Category Archives: History of Astronomy

Not German but also not Polish

I recently wrote a post concerning the problems historians can and do face assigning a nationality to figures from the past that they are studying. In the history of science one of the most contentious figures in this sense was and apparently still is the Renaissance astronomer Nicolas Copernicus. The question of his nationality produced a massive war of words between Poland and Germany, both of whom claim him as their own, which started in the late eighteenth century and unfortunately still rumbles on today.

Nicolaus Copernicus portrait from Town Hall in Toruń - 1580 Source: Wikimedia Commons

Nicolaus Copernicus portrait from Town Hall in Toruń – 1580
Source: Wikimedia Commons

Today is Copernicus’ birthday (19 February 1473) and all over the Internet British and American posters are being, what they see as, scrupulously, politically correct and announcing today as the birthday of the Polish astronomer… All very well but it isn’t factually right.

Nicolas Copernicus was born in the city of Toruń, which is today in Poland but wasn’t at the time of his birth. The whole area in which Copernicus was born and in which he lived for all of his life, except when he was away studying at university, was highly dispute territory over which several wars were fought. Between 1454 and 1466 the Thirteen Years’ War was fought between the Prussian Confederation allied with the Crown of the Kingdom of Poland and the State of the Teutonic Knights. This war ended with the Second Peace of Toruń under which Toruń remained a free city now under the patronage of the Polish King.

As I pointed out in an earlier post Copernicus spent all of his adult life, after graduating from university, as a citizen of Ermland (Warmia), which was then an autonomous Prince Bishopric ruled by the Bishop of Frombork and the canons of the cathedral chapter, of which Copernicus was one.

All of this means that Copernicus was neither German nor Polish but was born a citizen of Toruń and died a citizen of Ermland. I realise that this doesn’t fit our neat modern concept of national states but that is the historical reality that people should learn to live with and to accept.




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

Why Mathematicus?

“The Renaissance Mathematiwot?”

“Mathematicus, it’s the Latin root of the word mathematician.”

“Then why can’t you just write The Renaissance Mathematician instead of showing off and confusing people?”

“Because a mathematicus is not the same as a mathematician.”

“But you just said…”

“Words evolve over time and change their meanings, what we now understand as the occupational profile of a mathematician has some things in common with the occupational profile of a Renaissance mathematicus but an awful lot more that isn’t. I will attempt to explain.”

The word mathematician actually has its origins in the Greek word mathema, which literally meant ‘that which is learnt’, and came to mean knowledge in general or more specifically scientific knowledge or mathematical knowledge. In the Hellenistic period, when Latin became the lingua franca, so to speak, the knowledge most associated with the word mathematica was astrological knowledge. In fact the terms for the professors[1] of such knowledge, mathematicus and astrologus, were synonymous. This led to the famous historical error that St. Augustine rejected mathematics, whereas his notorious attack on the mathematici[2] was launched not against mathematicians, as we understand the term, but against astrologers.

The earliest known portrait of Saint Augustine in a 6th-century fresco, Lateran, Rome Source: Wikimedia Commons

The earliest known portrait of Saint Augustine in a 6th-century fresco, Lateran, Rome
Source: Wikimedia Commons

However St. Augustine lived in North Africa in the fourth century CE and we are concerned with the European Renaissance, which, for the purposes of this post we will define as being from roughly 1400 to 1650 CE.

The Renaissance was a period of strong revival for Greek astrology and the two hundred and fifty years that I have bracketed have been called the golden age of astrology and the principle occupation of our mathematicus is still very much the casting and interpretation of horoscopes. Mathematics had played a very minor role at the medieval universities but the Renaissance humanist universities of Northern Italy and Krakow in Poland introduced dedicated chairs for mathematics in the early fifteenth century, which were in fact chairs for astrology, whose occupants were expected to teach astrology to the medical students for their astro-medicine or as it was known iatro-mathematics. All Renaissance professors of mathematics down to and including Galileo were expected to and did teach astrology.

A Renaissance Horoscope Kepler's Horoskop für Wallenstein Source: Wikimedia Commons

A Renaissance Horoscope
Kepler’s Horoskop für Wallenstein
Source: Wikimedia Commons

Of course, to teach astrology they also had to practice and teach astronomy, which in turn required the basics of mathematics – arithmetic, geometry and trigonometry – which is what our mathematicus has in common with the modern mathematician. Throughout this period the terms Astrologus, astronomus and mathematicus – astrologer, astronomer and mathematician ­– were synonymous.

A Renaissance mathematicus was not just required to be an astronomer but to quantify and describe the entire cosmos making him a cosmographer i.e. a geographer and cartographer as well as astronomer. A Renaissance geographer/cartographer also covered much that we would now consider to be history, rather than geography.

The Renaissance mathematicus was also in general expected to produce the tools of his trade meaning conceiving, designing and manufacturing or having manufactured the mathematical instruments needed for astronomer, surveying and cartography. Many were not just cartographers but also globe makers.

Many Renaissance mathematici earned their living outside of the universities. Most of these worked at courts both secular and clerical. Here once again their primary function was usually court astrologer but they were expected to fulfil any functions considered to fall within the scope of the mathematical science much of which we would see as assignments for architects and/or engineers rather than mathematicians. Like their university colleagues they were also instrument makers a principle function being horologist, i.e. clock maker, which mostly meant the design and construction of sundials.

If we pull all of this together our Renaissance mathematicus is an astrologer, astronomer, mathematician, geographer, cartographer, surveyor, architect, engineer, instrument designer and maker, and globe maker. This long list of functions with its strong emphasis on practical applications of knowledge means that it is common historical practice to refer to Renaissance mathematici as mathematical practitioners rather than mathematicians.

This very wide range of functions fulfilled by a Renaissance mathematicus leads to a common historiographical problem in the history of Renaissance mathematics, which I will explain with reference to one of my favourite Renaissance mathematici, Johannes Schöner.

Joan Schonerus Mathematicus Source: Wikimedia Commons

Joan Schonerus Mathematicus
Source: Wikimedia Commons

Schöner who was a school professor of mathematics for twenty years was an astrologer, astronomer, geographer, cartographer, instrument maker, globe maker, textbook author, and mathematical editor and like many other mathematici such as Peter Apian, Gemma Frisius, Oronce Fine and Gerard Mercator, he regarded all of his activities as different aspects or facets of one single discipline, mathematica. From the modern standpoint almost all of activities represent a separate discipline each of which has its own discipline historians, this means that our historical picture of Schöner is a very fragmented one.

Because he produced no original mathematics historians of mathematics tend to ignore him and although they should really be looking at how the discipline evolved in this period, many just spring over it. Historians of astronomy treat him as a minor figure, whilst ignoring his astrology although it was this that played the major role in his relationship to Rheticus and thus to the publication of Copernicus’ De revolutionibus. For historians of astrology, Schöner is a major figure in Renaissance astrology although a major study of his role and influence in the discipline still has to be written. Historians of geography tend to leave him to the historians of cartography, these whilst using the maps on his globes for their studies ignore his role in the history of globe making whilst doing so. For the historians of globe making, and yes it really is a separate discipline, Schöner is a central and highly significant figure as the founder of the long tradition of printed globe pairs but they don’t tend to look outside of their own discipline to see how his globe making fits together with his other activities. I’m still looking for a serious study of his activities as an instrument maker. There is also, as far as I know no real comprehensive study of his role as textbook author and editor, areas that tend to be the neglected stepchildren of the histories of science and technology. What is glaringly missing is a historiographical approach that treats the work of Schöner or of the Renaissance mathematici as an integrated coherent whole.

Western hemisphere of the Schöner globe from 1520. Source: Wikimedia Commons

Western hemisphere of the Schöner globe from 1520.
Source: Wikimedia Commons

The world of this blog is at its core the world of the Renaissance mathematici and thus we are the Renaissance Mathematicus and not the Renaissance Mathematician.

[1] That is professor in its original meaning donated somebody who claims to possessing a particular area of knowledge.

[2] Augustinus De Genesi ad Litteram,

Quapropter bono christiano, sive mathematici, sive quilibet impie divinantium, maxime dicentes vera, cavendi sunt, ne consortio daemoniorum animam deceptam, pacto quodam societatis irretiant. II, xvii, 37


Filed under History of Astrology, History of Astronomy, History of Cartography, History of Mathematics, History of science, History of Technology, Renaissance Science

He fought for his mother

There are not many books about the Renaissance mathematician and astronomer Johannes Kepler in which he only plays a supporting role but this is the case in Ulinka Rublack’s The Astronomer and the Witch: Johannes Kepler’s Fight for His Mother[1]. In fact in Rublack’s excellent book even Kepler’s mother, Katherina, the nominal subject of the book only really takes a supporting role; the lead role being taken by the context within which the whole tragic story unfolds and it is exactly this that makes this book so excellent.


Regular readers of this blog will know that I champion the claims of Johannes Kepler to being the most significant natural philosopher of the Early Modern Period against the rival claims of Copernicus, Galileo, Descartes, Newton et al. So I am naturally interested in any new books that appear with Kepler as their subject. Having looked closely at one of the strangest events in Kepler’s unbelievably bizarre life, the arrest and trial of his mother, Katherina, on a charge of witchcraft – and having blogged about it twice – my interest was particularly piqued by an announcement of a new book on this topic. A decent, well-researched book in English devoted exclusively to the subject would be a very positive addition to the Kepler literature. Rublack’s book is just the bill.

Nearly all accounts of Katherina Kepler’s ordeal are merely chapters or sections in more general books about Kepler’s life and work and mostly deal chronologically with the original accusations of witchcraft, counter accusations, the attempted violent intimidation of Katherina, the frustrated strivings to bring charges against her tormentors, her arrest and finally the trial with its famous defence by Johannes. Except for thumbnail sketches of those involved very little attempt is ever made to place the occurrences into a wider or more general context and this is, as already said above, exactly the strength of Rublack’s book.

Rublack in having devoted an entire book to the whole affair draws back from the accusations, charges, counter charges and the trial itself to flesh out the story with the social, cultural, political and economic circumstances in which the whole sorry story took place. In doing so Rublack has created minor masterpiece of social history. Her research has obviously been deep and thorough and she displays a fine eye for detail, whilst maintaining a stirring narrative style that pulls the reader along at a steady pace.

One point in particular intrigued me having read all the prepublication advertising for the book, including several illuminating interviews on the subject with the author, as well as short essays by her. Rublack takes what might be seen as a strong feminist stand against the previous, exclusively male, characterisations of Katherina Kepler, all of which painted her as a mean spirited, crabby, old hag, who was, so to speak, largely to blame for the situation in which she found herself. Having over the years read almost all of these accounts I was curious how Rublack would justify her rejection of these portrayals of Katherina, which I knew were based on Kepler’s own accounts of his mother. Rublack does not disappoint. She points out quite correctly that Kepler’s description of his mother was written when he was still very young and is part of an almost psychopathic put down of himself and all those related or connected to him and calls rather his own mental state into question. Interestingly we have virtually no other accounts of Katherina from Johannes’ pen and to judge her purely on this one piece of strange juvenilia is probably, as Rublack makes very clear, a bridge too far. Piecing together all of the, admittedly scant, evidence Rublack paints a much more sympathetic picture of Katherina, a hard working, illiterate, sixteenth/seventeenth-century peasant woman, who had never had it easy in life but still managed to raise her children well and give them chances that she never had.

This book is not perfect, as Rublack relies in her accounts of Johannes on older standard biographies, whilst apparently not consulting some of the more recent scholarly studies of his life and work, and thus repeats several false claims concerning him. However I’m prepared to cut her some slack on this as none of the errors that she (unknowingly?) repeats have any direct bearing on the story of Katherina that she tells so skilfully.

The book is beautifully presented by the OUP. Printed in a pleasant, easy on the eyes typeface and charmingly illustrated with a large number of black and white pictures. The text is excellently annotated, but as always I would have preferred footnotes to endnotes, and there is an adequate index. I personally would have liked a separate bibliography but this might have been sacrificed on cost grounds, the hardback being available at a very civilised price for a serious academic volume. Although having called it that I should point out that the book is very accessible and readable for the non-expert or general reader.

I heartily recommend this book to anybody interested in seventeenth-century history, Johannes Kepler, the history of witchcraft or who just likes reading good informative, entertaining books, if one is allowed to call a book about the sufferings of an innocent woman entertaining. Put simply, it’s an excellent read that deserves to, and probably will, become the standard English text on the subject.

[1] Ulinka Rublack, The Astronomer and the Witch: Johannes Kepler’s Fight for His Mother. OUP, 2015





Filed under Book Reviews, History of Astronomy, Renaissance Science

Two views of the celestial spheres

When the Bishop of Salisbury scanned the heavens in the 1670s it was difficult to know if he was contemplating the wonders of his God, or those of Kepler’s planetary laws. Seth Ward, the incumbent of the Salisbury bishopric, was both a successful Anglican churchman and an acknowledge astronomer, who did much to boost Kepler’s theories in the middle of the seventeenth century.

Greenhill, John; Seth Ward (1617-1689), Savilian Professor of Astronomy, Oxford (1649-1660) Source: Wikimedia Commons

Greenhill, John; Seth Ward (1617-1689), Savilian Professor of Astronomy, Oxford (1649-1660)
Source: Wikimedia Commons

Born in Aspenden in Hertfordshire on an unknown day in 1617, Seth Ward was the son of John Ward, an attorney, and his wife Mary Dalton. Having received a basic schooling he was admitted to Sidney-Sussex College, Cambridge on 1 December 1632, where he graduated B.A. in 1637 and M.A. on 27 July 1640, following which he was elected a fellow of the college. Ward was a keen mathematician, who, like many others in the Early Modern Period, was largely self-taught, studying William Oughtred’s Clavis Mathematicae together with fellow maths enthusiast Charles Scarburgh, a future physician to Charles II. Finding some passages difficult the two of them travelled to Albury in Surrey where Oughtred was rector. Here they took instruction from Oughtred and it was the start of a relationship between Ward and Oughtred that lasted until Oughtred’s death in 1660.

Sir Charles Scarborough Jean Demetrius (attributed to) Royal College of Physicians, London Source: Wikimedia Commons

Sir Charles Scarborough Jean Demetrius (attributed to)
Royal College of Physicians, London
Source: Wikimedia Commons

In 1643 Ward was appointed lecture for mathematics for the university but he did not exercise this post for very long. Some of the Cambridge colleges, and in particular Sidney-Sussex, Cromwell’s alma mater, became centres for the Puritan uprising and in 1644 Seth Ward, a devote Anglican, was expelled from his fellowship for refusing to sign the covenant. At first he took refuge with friends in and around London but then he went back to Albury where he received tuition in mathematics from Oughtred for several months. Afterwards he became private tutor in mathematics to the children of a friend, where he remained until 1649. Having used the Clavis Mathematicae, as a textbook whilst teaching at he university he made several suggestions for improving the book and persuaded Oughtred to publish a third edition in 1652

William Oughtred by Wenceslas Hollar 1646 Source: Wikimedia Commons

William Oughtred
by Wenceslas Hollar 1646
Source: Wikimedia Commons

In 1648 John Greaves, one of the first English translators of Arabic and Persian scientific texts into Latin, also became a victim of a Puritan purge and was evicted from the Savilian Chair for Astronomy at Oxford. Greaves recommended Ward as his successor and in 1649, having overcame his scruples, Ward took the oath to the English Commonwealth and was appointed Savilian Professor.


These episodes, Wards expulsion from Sidney-Sussex and Greave’s from Oxford, serve to remind us that much of the scientific investigations that took place in the Early Modern Period, and which led to the creation of modern science, did so in the midst of the many bitter and very destructive religious wars that raged throughout Europe during this period. The scholars who carried out those investigations did not remain unscathed by these disturbances and careers were often deeply affected by them. The most notable example being, of course Johannes Kepler, who was tossed around by the Reformation and Counter-Reformation like a leaf in a storm. Anyone attempting to write a history of the science of this period has to, in my opinion, take these external vicissitudes into account; a history that does not do so is only a half history.

It was in his role as Savilian Professor that Ward made his greatest contribution to the development of the new heliocentric astronomy in an academic dispute with the French astronomer and mathematician Ismaël Boulliau (1605–1694).

Ismaël Boulliau  Source: Wikimedia Commons

Ismaël Boulliau
Source: Wikimedia Commons

Boulliau was an early supporter of the elliptical astronomy of Johannes Kepler, who however rejected much of Kepler’s ideas. In 1645 he published his own theories based on Kepler’s work in his Astronomia philolaïca. This was the first major work by another astronomer that incorporated Kepler’s elliptical astronomy. Ward another Keplerian wrote his own work In Ismaelis Bullialdi Astronomiæ Philolaicæ Fundamenta Inquisitio Brevis, which heavily criticised Boulliau’s theories and present his own, in his opinion superior, interpretations of Kepler’s ideas. He followed this with another more extensive presentation of his theories in 1656, Astronomia Geometrica; ubi Methodus proponitur qua Primariorum Planetarum Astronomia sive Elliptica sive Circularis possit Geometrice absolve. Boulliau responded in 1657 in his Ismaelis Bullialdi Astronomiæ Philolaicæ Fundamenta clarius explicata et asserta, printed in his Exercitationes Geometricæ tres in which he acknowledged errors in his own work but also pointing out inaccuracies in Ward’s. In final analysis both Boulliau and Ward were wrong, and we don’t need to go into detail her, but their dispute drew the attention of other mathematicians and astronomers to Kepler’s work and thus played a major role in its final acceptance as the preferred model for astronomy in the latter part of the seventeenth century.

The worst popular model of the emergence of modern astronomy in the Early Modern Period sees the inspiring creation of heliocentric astronomy by Copernicus in his De revolutionibus in the sixteenth century, the doting of a few ‘I’s and crossing of a few ‘T’s by Galileo and Kepler in the early seventeenth century followed by the triumphant completion of the whole by Newton in his Principia in 1687. Even those who acknowledge that Kepler created something new with his elliptical astronomy still spring directly to Newton and the Principia. In fact many scholars contributed to the development of the ideas of Kepler and Galileo in the decades between them and Isaac Newton and if we are going to correctly understand how science evolves it is important to give weight to the work of those supposedly minor figures. The scientific debate between Boulliau and Ward is a good example of an episode in the history of astronomy that we ignore at the peril of falsifying the evolution of a disciple that we are trying to understand.

Ward continued to make career as an astronomer mathematician. He was awarded an Oxford M.A. on 23 October 1649 and became a fellow of Wadham College in 1650. The mathematician John Wilkins was warden of Wadham and the centre of a group of likeminded enthusiasts for the emerging new sciences that at times included Robert Boyle, Robert Hooke, Christopher Wren, John Wallis and many others. This became known as the Philosophical Society of Oxford, and they would go on to become one of the founding groups of the Royal Society in the early 1660s.

During his time at Oxford Ward together with his friend John Wallis, the Savilian Professor of Geometry, became involved in a bitter dispute with the philosopher Thomas Hobbes on the teaching of geometry at Oxford and the latter’s claim to have squared the circle; he hadn’t it’s impossible but the proof of that impossibility came first a couple of hundred years later.

Thomas Hobbes Artist unknown

Thomas Hobbes Artist unknown

Ward however was able to expose the errors in Hobbes’ geometrical deductions. In some circles Ward is better known for this dispute than for his contributions to astronomy.

John Wallis by Godfrey Kneller Source: Wikimedia Commons

John Wallis by Godfrey Kneller
Source: Wikimedia Commons

When the alchemist and cleric John Webster launched an attack on the curriculum of the English universities in his Academiarum Examen (1654) Ward joined forces with John Wilkins to write a defence refuting Webster’s arguments, Viniciae Acadmiarum, which also included refutations of other prominent critics of Oxford and Cambridge.

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

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

Ward’s career as an astronomer and mathematician was very successful and his work was known and respected throughout Europe, where he stood in contact with many of the leading exponents of his discipline. However, his career in academic politics was not so successful. He received a doctorate in theology (D.D.) from Oxford in 1654 and one from Cambridge in 1659. He was elected principle of Jesus College, Oxford in 1657 but Cromwell appointed somebody else promising Ward compensation, which he never delivered. In 1659 he was appointed president of Trinity College, Oxford but because he was not qualified for the office he was compelled to resign in 1660. This appears to have been the final straw and in 1660 he left academia, resigning his professorship to take up a career in the Church of England, with the active support of the recently restored Charles II.

He proceeded through a series of clerical positions culminating in the bishopric in Salisbury in 1667. He was appointed chancellor of the Order of the Garter in 1671. Ward turned down the offer of the bishopric of Durham remaining in Salisbury until his death 6 January 1689. He was a very active churchman, just as he had been a very active university professor, and enjoyed as good a reputation as a bishop as he had enjoyed as an astronomer.










Filed under History of Astronomy, History of Mathematics, History of science

Christmas Trilogy 2016 Part 3: The English Keplerians

For any scientific theory to succeed, no matter how good or true it is; it needs people who support and propagate it. Disciples, so to speak, who are prepared to spread the gospel. Kepler’s astronomical theories, his three laws of planetary motion and everything that went with them, were no different from every other theory in this aspect; they needed a fan club. On the continent of Europe the reception of Kepler’s theories was initially lukewarm to say the least and it was not only Galileo, who did his best to ignore them. Therefore it is somewhat surprising that they found a group of enthusiastic supporters right from the beginning in England. Surprising because in general in the first half of the seventeenth century England lagged well behind the continent in astronomy, as in all things mathematical.

The first Englishmen to pick up on Kepler’s theories was the small group around Thomas Harriot, who did so immediately after the publication of the Astronomia nova in 1609.

Portrait often claimed to be Thomas Harriot (1602), which hangs in Oriel College, Oxford. Source: Wikimedia Commons

Portrait often claimed to be Thomas Harriot (1602), which hangs in Oriel College, Oxford. Source: Wikimedia Commons

The group included not only Harriot but also his lens grinder Christopher Tooke, the Cornish MP Sir William Lower (c.1570–1615) and his Welsh neighbour John Prydderch (or Protheroe). Lower had long been an astronomical pupil of Harriot’s and had in turn introduced his neighbour Prydderch to the science.

The cartoon of Lower and Prydderch on page 265 of Seryddiaeth a Seryddwyr By J.S. Evans. Lower looks through a telescope while Prydderch holds a cross-staff. The cartoon had been used earlier by Arthur Mee in his book The Story of the Telescope in 1909. The artist was J. M. Staniforth, the artist-in-chief of the Western Mail newspaper.

The cartoon of Lower and Prydderch on page 265 of Seryddiaeth a Seryddwyr By J.S. Evans. Lower looks through a telescope while Prydderch holds a cross-staff. The cartoon had been used earlier by Arthur Mee in his book The Story of the Telescope in 1909. The artist was J. M. Staniforth, the artist-in-chief of the Western Mail newspaper.

This group was one of the very earliest astronomical telescopic observing teams, exchanging information and comparing observations already in 1609/10. In 1610 they were enthusiastically reading Astronomia nova and discussing the new elliptical astronomy. It was Lower, who had carefully observed Halley’s comet in 1607 (pre-telescope) together with Harriot, who first suggested that the orbits of comets would also be ellipses. Kepler still thought that comets move in straight lines. The Harriot group did not publish their active support of the Keplerian elliptical astronomy but Harriot was well networked within the mathematical communities of both England and the Continent. He had even earlier had a fairly substantial correspondence with Kepler on the topic of atmospheric refraction. It is a fairly safe assumption that Harriot’s and Lower’s support of Kepler’s theories was known to other contemporary English mathematical practitioners.

Our next group of English Keplerians is that initiated by the astronomical prodigy Jeremiah Horrocks (1618–1641). Horrocks was a self-taught astronomer who stumbled across Kepler’s theories, whilst on the search for reliable astronomical tables. He quickly established that Kepler’s Rudolphine Tables were superior to other available tables and soon became a disciple of Kepler’s elliptical astronomy. Horrocks passed on his enthusiasm for Kepler’s theories to his astronomical helpmate William Crabtree (1610–1644). In turn Crabtree seems to have been responsible for converting another young autodidactic astronomer William Gascoigne (1612–1644) to the Keplerian astronomical gospel. Crabtree referred to this little group as Nos Keplari. Horrocks contributed to the development of Keplerian astronomy with an elliptical model of the Moon’s orbit, something that Kepler had not achieved. This model was the one that would eventually make its way into Newton’s Principia. He also corrected and extended the Rudolphine Tables enabling Horrocks and Crabtree to become, famously, the first people ever to observe a transit of Venus.


Like Harriot’s group, Nos Keplari published little but they were collectively even better networked than Harriot. Horrocks had been at Oxford Emmanual College Cambridge with John Wallis and it was Wallis, a convinced nationalist, who propagated Horrocks’ posthumous astronomical reputation against foreign rivals, as he also did in the question of algebra for Harriot. Both Gascoigne and Crabtree had connections to the Towneley family, landed gentry who took a strong interest in the emerging modern science of the period. Later the Towneley’s who had connections to the Royal Society ensured that the work of Nos Keplari was not lost and forgotten, bringing it, amongst other things, to the attention of a young John Flamsteed, who would later become the first Astronomer Royal. . Gascoigne had connections to William Cavendish, the later Duke of Newcastle, under whose command he served at the battle of Marston Moor, where he died. William, his brother Charles and his wife Margaret were all enthusiastic supporters of the new sciences and important members of the English scientific and philosophical community. Gascoigne also corresponded with William Oughtred who served as private mathematics tutor to many leading members of the burgeoning English mathematical community. It is to two of Oughtred’s students that we now turn

William Oughtred by Wenceslas Hollar 1646

William Oughtred
by Wenceslas Hollar 1646

Seth Ward (1617–1689) studied at Oxford Cambridge University from 1636 to 1640 when he became a fellow of Sidney Sussex College.

Greenhill, John; Seth Ward (1617-1689), Savilian Professor of Astronomy, Oxford (1649-1660) Source: Wikimedia Commons

Greenhill, John; Seth Ward (1617-1689), Savilian Professor of Astronomy, Oxford (1649-1660)
Source: Wikimedia Commons

In the same year he took instruction in mathematics from William Oughtred. In 1649 he became Savilian Professor of Astronomy at Oxford University the same year that John Wallis was appointed Savilian Professor of Mathematics. Whilst serving as Savilian Professor, Ward became embroiled in a dispute about Keplerian astronomy with the French astronomer and mathematician Ismaël Boulliau.

Ismaël Boulliau  Source: Wikimedia Commons

Ismaël Boulliau
Source: Wikimedia Commons

Boulliau was an early and strong defender of Keplerian elliptical astronomy, who however rejected Kepler’s attempts to create a physical explanation of planetary orbits. Boulliau published his Keplerian theories in his Astronomia philoaïca in 1645. Ward attacked Boulliau’s model in his In Ismaelis Bullialdi astro-nomiae philolaicae fundamenta inquisitio brevis from 1653, presenting his own model for Kepler’s planetary laws. Boulliau responded to Ward’s attack in his De lineis spiralibus from 1657. Ward had amplified his own views in his Astronomia geometrica from 1656. This public exchange between two heavyweight champions of the elliptical astronomy did much to raise the general awareness of Kepler’s work in England. It has been suggested that the dispute was instrumental in bringing Newton’s attention to Kepler’s ideas, a claim that is however disputed by historians.

Ward went on to make a successful career in the Church of England, eventually becoming Bishop of Salisbury his successor, as Savilian Professor of Astronomy was another one of Oughtred’s student, Christopher Wren (1632–1723).

Christopher Wren by Godfrey Keller 1711  Source: Wikimedia Commons

Christopher Wren by Godfrey Keller 1711
Source: Wikimedia Commons

Wren is of course much better known as the foremost English architect of the seventeenth-century but started out as mathematician and astronomer. Wren studied at Wadham College Oxford from 1650 to 1653, where he was part of the circle of scientifically interested scholars centred on John Wilkins (1614–1672), the highly influential early supporter of heliocentric astronomy. The Wilkins group included at various times Seth Ward, John Wallis, Robert Boyle, William Petty and Robert Hooke amongst others and would go on to become one of the groups that founded the Royal Society. Wren was a protégé of Sir Charles Scarborough, a student of William Harvey who later became a famous physician in his own right; Scarborough had been a fellow student of Ward’s and was another student of Oughtred’s. Wren was appointed Gresham Professor of Astronomy and it was following his lectures at Gresham College that the meetings took place that would develop into the Royal Society. As already noted Wren then went on to succeed Ward as Savilian Professor for astronomy in 1661, a post that he resigned in 1673 when his work as Surveyor of the King’s Works (a post he took on in 1669), rebuilding London following the Great Fire of 1666, became too demanding. Wren enjoyed a good reputation as a mathematician and astronomer and like Ward was a convinced Keplerian.

Our final English Keplerian is Nicolaus Mercator (1620–1687), who was not English at all but German, but who lived in London from 1658 to 1682 teaching mathematics.

Nicolaus Mercator © 1996-2007 Eric W. Weisstein

Nicolaus Mercator
© 1996-2007 Eric W. Weisstein

In his first years in England Mercator corresponded with Boulliau on the subject of Horrock’s Transit of Venus observations. Mercator stood in contact with the leading English mathematicians, including Oughtred, John Pell and John Collins and in 1664 he published a defence of Keplerian astronomy Hypothesis astronomica nova. Mercator’s work contained an acceptable mathematical proof of Kepler’s second law, the area law, which had been a bone of contention ever since Kepler published it in 1609; Kepler’s own proof being highly debateable, to put it mildly. Mercator continued his defence of Kepler in his Institutiones astronomicae in 1676. It was probably through Mercator’s works, rather than Ward’s, that Newton became acquainted with Kepler’s astronomy. We still have Newton’s annotated copy of the latter work. Newton and Mercator were acquainted and corresponded with each other.

As I hope to have shown there was a strong continuing interest in England in Keplerian astronomy from its very beginnings in 1609 through to the 1660s when it had become de facto the astronomical model of choice in English scientific circles. As I stated at the outset, to become accepted a new scientific theory has to find supporters who are prepared to champion it against its critics. Kepler’s elliptical astronomy certainly found those supporters in England’s green and pleasant lands.





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

I was robbed (twice)! – Vague ramblings on rites of passage, anniversaries, calendrics and the human desire to control time – on the occasion of the winter solstice.

Sunrise at Stonehenge on the Winter Solstice Photo: Mark Grant Source: Wikimedia Commons

Sunrise at Stonehenge on the Winter Solstice
Photo: Mark Grant
Source: Wikimedia Commons

As I was growing up in a remote corner of North-East Essex there were two birthdays that were considered to mark important moments in a person’s life, the twenty-first and the sixty-fifth. The first marked the entry into adulthood and the second the exit out of the world of work. Both were celebrated as special occasions, the former with a lavish party and, in well off families, with a spectacular coming of age present, the later with a somewhat more sombre ceremony and traditional the presentation of a timepiece (quite why it is/was traditional to give people a timepiece when they retire I have absolutely no idea!) The celebration of such points in ones life are known as rites of passage because they mark the transition from one socio-cultural group to another – coming of age from the community of the children to that of the adults, retirement from the working community to the community of the retired. Humans find it necessary/comforting/important to mark these transitions in some significant way.

I was going on nineteen when the British government decided to reduce the age of majority from twenty-one to eighteen meaning that my transition into adulthood took place on some arbitrary date by act of parliament without any form of acknowledgement/ceremony or whatever. As the title of this post says, I was robbed! Two days ago I celebrated my sixty-fifth birthday or rather didn’t celebrate but I still turned sixty-five. The German government is in the process of incrementally raising the retirement age to sixty-seven so I would have been due to retire at sixty-five and six months. However that same government persuaded me to retire at the beginning of September, actually carried out retrospectively meaning once more I was robbed of my rite of passage. As, however, I am self employed in that work that I do, and continue to do, there would have been nobody to hand around the cucumber sandwiches and the plastic glasses of cheap bubbly or to hold a boring and embarrassing speech whilst presenting me with my timepiece anyway.

Being from a non-religious, middle class, English household, and not for example Jewish, I did not undergo a biological coming of age at a nominal puberty such as the Jewish Bar Mitzvah. That is unless you count the eleven plus exam and the transition from primary school to secondary school. Which, at my very elite and very posh, grammar school included the tradition of being dragged through a hedge backwards or having ones head stuck in a toilet bowl and flushed by members of the fifth form during the mid morning break on the first day of school, delights that I managed somehow to avoid. By the time I reached the fifth form the tradition had thankfully died out.

Human seem to have some sort of innate desire to mark time and to celebrate certain events on some sort of regular basis. On the secular side birthdays, wedding anniversaries, first meetings, for some final school exams and whatever. On the religious side, for all religions, a whole cartload of religious festivals of various types. As political communities independence days, armistice days and an assortment of other national holidays. These celebrations and the rites of passage discussed above have one thing in common they are almost all arbitrary, the one exception being anniversaries to which we will return to in a minute.

The only natural timekeepers that we have are the diurnal rotation of the earth, the phases of the moon and the apparent passage of the sun around the ecliptic, which give us respectively the day, the (lunar) month and the year. All other divisions of time are of our own devising and as such arbitrary. Calendars were invented to help us keep track of those days that we have chosen to mark out for special attention of some sort – a public holiday, a religious observance or whatever. They are crib sheets for rites and rituals, which as already remarked almost all take place on arbitrary days. Good examples of arbitrary ritual days are the rapidly approaching Christmas and New Years festivals, as I have pointed out for the latter in an earlier post, different cultures having different New Years celebrations on differing dates.

The only rituals that are in a sense not arbitrary are, because the solar year is periodic, anniversaries. These occur, with a little bit of fudging, once every three hundred and sixty-five days. The fudging is necessary because the solar year is, as should be well-known, a little bit longer than three hundred and sixty-five days. With the Gregorian calendar we have a tolerably good system of fudging, although other calendars, the Jewish and Islamic ones for example, do things differently.

Because the ecliptic is tilted at approximately twenty-three degrees with relation to the equator, known technically as the obliquity of the ecliptic, we have as a result the seasons and also four days in the solar year that are not arbitrary. These are the equinoxes and the solstices. The equinoxes are the days in spring, the vernal equinox around the twentieth of March, and autumn, the autumnal equinox around the twenty-second of September, when the sun appears to be over the equator and the day and night are equally long. The summer solstice (Northern hemisphere, winter for Southern hemisphere) takes place when the sun appears to be over the Tropic of Cancer (approximately 23° of latitude north of the equator), that is its Northern most point on its journey around the ecliptic, around the twenty-first of June, and marks the longest day and shortest night in the Northern hemisphere and vice versa in the Southern hemisphere. The winter solstice (Northern hemisphere, summer for Southern hemisphere) takes place when the sun appears to be over the Tropic of Capricorn (approximately 23° of latitude south of the equator), that is its Southern most point on its journey around the ecliptic, around the twenty-first of December, and marks the shortest day and longest night in the Northern hemisphere and vice versa in the Southern hemisphere.

Many of the folk customs that occur around these days are celebrations of these astronomical events, their origins often forgotten, as they are co-opted into other, oft religious, celebrations. This is certainly true for many of the Christmas customs, which have their origins in various winter solstice celebrations, now lost in the mists of history.

I celebrate neither Christmas nor New Years but am prepared to acknowledge the winter solstice as a fulcrum or turning point of the year, so I wish all of my readers all the best for their next three hundred and sixty-five and a bit days journey around the sun, it is of course we who orbit the sun and not the sun us, and may you enjoy in your own ways those arbitrary calendrical dates that you choose to celebrate.


Filed under Autobiographical, History of Astronomy

I wish a certain (tv) star would think before he tweets

On a couple of occasions I have blogged about the publically displayed history of science ignorance of mega-star science entertainer Neil deGrasse Tyson (NdGT). On Sunday I stumbled over one his tweets, which stridently proclaimed:


If you wished upon that first Star you saw tonight in twilight,

then it will not likely come true. You wished on planet Venus

Venus is always brighter than all other planets or stars as seen from Earth. The second brightest object on the image is Jupiter Source: Wikimedia Commons

Venus is always brighter than all other planets or stars as seen from Earth. The second brightest object on the image is Jupiter
Source: Wikimedia Commons

My first reaction was that this tweet was very mean spirited and to ask myself what NdGT’s intention was in tweeting it. Then as a historian of astronomy I replied to this tweet by pointing out that from antiquity up to the beginning of the eighteenth century all illuminated celestial bodies – stars, comets, planets – were referred to as stars and so one would still be wishing upon a star. Now NdGT has a trillion sycophants followers, so the last thing I expected was a response from the great man himself to my tweet. Imagine my surprise when I got just that:


The 7 “planetes” (Greek for “wanderer”) were distinct from stars:

Sun Moon Mercury Venus Mars Jupiter Saturn.


Slam -Bam! A killer etymological put down or at least I assume that was what NdGT thought he had achieved. Unfortunately he had just ridden himself deeper into the mire. If we actually consult an etymological dictionary on the origins of the term planet we discover the following:

Planet (n): late Old English planete, from Old French planete (Modern French planète), from Late Latin planeta, from Greek planetes, from (asteres) planetai “wandering (stars),” from planasthai “to wander…

Oh dear, planet doesn’t mean wanderer in the original Greek; it means wandering star! The Greeks did indeed differentiate between fixed stars, our stars, wandering stars, the seven planets and hairy stars (I’ve always liked that one) the comets, but, and this is the decisive point, they are all stars, as I stated in the first place. Whether NdGT’s etymological error was out of ignorance or a result of deliberate quote mining I can’t say.

NdGT might have saved himself some embarrassment if he had paused for a moment to consider the etymology of astronomy, the mother discipline of his own profession, astrophysics. Astronomy is also derived from ancient Greek, as was astrology and as I pointed out in another post the two terms were, from their origin up till the late seventeenth century, synonyms. Let’s just check out those etymologies shall we.

Astronomy (n): c. 1200, from Old French astrenomie, from Latin astronomia, from Greek astronomia, literally “star arrangement,” from astron “star”

Astrology (n): late 14c., from Latin astrologia “astronomy, the science of the heavenly bodies,” from Greek astrologia “telling of the stars,” from astron “star”

So astrologia, which is the older of the two terms, means the science of the heavenly bodies, which of course includes the planets. Astronmia naturally includes the planets too, as stars.

What evidence can I bring forth that this was still the case in the Early Modern Period? I have no lesser witness than that well-known Elizabethan playwright and poet Will Shakespeare. In his tragedy Romeo and Juliet he refers to the fact that their doom has been predetermined by their astrological fate. Now an astrological horoscope determines the position of the planets along the elliptic, the apparent path of the sun around the earth, so astrology is very much planetary. So how does the good bard describe the astrological doom of his two young lovers?

From forth the fatal loins of these two foes,

A pair of star-cross’d lovers take their life

Note Romeo and Juliet are star-crossed, although it is the planets that determine their fate. In fact the expression ones fate is written in the stars is still very much used today in the English language.

I do have a last sad note for NdGT concerning his original tweet. Most people probably associate the expression ‘to wish upon a star’ with the pop song When You Wish Upon a Star originally from the Walt Disney film Pinocchio from 1940, which has been covered by many, many artists. However the tradition is much older and in fact goes back at least to the ancient Romans. The tradition says that if you make a wish when you see the first star of the evening then that wish will come true. Now the first star of the evening is ‘the evening star’ also known as the planet Venus and in fact the tradition derives from the Roman worship of Venus their goddess of love, so if you did make a wish upon seeing Venus, as NdGT claimed in his original tweet, then you would be doing exactly the right thing to have your wish come true. You are just offering up a prayer to the divine Venus.

The Birth of Venus, by Sandro Botticelli c. 1485–1486 Source: Wikimedia Commons

The Birth of Venus, by Sandro Botticelli c. 1485–1486
Source: Wikimedia Commons

The saddest aspect of this brief collision on Twitter is just how many of NdGT’s sycophants followers retweeted and/or liked his etymology of the term planet tweet thinking he had brilliantly seen of the bothersome history of astronomy troll. I wouldn’t mind him spouting history of science crap if he was some brain damaged loony with 15 followers on Twitter but unfortunately he is the most well-known and influential English language science communicator in the world and his false utterances mislead and misinform a lot of trusting people.





Filed under History of Astronomy, Myths of Science