The other day I came across the following tweet

The link is to an excellent piece about the history of European science which I recommend reading; as I do with this one.

I won’t pretend to be a historian but I can’t resist a comment from my perspective as a physicist. I am currently teaching a ~~course ~~module called *Theoretical Physics* which brings together some fairly advanced mathematical techniques and applies them to (mainly classical) physics problems. It’s not a course on the history of physics, but thenever I mention a new method or theorem I always try to say something about the person who gave it its name. In the course of teaching this module, therefore, I have compiled a set of short biographical notes about the people behind the rise of theoretical physics (mainly in the 19th Century). I won’t include them here – it would take too long – but a list makes the point well enough: Laplace, Poisson, Lagrange, Hamilton, Euler, Cauchy, Riemann, Biot, Savart, d’Alembert, Ampère, Einstein, Lorentz, Helmholtz, Gauss, etc etc.

There are a few British names too including the Englishmen Newton and Faraday and the Scot Maxwell. Hamilton, by the way, was Irish. Another Englishman, George Green, crops up quite prominently too, for reasons which I will expand upon below.

Sir Isaac Newton is undoubtedly one of the great figures in the History of Science, and it is hard to imagine how physics might have developed without him, but the fact of the matter is that for a hundred years after his death in 1727 the vast majority of significant developments in physics took place not in Britain but in Continental Europe. It’s no exaggeration to say that British physics was moribund during this period and it took the remarkable self-taught mathematician George Green to breath new life into it.

I quote from *History of the Theories of the Aether **and Electricity* (Whittaker, 1951) :

The century which elapsed between the death of Newton and the scientific activity of Green was the darkest in the history of (Cambridge) University. It is true that (Henry) Cavendish and (Thomas) Young were educated at Cambridge; but they, after taking their undergraduate courses, removed to London. In the entire period the only natural philosopher of distinction was (John) Michell; and for some reason which at this distance of time it is difficult to understand fully, Michell’s researches seem to have attracted little or no attention among his collegiate contemporaries and successors, who silently acquiesced when his discoveries were attributed to others, and allowed his name to perish entirely from the Cambridge tradition.

I wasn’t aware of this analysis previously, but it re-iterates something I have posted about before. It stresses the enormous historical importance of British mathematician and physicist George Green, who lived from 1793 until 1841, and who left a substantial legacy for modern theoretical physicists, in Green’s theorems and Green’s functions; he is also credited as being the first person to use the word “potential” in electrostatics.

Green was the son of a Nottingham miller who, amazingly, taught himself mathematics and did most of his best work, especially his remarkable *Essay on the Application of mathematical Analysis to the theories of Electricity and Magnetism (1828)* before starting his studies as an undergraduate at the University of Cambridge ,which he did at the age of 30. Lacking independent finance, Green could not go to University until his father died, whereupon he leased out the mill he inherited to pay for his studies.

Extremely unusually for English mathematicians of his time, Green taught himself from books that were published in France. This gave him a huge advantage over his national contemporaries in that he learned the form of differential calculus that originated with Leibniz, which was far more elegant than that devised by Isaac Newton (which was called the method of fluxions). Whittaker remarks upon this:

Green undoubtedly received his own early inspiration from . . . (the great French analysts), chiefly from Poisson; but in clearness of physical insight and conciseness of exposition he far excelled his masters; and the slight volume of his collected papers has to this day a charm which is wanting in their voluminous writings.

Great scientist though he was, Newton’s influence on the development of physics in Britain was not entirely positive, as the above quote makes clear. Newton was held in such awe, especially in Cambridge, that his inferior mathematical approach was deemed to be the “right” way to do calculus and generations of scholars were forced to use it. This held back British science until the use of fluxions was phased out. Green himself was forced to learn fluxions when he went as an undergraduate to Cambridge despite having already learned the better method.

Unfortunately, Green’s great pre-Cambridge work on mathematical physics didn’t reach wide circulation in the United Kingdom until after his death. William Thomson, later Lord Kelvin, found a copy of Green’s Essay in 1845 and promoted it widely as a work of fundamental importance. This contributed to the eventual emergence of British theoretical physics from the shadow cast by Isaac Newton. This renaissance reached one of its heights just a few years later with the publication a fully unified theory of electricity and magnetism by James Clerk Maxwell.

In a very real sense it was Green’s work that led to the resurgence of British physics during the later stages of the 19th Century, and it was the fact that he taught himself from French books that enabled him to bypass the insular attitudes of British physicists of the time. No physicist who has taken even a casual look at the history of their subject could possibly deny the immense importance of mainland Europe in providing its theoretical foundations.

Of course science has changed in the last two hundred years, but I believe that we can still learn an important lesson from this particular bit of history. Science moves forward when scientists engage with ideas and information from as wide a range of sources as possible, and it stagnates when it retreats into blinkered insularity. The European Union provides all scientific disciplines with a framework within which scientists can move freely and form transnational collaborations for the mutual benefit of all. We need more of this, not less. And not just in science.