catholic Church.

Again being somewhat pedantic, Galileo got the law of the pendulum wrong and modern day clocks stopped being pendulum driven some time ago. Also, and this is not so pedantic, it was Kepler, and not Galileo, who laid the groundwork for modern astronomy.

 He was tried for heresy and sentenced to imprisonment at the age of 68 where he would remain until his death nine years later at age 77.

A final point, that people love to forget because it rather spoils the image of Galileo the martyr, his sentence of imprisonment imposed for vehement suspicion of heresy, not heresy, was instantly commuted to house arrest, which whilst somewhat restrictive was by no means harsh.

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All of this ties in rather nicely with an exchange that I took part in yesterday evening on twitter. Tim Skellet (@Gurdur) asked me and others, “what’s the very best, most comprehensive bio of Galileo, please?” My answer was, “I don’t think it exists. Read several: Wootton, Heilbron, Biagioli, Shea/Artigas.” I was not trying to be clever or awkward. I genuinely believe that if you wish to study any major figure out of the history of science then you should consult multiple sources, as all sources have their advantages and disadvantages. History is, to a large extent, a game of interpretation. There are facts but they only give a partial picture and it is the role or responsibility of the historian to complete that picture to the best of their ability. All historians have agendas and biases and to obtain a rounded picture it is always advisable to view the facts through the eyes of more than one historian.

Turning to the special case of Galileo, the two most recent complete biographies are J. L. Heilbron’s Galileo (OUP, 2010) and David Wootton’s Galileo: Watcher of the Skies (Yale University Press, 2010). Both are very good but differ in their interpretations and emphases. I wouldn’t recommend one over the other, so if you only want to read one then toss a coin or something. If you really want to get to grips with Galileo then read both. One important aspect of Wootton’s book is that he systematically dismantles the myth that Galileo was a good devout Catholic. This myth is trotted out regularly to make the Church look even worse for having persecuted him. Wootton demonstrates, I think convincingly, that Galileo was at best an indifferent Catholic and in no way the devout son of the Church that historical myth has made him out to be.

Although not a complete biography in the traditional sense I would also strongly recommend Mario Biagioli’s Galileo Courtier: The Practice of Science in the Culture of Absolutism (University of Chicago Press, 1993) Biagioli examines Galileo the social climber who uses his scientific discoveries to further his social status rather than for any idealistic belief in truth. Biagioli’s work is a useful complement to the more conventional scientific style of biography; what did Galileo discover and when. In what is effectively a second volume to his first book, Galileo’s Instruments of Credit: Telescopes, Images, Secrecy (University of Chicago Press, 2006), Biagioli explains how Galileo used the telescopes that he manufactured and the images that he produced to broker social advantages.

William R. Shea’s and Mariano Artigas’ Galileo in Rome: The Rise and Fall of a Troublesome Genius (OUP; 2003) just deals with the six extended visits that Galileo made to Rome, the home-base of the Church and the centre of political and social power in the period, during his lifetime. These include, his triumphal visit in 1611, as the author of his sensational Sidereus Nuncius, his visit in 1615-1616 and his failed attempt to prevent the Church condemning heliocentricity and finally his summons to his trial in 1633. By concentrating only on Galileo’s interactions with the Roman culture of the period the authors succeed in shedding light from a different angle on Galileo’s fateful path to his condemnation and fall.

At some point David Wootton joined the Twitter discussion and he recommended Pietro Redondi’s Galileo Heretic (Princeton University Press, 1992), a recommendation that I would one hundred pro cent endorse. Although Redondi’s central thesis, that Galileo was actually attacked by the Church for his atomism has, in the meantime, been largely refuted this is a superb book and still very much worth reading by anyone who wishes to learn about Galileo and the culture in which he lived and worked.

If you read all of the books that I have recommended above you should, by the time you have finished, have a fairly good all round picture of the life and work of Galileo Galilei and the footnotes and bibliographies will have given you lots of information for further reading. I will however close with a warning, do not read Michael White’s Galileo Antichrist: a Biography (Weidenfeld & Nicolson, 2007). I can deliver a comprehensive and profound review of White’s book in three words, “It is crap!”

 

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Repeat after me! – They knew it was round, damn it!

Last week saw various reports about a rare stolen copy of a Columbus letter that had turned up in the Library of Congress and has now been restored to its Italian owners; a comparatively happy end to one of a series of recent stories about the theft of precious books and documents from archives and libraries. Unfortunately the report on the website of NPR (that’s National Public Radio a non-commercial public American educational radio network) opened with the following paragraph:

The heist of a major historical document apparently went undiscovered for more than 20 years. Now, a stolen letter from Christopher Columbus spreading the news that the world isn’t flat has been returned from the U.S. to Italy.

As some readers might already have guessed the second sentence, specifically the phrase spreading the news that the world isn’t flat, had me screaming and banging my head against the wall to relieve the pain. This is just horrendously wrong in several different ways.

Posthumous portrait of Christopher Columbus by Sebastiano del Piombo, 1519. There are no known authentic portraits of Columbus. Source: Wikimedia Commons

Posthumous portrait of Christopher Columbus by Sebastiano del Piombo, 1519. There are no known authentic portraits of Columbus.
Source: Wikimedia Commons

On his first voyage Columbus set sail from Spain in September 1492 and after approximately a month of sailing westward he landed on a set of previous unknown islands, unknown to the Europeans that is. This voyage proves or disproves absolutely nothing about the shape of the earth. To even contemplate a voyage proving the earth to be spherical and not flat we would have to fast forward thirty years to the return to Spain of the one ship and eighteen men from Ferdinand Magellan’s disastrous circumnavigation in 1522; just for the record Magellan was not one of the eighteen survivors, so to call him the first man to circumnavigate the world, as many people do, is simply false. Some flat-earthers could, and probably do/did, argue that Magellan’s fleet just sailed round in a circle on a flat disc and not around a spherical earth so even that is not a totally convincing proof (even if the objection is somewhat iffy).

Let us return to the good Cristoforo. One could argue that he set sail westward to reach the Spice Islands, instead of heading to the east, as was normal because he believed the earth to be a sphere and also believed that that sphere was small enough that the route west to the Spice Islands was shorter and thus quicker than the route east (A belief, as it turns out, that was based on faulty calculation, of which more later). Having reached what he erroneously believed to be the Spice Islands, leading to the equally erroneous name, the West Indies, he believed that he had proved the world to be spherical. There is however a fundamental flaw in this argument. Columbus did not sail westward because he believed the earth to be a sphere; he did so because he, like almost every other educated European, knew that it was a sphere, knowledge that had been part of the European cultural heritage for the best part of two thousand years.

This should in the meantime be well known, but for those, like the NPR reporter(s), who have been sitting at the back and not paying attention let us pass review over those two thousand years.

We have no direct records but latter authors tell us that the Pythagoreans in the sixth century BCE already accepted that the earth was spherical. Their reasons for doing so are unknown but it was possible in analogy to the celestial sphere of the so-called fixed stars. If you look up into the heavens on a clear dark night the sky appears to take the form of an inverted bowl or hemisphere. By the latest in the fourth century BCE, Aristotle, who would go on to have a massive influence on European intellectual history, knew that the earth was spherical and he offers up a series of empirical proofs for this claim. For example he wrote, “there are stars seen in Egypt and […] Cyprus which are not seen in the northerly regions.” Since this could only happen on a curved surface, he too believed Earth was a sphere “of no great size, for otherwise the effect of so slight a change of place would not be quickly apparent.” (De caelo, 298a2–10). He also pointed out that the shadow of the earth on the moon during a lunar eclipse is circular. Following Aristotle all Greek schools of philosophy accepted that the earth was spherical and following them the Romans. There was no doubt in the classical world that the earth was a sphere. Ptolemaeus, the most influential Greek astronomer, brought a series of arguments and proofs for the spherical form of the earth in his Syntaxis Mathematiké (Almagest) in the second century CE. Most notably that as ships approach over the horizon one sees the top of the mast before one sees the hull.

A lot of this specific knowledge got temporarily lost within Europe in the Early Middle Ages but still almost nobody who was educated doubted that the earth was a sphere. With the rise of the Islamic empire the astronomers writing in Arabic adopted the views of Aristotle and Ptolemaeus including the spherical form of the earth.

Back in the third century BCE the astronomer mathematician Eratosthenes from Alexandria determined the size of the sphere using the angle of the sun’s shadow and a bit of basic trigonometry. He achieved a fairly accurate result, its accuracy depends on which Stadia (an ancient measure of length) you think he used; we don’t know for certain. Other geographers and astronomers also determined the size of the earth’s sphere; all arriving at reasonable ball park figures. Ptolemaeus, in his Geōgraphikḕ (Geography) also determined that the known land area the oikoumenè, Europe, Africa and Asia, stretched over 180° of the earth’s surface from east to west.

In the High Middle Ages, Europe regained this knowledge, largely via the Islamic Empire through Spain and Sicily. The standard European university astronomy text Johannes de Sacrobosco’s De sphaera mundi, written in the twelfth century CE, contained all the standard Greek arguments for a spherical earth including the lunar eclipse shadow, ship breasting the horizon and the change in visible asterism travelling from south to north. There existed no doubt amongst the educated in the Middle Ages that the earth was a sphere.

Picture from a 1550 edition of De sphaera, showing the earth to be a sphere. Source: Wikimedia Commons

Picture from a 1550 edition of De sphaera, showing the earth to be a sphere.
Source: Wikimedia Commons

When Columbus started making his plans at the end of the fifteenth century he knew that the world was a sphere, as did all of the people he tried to get to back his scheme. The only disputed point was how big the earth’s sphere was, how long the central landmass, Europe, Africa and Asia, was and thus how far the Spice Islands were if one sailed west from Europe. It was here that Columbus made some fundamental calculating errors. The Arabic astronomer al-Farghānī gave 5623 Arabic miles (being 111.8 km) as the length of one degree of longitude, whereas Ptolemaeus gave 6023 Roman miles (being 89.7 km). Columbus took al-Farghānī’s figure but multiplied it with the length of a Italian mile (much shorter than the Arabic one) to determine the circumference of the earth thus arriving at a figure that was far too small: approx. 25,255 km instead of al-Farghānī’s very accurate figure of 40,248 km. Ptolemaeus’ estimate of the spread of the main landmass was 180°, whereas it is in fact only about 130°. Columbus however took the even more inaccurate estimate of Marius from Tyre of 225°. The sum of these error meant that Columbus thought he only had about 3,700 km from the Canary Islands to Japan instead of the real 19,600 km! Having convinced his sponsors of the correctness of his calculations he set sail. If America had not been in the way Columbus and his entire crew would have stared starved to death on the open ocean.

So where does the myth of the flat earth come from? There were a few European scholars in antiquity and the early Middle Ages who, against the evidence, still argued that the earth was flat. However none of them enjoyed much support. One of the ironies of history is that Copernicus probably drew attention to the most famous of them, the third century cleric Lucius Caecilius Firmianus Lactantius, by mentioning him in his De revolutionibus. The real myth of the medieval flat earth begins first in the eighteenth and nineteenth centuries and has two principal sources. Probably the most influential of these was the American author Washington Irving who in his fictional biography of Columbus claimed that Columbus had to fight against the Church’s belief that the world was flat in order to get permission and backing for his voyage, a complete fabrication. This falsehood was supported by the nineteenth centuries false interpretation of the medieval T and O Mappa Mundi.

The Hereford Mappa Mundi, about 1300, Hereford Cathedral, England. Source: Wikimedia Commons

The Hereford Mappa Mundi, about 1300, Hereford Cathedral, England.
Source: Wikimedia Commons

These medieval world maps were in the form of a circle, the O, with the three known continents, Europe, Africa and Asia, displayed in the form of a T with east at the top. These maps were interpreted in the nineteenth century as indicating that the medieval cartographers believed the earth to be a flat disc. This is not without irony as they were circular in order to indicate that the world in a sphere. The myth of the flat medieval world was taken up by two figures well known to readers of this blog John William Draper (1811–1882) and Andrew Dickson White (1832–1918) in their widespread myth of the eternal war between religion and science. Science believing in a spherical earth whereas the reactionary Church believed in a flat one.

That Europe in the Middle Ages believed in a flat earth is a total myth that just doesn’t seem to want to die. The next time somebody tells you that the medieval Church thought the world was flat, or that Columbus was a revolutionary for believing in a spherical earth or any other version of this nonsense, do me a favour, take a large, heavy, flat, round, metal object, such as a frying pan, and beat them around the head with it.

 

 

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

Bertrand Russell did not write Principia Mathematica

Yesterday would have been Bertrand Russell’s 144th birthday and numerous people on the Internet took notice of the occasion. Unfortunately several of them, including some who should know better, included in their brief descriptions of his life and work the fact that he was the author of Principia Mathematica, he wasn’t. At this point some readers will probably be thinking that I have gone mad. Anybody who has an interest in the history of modern mathematics and logic knows that Bertrand Russell wrote Principia Mathematica. Sorry, he didn’t! The three volumes of Principia Mathematica were co-authored by Alfred North Whitehead and Bertrand Russell.

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Now you might think that I’m just splitting hairs but I’m not. If you note the order in which the authors are named you will observe that they are not listed alphabetically but that Whitehead is listed first, ahead of Russell. This is because Whitehead being senior to Russell, in both years and status within the Cambridge academic hierarchy, was considered to be the lead author. In fact Whitehead had been both Russell’s teacher, as an undergraduate, and his examiner in his viva voce, where he in his own account gave Russell a hard time because he knew that it was the last time that he would be his mathematical superior.

Alfred North Whitehead

Alfred North Whitehead

Both of them were interested in metamathematics and had published books on the subject: Whitehead’s A Treatise on Universal Algebra (1898) and Russell’s The Principles of Mathematics (1903). Both of them were working on second volumes of their respective works when they decided to combine forces on a joint work the result of the decision being the monumental three volumes of Principia Mathematica (Vol. I, 1910, Vol. II, 1912, Vol. III, 1913). According to Russell’s own account the first two volumes where a true collaborative effort, whilst volume three was almost entirely written by Whitehead.

Bertrand Russell 1907 Source: Wikimedia Commons

Bertrand Russell 1907
Source: Wikimedia Commons

People referring to Russell’s Principia Mathematica instead of Whitehead’s and Russell’s Principia Mathematica is not new but I have the feeling that it is becoming more common as the years progress. This is not a good thing because it is a gradual blending out, at least on a semi-popular level, of Alfred Whitehead’s important contributions to the history of logic and metamathematics. I think this is partially due to the paths that their lives took after the publication of Principia Mathematica.

The title page of the shortened version of the Principia Mathematica to *56 Source: Wikimedia Commons

The title page of the shortened version of the Principia Mathematica to *56
Source: Wikimedia Commons

Whilst Russell, amongst his many other activities, remained very active at the centre of the European logic and metamathematics community, Whitehead turned, after the First World War, comparatively late in life, to philosophy and in particular metaphysics going on to found what has become known as process philosophy and which became particularly influential in the USA.

In history, as in academia in general, getting your facts right is one of the basics, so if you have occasion to refer to Principia Mathematica then please remember that it was written by Whitehead and Russell and not just by Russell and if you are talking about Bertrand Russell then he was co-author of Principia Mathematica and not its author.

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Filed under History of Logic, History of Mathematics