Gopnik, Galileo and Ed Yong: Galileo not admitting to being wrong.

Ed Yong (@edyong209) is a well-known and highly respected science writer. At regular intervals he posts lists of links on his website, Not Exactly Rocket Science, of science stories that he has found interesting, a sort of one-man blog carnival. On his links list for 20 April he included a link to Adam Gopnik’s BBC Point of View piece, which I recently criticised, with the following description.

Galileo was a great scientist because he wasn’t afraid to admit when he was wrong. If only more of us did the same.

Now in recent months we have had a series of talks and articles by such luminaries as Paul Nurse, President of the Royal Society, making similar claims for science and scientists in general. That is that scientists are characterised by their willingness to admit that they are wrong and to give up the theories they hold that have been proved to be defective. Such speeches have had historians of science all over the Intertubes banging their heads against the wall in collective displays of disbelief because even a cursory survey of the history of science would show that the exact opposite is true, scientists hang on to their cherished theories until the bitter end against all sorts of opposition and refuting evidence and Galileo is a prime example of such behaviour. For me this attitude, and it is not necessarily one that I condemn, was wonderfully summed up by Einstein when Eddington confirmed the General Theory of Relativity empirically. Asked by a reporter what he would have done if Eddington had refuted his theory Einstein is said to have replied then I would have said that Eddington’s measurement were wrong. A certain amount of tenacity is important in the early development of scientific theories, which are seldom born complete and perfect and are brought to their optimal condition through a process of criticism and modification to refute that criticism. Not giving up supposedly refuted theories is part and parcel of the scientific process but sometimes this tenacity can be and is misplaced and Galileo is one historical figure who delivers very good examples of a man who held onto wrong theories beyond the point of no return.

Galileo is well known as a supporter of Copernican heliocentricity and as one of the founders of the new mechanics but in both theories his adherence to an antiquated theory held him back an adherence that he maintained although he must have known that it was wrong. The antiquated theory that Galileo refused to abandon was the so-called Platonic axiom in astronomy. This metaphysical axiom says that the planets move with uniform motion in circles. Like Copernicus before him Galileo’s fidelity to this axiom meant the retention of the whole Ptolemaic apparatus of deferents and epicycles. Clinging to this axiom also meant that Galileo failed to formulate the principle of inertia properly as he believed, like a good Aristotelian, that only circular motion was natural motion. All well and good but why do I claim that he should have known better? The answer is Johannes Kepler.

Before Galileo had finished writing his Dialogo Kepler had already delivered his three laws of planetary motion thus completely refuting the Platonic axiom. Kepler’s laws were strict mathematical laws derived from Tycho Brahe’s empirical observations. Here was modern science in action if ever there was and Galileo ignored it clinging to the clearly refuted Greek orthodoxy, why? Faced with this seemingly inexplicable behaviour of their hero the Galileo fan club argue that Galileo could not accept Kepler’s bizarre Renaissance meta-physics and that is why he refused to accept Kepler’s work. This seems like a reasonable argument until one takes a closer look at the evidence. Kepler’s first two laws were delivered in his Astronomia Nova (1609) a book that contains none of his possibly off putting meta-physics. Also the clearest statement of his three laws and their application to a heliocentric system is in his Epitome astronomiae Copernicanae  (1617, 1620 & 1621) a textbook, which also is relatively free of anything that might have offended Galileo’s sensibilities.

I think that the answer is actually to be found in Galileo’s ego. Kepler’s work on the planetary orbits was a much better and more convincing argument for heliocentricity than anything Galileo had produced. In fact it was the Epitome Copernicanae combined with Kepler’s Rudolphine Tables that led to the acceptance of heliocentricity in the seventeenth century and not Galileo’s work.  If Galileo were to include Kepler’s work in his Dialogo then he would be merely the messenger and not the creator so he simply ignored it and stuck to the Platonic axiom that he knew to be wrong.

Galileo’s second case of refusing to admit that he was wrong is even more undignified. In 1618 a spectacularly bright comet was visible over Europe, which was of course carefully observed by nearly all the leading astronomers. One notable exception was Galileo who because of ill health had been unable to take part in the observations. By now Galileo was Northern Italy’s leading natural philosopher feted for his quick wit and his even quicker slicing tongue with which he took great pleasure in dicing his scientific opponents. Asked for his opinion on the nature of the new comet Galileo, who as already noted actually knew nothing about it, took the strange step of attacking the Jesuit astronomer Orazio Grassi who had carefully observed the comet and based on his observations had correctly calculated that the comet was a supra-lunar celestial body. Galileo now claimed that Grassi was wrong and presented what was in essence the out dated and discredited Aristotelian theory that comets were sub-lunar meteorological phenomena. This notorious dispute culminated in Galileo’s Il Saggiatore with its famous “the book of nature is written in the language of mathematics” quote. Here is Galileo bizarrely lecturing Grassi that investigations of nature must be empirical and mathematical in a situation where Grassi’s investigations were just that and Galileo’s own were definitely not. Of course Galileo’s brilliant polemic crushed his poor hard done by opponent without Galileo’s claque noticing that Grassi was in the right and Galileo very much in the wrong something that the maestro almost certainly knew, however his ego would not let him admit it. He had to win the argument at all costs even if he was horribly wrong.

We now turn to the most notorious case of Galileo refusing to accept that he was wrong his theory of the tides. This was the crowing glory of Galileo’s argumentation for heliocentricity his only empirical evidence. This took up the whole of the fourth day of his Dialogo delivering the climax and was the only argument that he brought forward in 1615 when he was trying to head off a condemnation of Copernicus by the Inquisition. This was Galileo’s trump. Unfortunately it suffered from one glaring defect it was wrong. It was empirically, irrefutably, undeniably, indisputably wrong.

This theory of the tides was first formulated in about 1596 by Galileo and Paolo Sarpi in one of their intellectual sparring sessions. In fact it is not clear if the theory is from Galileo or Sarpi, 1596 being the date that Sarpi first recorded it in his scientific diary. Of itself it is actually quite an ingenious idea. If the earth is actually moving as stipulated in a heliocentric hypothesis then wouldn’t the water on the earths surface slop around like water in a bowl being carried by someone and might this not be the explanation for the tides? If this were the case it would indeed be a solid empirical argument in favour of heliocentricity. In fact John Heilbronn in his Galileo biography dates Galileo’s conversion to Copernicanism to 1596 and the formulation of this theory.

As already stated above this theory has a major problem it was empirically refuted. As formulated by Galileo/Sarpi there would only be one tide a day but as every coastal inhabitant knows there are two. There is also another problem for this theory there already existed a better theory to explain the tides, a theory that we now know to be true; they are caused by the moon. The correlation between the tides and the phases of the moon had already been observed in antiquity but as every scientist knows, or should know, correlation does not equal causation and there was no known explanation as to how the moon could cause the tides. Newton was not even a blip on the horizon at this time.

Now Gopnik argued in his two essay’s that Galileo stuck to his refuted theory of the tides because the much more rational alternative smacked too much of magic for him to accept it, action at a distance would prove a difficult point even for Newton. Gopnik has solid evidence for his claim this is exactly the argument that Galileo brings for rejecting the lunar tide theory in book four of his Dialogo. So Gopnik is right? I don’t think he is. I think Galileo is being deceptive.

Galileo is convinced that his theory of the tides can deliver the empirical proof he so desperately needs for heliocentricity. If it were true then it would indeed the only such proof he has to offer. All the other arguments he marshals in his masterpiece are suggestive that heliocentricity might be a viable alternative but none of them is a proof or anything remotely like it. He needs his theory of the tides. He spent thirty years trying to cure its very obvious defect and failed but he is still not prepared to abandon it. Now as already pointed out there existed a much better empirically based explanation for the tides the lunar theory, one that for example Kepler backed. It of course lacked an explanatory mechanism but one could set up a research programme based on the concept of attractive forces, an idea that Kepler was already playing with, to find that mechanism, which is of course exactly what Newton did. If however Galileo accepted the greater plausibility of the lunar tide theory then his only “proof” of heliocentricity was down the drain so we look for a reason to reject it. In doing so he of course rejected the possibility of following Kepler down the path of considering forces controlling the solar system; a path that interestingly Galileo’s pupil Borelli took.

To summarise I don’t think that Galileo rejected the lunar tide theory because he thought it was magical. I think he rejected the lunar tide theory because it posed a serious threat to his own mechanical tide theory the only supposed proof that he had for a geocentric astronomy and having rejected it he looked around for an excuse to justify his rejection. There are lots of other examples of contemporary natural philosophers and astronomers employing the same tactic, Copernicus, Kepler, Newton and Galileo himself but to detail them here would make an already long post even longer. I shall save them for another post on another occasion.

As we have seen far from being unafraid to admit that he was wrong on three separate and highly significant occasion, significant for the evolution of science that is, not only did Galileo refuse to admit that he was wrong although he knew that he was but he actually did his best to bamboozle people into believing that he was right.

Isaac Newton: The Last Lone Genius?

The Friday before last, with much advanced publicity, the BBC broadcast a new documentary film biography of Isaac Newton with the title The Last Magician. This phrase is part of a famous quote by John Maynard Keynes, “not the first scientist but the last magician”, describing his feeling upon reading the Newtonian alchemical manuscripts that he acquired at the auction of the Portsmouth family Newton papers in 1936.  This of course together with the advanced advertising for the programme signalled that we were due for a fresh dose of “did you know that Newton was a secret alchemist?” A phenomenon that Rebekah “Becky” Higgitt has blogged on informatively in the past.

Based on quotes from Newton’s own writings and correspondence as well of those of his contemporaries the programme was in its basics factually correct. As usual for BBC historical documentaries it was well-produced and excellently filmed and thus pleasant to watch. The basic structure was the direct quotes being spoken by actors in costume and commented upon by five more or less experts. These were the historians of science Rob Iliffe head of the Newton Papers editing project and a genuine Newton expert, Patricia Fara author of an excellent book on the changing image of Newton down the centuries and Lisa Jardine expert on Renaissance history of science, as well as popular science writer James Gleick author of a competent popular Newton biography and astrophysicist turned novelist Stuart Clark.

Given all of these preconditions it should have been an excellent hours entertainment for a historian of science like myself, unfortunately it turned out to be a major disappointment for two reasons. The programme deliberately created two principle impressions that were and are fundamentally wrong.

The first of these turned up in the pre-programme publicity but also featured prominently fairly early in the documentary in what seems at first glance to be a fairly harmless statement:

By the age of 21, he had rejected 2,000 years of scientific orthodoxy…

This brief phrase contains two claims one implicit and one explicit. The implicit claim is how wonderful Newton was to take such a bold step when he was only 21 years old. Anyone who has spent anytime at all looking at the history of mathematics knows that mathematicians tend to be very precocious. Pascal wrote the paper that gained him entry to the top flight of seventeenth century mathematics at the age of sixteen. In the nineteenth century the teenage William Rowan Hamilton was trotted out in public like a circus pony to display his brilliance. The stories are legion and there is absolutely nothing unusual in Newton intellectual development it’s par for the course for a highly talented mathematician.

As Becky put it very succinctly in a tweet what they are actually saying here is that there had been no science since Aristotle, which is of course complete rubbish. The scientific orthodoxy of the day, which was by the way on the verge of disappearing, of which more shortly, came into being in the thirteenth century when Albertus Magnus and his pupil Thomas Aquinas created a synthesis of Catholic theology and Aristotle’s philosophy with the addition of Ptolemaic geocentric astronomy. This synthesis is known as Scholastic or Aristotelian physics or natural philosophy. However as Edward Grant, one of the leading experts on medieval science, points out Aristotelian philosophy is not Aristotle’s philosophy. It is also important to note that Aristotelian philosophy was never carved in stone but in fact changed and developed continuously over the next four hundred years. Examples of major changes are the work of the Oxford Calculatores and the Paris Physicists in the fourteenth century. The Aristotelian physics of the fifteenth century is a very different beast to that of the thirteenth century. The geocentric astronomy produced in the middle of the fifteenth century by Peuerbach and Regiomontanus differed substantially from that of the first Ptolemaic translations of the twelfth century.

Added to all this change and development the first seeds of what would become modern science began to poke their slender stems out of the substrate of scientific innovation around the beginning of the fifteenth century. By 1661 when Newton went up to university Keplerian heliocentric astronomy had become the new orthodoxy and Aristotelian physics was being pushed out by the new physics developed by mathematicians such as Tartaglia and Benedetti in the sixteenth century and Stevin, Galileo, Borelli, Descartes, Pascal, Huygens and others in the seventeenth. One should bear in mind that the Leopoldina, the Accademia del Cimento, the Royal Society and the Acadédemie des Sciences all institutions dedicated to the propagation and development of the new science were founded in 1652, 1657, 1660 and 1666 respectively. The young Newton did not like some Carrollian hero draw his Vorpal Blade to slay the Jabberwock of ancient Greek science but like any bright young academic would do jumped on the band wagon of modern science that was speeding full speed ahead into the future.

We now turn to what I see as the most serious failing of the documentary expressed in the question posed in the title of this post. For the best part of an hour the documentary banged on about Newton’s solitude, his isolation his lone path to the secrets of nature. We were presented with the ultimate lone genius of the history of science. It went so far that the only other contemporary researchers mentioned by name were Descartes in passing and Hooke purely in a negative light. The way that the programme was structured created a totally false impression of Newton’s scientific endeavours.

We actually know very little about Newton’s time as a student though it is safe to say that he was more the type to curl up in front of the fire with a good book on a Friday evening than to go to the latest rave at which ever student hostelry was in that term. As a fellow we know that he communicated and worked together with other scholars such as Isaac Barrow so to talk of total solitude as the documentary did is wrong. After he emerged from obscurity at the beginning of the 1670s with his reflecting telescope and his famous paper on the phenomenon of colours he was in no way isolated. Even if Cambridge was somewhat off the beaten track in those days Newton corresponded with other scholars in Britain and also abroad as can easily be seen in his voluminous correspondence as edited by Turnbull. He was also often visited by other mathematical scholars such as Halley or John Collins. When he left Cambridge to go to London he became positively gregarious. Maintaining a town house with his niece Catherine Barton, a renowned social beauty, as his housekeeper where he received and entertained visitors. At the Royal Mint, which he attended daily, he was surrounded by a large staff. After 1703 he presided over the weekly meetings of the Royal Society and on other evenings surrounded by his acolytes he held court in one or other of the then fashionable London coffee bars.

More important for me was the totally false impression created by the documentary of Newton’s mathematical and scientific work. Anyone being introduced to Newton for the first time would come away with the impression that he revolutionised mathematics, physics and astronomy in a superhuman solo endeavour completely isolated from the rest of the late seventeenth century intellectual world.

We got presented with Newton in 1666 creating a completely new branch of mathematics, he only actually started it then and it took a number of years to develop. At no point was any other mathematician mentioned. The fact that Newton either, directly or indirectly, knew of and built on the previous work in this field of Kepler, Cavalieri, Fermat, Pascal, Descartes, van Schooten, Barrow and others was quietly swept under the carpet. Even worse no mention what so ever of Leibniz who independently developed the same mathematics almost at the same time from the same sources. This of course led eventually to the most notorious priority dispute in the history of science involving many of the leading mathematicians of Europe.

The same thing occurred with the presentation of his work in optics, no mention of Kepler, Schiener, Descartes, Grimaldi, Gregory, Hooke, Huygens or anybody for that matter. Isaac apparently did it all alone in isolation.

This form of presentation continued with his greatest work the Principia. We got each of the famous laws of motion presented individually but no hint of the fact that the first was taken from Beeckman by way of Descartes, the second from Huygens and the third from his readings in alchemy. We were told that he derived the law of gravity from his three laws but no mention was made of the fact that the concept of the law of gravity was common, much discussed intellectual property in academic circles at the time. No mention of the contributions made to the substance of the Principia by the work of Kepler, Galileo, Cassini, Halley and above all Flamsteed. We had the strange spectacle of Hooke famous accusation of Newton having stolen his law of gravity and plagiarised him delivered in a passionate speech to the Royal Society in 1660 but no mention what so ever that Hooke’s accusation had more than a little substance. Hooke and Newton had corresponded on the subject in the early 1680s and Hooke had already formulated a concept of universal gravity before Newton. This correspondence was with certainty one of the spurs that led Newton to write the Principia although Hook’s claims as to the extent of his contribution are wildly exaggerated.

Isaac Newton did not live and work in an intellectual vacuum as was very strongly implied either deliberately or accidently through bad scripting by this documentary. He was part of a strong multi-faceted scientific community who supplied both the scaffolding and a significant part of substance of Newton’s life work in mathematics, physics and astronomy. He was in no way a lone genius but a highly significant cog in a large intellectual endeavour.

There was a time some decades back when some historians of science went so far as to decry the Principia as purely a work of synthesis with only a very small original contribution from Newton. This view was shown to be exaggerated and invalid and has been dropped but the opposite point of view implied by this documentary of the Principia as being alone the work of Newton’s genius is even more false.

Before I close there are a couple of small points from the film that I think should be mentioned. As is all too often the case we had the tired old statement that after Newton became President of the Royal Society he produced no more original scientific work. This was as always made without explicit comment but with a strong implicit negative aura. Dear people, when Isaac Newton became President of the Royal Society in 1703 he was already sixty years old. He had written and published two of the most important major scientific works in the history of mankind, his Principia and his Optics, as well as vast quantities of, largely unpublished, absolutely world-class mathematics, which he did however circulate in manuscript amongst his acolytes. What more did you expect him to do (FFS)?

I noted four major scientific/historical errors during the film, a fairly low quota; there may have been others. We of course get introduced to Newton’s reflecting telescope, the invention that first made him known to the world at large, but then we get informed that this instrument played a major role in marine navigation in the eighteenth century. Now whilst it is true that the reflecting telescope, mostly Gregorian’s and not Newtonian’s, had become the instrument of choice for astronomers by the middle of the eighteenth century they were for several good reasons not used for navigation on ships. Firstly reflecting telescopes whilst in principle smaller than refracting ones don’t telescope and so are more massive and cumbersome than the classical marine telescope. Secondly until the nineteenth century reflecting telescopes had metal mirrors made of so-called speculum metal an alloy that unfortunately was very susceptible to corrosion necessitating regular re-polishing. The salt-water atmosphere of sea voyages would have been very adverse for such mirrors requiring almost daily re-polishing and thus completely impractical.

The next error I spotted was a real howler. A voice over informed the viewer that, “for centuries light was considered the purest form of energy in the universe.” Really? Although etymologically derived from an ancient Greek word the physics concept of energy was first appeared in the nineteenth century, as did the recognition that light is a form of energy. Nuff said.

Moving along the historical time scale in the opposite direction voice over informed us the Newton’s Principia made possible the accurate prediction of comets and eclipses. Now the former is indeed true although the credit should properly go to Halley who first showed that some comets were periodical and obeyed Newton’s law of gravity. The latter is however again a real history of science howler. The Babylonians could accurately predict lunar eclipses in about the fifth century BCE and the ability to accurately predict solar eclipses was also developed in antiquity. No need to wait for Newton.

My final error is the one that as a historian of science causes me the most concern. Whilst discussing Newton’s alchemy voice over stated correctly Newton’s alchemical belief that light and matter are both products of some as yet undiscovered primal alchemical substance. The claim was immediately made that Newton had anticipated Einstein’s famous E = MC²! This claim being, to my surprise, repeated by Rob Iliffe an excellent historian of science. Now I’m not a big fan of the Kuhn/Feyerabend principle of the incommensurability of scientific theories. This says that one can’t compare scientific theories because the definitions of the concepts that they contain differ and are thus not comparable. Newton’s concept of force is not Maxwell’s concept of force for example. However I think that here we have a genuine case of incommensurability. The metaphysical concepts behind Newton’s alchemical theory and the metaphysical concepts behind Einstein’ theory of relativity are in no way comparable. It is not even comparing apples with oranges; it’s comparing apples with bicycles!

On the whole I think what was superficially a very good and certainly an excellently produced documentary failed miserably as a piece of history of science for the reasons that I have outlined above. Maybe I’m being too harsh but on the whole I don’t think so. For me the very strong emphasis of the biography of Newton as some sort of lone genius whether intended or an accidental product of ill considered scripting made this documentary next to worthless as a contribution to popular history of science.

 

 

Help! I’ve just been savaged by a toothless American bulldog.

I really think that the BBC is trying to piss me off this week. First they dish up the total disaster that was Great Lives “Galileo” on Radio 4. Then they present a highly questionable documentary on Isaac Newton on BBC 4, which, have no fear gentle readers, I will deal with in a later post. Finally Adam Gopnik abuses his position as one of the rotating cast of speakers on Radio 4’s Point of View to insult the critics of his highly dubious New Yorker Galileo essay. Add to this Radio 1’s totally wrong and highly cowardly refusal to play Ding Dong The Witch is Dead followed by some maverick BBC reporters making life very difficult for all student field trips to non democratic countries in the future and I could fall out of love with the Corporation that had nourished my soul since I first started to become aware of sound.

Mr Gopnik! Adam Gopnik chose this Sunday to answer those people who had possessed the infernal cheek to criticise his god given words on the great Galileo Galilei. Did he do so by engaging with his critics? Maybe he did so by producing some evidence to back up those of his utterances that had been deemed false by his detractors. Wrong on both counts. Our internationally renowned wordsmith resorted to the lowest form of riposte, the argumentum ad hominem.

I am conceited enough to thing that I personally was, at least, one of the targets at which his insults were launched, because of my criticism of his previous misrepresentation of John Dee, and having both heard the original broadcast and read the transcript of his talk all I can say is that I feel that I have been savaged by a toothless, arthritic American bulldog that is stone deaf and suffers from cataracts. It doesn’t really hurt and one feels slightly embarrassed at having to bat the poor demented creature away but its drool, which as all dog owners know if very slimy and gooey, is difficult to get out of one’s clothes.

So how does Mr Gopnik go about insulting his critics? He doesn’t do it directly but hides it behind even more waffle about Galileo, which only compounds his errors from the original article.

He starts of his talk with the following world-weary complaint of the plagued author:

When you write for a living, over time you learn that certain subjects will get set responses. You’re resigned to getting the responses before you write the story.

[…]

…you will get many letters and emails from what we call the cracked (and I think you call the barking)…

[…]

The oddest response, though, is if you write making an obvious point about an historical period or historical figure, you will get lots of letters and emails insisting that the obvious thing about the guy or his time is completely wrong.

By now you should be getting the drift, it is inconceivable that Mr Gopnik is wrong about anything, he obviously has god like powers and is omniscient, so it follows that his critics are not just wrong they are barking mad.

Now just in case you think that our god like author is only talking about those who are genuinely cracked he makes very clear that he isn’t:

Now these letters and emails come more often from the half-bright, some of them professional academics, than from the fully bonkers or barking.

You can tell the half-bright from the barking because the barking don’t know how little they know, while the half-bright know enough to think that they know a lot, but don’t know enough to know what part of what they know is actually worth knowing.

We now finally arrive at the grounds for our sterling authors woes his essay on Galileo. This time he choses to base his story around the myth of Galileo throwing balls off the Tower of Pisa. He sort of half admits that it might not be true. It’s actually a complete load of rubbish. However he doesn’t think that that matters because “it’s a legend that points towards the truth”. This shows that Gopnik neither understands Galileo nor physics. The story is a load of rubbish because it wouldn’t produce a result that confirms the laws of fall, it would instead confirm Aristotle’s view, which Galileo knew full well and which is why he would never had tried it. Galileo was not stupid.

Gopnik now goes into hagiographic modus:

In 1632 Galileo wrote a great book – his Dialogue On Two World Systems. It’s one of the best books ever written because it’s essentially a record of a temperament, of a kind of impatience and irritability that leads men to drop things from towers and see what happens when they fall.

The Dialogo is indeed a fine piece of polemic carefully constructed to cover the yawning gaps in the science that it contained. In those parts where Galileo sticks to his undoubted strengths as an experimental scientist it is about men who design carefully thought out, skilfully constructed and studiously carried out experiments and not about impatient and irritable idiots who throw things off towers.

Having led us away from his lament about the crackpots who make his life so difficult he now returns to stick the knife in to those barking critics who dared to contradict the master.

In that essay I wrote about Galileo I compared him to John Dee, the famous English magician, alchemist and astrologer, who was one of his contemporaries who was also a consultant to Queen Elizabeth I, and who read everything there was to read in his time and knew everything there was to know in the esoterica of his time – but didn’t know what was worth knowing.

Notice how he carefully avoids crediting Dee with being a Renaissance mathematicus, which he indubitably was, and one of the leading mathematical practitioners in Europe in the third quarter of the 16^th century. Also notice the subtle piece of invention at the end, “but didn’t know what was worth knowing”. This is a claim of Gopnik’s own creation and is in no way backed up by the historical facts about Dee.

He knew a lot about Copernicus, for instance, but he also spent half his life trying to talk to angels and have demons intervene to help him turn lead into gold.

Here we have a lovely example of rhetorical bait-and-switch. Dee might have known a lot about Copernicus but that knowledge was worthless because he talked to angels. In fact Dee and his group, Thomas Digges, John Feild (sic), Robert Recorde, Gemma Frisius etc, played an important and highly significant role in the propagation and dissemination of the Copernican heliocentric hypothesis, something that Gopnik with his black and white vision of the history of science is apparently incapable of understanding. Or more probably he can’t acknowledge because to do so he would have to admit that he is wrong and as we already know he can’t be wrong because he’s omniscient.

Now Mr Gopnik descends to the level of sneering condescension a sure sign that he has run out of real arguments and has to rely on argumentum ad hominem:

Well, it turns out that John Dee the magician and astrologer has his admirers – indeed his web pages and his fan clubs and his chatboard, just like Harry or Liam or Justin – and they took up the cause of the old alchemist with me. How dare you knock John, his fans, some of them half-bright, some of them just a little, well, barking, insisted. Wasn’t he a formidably erudite man particularly on just those subjects – stars and orbits and falling objects – that Galileo cared about too? Why shut him out of the scientific creed.

The only sentence worth noting in this gratuitous piece of slime is the final question, “Why shut him out of the scientific creed?” Gropnik’s answer is illuminating as it displays his total ignorance of the history of science:

Well, that was the point I was making. And it seems to me worth making again – and then again and then again. It just can’t be made too often.

The scientific revolution wasn’t an extension in erudition. It involved instead what we might call a second-order attitude to erudition – and if that sounds fancy, it just means the human practice of calling bull on an idea which you think is full of it, and being unafraid to do so.

Dee was a learned man – too learned a man, in fact, in whose head all kinds of stuff lodged, some obviously silly and some in retrospect sane, but impacted together like trash in a dump heap. Above all, his work is filled with supernatural explanations – with angels and demons and astrological spells.

There are two salient points to be made here “the scientific revolution […] means […] calling bull on an idea which you think is full of it, and being unafraid to do so”. Ignoring for the moment the fact that the majority of historians of science no longer believe in a thing called the scientific revolution Gopnik’s characterisation of what happened to science in the seventeenth century is totally and fundamentally wrong. Modern science emerged throughout the fifteenth, sixteenth and seventeenth centuries from an incredible jumble of rational, semi-rational, moderately weird and totally bat-shit insane ideas, concepts and theories. I would suggest that Mr Gopnik should avoid the works of Johannes Kepler who contributed considerably more to the development of modern science than Galileo (and yes I’m prepared at anytime to defend that claim). Kepler’s contributions to science emerged in a pot pourri of Renaissance ideas and theories that at times make even Dee’s conversations with angels seem almost rational. I shall come to Newton’s alchemy in a minute.

We return to Dr Dee:

Dee was a learned man – too learned a man, in fact, in whose head all kinds of stuff lodged, some obviously silly and some in retrospect sane, but impacted together like trash in a dump heap. Above all, his work is filled with supernatural explanations – with angels and demons and astrological spells.

Again we catch Gopnik making things up. Dee’s work was in no way, “impacted together like trash in a dump heap.” I challenge Mr Gopnik to search Dee’s mathematical writings on cartography, navigation and astronomy for the angels and demons. I will personally buy him a pint of his favourite beverage for every single one he finds. I know that I won’t actually have to open my wallet because unlike Mr Gopnik I have studied John Dee’s mathematical work and I know what I’m talking about.

Galileo, emphatically did not believe in magic. Galileo has no time for supernatural explanations of any kind – indeed, when he goes wrong, as he did when he rejected the idea that the Moon causes the tides, it’s because he resists the right explanation because it just sounds too strange or magical.[1]

I suggest that Mr Gopnik never reads Galileo’s Il Saggiatore, the polemic pamphlet containing his famous quote about the book of nature. Here he would find his hero vehemently defending the completely irrational Aristotelian theory of comets against the reasonably correct theory of Grassi based on observation just to score rhetorical points, a low point in the writings of the Tuscan polymath. This is just one example of several; Galileo was by no means as rational and scientific as Gopnik would wish him to be.

History has taught us that science didn’t just happen in a burst. Alchemy and astrology evolved slowly and over time into chemistry and astronomy.

Wow! Gopnik actually got something right for a change.

Galileo even made a buck in his youth by casting horoscopes for rich people.

You can almost hear the subtext screaming “But he didn’t believe in it, not my Galileo!” Just for the record Galileo was a professional teacher and practitioner of astrology and all of the available evidence suggests very strongly that he also believed in it.

There were no bright lines. Indeed sometimes science slipped back into astrology and alchemy and superstition and the occult. It’s well-known that Isaac Newton spent a lifetime searching for the Philosopher’s Stone.

Again Gopnik either doesn’t know what he is talking about or he is being deliberately misleading. Galileo in no way marks the end of astrology or alchemy as mainstream branches of knowledge in the seventeenth century so what we have is not a case of slipping back. Astrology first lost its academic and scientific status around 1660 and alchemy went on being acceptable, albeit in a strange secretive manner, into the beginnings of the eighteenth century. In fact I once wrote a short piece about the alchemical correspondence between Newton, Boyle and Locke. As I pointed out in another post on the entanglement of science and pseudo-science Newton’s very serious study of alchemy played a very significant role in the development of his universal theory of gravity. But that of course cannot be because as Gopnik informs us alchemy is bull and that has nothing to do with real science.

The closing paragraphs of Gopnik’s piece are a pathetic pleading for his version of science against the esoteric of the cracked and barking. It is straight out of the neo-positivist’s handbook of nineteenth century rationalism which I cannot be bothered to waste you time dismantling

Mr Gopnik if people criticise what you have written about the history of Renaissance science you might do well to open your ears and listen to what they have to say. If you did so then you might just learn something. However instead of listening you decided to insult your critics and to make stuff up to justify the false claims you made in the first place. If you are going to pontificate about the history of science in the Early Modern Period then might I suggest that you go away and learn something about it first before you start shouting your mouth off. Even better why don’t you write something about art instead? I’ve head that’s a subject that you might actually know something about.

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[1] I was planning on tackling Galileo’s claims on his reasons for rejecting a lunar tides theory in this post but as it is already far too long and still growing I think I’ll save that for a separate one.

F#*K the BBC

I have just listened to the BBC Radio 4 broadcast Great Lives “Galileo” and all I can say is that if I paid a licence fee in Britain then I would demand my money back. It wasn’t just awful it was a major traffic pile up in slow motion. The expert witness was not a historian of science but a physicist who very obviously didn’t have a clue. I can’t be bothered to excoriate the whole thing but one single quote should illuminate the level of historical knowledge of the so-called expert witness.

Toward the end of the programme he informed us that “by then Urban VIII had replaced Urban VII as Pope”! Maffeo Barberini did indeed become Pope in 1623 adopting the title Urban VIII but his predecessor was Gregory XV! Also the Pope who was in power in 1616 when Galileo first came into conflict with the Catholic Church was Paul V!

I rest my case.

 

 

What was when modern?

Darin Hayton has a short post discussing a review of John Hessler’s A Renaissance Globemaker’s Toolbox, a new book about the cartographical endeavours of the Renaissance mathematicus Johannes Schöner.  As well as being the addressee of Rheticus’ Naratio Prima, the first published account of Copernican heliocentricity, Schöner played a very central roll in the history of globe making as well as the evolution of cartography in the sixteenth century and it is with this aspect of his life that the new book is concerned. Schöner put together a private bound volume of cartographical material that he used for his own work. This volume contained, amongst other things, the only known copy of the first map to name the newly discovered western continent America, Martin Waldseemüller’s 1507 map of the world, that was purchased by the Library of Congress for ten million dollars in 2003. In his latest book Hassel analyses all the cartographical material contained in Schöner’s “toolbox” to develop a picture of how he worked. I might write more about this book when I’ve read it, I ordered it today, but here I’m concerned with one troubling paragraph of the review to which Darin has already drawn attention in his post. The reviewer, John Wilford, wrote at the end of his piece the following:

Nothing in the book points up more clearly Schöner’s pivotal place in a world in transition from the medieval to the modern than his residual interest in astrology and his awakening curiosity when he apparently heard reports of a new theory being formulated by a Polish Catholic cleric. A brilliant young student of Schöner’s, Georg Joachim Rheticus, went to see Copernicus in 1539 and learned more about the Earth orbiting the Sun. Rheticus then composed a short treatise, written in the form of a letter to his teacher, “most illustrious and learned” Johannes Schöner.

In his post Darin comments on this paragraph thus:

Schöner’s interest in that “new theory being formulated by a Polish Catholic cleric” probably owed more to his interest in astrology and making astrological prognostications than the modernity we see in Copernicus’s theory. Along with his prognostications and calendars, Schöner also wrote books on astrology before and after Copernicus’s De revolutionibus was published, notably his Opusculum Astrologicum in 1539 and De iudiciis nativitatum Libri Tres in 1545. Schöner might also have been the author of a horoscope cast for Copernicus. Judging from the table of contents, Hessler spends some time assessing Schöner’s astrology. Schöner’s interest in astrology shouldn’t diminish our interest in him, but it should, perhaps, prompt us to wonder about the labels “modern” and “medieval” and the work they do for us…

Darin criticism is right on the button and in what follows I would like to expand upon it somewhat and expose what I see as a common misconception concerning the history of astrology.

Darin is perfectly correct when he surmises that any interest that Schöner had in the work of Copernicus was almost certainly motivated by his very active interest in astrology and it should be noted that Schöner’s “brilliant young student”, Georg Joachim Rheticus, who famously undertook the arduous journey to Frauenburg to visit Copernicus did so after spending several months in Nürnberg studying astrology under Schöner. The central section of Rheticus’ Naratio Prima consists of an excurse on what he sees as a confirmation of an astrological cyclical theory of history, popular at the time amongst Renaissance scholars, delivered by Copernicus’ theory of the precession of the equinoxes. However I see a major problem in Wilford’s labelling of Schöner’s astrology as medieval.

Schöner’s astrology is Renaissance astrology and it is for various reasons a very different beast to medieval astrology. His astrological practice cannot and should not be seen, as Wilford wishes us to do so, as a residual left over from earlier times but as the, for the sixteenth century, central and actual activity of the working Renaissance mathematicus; Schöner’s astrology was modern.

European horoscope astrology, there are other sorts that I won’t discuss here, began life in Greece sometime in the fifth and fourth centuries BCE, combing elements of earlier Egyptian and Babylonian systems of prognostication. Its fortunes waxed and waned over the following centuries and reached a zenith in the work of Ptolemaeus in the second century CE. From here like all the other sciences of antiquity, and its adherents certainly regarded it as a science, it went into decline, almost disappearing completely in the Early Middle Ages. Although it should be pointed out that those works of astronomy from antiquity that remained known in this period such as Martianus Capella’s De nuptiis Philologiae et Mercurii and Microbius’ Commentarii in Somnium Scipionis are strongly astrological.

With the first major revival of learning at the beginning of the High Middle Ages, twelfth and thirteenth centuries, and the rise of the European universities astrology enjoyed a rather dubious reputation. It stood in conflict with the dominating Catholic theology. Horoscope astrology with its seemingly deterministic prognostications appeared to contradict the central Church tenet, the belief in free will.

With the advent of Humanist Renaissance in the fifteenth century astrology enjoyed a major revival centred around astro-medicine, or as it was also known iatro-mathematics, a discipline that like astrology had its roots in fourth century BCE Greece. This form of medicine believed that the causes and cures of diseases were controlled by celestial influences and that a medicus must study the horoscopes of both the patient and the disease to determine the correct course of treatment. Chairs of astrology were established at the Northern Italian humanist universities and also in Cracow in Poland, later in other parts of Europe. By the end of the century astrology was the central discipline studied and practiced by the Renaissance mathematicus. This revival in the fortunes of astrology was also made possible because the new astrologers interpreted horoscopes as being indicative and no longer deterministic. That is a horoscope indicated a possible course for the future but one that could be altered by the subject of the horoscope if he took the right actions. Actions defined by the astrologer, of course, for a further fee.

In the sixteenth century at the start of the Reformation Philipp Melanchthon, who was responsible for the curricular of the Lutheran Protestant schools and university, established chairs for mathematics in all of the Protestant educational establishments to further the study of astrology of which he was a passionate adherent. Johannes Schöner professor for mathematics at the Egidian Oberschule in Nürnberg was one of the first of those appointees. Favoured for his already excellent reputation as an astrologer. Far from being a medieval residue Renaissance astrology, as practiced by Schöner, was a cutting edge academic discipline and for its time the epitome of modern.

Astrology was also not in the process of dying off following Schöner’s own demise in 1547 it continued to be a central field of study for the cartographers and astronomers who created the modern disciplines over the next hundred years. Both Gemma Frisius and Gerard Mercator, who are regarded as two of the principle founders of modern cartography and who were both highly influenced by Schöner’s work, were highly respected practicing astrologers. Rheticus the midwife of Copernican heliocentricity who became a medicus practicing astro-medicine in Cracow in the later part of his life gained a European wide reputation for his astrological prognostica. Michael Maestlin, Kepler’s teacher, and Tycho Brahe, his most significant employer, who each made important contribution to the evolution of the new astronomy were both practicing astrologers who regarded astrology as central to their astronomical research. Kepler himself, probably the most important of the modern astronomers, was also a passionate believer in celestial influence even if he rejected the traditional horoscope astrology and wished to replace it with one of his own devising. Finally even Galileo Galilei, supposedly the first really modern “scientist” taught astrology to the medicine student at the University of Padua a discipline that he himself obviously believed in as evidenced by the horoscopes that he drew up for his own family. This list of sixteenth and early seventeenth century astrologers is of course not exhaustive but merely an indication of just how deep the study and practice of astrology was embedded in the work of a Renaissance mathematicus.

Astrology first went into decline and lost its social and academic status in the second half of the seventeenth century with the general decline of the scholastic Aristotelian philosophy and with it the Renaissance belief in the micro-cosmos/ macro-cosmos philosophy, the fundamental justification for celestial influence and astrology.

Returning to the starting point of this post I hope I have made clear with my brief exposition of the history of European horoscope astrology that Schöner’s “residual interest in astrology” in no way indicates his “pivotal place in a world in transition from the medieval to the modern” as there was nothing medieval about his astrological activities for they were in themselves a sign of modernity in the sixteenth century.

Grumpy old astronomers behaving badly or don’t just blame Isaac!

People who consider themselves well informed about the general history of science know that Isaac Newton, who died on 20^th March 1727 (OS), was a cantankerous, argumentative, self-opinionated, unforgiving old ghoul who did his best to ruin the reputations and careers of several of his contemporary natural philosophers, most notably Robert Hooke, John Flamsteed and Gottfried Wilhelm von Leibniz.

This supposed knowledge led David and Stephen Clarke to make their highly erroneous claims concerning Newton’s alleged persecution of the early pioneer in electrical research, Stephen Gray, that I dealt with in my annual Christmas Newton post.

I was reminded of this highly negative view of Newton by a recent post by Rebekah “Becky” Higgitt on historical over-identification in the case of the recent Richard III kerfuffle. Becky wrote:

Exposing injustice is a key element for generating interest and enthusiasm beyond the academy. If someone usually held in high regard (Tudor monarchs, Shakespeare) is thought responsible for the oppression of a rediscovered, wronged hero, then identification with and emotional attachment to the story can become particularly intense. This is true of the mission to rescue Richard, and history of science examples are Robert Hooke and Nikolai Telsa, seen as victims of Isaac Newton and Thomas Edison respectively.

The “Robert Hooke was robbed” fan club being convinced that their hero would long ago have been recognised as the greatest thing since sliced bread if it hadn’t been for the evil Isaac.

I was reminded again last Sunday by Lisa Jardine on BBC Radio 4’s A point of View, who discussing the actual science communication hot topic, open access, in terms of the cooperation between astronomers in the 17^th century actual gave a very 18^th century and historically highly inaccurate version of the dispute between Newton and Flamsteed. Putting the blame highly unfairly totally on Flamsteed’s shoulders as if Francis Bailey’s 19^th century Flamsteed biography and everything that has followed since in the history of Early Modern astronomy had never taken place. Given that Ms Jardine is fêted as an expert on the history of science of the period she ought to know better.

Having had my interest in the topic reawakened I thought I would take the opportunity on the 286^th anniversary of Newton’s passing to do a bit of adjusting to what is supposedly known about Isaac and his grumpy personality.

In the 18^th century Newton was regarded as a saint and the hagiographical biographies painted him as if he could do no wrong. Flamsteed was an evil nobody who hindered the great genius from realising his aims. Hooke had largely ceased to exist in the popular memory; an unfair fate that actually had very little to do with Newton or the disputes between the two of them. Finally Leibniz was, for the English at least, a dastardly foreign blaggard, who had tried to steal Newton’s crowing achievement, the calculus.

In the 19^th century the picture began to change and Newton’s feet of clay started to be exposed in a new biographical debate excellently described by Rebekah Higgitt in her book Recreating Newton. At the latest Frank Manuel’s psychological study of Newton A Portrait of Isaac Newton, published in 1968, exposed the revenge-obsessed monster that people now take to be the true face of Isaac. However it is not that simple. People’s over-interpretation of Manuel’s excellent study have led to a vision of Isaac that is just as much a myth as the 18^th century saint of science, as the saying goes it takes two to argue and Newton’s supposed victims all gave as good as they got and in one of the three notorious cases mentioned in the first paragraph it was Newton who was the victim and not the villain.

At the beginning of the 1670’s Newton who was already approaching thirty was a nobody. A few people in the know had heard about this man in Cambridge who was a bit of a whizz at maths but that was about it. Then he presented his reflecting telescope to the Royal Society and became almost literally overnight a star of the then scientific community. However it was anything but plain sailing. He got accused of plagiarising the telescopes of both the Scottish optical physicist, James Gregory, and the rather mysterious French inventor Laurent Cassegrain. A situation that was saved by Gregory graciously acknowledging Newton’s superiority and the chauvinistic Royal Society dismissing the French case out of hand. Encouraged by the success of his telescope Newton then submitted his legendary paper on the nature of light a true milestone in the history of optics. Instead of being hailed for the masterpiece that it undoubtedly is this paper met an avalanche of criticism that I have dealt with in some detail here. Leading the pack was Robert Hooke who considered himself the leading authority on all matters optical. Hooke dismissed Newton’s first venture into scientific publishing with scorn. His attacks on Newton and his theories were so vitriolic that in the end Newton withdrew from publication the extensive paper that he had written in reply to his critics, especially Hooke, and famously only published it thirty years later, after Hooke’s death, as the first part of his justifiably famous Optics.

Time past and the quarrel was put aside, if not forgotten, and at end of the 1670s and the beginning of the 1680s the two corresponded quite cordially on the subject of gravity and falling bodies; a correspondence that was certainly one of the stimuli that led to Newton composing his Principia. Unfortunately as this work was approaching completion and publication by the Royal Society Hooke piped up again claiming that Newton was plagiarising him and that he alone deserved credit for the discovery of the laws of gravity. Newton went ballistic and threatened to withdraw his masterwork from publication a situation that required all of Edmond Halley’s skill of persuasion to smooth over. However any relations that Newton and Hooke might have had were now once and for all dead and Newton, who had been previously prepared to acknowledge Hooke’s contributions to his work, removed all mention of him from the Principia.

I know that it’s a hard pill for the “Robert Hooke was robbed” fan club to swallow but there is no doubt that the villain of the peace in this private war of words was Hooke and not Newton. There are stories of Newton extracting his revenge after Hooke’s death when he became President of the Royal Society but there is no evidence to back them up and I personally think they can be considered myths.

It might be claimed that for some reason Hooke was just allergic to Newton, an unfortunate twist of history, but Hooke was notorious for his high-octane disputes with anybody and everybody in the scientific community. He had spectacular rows Christian Huygens, Henry Oldenburg the secretary of the Royal Society and with John Flamsteed as well as a boat load of other minor figures. Hooke was definitely not a happy man and not an easy one to get on with.

The dispute with Flamsteed was more of a two sided affair with the two very stubborn astronomers butting heads for a couple of decades before their mutual dislike exploded into open warfare. I have already written twice about this dispute here and here and won’t go into details here but as I already said in the past both of the antagonist gave as good as they got and although Newton was probably more to blame than Flamsteed, England’s first Astronomer Royal was no angel.

Like Hooke Newton was by no means the only person with whom Flamsteed, who was notoriously grumpy, clashed horns. As already mentioned Flamsteed and Hooke couldn’t stand each other but Flamsteed’s special wrath was saved for Edmond Halley. Halley and Flamsteed had originally worked together and how and why the fell out is not really known and a topic of much speculation. Flamsteed’s hatred of Halley grew to the point where he refused to use Halley’s name referring to him only as Reymers after Nicolai Reymers Baer the German astronomer whom Flamsteed believed had plagiarised his great hero and role model Tycho Brahe, Baer being for Flamsteed the most despicable person who had ever lived.

Leibniz was probably the least belligerent of all the disputants discussed here and he became the victim of Newton’s most vindictive actions in their notorious calculus dispute; however even Leibniz was not entirely blameless. When they initial got to know each other Newton and Leibniz treated each other with respect and as the accusation of plagiarism of the calculus was first made against Leibniz in the 1690s it was Newton who stomped it down and even apologised to his German colleague.  So what had changed when the accusations were raised again at the end of the 1710s? In the meantime Leibniz had launched his attack on Newton’s theory of gravity.

Now criticism is the lifeblood of scientific progress so it was, of course, fully legitimate for Leibniz to criticise Newton but he did so by hitting below the belt. Unable to fault the mathematics of Newton’s theory Leibniz criticised his religion. He pointed out that if Newton’s theory was correct it would inevitably lead to deism at best and atheism at worst. Newton was deeply religious and even believed that God had chosen him personally to uncover the secrets of His creation. He was well aware of the possible danger to religious belief of his theory and having his nose rubbed in it did not make him a happy boy. Even worse Leibniz did not restrict his criticism to philosophical subtleties but mocked and ridiculed Newton for his rather pathetic attempts to recuse his theory from the accusations. This was more than the, in the meantime, almost seventy year old Newton could take and so when the chance opened up to take revenge on his adversary in the calculus dispute he took it in spades pursuing his enemy even beyond the grave. If Leibniz had not been so keen to tread on Newton’s sensibilities on the religious questions then the calculus dispute would probably have taken a less vitriolic route.

I certainly don’t want to explain away or even excuse Newton’s incontestable bad behaviour but in all of the legendary disputes of his life he had to deal with opponents whose behaviour was often not better than his own and in the case of Robert Hooke definitively worse. The late 17^th century scientific community was full of grumpy old men behaving badly.

 

 

A little learning is a dangerous thing

“A little learning is a dangerous thing


Drink deep, or taste not the Pierian spring: 


There shallow draughts intoxicate the brain,


And drinking largely sobers us again. 


Fired at first sight with what the muse imparts,


In fearless youth we tempt the heights of arts 


While from the bounded level of our mind 


Short views we take nor see the lengths behind 


But more advanced behold with strange surprise,


New distant scenes of endless science rise!”

In a recent New Yorker essay Adam Gopnik delivered up his view of Galileo Galilei. The essay is long and meandering and I don’t intend to do a complete analysis but there is one central point of Gopnik’s that I do wish to discuss. He gets off to a lousy start by calling Galileo “The founder of modern science”. I’ve already dealt with this elsewhere and don’t intend to repeat myself here. However Gopnik returns to the theme towards the end of his essay with proof! He begins with the following:

Contemporary historians of science have a tendency to deprecate the originality of the so-called scientific revolution, and to stress, instead, its continuities with medieval astrology and alchemy. And they have a point. It wasn’t that one day people were doing astrology in Europe and then there was this revolution and everyone started doing astronomy. Newton practiced alchemy; Galileo drew up all those horoscopes. But if you can’t tell the difference in tone and temperament between Galileo’s sound and that of what went before, then you can’t tell the difference between chalk and cheese.

Those historians of science can make their claims but Gopnik, a literary critic/humourist/art critic [please choose the appellation for Gopnik that best fits your prejudices or lack of them: see comments] knows better! He has read a book!

The difference is apparent if you compare what astrologers actually did and what the new astronomers were doing. “The Arch-Conjuror of England” (Yale), Glyn Parry’s entertaining new biography of Galileo’s contemporary the English magician and astrologer John Dee, shows that Dee was, in his own odd way, an honest man and a true intellectual. He races from Prague to Paris, holding conferences with other astrologers and publishing papers, consulting with allies and insulting rivals. He wasn’t a fraud. His life has all the look and sound of a fully respectable intellectual activity, rather like, one feels uneasily, the life of a string theorist today.

Now I have read the same book and although that book is excellent it, in my opinion, suffers from a major deficiency that I actually discussed on twitter a while back with Ted Hand (@t3dy) a historian of alchemy. However before we turn to Parry’s book and its deficiency let us see how Gopnik uses it to justify his belief in Galileo’s modernity.

The look and the sound of science . . . but it does have a funny smell. Dee doesn’t once ask himself, “Is any of this real or is it all just bullshit?” If it works, sort of, and you draw up a chart that looks cool, it counts. Galileo never stopped asking himself that question, even when it wasn’t bullshit but sounded as though it might well be. That’s why he went wrong on the tides; the-moon-does-it-at-a-distance explanation sounds too much like the assertion of magic. The temperament is not all-seeing and curious; it is, instead, irritable and impatient with the usual stories.

So there we have it. Galileo may have been a practicing astrologer but he was also a questioning scientist whereas his near contemporary John Dee was just a gullible pseudo-scientist. Case closed. Galileo is different. He is the founder of modern science as claimed. Gopnik 1 historians of science 0.

Unfortunately for Gopnik reading one book on Dee, no matter how good, isn’t enough. He has fallen head first into the error illustrated by the famous quote from Alexander Pope with which this post is headed, “a little learning is a dangerous thing”. If instead he had drunk deep of the springs of Dee scholarship he would not have so confidently labelled Dee chalk to Galileo’s cheese.

What is Parry’s deficiency and why is Gopnik wrong?

To understand the problem we have to look at how John Dee’s image has changed over the centuries. In the 16^th century Dee was a highly respected member of the European scientific community highly involved in mathematics, astronomy, astrology, alchemy, cartography, navigation and history. By the middle of the 17^th century his star was fading fast and he was largely forgotten then Meric Casaubon published the so-called Angel Diaries, Dee’s supposed conversations with angels through the medium Edward Kelly. Through this publication of previously unknown material Dee became the archetypal Renaissance magus in the popular imagination, a dabbler in magic probably in league with the devil.

This remained the public persona of Dee right up to the beginning of the twentieth century and he became a notorious trans-continental figure turning up as the essence of sorcery in several works of fiction. In the twentieth century, however, historians began to investigate and re-assess the real historical John Dee and the role that he played in European Renaissance culture. What emerged was a very different figure from the archetypal Renaissance magus. The last forty or fifty years has seen the publication of many academic papers and a series of monographs containing biographical studies of Dee, illustrating various aspects of his highly complex character. Glyn Parry’s The Arch Conjuror of England: John Dee is the latest such biography to be published.

Parry’s book, which is excellent and highly recommended for those interested in the subject, is a well researched and minutely documented study of the role played by alchemy and magic in the European royal courts of the sixteenth century, in particular the court of Elizabeth I of England, structured around the life story of John Dee. This is not the first such study but follows in the tradition of R. J. W. Evan’s excellent Rudolph II and his World: A study in intellectual history, 1576–1612 and Bruce T. Moran’s equally excellent The Alchemical World of the German Court: Occult Philosophy and Chemical Medicine in the Circle of Moritz of Hessen (1572–1632) both of which also feature John Dee, albeit in a less central role, who was active on both courts. Both books are regarded as classics and standard works on the role of the occult in Renaissance culture and Parry’s book is a more than worthy companion but there is a minor and important difference. Both Evan’s and Moran’s books were marketed as academic books written for specialists and although Parry’s volume is equally academic his publishers have seized upon Dee’s public popularity and marketed it as a popular book. They have also, and this is the crucial point, marketed it as a biography. This marketing strategy has led Gopnik to the belief that having read Parry’s book he now knows all about John Dee but unfortunately he is highly mistaken.

Parry actually only deals with one aspect of Dee’s multi-faceted nature, his activities as a magus almost completely ignoring Dee the mathematicus and it is here that Gopnik walks straight into a trap of his own making. If instead of just reading Parry’s book he had done some basic research on Dee he would have discovered that Dee and Galileo are by no means so far apart as he would like to think.

Several times in his book Parry alludes to the fact that mathematics plays a very central role in Dee’s whole philosophy but never bothers to elucidate what or why, concentrating instead on Dee’s occult activities leading Gopnik to a totally false picture of Dee the mathematical scientist. Early in his book Parry explains that after graduating from Cambridge Dee paid two visits to the University of Leuven, in the Spanish Netherlands, one short and one substantially longer to study under Gemma Frisius and Gerard Mercator. Parry discusses the astrology that Dee studied under the two Netherlanders but makes no mention of the mathematics. In fact Frisius was one of the leading teachers of the cutting edge mathematical sciences of the age and Dee came back to Britain with the best mathematical education available anywhere in the world at the time. He introduced into Britain, which lagged far behind the rest of Europe in the development of the mathematical sciences, the newest procedures in mathematics, astronomy, cartography and navigation as well as bringing with him the newest terrestrial and celestial globes and astronomical instruments from the workshops of Frisius and Mercator. On his early journeys through Europe Dee also got to know and to learn from other leading European mathematical practitioners such as Pedro Nunes in Portugal and Federico Commandino in Italy.

In his house in Mortlake Dee set up a research centre for the mathematical sciences, which contained the largest private scientific library in Europe, including at least two copies of Copernicus’ De revolutionibus, where other interested scholars could and did come to learn and discuss the latest in mathematical knowledge. Dee’s foster son Thomas Digges wrote and published one of the first works on Copernican astronomy in English, which contained the first published partial translation of De revolutionibus into the vernacular. Another acolyte of Dee’s John Feild (sic) published, at Dee’s urging, the first ephemeris based on Copernicus’ work. Dee himself wrote the extensive preface to Henry Billingsley’s English translation of The Elements of Euclid. This preface is an important early work on the philosophy of mathematics. Dee corresponded on mathematical topics with many of the leading mathematicians and astronomers in Europe including a correspondence with Tycho Brahe on the problems of determining the parallax of moving celestial bodies, i.e. comets, a topic at the cutting edge of contemporary astronomical research. Dee was also a close friend and colleague of Thomas Harriot the greatest of English Renaissance mathematicians whose scientific discoveries easily rivalled those of Galileo but because he never published anything remained unknown and unacknowledged.

His English language preface to Billingley’s Euclid was not a one off but is symbolic for one of Dee’s most important contribution that of co-founder of the so-called English school of mathematics. As already mention in the second half of the sixteenth century England lagged behind the rest of Europe in the mathematical sciences. The first person to undertake series efforts to correct this deficit was Robert Recorde who wrote and published a series of textbooks in English covering the mathematical sciences including Copernican astronomy. After Recorde’s death Dee brought out several revised and expanded editions of those textbooks. The two of them started a tradition of English mathematics that stretched through the second half of the sixteenth century all the way through the seventeenth century up to Newton, which encompasses such important figures as William Oughtred, Seth Ward, John Wallis, Christopher Wren and even Newton himself.

Far from being the naïve magician that Gopnik imagines him to have been John Dee was acknowledged and recognised as one of the leading European mathematical practitioners in the third quarter of the sixteenth century. Whose mathematical heritage echoed all the way through the seventeenth century and the creation of modern science.

Contrary to the commonly held myth Galileo did not invent modern mathematical science but built his research on a solid foundation a Renaissance mathematical advances that goes back all the way to Georg Peuerbach and Regiomontanus in the middle of the fifteenth century. One of the Renaissance mini-giants on whose shoulders Galileo and his contemporaries constructed their contributions to the evolution of modern science was John Dee. Far from being the contrast obsolescent model to Galileo’s shiny new show room model as Gopnik would have us believe John Dee, in his own way, contributed as much to the creation of modern science as Galileo himself.

Shakespeare was clairvoyant.

This may come as somewhat of a surprise, as it is only the middle of February, but we already have a serious candidate for the worst piece of history of science blogging for 2013! Anybody who wishes to win this much coveted prize is going to have to try very hard indeed if they want to surpass the piece of total inanity that Carole Jahme served up on The Guardian’s science blog today under the title Renaissance Brains: William Shakespeare and Galileo Galilei.

Given that William and Galileo were both born in the year 1564 we are going to have to put up with lots of media pundits drawing comparisons between the two of them as we approach the collective 450^th anniversary of their births. We have already seen one attempt by Adam Gopnik in The New Yorker and now, also taking the Royal Shakespeare Company’s production of Brecht’s Life of Galileo as her kick off point, we have Ms Jahme. I’m in the middle of a longer refutation of one of the main claims in Gopnik’s article but to keep you happy in the mean time let us examine Ms Jahme’s astounding knowledge of the history of Renaissance science. She informs us that:

Shakespeare was friends with the British astronomer Thomas Digges who believed the universe to be infinite and that the sun not the Earth was the centre of our solar system. Digges would have been aware of Galileo’s work The Starry Messenger, published in 1610, about his observations of the heavens and may well have kept Shakespeare informed about the latest on Copernican philosophy.

I have to admit that I wasn’t aware of a friendship between Digges and Shakespeare but I assume that it’s is probably true as Digges’ younger son Leonard, a writer and poet, shared a publisher with Shakespeare and supplied one of the prefatory poems for the Shakespeare First Folio. However the next claim is quite extraordinary as it attributes clairvoyant powers to the good Bard of Avon because his friend Thomas died, fifteen year before the publication of Galileo infamous pamphlet, in 1595!

There is a strong possibility that Ms Jahme is confusing Thomas Digges with his friend and contemporary Thomas Harriot. Now although Digges and Harriot are both called Thomas and they are both English Renaissance mathematicians and astronomers I can assure Ms Jahme that they are in fact two different people. Apart from anything else Thomas Harriot was still very much alive in 1610 and in fact was one of the first people to read one of the two copies of Galileo’s The Starry Messenger that Sir Henry Wotton, the English Ambassador to Venice, sent to London on its day of publication. Now my claim that Ms Jahme is confusing her Thomases is, I’m quite happy to admit, pure speculation. However Ms Jahme is not above quoting dubious speculation herself:

Digges’s expertise was creatively used by Shakespeare and astronomical references and metaphors are integral to his dialogue, ” … and count myself a king of infinite space” (Hamlet). Shakespeare may be referring to Galileo in Cymbeline (published in 1611) ” … O, learn’d indeed were that astronomer that knew the stars as I his characters … “. In the play’s final scene, the god Jupiter descends to the stage surrounded by four angels, which could be interpreted as the planet and its four moons, which had been discovered by Galileo and were described in The Starry Messenger. (The Roman Inquisition imprisoned Galileo for refusing to deny Jupiter’s satellites and Earth’s orbit around the sun.)

Here, Ms Jahme is quoting, without attribution, the highly contentious theories of American astronomer Peter D Usher as put forward in his book Shakespeare and the Dawn of Modern Science. Usher claims that five of Shakespeare’s plays contain coded references to the astronomical debates of the beginning of the seventeenth century. Not the work of a serious historian bur closer to the Bible decoders and certainly not something to be dished up as historical fact in a supposedly serious article.

The last sentence quoted above, in brackets, is one of the worst misrepresentations of the infamous Galileo trial that I have read in a long-time. The Roman Inquisition did not imprison Galileo; it subjected him to house arrest first in the Archbishop in Siena’s palace and then later in his own villa in the Duchy of Florence. A minor but rather significant detail that people love to get wrong. It doesn’t do to have your martyr for science wining and dining in luxury in an archbishop’s palace. It creates the wrong impression. However this error pales into insignificance when compared to the claim, “imprisoned Galileo for refusing to deny Jupiter’s satellites. Given the fact that it was the Churches own astronomers, from Christoph Clavius’ seminar for advanced mathematics at the Jesuit Collegio Romano, who provided the necessary scientific confirmation of Galileo’s discovery of the four largest moons of Jupiter it would have been rather embarrassing for the Inquisition to demand that Galileo deny their existence. Surprisingly enough they did no such thing.

Not unexpectedly I also have major problems with Ms Jahme’s next statement:

It could be argued that Galileo and Shakespeare have between them shaped modern Western culture more than any other Renaissance thinkers. Einstein described Galileo as the father of modern science;

It could be argued but I would immediately bring historical proof that Johannes Kepler actually had a much larger impact on Western culture than Galileo although I’m not really a fan of such historical pissing contests. Regular readers of this blog will know that I am extremely allergic to the phrase “father of” and that I have also written a strong polemic disputing Galileo’s claim to being “father of modern science”. Of course my opinion cannot really count much against that of that well-known historian of Renaissance science Albert Einstein.

It is not my area so I won’t do a detailed criticism of it, but I really do wonder what purpose making brain scans of an astronomer reading an English translation of The Starry Messenger and an actor reading an English translation of Bretch’s Leben des Galileis is supposed to have. This seemingly pointless piece of actionism being the main reason for Ms Jahme’s article.  I also can’t resist asking a question about the next planned Shakes Sphere that Ms Jahme advertises. She writes:

The alchemical quest for the Philosopher’s Stone was a Renaissance obsession. Professor Andrea Sella, a chemist at University College London, knows that “All that glisters is not gold” and will join Kukula and use a mix of chemistry and magic upon the audience as he attempts the live transmutation of elements.

If the theme really is Renaissance alchemy why is the demonstration being made by a chemist instead of by a historian of alchemy such as the excellent Anna Marie Roos?

A play is not a history book.

The RSC is currently staging a new production of Bertolt Brecht’s Life of Galileo, a play that I studied for German A-Level. Yes folks, I really do have a rather ropey A-Level in German literature. Stuart Clark, who apparently was employed by the RSC as scientific advisor on the production, has written a post on the Guardian’s Science Blogs about it. In the middle of his piece he makes the following extraordinary claim:

Brecht does subvert the Galileo story for artistic purposes. The most significant departure is the relationship that Galileo has with his eldest daughter, Virginia. In the play, her marriage prospects are ruined by Galileo’s dogged championing of his observations.

In realty, Galileo could not raise sufficient dowry and so placed Virginia and her younger sister in a convent. Nevertheless, his relationship with Virginia was a strong and loving one, as their letters prove.

When I read that I experienced a “wot the f…” moment. It’d had been a couple of decades or more since I last read Brecht’s play but my memory said that whatever its literary merits might or might not be it’s anything but historically accurate. If anything Galileo’s relationship with his daughter is the least significant departure from the historical reality.

Not wishing to run into a bun fight based on old unreliable memories I acquired a copy of the German original, the RSC production is apparently a new translation so its based on the original (1937 – 1939) and not the later American version (1945 – 1947), and have spent the last couple of days rereading it. In what follows I’m not criticising Brecht who wrote a piece of fiction but Clark whose knowledge of the real life of Galileo appears to be somewhat deficient.

Before looking at any of the specific details of the play and comparing them to the actual history there are two powerful subtexts to Brecht’s piece that distort the historical facts immensely. Firstly throughout the drama it is continually implied that the Church is anti science per se this is historically completely untrue. In the Early Modern Period the Catholic Church only opposed scientific theories that stood in contradiction to established central tenets of the Church. In the 17^th century these were principally heliocentricity and atomism. Heliocentricity of course contradicted important passages in the Old Testament whereas atomism contradicted the accepted Aristotelian explanation of transubstantiation. The latter dilemma was solved by Pierre Gassendi who showed that it was possible to integrated atomism into Catholic theology doing so in a similar manner to Albertus Magnus’ and Thomas Aquinas’ integration of Aristotelian philosophy and Catholic theology in the 13^th century. A similar compromise for heliocentricity would probably have been found if Galileo and Foscarini hadn’t forced the issue. On other scientific developments in this period the Church remained open, the research often being done by members of the Church. Christoph Clavius’ seminar for mathematical research at the Jesuit Collegio Romano, for example, provided the necessary observational confirmation of Galileo’s telescopic discoveries; a fact to which we will return later.

Brecht’s second subtext concerns his own political views. Brecht was a Marxist and throughout the play he presents Galileo as some sort of 17^th century Che Guevara fighting for the proletariat against the oppressive ruling classes i.e. the Catholic Church. This is so far from the historical truth as to be grotesque. Galileo was a social climber, scion of an impoverished minor aristocratic family he used his scientific discoveries as instruments of credit in order to climb the social greasy pole of North Italian absolutist politics. He became a courtier cashing in his astronomical discoveries for a position at the Medici’s court in Florence from which base he set out to become an accepted and celebrated favourite in the much more powerful Papal court circles of Rome. In a revolutionary analogy Galileo would be closer to Rasputin than Lenin.

Turning to more detailed factual aspects of the play I shall go through it scene by scene picking some but not all of the salient historical falsehoods.

The opening scene takes place in Galileo’s “humble study” in Padua, where he is the university’s professor of mathematics, and the only characters who appear to constitute his household are his housekeeper her young son and one daughter of Galileo’s. Later a potential private student makes an appearance, who Galileo very reluctantly takes on at the urging of his housekeeper. In reality Galileo, who was actually quite well paid but who was permanently in debt because he lived beyond his means, ran a large prosperous household with several servants and quite a large number of private students who paid handsomely for their private tuition. The numbers varied over the years but an average of twenty inhabitants was not unusual. The play makes no mention of Galileo’s mistress, the mother of his children who he never married and who lived in a separate establishment, or of his second daughter and his son. In this scene in a discussion with the head of the university Galileo is describes as famous throughout Europe, whereas before he made his telescopic discoveries Galileo was an unimportant mathematicus totally unknown outside of Northern Italy.

The second scene is largely correct and concerns Galileo’s presentation of ‘his’ telescope to the Senate of Padua in 1609. The only strange thing is the involvement of his daughter Virginia in the scene who is presented as 15 years old whereas in reality she was only 9 in 1609.

The third scene has Galileo making his astronomical discoveries the whole process, which in reality took many months, is for dramatic purposes telescoped (pun intended) into one evening, which is OK. What is not OK is the claim, that appears here for the first time and is repeated throughout the play, that these discoveries prove Copernicus right. They didn’t, as I’ve posted before, and even Galileo never claimed that they did.

The fourth scene has Galileo now ensconced in Florence and preparing to receive Cosimo Medici in his abode to show him the Medician stars, the moons of Jupiter. This whole scene is from beginning to end historical codswallop. Firstly Galileo travelled to Florence from Padua to demonstrate his telescope and to show Cosimo and his Court the moons of Jupiter before he was appointed to that court and moved to Florence. He would not have received the appointment if the demonstration had been a failure, as it is in fact presented in the play. Secondly Cosimo is presented as a ten year old and a stranger to Galileo. In reality in 1610 when Galileo wrote the Sidereus Nuncius Cosimo was already twenty years old and he and Galileo were already old friends, as Galileo had been his private tutor for several summers in the preceding decade. Also Cosimo, as one of the richest and most powerful aristocrats in Europe, would never have gone to Galileo’s house for such a demonstration but Galileo would have gone to the Medici palace. When the members of the court arrive for the demonstration Brecht repeats one of the biggest of the Galilean myths, that of the Aristotelian philosophers who refused to look through the telescope. I have dealt with this falsehood elsewhere and won’t repeat the story here.

The next scene is a piece of pure invention and has a heroic Galileo refusing to interrupt his researches to leave Florence during an outbreak of the plague. As I say pure invention.

The next scene is viewed from an historical standpoint simply bizarre. Set in 1616 it has Christoph Clavius singlehandedly confirming the truth of Galileo’s astronomical discoveries and having done so leaving the building in silence whilst studiously ignoring Galileo. Where to start? Maybe with the simple inescapable fact that Christoph Clavius died in 1612! Far from ignoring or giving Galileo the cold shoulder Clavius and Galileo had been friends since 1586 and it was to Clavius that Galileo himself turned in 1610. The confirmation was actually carried out in 1610 and 1611 by Grienberger and Maelcote in direct correspondence with Galileo, who offered helpful tips from the sidelines. Clavius was by then all ready too old and infirm to do the work himself although even he was finally able to view and confirm the discoveries. Having confirmed them the Jesuits invited Galileo to Rome and held a banquet in his honour at which Maelcote held an oration in praise of their guest. Here play and reality have truly nothing in common.

We now have the famous confrontation between Galileo and Robert Bellarmin in 1616. Whereas the historical meeting took place in private in Bellarmin’s office, in the play it takes place during a masked ball in Bellarmin’s palace with both Bellarmin and Barberini, the future Pope Urban, talking to Galileo. The scene is set up to contrast the decadent and depraved Cardinals, Bellarmin and Barbarini, with the humble and honest scientist Galileo. Unfortunately whereas Barbarini a long-time party companion of Galileo’s was certainly, like Galileo, a connoisseur of the pleasures that life has to offer, it would be difficult to find a more straight-laced figure than Bellarmin in the history of the Catholic Church.

I’ll skip the next scene as of no significance but the one following it again mixes up the historical facts in a way that is astounding. We now have 1624. Firstly we have a Galileo presented as one who has been prevented from all future astronomical research as a result of his meeting with Bellermin. This is simply not true. Galileo effectively gave up his astronomical researches of his own accord in 1613, moving on to other fields of investigation. Also although Bellarmin told him that he could no longer hold or teach heliocentricity as a true theory he was perfectly free, should he choose to do so, to conduct further astronomical research. Also in this scene Galileo is presented as doing his (boring!) research on floatation only out of frustration because he isn’t allowed to do astronomy. Again complete rubbish. Galileo was very proud of his work on floatation, which was by the way carried out before 1616. We then receive the news that the Pope is dying and that Barbarini, a mathematician (?), will be elected to the Papacy. Barbarini was an intellectual and a poet but he was not a mathematician. Believing that Barbarini will support him Galileo restarts his astronomical research refuting the sunspot theories of a Fabrizius from Holland!

Galileo’s dispute concerning the sunspots was with Christoph Scheiner, a German, in 1612 and both of them either ignored or were unaware of the sunspot publication of the Frisian astronomer Johannes Fabricius. Post 1616 Galileo was involved in a dispute over the nature of comets with the Jesuit astronomer Orazio Grassi. The dispute started in 1618 and dragged on through several polemical publications peaking in 1623 in Galileo’s legendary Il Saggiatore (The Assayer), which was in fact dedicated to the newly crowned Pope Urban VIII, Barbarini.

Brecht’s play is now drawing to a close. He doesn’t actually deal with the writing and publication of Dialogo the next scene being Galileo’s rejection by Cosimo Medici. Here again Brecht bends the historical truth. He has Cosimo simply letting Galileo fall, which is not quite what happened. Being part of the system, Cosimo was in fact not prepared to fight the Vatican and the Inquisition on Galileo’s behalf but he did supply him with transport to Rome. He also allowed Galileo to reside in a Medici residence during his time in Rome during the investigation and also paid his living expenses.

There follows a short scene where the Inquisitor demands that Galileo be tried and Urban argues against. Once again this is not historically correct. It was Urban who demanded that the Dialogo be examined to see if it was actionable and when the three assessors said it was, it was Urban who demanded the trial.

Brecht skips the trial and just has Galileo’s supporters waiting for news that he has martyred himself for the cause of science. However Galileo recants and is criticised by his supporters for doing so. This scene, that closes with Galileo quoting a passage from the Discorsi, has little in common with the historical events.

The play closes with an almost blind Galileo under house arrest in his villa. He is presented as being under constant supervision by a monk, historically false. Andrea his housekeeper’s son who in the process of the play became his disciple and then spurned him when he recanted comes to visit him on his way to Holland to research in freedom. The dialogue that takes place between the two is pure Brecht. At the end of the play Andrea leaves for Holland with the manuscript of the Discorsi.

I hope I have made clear that Brecht’s play is a massive misrepresentation and to a large extent falsification of the episodes that actually constituted Galileo’s life. Anybody who has bothered to read this far is probably saying so what? It’s a play and not a history book. That is my whole point Brecht wrote a fictional piece very, very loosely structured around some real historical figures and events and this piece should not be used as the basis of comment on science policy or science communication as some people have started to do since the RSC announced their revival of the play. Any discussion about science policy or science communication should and must be based on the real practice of science in the present and accurate historical accounts of how it was practiced in the past and not on fictionalised fantasy whoever may have written it.

 

 

What Kepler and Newton really did.

This has been a good week[1] for people getting the history of astronomy in the seventeenth century wrong. Darin Hayton drew my attention to what is basically a rather good article by John O’Neil in the New York Times on the equation of time and the difference between local time measured by the sun and standard time measured by the clock. The article is just fine except for one sentence that instantly awoke the Histsci Hulk in me.  The author wrote:

The changes in the solar time follow a different cycle. In the early 1600s Kepler discovered that planets move faster at the part of their orbit that is closest to the sun, the perihelion. For Earth, perihelion comes a little after the winter solstice, so from November on, Earth is accelerating. [my emphasis]

Kepler didn’t discover that planets (actually in the case under discussion the sun) move faster in some part of their orbits he suggested a new, and as it turned out correct, solution to explain the differences in speed in the various segments of planetary orbits; a phenomenon that had been know about for at least two thousand years.

In what follows I will mostly talk about the sun. In ancient Greek astronomy explanations of the suns apparent progression throughout the year were governed by the so-called Platonic axioms. All celestial motion including planetary motion, and the sun was considered to be one of the seven planets, was circular and uniform. These axioms as the name suggest go back at least to Plato in the fourth century BCE and probably to Empedocles in the fifth century BCE. The only problem was that planetary motion was obviously neither circular nor uniform. The major problem of Greek astronomical thinking was therefore to fit the observed facts to the a priori theory rather than to develop a theory to fit the facts. This has become know as saving the phenomena. Already in the second century BCE Hipparchus knew, and he probably wasn’t the first to do so, that the seasons measured from equinox to solstice and from solstice to equinox differed in length, whereas if the sun’s orbit were truly circular they should be equally long thus demonstrating that if the segments were equally long as the circular orbit demanded the speed of the sun during its orbit must vary i.e. it was not uniform. Over the centuries various Greek astronomers came up with various geometric models to explain away this anomaly peaking in the epicycle deferent model of Ptolemaeus in the second century CE. This model being further modified, that is improved, by various Islamic astronomers in the Middle Ages. Then along came Johannes!

Using the new more accurate data of Tycho Brahe Kepler, after much calculation and even more soul searching, abandoned the Platonic Axioms and determined the planetary orbits to be ellipses and not circles and the speed of the heavenly bodies to be non-uniform but to follow his second law of planetary motion. As stated above didn’t make the discovery that the speed of planets vary during their orbits he just found the correct explanation for it.

What exactly Kepler did or didn’t do cropped up in another post this time on Chad Orzel’s Uncertain Principles blog. Chad wrote a nice post about the relative merits of theoretical and experimental physics, basically complaining correctly that people tend to underrate experimental physics. The misconceptions about seventeenth century astronomy turned up in the comments column. Commentator Peter Morgan wrote:

I suppose there is a difference between Ptolemy, Copernicus and Kepler that is not much connected to experiment, which are largely different models for more-or-less the same experimental data (that is, all models depend on there being data *to* model, but sometimes there are different models for more-or-less the same data). Even Newton didn’t have that much more experimental data to work with; new data mostly came after him, when it was partly his theories that gave physicists the tools to imagine and construct new apparatus.

This is of course fundamentally wrong as was pointed out to him by Steinn Sigurdsson:

Kepler had Brahe’s data, which was a qualtitative improvement on previous quantifications. Newton most certainly had access to new experimental data, notably that of Kepler and Galileo, but Halley! Newton also did his own experiments, eg in optics.

To add to the fun Eric Lund decide to have his tuppence worth:

@Peter: Your argument about Ptolemy vs. Copernicus might be granted, but by the time Kepler started looking at things, Galileo had disproven Ptolemy’s model–Galileo, using the recently invented telescope, observed phases of Venus that Ptolemy’s model predicted would never occur. And as Steinn points out, Kepler had new data that were not available to Ptolemy or Copernicus–data which in fact disproved the notion (adhered to based on philosophical arguments) that the orbits of celestial bodies were necessarily circular. Without Kepler’s data analysis, Newton probably would not have come up with the inverse square law.

Taken together the three statements contain quite a few errors, which I will now attempt to correct.

Firstly seventeenth century astronomical theory isn’t based on experimental data but on observational data, which isn’t really the same thing. Steinn is perfectly correct to point out that Kepler had a completely new set of observational data, supplied by Tycho Brahe, on which to base his theories; a fact that separates him from Ptolemaeus and Copernicus. The data however does not, as Eric claims, disprove the notion of circular orbits. If Kepler had kept to the Platonic Axioms he could have, using Tycho’s data, provided circular models to save the phenomena. His obsession with accuracy led him to abandon the Platonic Axioms when he realised he could get a better fit with ellipses, a move that cost him an immense amount of soul searching. If he had had a more advanced set of mathematical tools (Fourier Analysis!) he could have obtained exactly the same level of accuracy with an epicycle deferent model.

Turning to Newton we have from all three commentators a lot of confusion concerning the data and theories available to him when he wrote his Principia.

Peter is of course wrong as Newton did have substantially new data, which I will explain in a minute. Steinn is wrong as he did not have any experimental data from Kepler but he did have Galileo’s theory of parabolic motion, his laws of fall and the law of inertia, which he falsely believed came from Galileo. These are theories and laws derived from experimental data but not in themselves experimental data. The data that Newton had and which were central to his theories was that on the orbits of the moons of Jupiter and Saturn. Although Galileo and Marius had supplied the original data on the moons of Jupiter, Newton’s source on both sets of moons was the much more up to date and accurate data of Cassini. Newton of course also had access to the new and considerably more accurate observational data of John Flamsteed.

The data on the orbits of the moons of Jupiter and Saturn provided empirical proof of Kepler’s third law of planetary motion, something that Newton explicitly states in the Principia, this law playing a central role in Newton’s argumentation for his theory of universal gravity, of which more in a minute.

Eric Lund muddies the water with his claim that Galileo’s observations of the phases of Venus (Ptolemaeus’ theory also predicts phases for Venus but they are different to the ones observed) were carried out before “Kepler started looking at things”. Kepler did the work on his Astronomia Nova containing his first two laws of planetary motion between 1600 and 1606 although the book itself was first published in 1609. Galileo, Harriot and Marius first started astronomical telescopic observations in 1609 and the first publication of such observations was Galileo’s Sidereus Nuncius in 1610. It’s difficult to date exactly but the first observations of the phases of Venus are later than the publication of the Sidereus Nuncius.

Also as should be well known to diligent readers of this blog Newton didn’t “come up with the inverse square law”, as claimed by Eric Lund. That honour goes to Ismael Boulliau. I think I’ve probably said this before but its worth repeating Newton’s great achievement was in showing that under the assumption of his three laws of motion the inverse square law of gravity implies Kepler’s third law and under the same assumption Kepler’s third law implies the inverse square law of gravity, i.e. the inverse square law of gravity and Kepler’s third law are, under this assumption, equivalent. As Kepler’s third law had been proved to be empirically valid, remember those Jupiter and Saturn moons, it follows that the law of gravity is also (empirically) valid.

Given that the story of the so-called astronomical revolution is probably the most often told and repeated piece of the history of science I find it sad that even educated people mostly have a very vague and largely inaccurate idea of what actually took place.

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[1] I actually wrote this post a couple of weeks ago and have only now got round to posting it. There are a couple of others in the pipeline, too.