Essential Information Location Royal Observatory 29 Oct 2014 Earlier this year the National Maritime Museum’s blockbuster exhibition Turner and the Sea showcased one of Britain's greatest artists, the nineteenth-century painter Joseph Mallord William Turner, focussing on his fascination with marine subjects. The Maritime Museum was therefore an obvious place to go for historical and artistic advice for the team behind Mr Turner, Mike Leigh’s new film about the painter’s life, which is currently receiving critical acclaim. However, perhaps more surprising is that the astronomers of the Royal Observatory were also called on for behind-the-scenes assistance on the film. What’s the connection between astronomy and one of the greatest painters in the history of British art? London from Greenwich, 1811. Etching & mezzotint after an oil painting by J.M.W. Turner, in the collection of the National Maritime Museum. The answer lies in the intellectual world of the early nineteenth century where in many ways there was far less separation between the arts and sciences than there is today. As a well-known painter, Turner moved in the same circles as many other artists, writers and musicians - but also with scientists and inventors such as Richard Owen, Michael Faraday and Humphry Davy. Among them was the ground-breaking polymath and science writer Mrs Mary Somerville. The daughter of a Vice-Admiral, Mary was born in Jedburgh in the Scottish Borders in 1780. In many respects she led the life of a conventional society lady, marrying twice, successfully managing a household and bringing up a family. But her inquiring mind refused to be bound by convention and with a combination of talent and willpower she also managed to educate herself to a high level in mathematics, astronomy and other sciences - despite the fact that these were considered highly unsuitable interests for a respectable woman at the time. By the 1820s, Mrs Somerville was widely recognised in Britain and abroad as a leading authority on astronomy and mathematics. Her skill in explaining complex scientific ideas clearly and accessibly was particularly praised: she translated Pierre-Simon Laplace’s great astronomical work Mécanique Céleste from French into English, at the same time rendering it “from algebra into common language". Mary’s friend, the writer Maria Edgeworth, said that “While her head is among the stars, her feet are firm upon the earth”. In 1826 her paper, The Magnetic Properties of the Violet Rays of the Solar Spectrum, was presented at the Royal Society - although since women were not allowed to attend meetings of the Society at that time it was actually read by her husband on her behalf. Mary was interested in a possible connection between magnetism and the violet part of the solar spectrum - two phenomena that gripped the scientific imagination of the day. Her painstaking experiment used a prism to separate out the violet component of sunlight and focus it onto a steel needle. To test whether the needle had been magnetised she then floated it in a dish of water to see if it would respond to a magnetic field by moving like the pointer of a compass. Glass prism formerly belonging to the Herschel family and now in the collection of the National Maritime Museum. Prisms like this can split sunlight into its constituent spectrum of colours, and Mary Somerville would have made use of similar equipment for her experiments on violet light. Her results appeared to show that the needle did indeed become magnetised by its exposure to violet light although with the equipment available at the time it was hard to be absolutely sure. It's certainly not hard to see how an experiment on the properties of colour and light would be of interest to a painter like Mr Turner and Mike Leigh's film references the interlocking worlds of nineteenth century art and science with a compelling scene in which Mrs Somerville visits Turner’s studio to give him a demonstration. To help create the scene the film's research consultant Jacqueline Riding and actress Lesley Manville paid a visit to the Royal Observatory last year to find out how Mary might have approached her demonstration and to get a feel for how scientists try to explain their ideas to the public. We had great fun reading through Mary's original step-by-step description of her experiment with violet light and also trying to imagine the excitement of being part of her circle of artistic and scientific friends. Of course, Mr Turner is a drama and not a history (or science) textbook and so I was fascinated to see what sort of character Lesley would create, based on contemporary descriptions alongside her own insight and imagination. In the end I was extremely pleased to see her performance in the film, which presents Mary as a lively, charismatic figure brimming with enthusiasm and curiosity. We'll never know exactly what Mary Somerville was like in real life but Lesley's portrayal seems a fitting and affectionate tribute to an extraordinary character. Mary Somerville (Lesley Manville) prepares to demonstrate her experiment on violet light to J.M.W. Turner (Timothy Spall) and his household (Paul Jesson & Dorothy Atkinson) in Mike Leigh's 2014 film Mr Turner. Turner would certainly have had many opportunities to discuss the latest scientific ideas of the day and his biographer James Hamilton argues that some of these might have found expression in his paintings. Hamilton even suggests that Turner may have referenced his friendship with Mary Somerville and her 1826 paper on magnetism and violet light in the 1829 painting Ulysses deriding Polyphemus, in which a pale violet tone appears in the sky to the north - the direction to which the magnetic needle of a compass is attracted. Mary later retracted her claim that violet rays could magnetise a steel needle when further experiments failed to give the same result - exactly as any modern scientist would do when new and better evidence becomes available. But her place in history was already secure. Reviewing Mary's book On the Connexion of the Physical Sciences in 1834, William Whewell first coined the word “scientist”, and a later edition of the same book helped to encourage astronomers to search for - and eventually discover - the eighth planet, Neptune. The University of Oxford’s Somerville College is named after Mary and, along with Caroline Herschel, she also became the first female member of the Royal Astronomical Society. In their fictionalized meeting in Mike Leigh’s film, Mary compliments Mr Turner on being a man of great vision, whose art helps us to see the universe as it truly is. Similar praise could be heaped upon the pioneering Mrs Somerville herself. In a film about the power and beauty of art it’s good to see the wonder and excitement of science given such prominence too. Some idea of the extraordinary lengths that were taken to ensure Mr Turner was as accurate as possible can be seen in the video below where the team recreate his Queen Anne Street Gallery.