Aristocrats and paupers, farmers and tradesmen – Where do the scientists come from?

A few days ago on Twitter I stumbled across the following exchange, a certain Alex Wild (@Myrmecos) tweeted:

What does it say about modern science that most of the #scienceamoviequote tweets are about grants, publishing, tenure, and careers?

To which Claus Wilke (@ClausWilke) responded:

200 years ago no scientist worried about grants, tenure, careers.

All were wealthy lords with free time on their hands.

Or monks.

To which Gomijacogeo (@gomijacogeo) added:

Or had patrons…

Yours truly, as ever, eager to play Whac-A-Mole with any myth in the history of science, as soon as it pops its head above the parapet, it not being the first time that I’ve seen the same or similar expressed, reciprocated:

Sorry, but that is simple not true.

Referring to Claus Wilke’s comment rather than Gomijacogeo’s, which does have a certain amount of historical validity.

This brief exchange led me to think about the origins of the various figures from the history of science that I write about on a fairly regular basis and what follows is a totally informal survey of the backgrounds of those scholars. Mr Wilke’s remark only extends back to 1815 but my survey goes back to the fifteenth century on the principle that the further back one goes the more likely it is that a scholar needs to be independently wealthy or a monk.

Johannes Müller, aka Regiomontanus, was most probably the son of miller, miller by name miller by trade, who was obviously wealthy enough to send his son to university, where he became a lecturer on having completed his studies. Later he enjoyed the support of a series of patrons over a period of about fifteen years until his death. As is all too often the case, we no nothing about the background of Regiomontanus’ teacher Georg von Peuerbach before he became a lecturer at the University of Vienna. We do however know that he enjoyed the patronage of various kings and emperors in his role as an astrologer.

Moving into the sixteenth century we little about the backgrounds of the three Nürnberger mathematicians, Johannes Werner, Georg Hartmann and Johannes Schöner but all three were university graduates and all three held secure but relatively lowly and poorly paid jobs in the church, which however gave them the freedom to pursue their diverse mathematical activities. Georg Rheticus who knew all three of the Nürnberger came from a wealthy bourgeois background, although his father a town physician was executed for theft and fraud when he was a child. His mother was, however, independently wealthy and Achilles Grasser, another town physician, took over guiding his education until he became a university lecturer. Rheticus of course brought Copernicus’ magnum opus, De revolutionibus, to the world and it is to the good Nicolaus that we now turn. His father was a rich businessman, who also passed away whilst Copernicus was still a child. In his case his career was directed and supported by his uncle, Lucas Watzenrode, who was Prince Bishop of Ermland and thus a very powerful patron who also secured a church sinecure for his nephew, who thus needed never to work in his whole life, although he did take on important administrative posts in the Bishopric of Frauenburg.

Up until now with had quite a lot of wealthy and important patrons but not one wealthy lord, as a scholar in his own right. This changes with Tycho Brahe who was a genuine, bone fide, wealthy aristocrat, whose scientific career was footed on a very generous appanage from the Danish Crown, although as I have pointed out in an earlier post his appanage would almost certainly have been much larger had he decided to become a courtier instead of an astronomer.

The opposite end of the scale can be found in Tycho’s most famous assistant Johannes Kepler. His parents were poor, mostly working as innkeepers, although his father was a mercenary who regularly disappeared of to war and at some point never came back. Kepler, very obviously a gifted child, only got an education because of the very generous scholarship scheme that existed at the time in Baden-Württemberg to educate the large number of Protestant priest and school teachers needed following the conversion from Catholicism. Kepler then worked as a schoolteacher and district mathematician, a lowly paid job, in Austria before moving to Prague and becoming Tycho’s assistant and shortly afterwards his successor as Imperial Mathematicus. This was in theory a well-paid position but, as was all too often the case with royal and aristocratic patrons, actually getting paid was a major problem. Kepler would later enjoy the patronage of the Catholic General Albrecht Wenzel Eusebius von Waldstein, better known as Wallenstein, although I’m not sure that enjoy is the right word for their relationship.

With Kepler’s great rival in the heliocentricity stakes, Galileo Galilei, we have another aristocrat albeit a minor impoverished one, with an emphasis on impoverished. This is probably the reason that his father wanted him to study medicine, a profession that would guarantee a good income. Unfortunately he chose instead to become a mathematician a profession that was notoriously badly paid in the early seventeenth century. Galileo became a university professor for mathematics and despite subsidiary income from his thriving instrument workshop and providing boarding for students, a common practice amongst Renaissance professors, he was always infamously hard up. This was partially because he enjoyed la dolce vita and lived beyond his means and partially because of the financial demands of his brother and sisters for whom he took over responsibility after the death of his father. This is probably the main reason that Galileo used his scientific discoveries as capital to acquire the patronage of the Medici and became a courtier, leaving academia behind him.

Simon Marius, astronomical colleague, of both Kepler and Galileo, although his relations with both of them were fraught, was the son of a barrel maker and relied on the patronage of the local lord of the manor to obtain his education. The same lord then employed him as court astrologer thus ensuring that he could devote his live to his scientific activities.

Christoph Clavius, about whose background we know absolutely nothing, was like all the other Jesuit mathematicians and astronomers, who I’ve written about over the years, a monk. Although it should be remembered that the Jesuits were/are essentially a teaching order so the scientific Jesuits can almost be considered as proto-professional scientist (excusing here the anachronistic use of the term scientist and it further uses in this post).

Mathematician and physicist, Marin Mersenne, was a genuine monk who conducted his voluminous scientific correspondence from his humble monk’s cell. His colleague, contemporary and fellow Jesuit academy graduate, René Descartes was the son of a wealthy lawyer and politician, who after graduating from university as a lawyer became a mercenary. After he retired from soldiering he lived from his inherited wealth although he also had patrons at different stages of his life. Pierre Gassendi, a priest who lived and worked as a university professor, came from a similar bourgeois background. Holland’s most famous Cartesian, Christiaan Huygens was the son of a wealthy Dutch aristocrat, who however on his appointment to the French Académie des sciences became a, highly paid, professional scientist.

Crossing the channel to the British Isles we meet another aristocrat in the form of Robert Boyle, who was wealthy enough to live the life of an independent scholar. Boyle’s closest colleague and one time assistant, Robert Hooke, was the exact opposite. Born the son of an Anglican curate he was left almost penniless when his father died. Hooke had to strive for everything he got in life and his inherent feelings of social inferiority might go a long way to explaining his less than pleasant character. Hooke strove well, dying a wealthy man, money earned by his own honest labour. No patronage here.

Hooke’s nemesis Isaac Newton was the son of a yeoman farmer, albeit a wealthy one. Later in life when he inherited them, the Newton acres generated an annual income of six hundred pounds per annum, not bad compared to the one hundred pounds per annum paid to the Astronomer Royal, for example. Newton’s mother, however, put him through university as a sizar, a student who earns his tuition fees by working as a servant to other students. After graduating MA for which he had received a fellowship, Newton became Lucasian Professor and later, famously, warden of the mint thus earning his own living without patronage. Newton’s sidekick Edmond Halley was the son of a wealthy soapboiler, a not especially romantic profession but obviously a profitable one, as Halley inherited a substantial fortune after his father was murdered. Halley would go on to hold various positions including Savilian Professor and most notably Astronomer Royal.

At the moment I’m (supposed to be) preparing a lecture on the eighteenth-century pneumatic chemists, so let us now turn our attention to them. Stephen Hales was the son of a Baronet, a purchasable title, who went on to become an Anglican clergyman. Although this survey does not include many of them, clergymen made considerable contributions to the sciences, as amateurs, throughout the eighteenth and nineteenth centuries. Joseph Black was the son of a wine trader who after a very successful studentship went on to become professor of medicine and chemistry and thus a professional scientist. Black’s student Daniel Rutherford was the son of a professor of medicine and went on himself to become a professor of botany. William Brownrigg the son of landed gentry became a medical practitioner. Henry Cavendish was a scion of one of the oldest and most powerful aristocratic families in Britain, who was thus, like Robert Boyle, able to lead the life of a gentleman scientist, making him the third scientist to fulfil the cliché expressed in the tweet that prompted this post. The most famous of the pneumatic chemists, Joseph Priestley, was the son of a cloth finisher, supported by wealthy relatives he studied to become a dissenting preacher and teacher both of which professions he practiced for many years before relatively late in life moving to Birmingham, where he effectively became house chemist to the Lunar Society. For a number of years he had been private tutor to the children of Lord Shelburne, who might thus be considered a patron.

The astronomer William Herschel was the son of a military musician who followed his father into the Hanoverian army as an oboist. After a military defeat he fled to Britain (as a deserter!) where he successfully established himself as an organist, composer, conductor and music teacher, astronomer was his hobby. Following the discovery of Uranus he was appointed The King’s Astronomer, enjoying the patronage of George III and able to devote himself full time to the study of the stars.

Closing out in the nineteenth century with three rather random scientists, all of who achieved notoriety and fame, Joseph Fraunhofer, Humphry Davy and Michael Faraday all started life in poor families but went on, largely through their own efforts to become professional scientists who help shape modern science.

The above is, of course, all anecdotal and as is well known the plural of anecdote is not data. However I think that it demonstrates that at least since the fifteenth century, in Europe, men who went on to become important contributors to the evolution of science could and did come from a wide variety of backgrounds and managed to conduct their investigation through an equally wide variety of channels. They were by no means all “wealthy lords with time on their hands or monks”.

On the subject of patronage, which helped many of those I have sketched to follow their chosen paths in the sciences. I personally don’t see a great deal of difference between a wealthy ruler in the Renaissance supporting the work of an outstanding researcher and some modern international business conglomeration paying for a new research facility at some modern elite university. Both are institutions with substantial resources, which see the utility of supporting scientific research for whatever reasons they might have.




Filed under History of science, Myths of Science

Misusing Galileo to criticise the Galileo gambit

Yesterday The Guardian website had an article on climate change denialists entitled, Here’s what happens when you try to replicate climate contrarian papers[1].

The article is headed with this portrait of Galileo

Galileo demonstrating his astronomical theories. Climate contrarians have virtually nothing in common with Galileo. Photograph: Tarker/Tarker/Corbis

Galileo demonstrating his astronomical theories. Climate contrarians have virtually nothing in common with Galileo. Photograph: Tarker/Tarker/Corbis

And it opens with the following paragraph:

Those who reject the 97% expert consensus on human-caused global warming often evoke Galileo as an example of when the scientific minority overturned the majority view. In reality, climate contrarians have almost nothing in common with Galileo, whose conclusions were based on empirical scientific evidence, supported by many scientific contemporaries, and persecuted by the religious-political establishment. Nevertheless, there’s a slim chance that the 2–3% minority is correct and the 97% climate consensus is wrong.

Now it is true that climate change denialists, like denialists in many other areas of scientific consensus, commonly use what is now known as the Galileo Gambit. This involves claiming in some way that Galileo was persecuted for his theories, although he was proved right in the long run. Implying that the denialist will also be proved right in the long run and hailed as another Galileo. Bob Dylan provided the perfect answer to the Galileo Gambit in his song Bob Dylan’s 115th Dream way back in 1965.

I said, “You know they refused Jesus, too”

He said, “You’re not Him

I would not object to the author’s comments on the contrarians misuse of the name of Galileo if her his comment had stopped at, climate contrarians have almost nothing in common with Galileo, however she he goes on to spoil it with what follows.

Although Galileo’s views on heliocentrism, and that is what stands to discussion here, had their origins in empirical observations made with the telescope he unfortunately did not stop there and they were not supported by a consensus of his contemporaries by any means. In fact at the time of Galileo’s trial by the Catholic Church the majority of astronomers qualified to pass judgement on the subject almost certainly rejected heliocentricity, most of them on good scientific grounds.

In his Dialogo, the book that caused his downfall, Galileo knew very well that he did not have the necessary empirical facts to back up the heliocentric hypothesis and so he resorted to polemic and rhetoric and brought as his pièce de résistance, his theory of the tides, which was fatally flawed and contradicted by the empirical evidence even before it hit the printed page.

Although it became largely accepted by the experts by around 1670, the necessary empirical evidence to substantiate heliocentricity didn’t emerge until the eighteenth and in the case of stellar parallax the nineteenth centuries.

I have written about this historical misrepresentation of Galileo’s position on various occasions and I don’t intend to repeat myself in this post. However anybody who is interested can read some of my thoughts in the post collected under the heading, The Transition to Heliocentricity: The Rough Guides. I also strongly recommend Christopher M. Graney’s recently published Setting Aside All Authority: Giovanni Battista Riccioli and the Science against Copernicus in the Age of Galileo, my review of which should, hopefully, appear here in the not to distant future.

Addendum: Seb Falk has pointed out that Dana Nuccitelli is a he not a she and I have made the necessary corrections to the text. I apologise unreservedly to Mr Nuccitelli for this error.

[1] h/t to Seb Falk (@Seb_Falk) for drawing my attention to this latest misstatement of Galileo’s scientific situation.


Filed under History of Astronomy, Myths of Science

Printing mistakes

Today during my usual early morning perusal of my Twitter steam I came across the following tweet:

Today is not just the anniv. Of Gutenberg printing his first bible, this is the day of our literacy liberation

Now I found this tweet, to say the least, more than somewhat bizarre, as we are not even certain in which year Gutenberg printed his first bible let alone on which day. In fact it is absolutely certain that there was no publication date for this epoch defining work but that it rather dribbled gradually into the public sphere over quite a wide period of time. That this supposed anniversary is totally fictitious is confirmed by a Time magazine article from yesterday:

It’s hard to pin down the exact day the book was born, but August 24 is as fine a day to celebrate as any: it was on this day in 1456 that at least one copy of the original Gutenberg Bible was completed.

It seems that it is in order now to make up historical anniversaries.

My curiosity awakened I read through the responses to this tweet and stumbled across this even more fascinating claim concerning the history of printing:

How about “Muslims were practising the craft of printing for some five centuries before Gutenberg”

Now I’ve read an awful lot about the history of printing and although I’m well aware that Gutenberg was by no means the first person to invent movable type I was not familiar with any Muslim predecessors, in fact I thought the exact opposite to be true; that is the Arabic Empire had never invented our acquired movable type printing. So it was with some interest that I followed the supplied link to an article with the title Muslim Printing Before Gutenberg.

The article starts with a whole paragraph presenting an overblown statement of the author’s qualifications and expertise for writing the article. I wouldn’t mention this if the article didn’t contain a fundamental flaw, which I will elucidate shortly and which no qualified expert should have made. We will let the author introduce himself in all his glory:

Dr Geoffrey Roper is an international bibliographical and library consultant, working with the Institute for the Study of Muslim Civilisations in London and other scholarly bodies. Educated at the University of Durham and the American University in Cairo, he was from 1982 to 2003 head of the Islamic Bibliography Unit at the University of Cambridge and editor of Index Islamicus, the major current comprehensive bibliography and search tool for publications on all aspects of Islam and the Muslim world. He has also been editor of Al-Furqan Foundation’s World Survey of Islamic Manuscripts, Chairman of the Middle East Libraries Committee (MELCOM-UK) and contributor to various reference works. He has researched, written and lectured extensively on bibliography and the history of printing and publishing in the Muslim world, and has curated exhibitions on the subject at Cambridge University Library and the Gutenberg Museum in Mainz. He is currently an Associate Editor of the forthcoming Oxford Companion to the Book. For a comprehensive list of his publications, see below at the end of this article.

We now turn to Gutenberg and the history of printing:

The 15th-century German craftsman Johannes Gutenberg of Mainz is often credited with inventing the art and craft of printing. There is no doubt that this brought about a tremendous revolution in human communication and accumulation of knowledge, but was it really “invented” in 15th-century Europe?

The straight answer to Roper’s question is no, and once again I shall be returning to it again shortly. Roper gives he own answer to his question.

Gutenberg does seem to have been the first to devise a printing press, but printing itself, that is, making multiple copies of a text by transferring it from one raised surface to other portable surfaces (especially paper) is much older. The Chinese were doing it as early as the 4th century, and the oldest dated printed text known to us is from 868: the Diamond Sutra, a Chinese translation of a Buddhist text now preserved in the British Library

This answer is totally correct as far as it goes, except that the earliest examples of Chinese printing date back to the second century CE. So far so good but what about the Muslims? Roper now turns to them:

What is much less well known is that, little more than 100 years later, Arab Muslims were also printing texts, including passages from the Qur’an.

This I have to admit was new to me and an interesting addition to my knowledge of the history of printing. It should be pointed out, because it is somewhat ambiguous, that 100 years later is one hundred years after the printing of the Diamond Sutra and not after the fourth century. What follows, is some details of the history of Arabic printing and the inevitable question as to whether it influenced the introduction of printing into Europe; for which Roper admits there is no evidence before he closes with the conclusion already stated in the title:

What is not in doubt is that Muslims were practising the craft of printing for some five centuries before Gutenberg.

I wouldn’t deny this statement so what’s my beef? Why am I writing this post and what is the author’s fundamental flaw that I alluded to earlier?

Our supposed expert on printing is, in his article, confounding and confusing two different technologies, block printing, and movable type printing, which whilst related are not the same at all. Worse than this, his claim that the Muslims got there five hundred before Gutenberg is based on this confusion.

His article is about the history of block printing, that is when a relief is cut out of a block of material, wood or as many of us know from our childhood even the humble potato, is smeared with some form of pigment, paint or ink, then pressed on to an absorbent surface, fabric, paper or whatever, to produce a reverse image of the cut out relief. All of the printing that Roper describes is block printing including the Diamond Sutra, the earliest known example of a so-called block book. This technique has its origins in the shapes pressed into unfired clay using seals and stamps, going back thousands of years, and as a form of printing appears to have first appeared in China around the beginning of the Common Era.

What Gutenberg is credited with having introduced into Europe is movable type printing, a different beast altogether. In moving type printing the texts to be printed are composed of individual letters carved or cast in reverse, which can be then taken apart and reused in different combination multiple times.

This technology was not first invented by Gutenberg but had been invented several times before. The Chinese used both wood and ceramic movable type in the eleventh century CE, the latter replacing the former as it proved problematic. The Chinese were also using bronze metallic movable type by the twelfth century CE, using it to print money and documents. There is evidence that they also used it to print books but the oldest surviving Chinese book printed using movable type post dates Gutenberg. The Koreans are known to have printed books using bronze movable type in the thirteenth century CE but the oldest surviving Korean printed book dates from the fourteenth century, i.e. before Gutenberg.

This brief sketch of the history of printing throws up some interesting questions. If block printing dates back to the first century CE, or possibly even earlier, why did this technique only appear in Europe in the fifteenth century around the same time as Gutenberg invented his version of movable type printing? I know of no reasonable answer to this question.

Did Gutenberg or the other Europeans who were experimenting with movable type around the same time have knowledge of the Asian movable type? Was there a technology transfer? This question has been thoroughly investigated from all sides by many scholars and absolutely no evidence of a technology transfer has been found leading to the tentative conclusion that Gutenberg’s was an independent invention. It should also be pointed out that Gutenberg seems to have been the first to use movable type in a printing press and also to have been the inventor of an oil based ink that greatly facilitated the process of printing on paper.

Another interesting question that relates directly to Roper’s article is, if the Muslims acquired the technique of paper making (along with many other things) from the Chinese, which Roper mentions in his article, and which they passed onto the Europeans through Spain, why didn’t they also acquire the technique of movable type printing? This is a question that has also been investigated by many scholars without reaching any really convincing conclusions.

I find Roper’s article both disingenuous and disturbing. For people not knowledgeable in the various types of printing and their histories it would appear that Roper has uncovered another example of Europeans claiming credit for an invention that by rights belongs to the Muslims of the Arabic Empire. However this is not the case and I personally think that somebody as qualified as Roper should have made this clear in his article.


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Filed under History of Technology

To Explain the Weinberg: The discovery of a Nobel Laureate’s view of the history of science

In my dim and distant youth, I was an ardent fan of twentieth-century physics and consumed a large quantity of popular books and articles (mostly New Scientist and Scientific American) on the subject as well as graduating to some high-grade serious history of science on both relativity and quantum physics. One of the books I read was The First Three Minutes: A Modern View of the Origin of the Universe by theoretical physicist and Nobel Laureate Steven Weinberg. This book impressed me very much, as it did the reviewers at the time, and I came away with a deep respect for Steven Weinberg as a science writer. Now in his eighties Weinberg is still highly active and this year he published his own history of science, To Explain the World: The Discovery of Modern Science. This book proved to be highly contentious because of Weinberg’s avowed presentist approach to writing history of science and its appearance generated a lot of debate some of which I collected in one edition of Whewell’s Gazette (scroll down to book reviews). This situation led me to the thought that I should read and review Weinberg’s tome for myself, a thought that for various reasons didn’t really appeal. However rescue was at hand. Chris Graney, Renaissance Mathematicus friend and more than welcome guest blogger, has taken on the task, read, analysed and reviewed To Explain the World and it is with great pleasure and some relief (I won’t have to read it after all) that I present his thoughts on Weinberg’s book to the eager readers of the Renaissance Mathematicus.

In To Explain the World: The Discovery of Modern Science, author Steven Weinberg covers science history from the Milesians of ancient times to the Standard Model of today. His emphasis is on physics and astronomy, and he includes thirty-five ‘Technical Notes’ for the mathematically advanced reader that explain the physics and mathematics of things such as ellipses, refraction, and centripetal acceleration. His treatment of science’s history is not just a re-hashing of stock stories: he gives attention to Tycho Brahe; he does not lionize Galileo. He tries to show what he thinks science is and is not. The average Joe or Jane who has a casual interest in science and history and wants an overview by a prominent scientist should read the book. He or she will learn quite a few things, most of them not wrong.

However, the Renaissance Mathematicus is about neither casual interest in the history of science, nor history in which most things are not wrong, nor deference to prominent authors. And so, having generally recommended this book, I have two big specific criticisms of it: one regards facts; and the other regards philosophizing.


Weinberg makes factual errors. For example, in Chapter 10 on Medieval Europe, he discusses how the French cleric Jean Buridan rejected the Aristotelian idea that all motion requires a mover and introduced the idea that objects remain in motion once set in motion. Buridan called this impetus. Weinberg mischaracterizes impetus, saying that it was a foreshadowing of the modern idea of momentum, not momentum itself. “He [Buridan] never identified the impetus carried by a body as its mass times its velocity,” writes Weinberg (p. 133), “which is how momentum is defined in Newtonian physics.”

This is not correct. Buridan wrote regarding impetus that a moving body is impressed with —

…a certain impetus or a certain motive force of the moving body, in the direction toward which the mover was moving the moving body, either up or down, or laterally, or circularly. And by the amount the [mover] moves that moving body more swiftly, by the same amount it will impress in it a stronger impetus… by the amount more there is of matter, by that amount can the body receive more of that impetus and more intensely.

Thus Buridan plainly says that impetus is proportional to mass and proportional to velocity. That is mass-times-velocity momentum. He differs from modern momentum only in that he does not separate angular momentum, moment of inertia, etc. He uses momentum to explain the motion of bouncing balls, vibrating strings, and falling bodies in a manner consistent with Newtonian physics. He says that in the absence of resistive forces that will corrupt momentum, an object will continue in motion forever.

The Buridan quote above is from Edward Grant’s Source Book in Medieval Science p. 276-277. Weinberg cites the Source Book twice in that chapter, but not regarding Buridan. Regarding Buridan he cites the Dictionary of Scientific Biography.

Buridan is not the only instance of Weinberg getting things wrong. He says a number of weird things about the appearance of stars, mostly because he insists on discussing the stars in modern terms of brightness, rather than of size as they were traditionally viewed. He tries to explain the term magnitude (p. 88), never drawing the connection to size. This creates problems in a number of places, most notably when he wonders how Copernicus could speak of the Sun, Moon, planets, and stars all being seen to be circular in shape — “how could [Copernicus] know anything about the shape of the stars?” Weinberg asks (p. 155; I wonder how he thought Copernicus might know anything about the shape of the planets?). The answer is found by looking at the sky with good eyes. Then one sees that Copernicus (like Ptolemy and Tycho and many others) was right and that all these bodies do appear round to the eye. They appear as little round dots — the more prominent ones look like larger round dots, the less prominent like smaller round dots. Thus the term magnitude — size — and thus Copernicus’s comments.

There are other examples of, if not errors, at least odd phrasing:

  • Weinberg tries (p. 58) to distinguish a gnomon (“simply a vertical pole, placed in a level patch of ground open to the Sun’s rays”) from a sundial (“different from a gnomon; its pole is parallel to the Earth’s axis rather than to the vertical direction, so that its shadow at a given hour is in the same direction every day. This makes a sundial more useful as a clock, but useless as a calendar.”). But all shadows fall in the same direction at a given hour, and so both the vertical pole and the sundial pole can be used to keep time; and all shadows vary in length with the seasons, and so both can be used to mark the time of year.
  • He cites Newton as noting that “the observed phases of the five planets other than Earth show that they revolve around the Sun [p. 237]”, but Jupiter and Saturn show no observable phases, and Mars only shows a gibbous phase consistent with it having a certain position relative to Sun and Earth. Only the phases of Venus and Mercury prove their motions around the Sun. Newton did talk about phases of all five planets (in his Phenomena), but Weinberg’s phrasing is odd.
  • He says the Inquisition gave a public formal order censoring Copernican books (p. 184), but according to Maurice Finocchiaro, the historian who translated and published the relevant documents, the Inquisition took no formal action; it was the Congregation for the Index (which Weinberg does mention elsewhere) that issued the censoring order.
  • Weinberg states that Kepler made a case for heliocentrism “based on mathematical simplicity and coherence, not on its better agreement with observations [p. 172]”, but Kepler seems to indicate otherwise. “It behoves us,” Kepler wrote, “to whom by divine benevolence such a very careful observer as Tycho Brahe has been given, in whose observations an error of 8′ of Ptolemy’s computation could be disclosed, to recognize this boon of God with thankful mind and use it by exerting ourselves in working out the true form of celestial motions….”

Almost all the errors/oddities that I have pointed out here could have been fixed with relatively little effort, and without substantially changing the book. I have read complaints from historians concerning Weinberg writing about history as a non-historian, and in particular writing as a scientist who judges the past by his own standards as a scientist of today (see Steven Shapin’s review in the Wall Street Journal; there was an editorial about this in Physics in Perspective). In my opinion, Weinberg is clear about his approach, often stating “I think this” or “I don’t think that”. An example is found in his discussion of Descartes, where he both praises Descartes (“This was Descartes at his best as a scientist [p. 209]”) and criticizes him (“The writings of Descartes on scientific method have attracted much attention among philosophers, but I don’t think they have had much positive influence on the practice of scientific research…. [p. 213]”). I have no complaint with what Weinberg is doing. His position is clear. The reader can consider accordingly. But Weinberg is obligated to get the historical facts right.


Weinberg peppers To Explain the World with comments related to philosophy and religion, some of which are problematic. For instance, at one point Weinberg writes “whatever the final laws of nature may be, there is no reason to suppose that they are designed to make physicists happy [p. 165]”. But then later we find, “We learn how to do science, not by making rules about how to do science, but from the experience of doing science, driven by desire for the pleasure we get when our methods succeed in explaining something [p. 214].” And so apparently science exists because indeed the laws of nature are designed to make physicists happy — a sentiment Weinberg repeats elsewhere (p. 248, 255).

Weinberg also writes, “Modern science is impersonal…; it has no sense of purpose; and it offers no hope for certainty…. We learn not to worry about purpose…. We learn to abandon the search for certainty [p. 254-255]”. But then later we find, “…the Standard Model provides a remarkably unified view of all types of matter and force (except for gravitation) that we encounter in our laboratories, in a set of equations that can fit on a single sheet of paper. We can be certain that the Standard Model will appear as at least an approximate feature of any better future theory [p. 264].” And so apparently there is hope for certainty after all.

Such contradictions arise because Weinberg juxtaposes an insistence on purposelessness with an insistence that science is purposeful and inevitable because it uncovers a beautiful (i.e. makes physicists happy) reality, or at least it approaches that reality over time (p. 252, 254, 268). He describes the Standard Model (p. 264-265) as impersonal, lacking element of purpose, not being deduced from mathematics or philosophical preconceptions, and not following straightforwardly from observation of nature, yet he then states that it is a product of guesswork and aesthetic judgment, validated by its successes. Is there nothing personal, purposeful, and philosophically preconceived in aesthetic judgment? In closing the last chapter Weinberg writes, “Still, we have come a long way on this path, and are not yet at its end…. It is toward a more fundamental physical theory that the wide-ranging scientific principles we discover have been, and are being, reduced [p. 268]”. Is there nothing personal, purposeful, and hope-filled about being on a path, moving toward some fundamental end but not yet being there? The point here is not to argue for purpose in science or for a nature designed to make physicists happy, but to illustrate the contradictions in Weinberg’s philosophical musings.

Unfortunately, where Weinberg is more consistent in his philosophizing is on religion, and there he does a disservice to science. To Explain the World is not especially hard on religion as these things go, but Weinberg does insert comments that seem religion-unfriendly, and entirely disposable. There is a comment about the Copernican “demotion of earth” (p. 156) being a problem for all religions; a comment about the works of Descartes being placed on the Index of books forbidden to Roman Catholics (p. 213); a comment about how even if Galileo had been mistaken it would still have been wrong for the church to sentence him to imprisonment and deny his right to publish, just as it was wrong to burn Giordano Bruno for being a heretic (p. 187-188).

Each of these are isolated remarks that do not tie in with the rest of the text, and each can be debated. Kepler thought the Copernican system actually elevated Earth’s position up from the sump of the universe. As for the church being wrong about censorship and treatment of Galileo, well, Weinberg is clear on judging the past by the standards of today, and no, we do not do such things today. But he is selecting what to judge. It was also wrong to execute people for who-knows-what crime and to stick their heads on pikes by the dozen on the town bridge for everyone and their toddler to see, as was done at the time, and we do not do such things today. Yes, some church people in the seventeenth century behaved like ogres. But at that time a lot of other people behaved like ogres in many ways, too. To insert comments about these ogres but not those ogres is to select your data points, and, as judged by the standards of the modern scientist, that is poor practice.


Impaled heads on the south gate of London Bridge, 

from Claes Visscher’s Panorama of London in 1616.

This selecting of data points extends more deeply than just throwaway comments. Weinberg’s discussion of figures such as Kepler, Boyle, and Newton omits just how large religion loomed in their thinking. The Kepler discussion is the most egregious example of this (Weinberg does include some references to religion regarding Boyle and Newton). Kepler was an astronomer who wrote about how he originally wanted to be a theologian but how he was able to glorify God through astronomy; who saw the Holy Trinity reflected in the Copernican universe, with the Sun representing God the Father and thus properly placed at the focus of elliptical orbits; whose Mysterium Cosmographicum (which Weinberg discusses) was an effort to uncover the mathematical rationale God used in building the solar system. But none of this is in To Explain the World. Weinberg portrays Kepler as simply a Platonist who applied to historical accidents an interest in mathematical oddities (p. 163-164). Perhaps most annoying is the following Kepler quote, which Weinberg includes (p. 179) to illustrate how Kepler challenged opponents of Copernicus:

Advice for Idiots. But whoever is too stupid to understand astronomical science, or too weak to believe Copernicus without affecting his faith, I would advise him that, having dismissed astronomical studies, and having damned whatever philosophical opinions he pleases, he mind his own business and betake himself home to scratch in his own dirt patch, abandoning this wandering about the world.

Now look at Kepler’s words in a larger context:

So everything the psalmodist said of the world relates to living things. He tells nothing that is not generally acknowledged, because his purpose was to praise things that are known, not to seek out the unknown. It was his wish to invite men to consider the benefits accruing to them from each of these works of the six days.

I, too, implore my reader, when he departs from the temple and enters astronomical studies, not to forget the divine goodness conferred upon men, to the consideration of which the psalmodist chiefly invites. I hope that, with me, he will praise and celebrate the Creator’s wisdom and greatness, which I unfold for him in the more perspicacious explanation of the world’s form, the investigation of causes, and the detection of errors of vision. Let him not only extol the Creator’s divine beneficence in His concern for the well-being of all living things, expressed in the firmness and stability of the Earth, but also acknowledge His wisdom expressed in its motion, at once so well hidden and so admirable.

But whoever is too stupid to understand astronomical science, or too weak to believe Copernicus without affecting his faith, I would advise him that, having dismissed astronomical studies and having damned whatever philosophical opinions he pleases, he mind his own business and betake himself home to scratch in his own dirt patch, abandoning this wandering about the world. He should raise his eyes (his only means of vision) to this visible heaven and with his whole heart burst forth in giving thanks and praising God the Creator. He can be sure that he worships God no less than the astronomer, to whom God has granted the more penetrating vision of the mind’s eye, and an ability and desire to celebrate his God above those things he has discovered.

To talk about Kepler as a Platonist while leaving out this aspect of Kepler is to select the data points. (Note — “Advice to Idiots” is a marginal note in Kepler’s book, not part of the text itself.)

My real job is to be a community college professor — to, ahem, Bring Science to The Community — and I absolutely hate the sort of thing Weinberg is doing. Not only is selecting the data not in the spirit of science, it does a disservice to science in general, and makes my job harder in particular. Why? Because Weinberg is in the USA (Texas, specifically), and here in the USA (especially Texas) we have many flare-ups over religion, science, school textbooks, and the like. See the March issue of National Geographic, whose cover story is “The War on Science” for a recap. I experience this issue directly with a number of my students. Weinberg, by choosing to highlight books on the Index or the troubles of Galileo, while being silent on the deep religious motivations of people like Kepler, skews the story of science in such a way as to add fuel to those flare-ups, when he could instead help to cool them down (he is not alone in this regard). Kepler is obviously a possible point of connection between “science people” and “religion people”. It is in science’s interest to emphasize such points of connection, as science is not winning in “The War on Science”. We need what allies (or at least non-enemies) we can get. Science needs prominent writers like Weinberg to talk up Kepler’s religion just as much as they talk up the Inquisition. Weinberg’s philosophy comments and selecting the data points on religion is a missed opportunity for science.

Read it — but with eyes open

The problems with facts and philosophizing are significant in To Explain the World, but they will not prevent its readers from learning a good deal about science and its long history. Indeed, the amount of history touched upon is at times itself a drawback. Chapter 9 on Arab scientists is a particular example of this. Here Weinberg introduces one scientist after another — in two pages of text (p. 110-111) we meet, and leave, Omar Khayyam, Ibn Sahl, Jabir ibn Hayyan, al-Kindi, al-Razi, and Ibn Sina. But, most readers probably know nothing about any of these scientists, and after finishing the book they will know something. And, the problems with facts and philosophizing will not prevent readers from picking up some technical details on physics and mathematics — although those readers should be aware that Weinberg occasionally includes mathematical material that many readers will not follow. For example, his discussion of the derivative, which includes invoking the idea that squares and cubes of small terms can be neglected (p. 223), will likely be useless to readers not already familiar with that material. The readers can just wade through and continue on, knowing they will likely learn something about the derivative no matter what. The problem regarding technical material is not aided by the absence of any illustrations in the main text, where they are often needed — where Weinberg describes Kepler’s nesting of Platonic solids, for instance (p. 162).

The problems with Weinberg’s book will not prevent readers from learning a good deal about science and its history, and will not prevent them from getting a scientist’s perspective on this subject. Read To Explain the World. Just keep your eyes open for its problems.


Filed under Book Reviews

Der Erdapfel

Erdapfel is the word for potato in my local Franconia dialect, in fact in most of Southern Germany and Austria. In High Germany a potato is ein Kartoffel. Don’t worry this is not a post about root vegetables or variations in German regional dialects. Der Erdapfel is also the name given to the so-called Behaim Globe, the oldest known surviving terrestrial globe, Nürnberg’s most famous historical artefact. The name, which literally translates as Earth Apple, is thought to be derived from the medieval term Reichsapfel (Empire Apple), which was the name of the Globus Cruciger, or orb, as in orb and sceptre, the symbols of power of the Holy Roman Emperor; the orb symbolising the earth. The Behaim globe, which was conceived but not constructed by Martin Behaim, is together with Behaim, the subject of many historical myths.


Martin Behaim was born in Nürnberg in 1459 and lived with his parent on the market place next door to the businessman Bernhard Walther (1430–1504) who was the partner to Regiomontanus in his printing and astronomical activities during the last five years of his life living in Nürnberg. Martin’s father was one of the rich traders, who dominated Nürnberg culture. In 1576 he was sent away to Flanders to apprentice as a cloth trader. In 1484 he journeyed to Portugal, which is where to mythological part of his life begins. According to the traditional version of his life story he took part in two sea voyages down the west coast of Africa with Diogo Cão. He was knighted by the Portuguese king and appointed to the Portuguese Board of Navigation. All of this took place because he was supposedly a student of Regiomontanus, whose ephemerides, the first ever printed ones and highly accurate, were well known and respected on the Iberian Peninsula. All of this information comes from Behaim himself and some of it can be read in the texts on the Behaim Globe.


Artist's impression of Martin Behaim with his globe. Artist unknown

Artist’s impression of Martin Behaim with his globe. Artist unknown

Between 1490 and 1493 Behaim returned to Nürnberg to sort out his mother’s testament and it was during this period that he persuaded to city council to commission him to produce a globe and a large-scale wall map of the world. It is not certain if the wall map was ever produced and if it was it has not survived but the globe certainly was and it is now, as already said, the oldest known surviving terrestrial globe. It is not however, as is often falsely claimed the oldest or first terrestrial globe. The earliest recorded terrestrial globe was constructed by Crates of Mallus in the second century BCE. Also Ptolemaeus in his Geographia, in his discussion of different methods of cartographical projection, acknowledges that a globe in the only way to accurately represent to earth. The Behaim Globe is not even the earliest European medieval globe as the Pope in known to have commissioned earlier terrestrial globes, which have not survived. Given their method of construction and the materials out of which they are made the survival rate of globes is relatively low.

The globe remained the property of the city council of Nürnberg until the middle of the sixteenth century when it was returned to the Behaim family who basically threw it into the corner of an attic and forgot about it. In the nineteenth century it was rediscovered and studied by various historians of cartography and a copy was made for a museum in Paris. Unfortunately it was also ‘restored’ several times through processes that did far more damage than good. In the early twentieth century it was lent to the Germanische Nationalmuseum in Nürnberg. In the 1930s the Behaim family considered selling the globe, most probably in America, and to prevent this Adolf Hitler bought the globe with his own private money and presented it to the German nations. It still resides in the Germanische Nationalmuseum.

I said that the globe is veiled in myths and we will start to sort them out. Firstly Behaim only conceived the globe he didn’t construct it as many people believe. The globe was made by pasting strips of linen onto a fired clay ball. The ball produced by Hans Glockengiesser (a family name that translates as bell founder) and the globe constructed by Ruprecht Kolberger. After the paste had set the globe was cut free from the clay form by a single cut around its equator and the two halves we then pasted together on a wooded frame. The actually map was painted onto the linen ball by the painter and woodblock cutter Georg Glockendon and the lettering was carried out by Petrus Gegenhart. Behaim only seems to have directed and coordinated these activities.


Another popular myth is that because of Behaim’s activities in Portugal the cartography of the globe is cutting edge up to the minute modern; nothing could be further from the truth. The basis of the cartography is Ptolemaeus with obvious additions from other ancient Greek sources as well as The Travels of Sir John Mandeville and The Travels of Marco Polo. Much of the cartographical work is inaccurate even by the standards of the time, including surprisingly the west coast of Africa that Behaim supposedly had explored himself, which brings us to Behaim’s personal claims.


His claim to have sailed with Diogo Cão is almost certainly a lie. At the time of Cão’s first voyage along the African coast Behaim is known to have been in Antwerp. On his second voyage Cão erected pillars at all of his landing places naming all of the important members of the crew, who were on the voyage, Martin Behaim is not amongst them. They is no confirmatory evidence that Behaim was actually a member of Portuguese Board of Navigation and if he was his membership almost certainly owed nothing to Regiomontanus, as there is absolutely no evidence that he ever studied under him. The historian of navigation, David Waters, suggests that if Behaim was actually a member of this august body then it was because the Portuguese hoped to persuade the rich Nürnberger traders to invest money in their expeditionary endeavours, Behaim thus functioning as a sort of informal ambassador for the Republic of Nürnberg.

The picture that emerges is that Martin Behaim was con artist probably deceiving both the Portuguese court and the Nürnberg city council. The Behaim Globe is an interesting artefact but its historical or scientific significance is minimal. If you are in Nürnberg, I can recommend going to the Germanische Nationalmuseum to see it but when you are there also take a look at the Schöner 1520 terrestrial manuscript globe in the neighbouring room. It’s cartographically much more interesting and Schöner, as opposed to Behaim, plays a very important role in the history of globe making.


Johannes Söner's 1520 terrestrial Globe. Germanische Nationalmuseum

Johannes Söner’s 1520 terrestrial Globe.
Germanische Nationalmuseum




Filed under History of Cartography, History of science, Myths of Science, Renaissance Science, Uncategorized

Made in Nürnberg

In the period from roughly 1550 and 1650 Nürnberg was the leading centre in Europe, and thus probably the world, for the manufacture of scientific instruments. It is historically interesting to look at how this town in the middle of Europe came to acquire this status and also to take a brief look at some of the more famous of the Nürnberger instrument makers from this ‘golden’ period.

Like many European towns and cities, Nürnberg, as an entity, began to emerge at the beginning of the High Middle Ages, probably around the year 1000 CE. Like many such settlements it was initially not much more than a fortified hill top at a crossroads. The first record of the name is 1050 CE as nuorenberc, which later evolved into Nuremberg, the name by which it is still known in English. This name is the subject of a rare German bad pun; the Germans don’t really go in for puns. According to folk etymology the name was originally ‘Nur einem Berg’, which translates as ‘just a hill’. The geographical position of Nürnberg played an important role in its development. If you take an outline map of Europe and draw a straight line from Kiel, in Northern Germany, to Northern Italy and a second one from Paris to Prague, the point where they cross is Nürnberg. This led to Nürnberg becoming a major European trading hub in the medieval period; importing wares from the Northern Italian trading cities and then distributing them throughout Europe.

Germany didn’t exist as a country in the Middle Ages but was a loose conglomerate of large and small states interconnected through a network of feudal obligations and vaguely held together in the so-called Holy Roman Empire, which as somebody once quipped was neither holy nor Roman nor an empire. Within this patchwork of large and small Germanic states Nürnberg was one of the so-called Free Imperial Cities, small independent city-states, which only owed feudal allegiance to the Holy Roman Emperor. From 1105 CE Nürnberg was ruled by a hereditary Burggraf, a title that translates as Lord of the castle. From 1192 till 1427 the Burggrafen of Nürnberg came from the Hohenzollern family, who would go on to play a significant role in German history. In 1427 the rich traders of Nürnberg, of whom more shortly, bought the Burggraf rights from the Hohenzollern and from then on until 1806, when Nürnberg became part of Bavaria, the city was ruled by the town council. Although dominated by the rich trader families the town council was surprisingly democratic with three groups of councillors being appointed/elected from the three tiers of citizenry at regular intervals. During the Renaissance Nürnberg, like one of its major trading partners Venice, called itself a republic.

The Holy Roman Emperor granted the city of Nürnberg special tax privileges, which combined with its favourable geographical position and the large Europe wide demand for the spices that came into Europe through the Northern Italian trading cities meant that the Nürnberg traders became very, very wealthy. This led to them looking for new opportunities to invest their surplus profits. The High Middle Ages saw a steeply rising demand for metals (gold, silver, copper, lead, iron) and with it an expansion of the metal ore mining industry. The major ore deposits, and thus the mines, were situated in the eastern part of Middle Europe, Eastern Germany, Hungary, Rumania, Austria etc. Realising that it was an expanding business with a future the Nürnberg traders began investing in the metal ore mines and soon controlled a large part of this industry. At first content just to sell the ore they soon realised that they could make more profit if they smelted the ore themselves and so built their own smelters and began selling refined metal. It did not take long before the artisans of Nürnberg began to work the metal themselves producing finished metal objects for sale. By the fifteenth century Nürnberg had become one of the major metal working centres of Europe producing quite literally everything that could be made from metal from pins and needles to suits of armour. A sign of this development is that the first mechanical wire drawing machine was developed in Nürnberg. The Nürnberg guilds were incredibly well organised with single families responsible for the production of one object or group of objects. When Karl V (Holly Roman Emperor 1519–1556) ordered 5000 suits of armour from Nürnberg, one group of families was responsible for the leg plates, another for the breast plates and so on. Highly organised piecework.

Nürnberg as depicted in the Nuremberg Chronicles 1493

Nürnberg as depicted in the Nuremberg Chronicles 1493

Of course many scientific instruments are made of metal, mostly brass, and so Nürnberg in its all inclusiveness became a major centre for the manufacture of all types of scientific instruments. In fact it became the leading European centre for this work and thus, most probably, the leading world centre in the fifteenth and sixteenth centuries. We have two important historical attestations of Nürnberg’s supremacy in this area. The philosopher Nicholas of Cusa (Cusanus) (1401–1464) was very interested in astronomy and he purchased a celestial globe and other astronomical instruments from Nürnberg and this can still be viewed in the Cusanus Museum in his birthplace Kues. In 1470 when Johannes Regiomontanus set out to reform and modernise astronomy he moved from Budapest to Nürnberg because, as he tells us in a letter, Nürnberg had a good communications network through which he could communicate with other astronomers and because the best astronomical instruments were manufactured in Nürnberg. The communications network was an essential element of any Renaissance trading city and Nürnberg’s was second only to that of Venice.

By 1500 Nürnberg was the second biggest German city with a population of around 40 000, half of which lived inside the city walls and the other half in the surrounding villages, which belonged to the city. It was one of the richest cities in the whole of Europe and enjoyed a high level of culture, investing both in representative architecture and the arts, with many of the leading German Renaissance artists fulfilling commissions for the rich Nürnberg traders, known locally as the Patrizier; most famously Albrecht Dürer. Interesting in our context, Dürer’s maths book contained the first printed instructions in German of how to design and construct sundials. The first half of the sixteenth century was the golden age of scientific instrument production in Nürnberg with many of the leading instrument makers selling their wares throughout Europe, where they can still be found in museums in many different countries. In what follows I shall give brief sketches of a couple of the more well known of these craftsmen.

Nürnberg was famous for it’s portable sundials with family dynasties producing high quality products over three, four or even five generations. At the beginning of the sixteenth century the most significant sundial maker was Erhard Etzlaub (ca. 1460–1532) who like many other Nürnberger instrument makers was as much as a scholar as an artisan. As a cartographer he produced the first map of the Nürnberg region. He followed this with the so-called Rome pilgrimage map displaying the routes to Rome for the Holy Year of 1500, which famously Copernicus also attended. This map plays an important role in the history of modern cartography because it’s the first map with a scale, enabling the pilgrim to plan his daily journeys.

Etzlaub's Rome Pilgrim Map Source: Wikimedia Commons

Etzlaub’s Rome Pilgrim Map
Source: Wikimedia Commons

Etzlaub also constructed a map on the cover of one of his compasses in 1511 that is drawn in a projection that comes close to the Mercator projection. Etzlaub was a member of the so-called Pirckheimer Circle. A group of like minded proponents of the mathematical sciences centred around Willbald Pirckheimer, soldier, politician humanist scholar and translator from Greek into Latin of Ptolemaeus’ Geographia; a translation that became a standard work.

Willibald Pirckheimer, porträtiert von Albrecht Dürer (1503) Source: Wikimedia Commons

Willibald Pirckheimer, porträtiert von Albrecht Dürer (1503)
Source: Wikimedia Commons

This group of mathematical scholars demonstrated their interest in the mathematical sciences and in the construction of complex instruments in the highly complex sundial that they painted on the side of the Lorenzkirche in 1502, which also displays the time according to the Great Nürnberger Clock:

Lorenzkirche Sundial Source: Astronomie in Nürnberg

Lorenzkirche Sundial
Source: Astronomie in Nürnberg

And the clock on the Frauenkirche constructed in 1506:

Frauenkirche Clock

Frauenkirche Clock

The gold and blue ball above the clock dial displays the phases of the moon and is still accurate today.

Another member of the Pirckheimer Circle was Johannes Schöner(1477–1547), addressee of Rheticus’ Naratio Prima, the first published account of Copernicus’ heliocentrism.

Johannes Schöner Source: Wikimedia Commons

Johannes Schöner
Source: Wikimedia Commons

Schöner was the first producer of serial production printed globes both terrestrial and celestial. He also wrote, printed and published pamphlets on the design and manufacture of various scientific instruments. Schöner was Europe’s leading globe maker whose globes set standards for globe making, which influenced the manufacture of globes down to the nineteenth century.

Schöner Celestial Globe 1535 Source: Science Museum London

Schöner Celestial Globe 1535
Source: Science Museum London

Also a member of the Pirckheimer Circle and a close friend of Schöner’s was Georg Hartman (1489–1564).

Georg Hartmann Source: Astronomie in Nürnberg

Georg Hartmann
Source: Astronomie in Nürnberg

Hartmann like Schöner was a globe maker although none of his globes have survived. He was also one of the leading sundial makers of his generation and his complex and beautiful dials can still be found in many museums.

Hartmann Bowl Sundial Source: Wikimedia Commons

Hartmann Bowl Sundial
Source: Wikimedia Commons

In the early sixteenth century Nürnberg was the main European centre for the production of astrolabes and here Hartmann played a leading role. As far as can be ascertained Hartmann was the first person to produce astrolabes in series.

Hartmann Astrolabe Yale Source: Wikimedia Commons

Hartmann Astrolabe Yale
Source: Wikimedia Commons

Previously all astrolabes were produced as single pieces, Hartmann, however, produced series of identical astrolabes, probably employing other craftsmen to produce the individual parts according to a pre-described plan and them assembling them in his workshop. As a young man Hartmann had spent several years living in Italy where he was friends with Copernicus’ brother Andreas. As a scholar Hartmann was the first to investigate magnetic inclination or dip. However his studies were never published and so the credit for this discovery went to the English mariner Robert Norman.

Handmade metal instruments were, of course, very expensive and could in reality only be purchased by the wealthy, who often bought them as ornaments of status symbols rather than to be used. To make scientific instruments available to those with less money both Schöner and Hartmann produced paper instruments. These consisted of the scales and tables, normally found engraved on the metal instruments, printed accurately on paper, which the user could then paste onto a wooden background and so construct a cheap but functioning instrument.

Paper and Wood Astrolabe Hartmann Source: MHS Oxford

Paper and Wood Astrolabe Hartmann
Source: MHS Oxford

A later instrument maker was Christian Heiden (1526–1576) who like Schöner was professor for mathematics on the Egidiengymnasium in Nürnberg, Germany’s first gymnasium (similar to a grammar school). He made a wide range of instruments but was especially well known for his elaborate and elegant sundials, as much works of art as scientific instruments these were much prized amongst the rich and powerful and could be found on many a German court.

Column Sundial by Christian Heyden Source: Museumslandschaft Hessen-Kassel

Column Sundial by Christian Heyden
Source: Museumslandschaft Hessen-Kassel

This is of course only a very, very small sample of the Nürnberger instrument makers, the history pages of the Astronomie in Nürnberg website, created and maintained by Dr Hans Gaab, lists 44 globe makers, 38 astronomical instrument makers and more than 100 sundial makers between the fifteenth and nineteenth centuries; with the greatest concentration in the sixteenth century. Nürnberg was known throughout Europe for the quality and the accuracy of its scientific instruments and examples of the Nürnberger handwork can be found in museums in many countries, even outside of Europe.


Filed under History of Astronomy, History of science, History of Technology, Renaissance Science

Sorry Caroline but Maria got there first!

Astronomer Caroline Herschel observed her first comet on 1 August 1786 an anniversary that was celebrated by various people on Twitter yesterday. Unfortunately many of them, including for example NASA History Office (@NASAhistory), claimed that on this date she became the 1st woman to discover a comet. This is quite simply not true.

Maria Margarethe Kirch (née Winkelmann), the wife of Gottfried Kirch the Astronomer Royal of Berlin, discovered the comet of 1702 (C/1702 H1) on 21 March 1702 that is forty-eight years before Caroline Herschel was born. Unfortunately the discovery was published by her husband and it was he who was incorrectly acknowledged as the discoverer. In 1710 Gottfried admitted the error and publically acknowledged Maria as the discoverer but she was never official credited with the discovery.

Both Maria Kirch and Caroline Herschel were excellent astronomers with much important work to their credit. However credit where credit is due, Caroline was not the first woman to discover a comet, Maria was.


Filed under History of Astronomy, Myths of Science