In defence of the indefensible.

Friday was the 23^rd of October and the Internet sceptics had a field day mocking one of their favourite punching bags James Ussher (1581 – 1656) Archbishop of Armagh. Ussher is notorious for dating the creation of the world to 6 pm on the 22^nd of October 4004 (and not 9 am on 23^rd October as Pharyngula falsely stated) a fact that the hordes of Pharyngula and other similar self appointed defenders of scientism love to brandish as a proof of the stupidity of Christians.

However Ussher has a right to be judged by the social and cultural standards of his own time and not those of the twenty first century. Who knows which things that we hold sacred will be ridiculed by sneering sceptics in three or four hundred years? “Can you believe it in the early 21^st century they actually believed…?” How much and how fast social norms can change is illustrated by the fact that as I was growing up in Britain in the 50s and 60s, in what was then one of the most open and liberal societies in the world, sexism, racism and homophobia were all acceptable and widespread social attitudes, a thought that makes me shudder today. I, at least, had the good fortune to have parents who openly rejected and condemned such behaviour and so never had to go through the painful process of adjusting my own warped prejudices.

But back to Ussher, in reality he was a widely respected, highly intelligent, well-educated scholar who was also an excellent mathematician. When considering his Bible chronology one has to take the following facts into consideration, firstly almost all well educated Europeans of the period believed in the literal truth of the Bible. Secondly, a large number of them were chiliast or millenarianists, i.e. people who believed in the second coming of Christ when the earth would be six thousand years old; a belief based on a Biblical saying. Now the generally accepted interpretation of the Bible placed the creation of the earth somewhere between 3000 and 5000 BC so for a chiliast, in the middle of the 17^th century, determining the correct date of the creation was very important. If the world had come into being 4500 BC then your whole theory was wrong but if it materialised in 4300 BC then you had better start preparing for the return of Christ. Ussher was by no means the only prominent Bible chronologist of the 16^th and 17^th centuries the most famous being the philologist and historian Joseph Justus Scaliger and of course Isaac Newton; others such as Johannes Kepler and Phillip Melanchthon also dabbled.

How did Ussher arrive at his strange date? He originally determined on theoretical theological grounds that the creation took place in 4000 BC and proceeded to fit the entire Old Testament history into those 4000 years but then corrected the birth of Christ to 4 BC, due to the calculation errors of Dionysius Exiguus when he first set up the AD/BC dating system, and so pushed creation back to 4004 BC. Ussher’s achievements in his analysis of Old Testament history are in fact a great feat of scholarship and earned him the accolades of his fellow chronologists. But why 6pm and the 22^nd of October? Here we see a reflection of a belief commonly held by scientists in the early modern period, God is a Geometer i.e. Mathematician i.e. Astronomer, all three names being synonymous in this period. For many scientists in the early modern period the concept of a rational mathematical God whose creation was a logical scientific structure functioned as a fundamental heuristic principle, most notably for Galileo, Kepler, Boyle and Newton. Ussher shared this belief and like many chronologists he believed that the point of creation would be determined by some sort of logically reasonable astronomical event, i.e. God setting the great astronomical clock in motion. For various reasons Ussher chose the autumnal equinox and placed the moment of creation on the beginning of the Sunday preceding the 4004 BC equinox, 25^th October, that he had determined using Kepler’s Rudolphine Tables. He chose the Sunday as the first day of creation because the Bible says that the creation took six days and God rested on the seventh, which is the Jewish Sabbath, the Saturday. The point of creation is 6pm on Saturday the 22^nd October because in the Jewish calendar the new day starts at 6 pm. All of this is within the social and cultural norms of his times perfectly sensible and rational and only appears idiotic when viewed from our perspective. Ussher was not the fool that he is presented as being by the modern sceptics but a highly regarded scholar of his times.

Now I hear the thoughts of a potential reader who is thinking that this is all well and good but when Ussher wasted his time and intellectual energy on a subject that viewed from the modern perspective is pure rubbish why should we cut him some slack now? At first this attitude seems to be correct and Ussher and his ilk should probably be assigned to the dustbin of history only to be pulled out and dusted off for a bit of healthy mockery on the anniversaries of their inanities but appearances can be, and indeed in this instance are, deceptive. The popular presentation of the scientific revolution usually presents it as fundamentally a revolution in astronomy and physics with a bit of medicine tacked on to justify the wider concept science, however this view is highly restrictive and fundamentally wrong. In the 16^th and 17^th centuries the fundaments were laid for a very wide range of modern academic disciplines and amongst them history and archaeology. In antiquity and the Renaissance the understanding and function of history was very different to that of today and a factual reconstruction of the past was not the aim of historians. The original concept of history was to use historical figures to tell moral or political fables for educational purposes. This concept changed radically in the 16^th and 17^th centuries towards our modern conception of history, this change was to a large extent due to the work of the chronologists. In their attempts to accurately reconstruct the march of time they started to develop and utilize methods of philological analysis and dating that had not existed previously and in so doing laid the foundation of both modern history and archaeology. Although their motivation was one that seems totally ridiculous from a modern standpoint the results of their efforts still play a central role in our academic world.  As so often in the history of the sciences rational results can and do emerge from irrational motivations.

Not just an architect.

Today is the birthday of Britain’s most famous architect, the man who built St. Paul’s Cathedral, Sir Christopher Wren (1632 – 1723). My first knowledge of Wren was as the subject of an oft-repeated Clerihew,

Sir Christopher Wren

Went to dine with some men

He said, “If anyone calls

Say I’m designing St. Paul’s”

Most people don’t realise that as well as being Britain’s most famous 17^th century architect, Wren was also a highly respected mathematician. In fact Isaac Newton named him along with John Wallace and William Oughtred as one of the three best English mathematicians of the 17^th century. As a young man he was an active astronomer and was a highly vocal supporter of the then still relatively young elliptical astronomy of Johannes Kepler.

In 1657 he was appointed Gresham Professor of Astronomy one of the two top positions for astronomers in Britain at the time. Gresham College had been founded, at the end of the 16^th century, with a bequest from Sir Thomas Gresham, he of the bad money law, and consisted of eight professorships, the holders of which were expected to hold public lectures both in English and Latin in their appointed subjects for the benefit of the artisans of London. As such the Gresham Chairs for Geometry and Astronomy were the first ever chairs for mathematics established in England. During the 17^th century many notable English scientist occupied one or other of these chairs.

It was during his time as Gresham Professor that the semi-formal group of scientists came together at Gresham in the grouping that led to the founding of the Royal Society, in which Wren played a leading role serving at times as its president.

In 1661 he was appointed to the other chair for astronomy, the Savilian in Oxford, the same route taken by some of his predecessors such as Briggs and his successors such as Halley. Whilst at Oxford he developed his interest in architecture, which led to him being appointed Surveyor of Works to Charles II. Wren was a true polymath whose scientific activities covered a very wide range of bases. Both the Wikipedia and the MacTutor articles are worth a read for more details and for anyone really interested in Wren the scientist I recommend Jim Bennett’s  The mathematical science of Christopher Wren (Cambridge-New York, 1982).

In the history of astronomy Wren occupies a legendary position as the man who offered a book token as a prize for the first person who could demonstrate that an inverse square law of gravity would lead to elliptical planetary orbits. Unable to solve the challenge Edmond Halley famously asked Isaac Newton, the start of a process that would culminate  in the publication of the Principia.

How not to report (history of) science

The BBC has a short announcement on their web site announceing the Vaticans exhibition in honour of Galileo Galilei

Unfortunately all three of the four of the main
statements are incorrect:

“The Catholic Church once labelled Galileo, now regarded as modern
astronomy’s founding father, a heretic.”

If Galileo had been held by the Church to be a heretic he would have been
executed and not imprisoned. He also is not modern astronomy’s founding father

“He was tried for challenging the widely held belief that the Sun travelled
around the Earth.”

The belief that the sun travelled around the earth was anything but widely
held at the beginning of the 17th century.

I done fucked up! At least it proves that I’m not the Pope!

Memo to self: Engage brain before writing a post!

“Although Copernicus did much ground-breaking work on the link between the
Sun and the Earth, it was Galileo’s instruments that proved the theory.”

As I have already blogged here Galileo’s observations did not prove the heliocentric theory.

“It was not until 1992 that Pope John Paul II declared that the Church’s
ruling was an error and that Catholics were not hostile to science.”

Whilst formally correct the above statement is misleading. The church
removed the ban on teaching  heliocentrism in 1752 and had effectively not
enforced it considerably before that. The books on heliocenticity were
removed from the index in 1835 (I think or 38?).

Not very good reporting, or?

The Last Magician

On my last post John Pieret of Thoughts in a Haystack added the following comment;

I notice that people often ridicule Newton for practicing alchemy. However, especially given as I understand it, the lack of much in the way of notes left by Newton about what he was doing, I don’t think we can say any more than he was exploring the closest thing to organized chemistry there was at the time. Trades like dying, metallurgy, glass making etc. probably didn’t share information and techniques very much and secrecy was, I’m guessing, pretty wide spread.

As John is obviously confused as to the true extent of Newton’s alchemical activities and their motivation I have written this post for him. On John’s comment Jeb commented;

I think to ridicule Newton for an interest in alchemy or indeed prophecy is an example of presentism.

His interests mark him as a man of his time not our own.

The society and culture he belonged to is a very diffrent ‘kind’ of thing than our own.

He is of course 100% right.

The title of this post is taken from a legendary essay by John Maynard Keynes (yes that J.M. Keynes!) on the life of Isaac Newton in which he revealed a Newton who had remained unknown to the world for two hundred years. When Newton died his papers were inherited by his niece Catherine Conduit (née Barton) who in turn passed them onto her daughter, Catherine who married into the family of the Earl of Portsmouth in whose possession the papers remained until they were auctioned in the 1930s. Keynes managed to acquire many bundles of the auctioned treasures and what he discovered as he read them both shocked and excited him. Newton’s biographers in the 18^th and 19^th centuries had presented him as the brilliant, rational, mathematical father of modern science a man who had guided the world into a modern age freed of superstition and wizardry. The man whom Keynes discovered in his unpublished manuscripts was a very different animal indeed, a man of very strange beliefs and practices who appeared more at home amongst the necromancers of the Renaissance than the mathematical physicists of the twentieth century. Newton was an alchemist! This discovery seemed almost blasphemous to many of his admirers and at least one Newton expert, whom I wont name, insist against overwhelming evidence that he only dabbled a bit in chemistry and the claims of alchemical secrets and strange beliefs are pure fantasy.

In order to understand Newton’s very deep involvement in the alchemical arts it is first necessary to understand his strange philosophy of knowledge. Newton was a Bible literalist, that is he believed that the Bible was a true and largely accurate account of the history of mankind, and he was a millennialist, that is he believed in a comparatively soon to take place second coming. He devoted a great deal of time and effort into trying to accurately date the creation (teaching himself Greek and Hebrew in the process) as he believed, along with many others in the 16^th and 17^th centuries, that the second coming would take place six-thousand years after the beginning of the world and that something in the region of five and a half thousand years had already passed. He was also a prisca theologian that is he believed that the original inhabitants of the earth had had a perfect knowledge of the laws of nature and that this knowledge had been lost in the march of time. According to this belief scholars like himself did not discover the laws of nature but rediscover them. Newton actually believed that he had been special chosen by God to receive this knowledge. Newton took up the study of alchemy because he believed that it was one of the oldest forms of Knowledge and therefore by definition closest to the original perfect knowledge that had been lost. Like most contemporary alchemist Newton was most interested in the so-called Hermetic Corpus a collection of Greek texts of supposed Egyptian origins, attributed to Hermes Trimegistus (thrice great) a supposed contemporary of Moses. These texts had been translated into Latin in the 15^th century by Ficino but already at the beginning of the 17^th century Isaac Causabon had shown by philological analysis that the texts were a product of the 2^nd and 3^rd centuries CE.

Newton’s studies in this direction actually started in about 1666 with the chemistry of Robert Boyle’s The Sceptical Chymist but had changed within a couple of years to Boyle’s other interest alchemy. Newton would spend a large part of the next thirty years studying alchemy including six months every year of alchemical experiment in a garden shed that he had erected in the gardens of his college especially for this purpose. He acquired, read and annotated a large library of alchemical literature and wrote a vast number of manuscripts on the subject (some of which Keynes acquired), which however display little originality but are more an attempt to organise and codify his readings into some sort of systematic science. His alchemy was not conducted in isolation from his other more legitimate scientific activities but actually informed and guided his entire academic endeavours.

When he finally left Cambridge for London to take up his post as Warden of the Mint in 1696 he also gave up his alchemical investigations but in his new work he put the practical knowledge of experimental chemical procedures that he had acquired in all those years of investigation to use. At the mint he devised new and better methods of assaying metals to control their purity.

For thirty of his years in his prime Isaac Newton was a fully-fledged practicing alchemist searching for the ancient secrets of knowledge that he believed alchemy could and would reveal to him, God’s anointed. He even conducted an alchemical correspondence with Robert Boyle and John Locke the thought of which fills me with a certain sense of amusement. Here we have three of the greatest founders of the modern rational scientific world indulging in the pursuit of one of the most arcane forms of woo that have ever existed.

Literature:

The definitive books on Newton the Alchemist are both by Betty-Jo Teeter Dobbs;

The Foundations of Newton’s Alchemy or “The hunting of the greene lyon”, CUP, 1975

The Janus Faces of Genius: The Role of Alchemy in Newton’s Thoughts, CUP, 1991.

Naïve or everyday presentism

Presentism in history is the attempt to read or interpret the past in terms of the present. By using present-day ideas and perspectives the person doing the interpreting distorts and falsifies the past. Sometimes this is done deliberately in order to support a particular political or philosophical standpoint. Very often however something occurs that I would label naïve or everyday presentism, which takes place when people apply modern terms and concepts to discussion of the past without being really aware that they are not applicable. A very crass example of this occurred recently in the comments at Uncertain Principles when a commentator, calling himself mad the swine, asked the following question;

I’m not sure how much basic physics, chemistry, or biology Shakespeare […] knew…

Now the straightforward answer to the question is absolutely none, as the three disciplines listed didn’t exist during Shakespeare’s lifetime. This might seem fairly trivial but it is indicative of a very serious problem for the historian of science. Our concepts of the various academic disciplines and their boundaries is not applicable to past ages and when using modern terminology the historian must always be very aware that these terms means something very different to their predecessors in earlier ages. In my area for example modern mathematics and Renaissance mathematics have very little more than the name in common but this is something that I intend to write about later and wont go into now.

Going back to the quote above I shall give a brief outline as to when the three disciplines listed did become something similar to that which we understand when we use them today.

The word physics certainly existed in the Shakespearian Age but with a very different meaning to that which it now has. Anybody referring to physics at the beginning of the 17^th century would be using it in the Aristotelian sense that is a description of the natural word that specifically excludes most of the mathematical discipline that constitute the modern concept of physics. Modern physics has a long prehistory that includes the Oxford Calculatores and the Paris Physicists in the 14^th century as well as the Italian mathematicians such as Tartaglia and Benedetti in the 16^th century but it is first in the 17^th century that physics as we understand it slowly emerges from the work of Kepler, Galileo, Descartes, Huygens and others. It is often claimed that Isaac Newton is the first modern physicist and his Principia the first modern physics book but in fact anybody reading the Principia has to filter the modern concepts out of a majority of distinctly non-modern material. Modern mathematical physics was born in the generation following Newton in the 18^th century.

Chemistry also has a very long prehistory that stretches back into the mists of time and the discoveries of various technologies such as dying, metallurgy, glass making etc that provide one of the areas out of which chemistry grew the other being the arcane alchemy. Although the roots of modern chemistry can be found in the works of Andreas Libavius, Jan Baptist van Helmont and Robert Boyle in the 17^th century, chemistry as we know doesn’t really come into being until the late 18^th century and the work of Lavoisier and Dalton.

The same can be said of biology, which also has a long prehistory stretching back into the mist of time and the earliest animal breeders and farmers who practiced a form of trial and error experimental biology. In antiquity biology is subsumed in what was later called natural history, which has a much broader scope than modern biology, which starts to emerge very slowly in the works of the 16^th century natural historians. Again like chemistry and physics the modern discipline is a product of the 18^th century.

Because we can identify elements of what we now study as biology in the works of Aristotle or physics in the works of Archimedes it is very easy to fall into the trap of considering this to actually be biology or physics as we understand it but it is not. There is a vast difference between our modern scientific disciplines and those areas of study in the past out of which they grew and anybody who wishes to study the past of those disciplines must carry an awareness of this with him.

It was 401 years ago today…

On the 2^nd of October 1608 Hans Lipperhey a spectacle maker from Middelburg in Zeeland applied to the States-General (the ruling council of the newly formed United Provinces) for a patent for ‘a certain device by means of which all things at a very great distance can be seen as if they were nearby by looking through glasses’ that he claimed was a new invention. This certain device was of course the telescope and Lipperhey’s patent application marks its official birthday. It was however not the first written record of the existence of the telescope, one week before on 25^th of September the Council of Zeeland had written a letter of introduction to Zeeland’s delegates to the States-General requesting them to arrange an audience for Lipperhey with Prince Maurice of Nassau the Commander in Chief of the Dutch Armed Forces so that he could demonstrate his new device and some historians therefore prefer this date as the official birthday of the telescope. The telescope is lucky it has two birthdays.

Between the 25^th of September and his patent application Lipperhey had got his audience and could demonstrate his new device to Maurice who was not only the most powerful political figure in the United Provinces but also a dedicated fan and supporter of science and technology who employed one of the leading European mathematicians Simon Stevin as his scientific advisor. We know of this demonstration because as Lipperhey arrived in Den Hague a peace conference was taking place in the war between the United Provinces and Spain and this peace conference also coincided with the visit to Maurice’s Court of the Ambassador of Siam. The Ambassador’s visit was documented in a French flyer (this is before the establishment of regular newspapers) that also contains an account of Lipperhey’s very impressive demonstration. Through this flyer news of the new invention spread very rapidly throughout Europe.

However despite the success of his demonstration Lipperhey was in the end not grated his patent, why? On the 14^th of October an unidentified young man offered to sell a telescope to the Council of Zeeland without requesting a patent; obviously Lipperhey was not the only lens maker who possessed the secret of how to manufacture telescopes. Even worse on the 17^th of October Jacob Adriaenzoon, known as Metius, a spectacle maker from Alkmaar also applied for a patent claiming that his device, on which he had been working for more than two years, was at least as good as that from Middelburg. Under these circumstances the States-General refused to grant a patent for an instrument that could apparently be bought on every street corner.

The literature on the history of the telescope has identified the young man as Sacharias Janssen on the very shaky and contradictory testimony of his son Johannes Sachariassen. In 1634 Johannes told Isaac Beeckman, whom he was teaching lens grinding, that his father had constructed his first telescope in 1604 but that he did not invent it but copied it from an earlier Italian device. However when questioned in 1655 by the Middelburg Town Council, who had been commissioned by the Dutch Ambassador to France to clarify the origins of the telescope, Johannes now claimed that his father had invented the telescope in 1590 and that he and his father had invented the “long” telescope (that is the Keplerian or astronomical telescope) in 1618. He also said that he was now 52 years old whereas he was in fact only 41. He did this because in 1618 he was only 9 years old and it would have been very unlikely that he was involved in the invention of anything at that age. In fact the astronomical telescope was invented in 1611 by Kepler as its alternative name implies and these are not the only implausible claims in Johannes’ statement. In 1590 his father was only 2 years old!

Despite these inconsistencies in the testimony of his son Sacharias Janssen was officially recognised as the inventor of the telescope in Holland and a statue was erected in his memory. The reason why Janssen received this honour and not Lipperhey was an unfortunate case of nationalism; Janssen was a Dutchman whereas Lipperhey was born in the German town of Wesel. Modern research carried out by Huib Zuidervaart of the Huygens Institute in Den Hague have revealed that the first contact that Janssen had with the profession of spectacle making was in 1616 when he adopted the children of a spectacle maker who had died and thus he could not have been involved in the invention of the telescope. Zuidervaart has also unearthed new information on Metius and all of this will be published in the report from the conference held in Middelburg to celebrate the 400^th anniversary of the invention of the telescope in 2008. (This is cutting edge information in the history of optics and remember you read it here first.)

This is however not the end of the story or the confusion concerning the origins of the telescope. In his book from 1614 Mundus Jovialis Simon Marius the Court Astronomer from Ansbach in Franconia reports that his friend Johannes Philipp Fuchs von Bimbach was offered a telescope at the Book Fair in Frankfurt in 1608. Many authors, without checking the facts, take this as an indication of how fast the news of the telescope had spread after Lipperhey’s demonstration in Den Hague. Unfortunately for this theory the Frankfurt Fair in 1608 was about a week before Lipperhey’s performance for Maurice and his guests making for another unknown purveyor of telescopes in the autumn of 1608.

The general position among historian of the telescope today is that Lipperhey made the first patent application and therefore he is the official inventor of the telescope and so we celebrate the 401^st birthday of his device today.

Niall at weareinthegutter has a post that draws attention to an interesting article on early depictions of the telescope in the paintings of Jan Brueghel

Cannonballs, Cherrios and Snowflakes

At Uncertain Principles Chad Orzel has an amusing and highly informative post on the mathematical theory* of close packing based on his experiences of the amount of milk left in his bowl depending on which breakfast cereal he eats. Now the reader could be forgiven for thinking that this subject has nothing to do with Renaissance science but he or she would be mistaken, as the mathematical theory of close packing began in an exchange of letters between the English polymath Thomas Harriot and his German counterpart Johannes Kepler.Amongst other scientific topics discussed by the two genial mathematicians was a problem put to Harriot by his patron Sir Walter Raleigh, how best to stow cannonballs on a ship so that they take up the least possible space.

The consideration of this question led Kepler to a solution that is known as Kepler’s Conjecture: The Kepler conjecture, named after Johannes Kepler, is a mathematical conjecture about sphere packing in three-dimensional Euclidean space. It says that no arrangement of equally sized spheres filling space has a greater average density than that of the cubic close packing (face-centred cubic) and hexagonal close packing arrangements. The density of these arrangements is slightly greater than 74%.

Kepler originally published his conjecture in a small pamphlet STRENA SEU DE NIVE SEXANGULA. (The Six-Cornered Snowflake), which he wrote as a present for his friend Johannes Matthaeus Wacker von Wackenfels and published in 1611. This pamphlet is not only the founding document of the theory of close packing but also of the scientific discipline of crystallography because it contains Kepler’s analysis of the snow crystals.

Like its better known mathematical companions Fermat’s Last Theorem and Euler’s Four Colour Theorem Kepler’s Conjecture proved intractable and the attempts of numerous high ranking mathematicians over the centuries to prove or disprove it generated a lot of significant high level mathematics. In 1900 David Hilbert included it in his legendary list of the 23 most important mathematical problems to be solved in the coming century. In 1998 the American Mathematician Thomas Hales announced that he had proved the conjecture but his proof is based on a complex computer proof by exhaustion and up till now the referees are only 99% certain that the proof is correct. However the days of Kepler’s Theorem seem to be just around the corner.

* Chad being a physicist would of course call it the physical theory!

Where’s the Author?

Well the book arrived this morning so all we need now is for the author to come by and sign it.

The Book of Curiosities

Regular commentator Jeb, both here and at the Aussie Anthropoids Pad (he who has lost his underpants), has drawn my attention in the comments to Mapping Africa to the online exhibition at the Bodlian Library of the Arabic “Book of Curiosities”. This is truly a wonderful presentation of a fascinating document and so I have promoted the tip up front with thanks to Jeb.

Riding the Wave

Matt Springer at Built on Facts has a nice little post on a crucial experiment proving a surprising prediction in the history of the wave theory of light in the 19^th century that is well worth reading. However Matt and his commentators are a little bit shaky on the historical development of this theory so I thought I would post a brief chronicle on the subject here.

Some historian see a prototype of the wave theory in Aristotle’s theory of vision but on the whole this seems to be a case of over interpretation and backwards projection. However there is a grain of truth in the claim as both theories are so called mediumistic theories.

Again some historians, in particular Italian ones, see the wave theory of light in some of Leonardo’s notes on the propagation of light in the Codex Atlanticus, also in my opinion an over interpretation. The first real exponent of a wave theory was Grimaldi who used a wave theory to explain his discovery of diffraction.

The first real wave theory publication was Robert Hooke in his Micrographia in 1665 although his explanation of the theory was somewhat rudimentary.

In 1672 Isaac Newton published his theory of colour and included in his paper his belief that this theory provided proof for his own particle (corpuscular) theory of light. Hooke interpreting this to mean that Newton’s theory of colour was dependent on a particle theory of light rejected it because as he claimed he had demonstrated that light is propagated in waves. In his reply Newton showed that his theory of colour worked equally well with a wave theory and at the same time produced the strongest formulation of the wave theory in the 17^th century.

In 1690 Huygens’ published his version of the wave theory that differed from those of both Hooke and Newton and was not compatible with Newton’s theory of colour, a major disadvantage. In 1704 Newton published his Optics, a masterpiece in the history of the discipline, and although he demonstrated his discoveries independent of any theory of the nature of light in Query 28 at the end of the book he undertook a blistering demolition of the wave theory; for the time being Newton carried the day.

In the middle of the 18^th century Leonard Euler the leading mathematical physicist of the age supported the wave theory but the generality accepted Newton’s particle theory. In 1802 Thomas Young published his version of the wave theory supported by his own now legendary two slits experiment but ran foul of the Newton lobby. In the 1820s Fresnel and Argo extended the work of Young and placed the wave theory on a solid empirical experimental footing however it was only when George Airy threw his considerable weight behind Young and Fresnel and the wave theory that the particle theory of Newton was final dethroned.

I for one find it amusing when people use this development in the history of optics to crow about the great Newton being wrong given the fact that at the beginning of the 20^th century the wave theory was in its turn dethroned by the particle theory of Planck and Einstein.