Watch Tom McLeish talking through Grosseteste on Colour and the Rainbow at the Royal College of Art, for a conference on Colour through Time: Enjoy!
In more news from the Ordered Universe creative arts strands, we’re delighted that Colin Rennie’s sculpture Magnitudo, having been entered into the Toyama International Glass Prize, a Triennial open competition for glass art. Created for the Illuminating Colour exhibition at the National Glass Centre (2017-18), Magnitudo also featured in the Light Embodied exhibition at Pembroke College, University of Oxford, April-June 2018.
The sculpture is now in Japan, as one of 57 pieces selected for the final judging show in September. There were over a thousand entries globally. That a piece of glass sculpture should be inspired by Grosseteste’s 13th century writings on colour, light and the rainbow, and the modern science that resulted from its investigation, is a wonderful story. Let’s hope the judges think similarly. We’ll let you know how the competition proceeds.
Colin has also entered Concurrentes to the annual New Glass Review at the Corning Museum of Glass, upstate New York. Another journey across the seas awaits perhaps.We all wish Colin the very best of luck!
Last week, Thursday 23rd and Friday 24th November, Ordered Universe members were made very welcome at the Centre for Medieval and Early Modern Research, and the Department of History at Swansea University. Continue reading
For those that haven’t yet managed to get to the National Glass Centre in Sunderland, we have here a guided tour to the exhibition by Cate Watkinson and Colin Rennie. Rosie Reed Gold took the photographs, adding another level of interpretation to the movement from 13th century Latin manuscripts, to editions and translations, to textual analysis (by Continue reading
A post by Joshua Harvey, D.Phil. student, Department of Engineering Science and Pembroke College, University of Oxford, funded by the Andrew W. Mellon Foundation as part of ‘The Mental and Material Laboratories of Medieval Science’ project, under the aegis of the Ordered Universe.
The latest research article from the Ordered Universe project: “Bow-shaped caustics from conical prisms: a 13th Century account of rainbow formation from Robert Grosseteste’s De iride” is available to read now, open access at the Optical Society of America’s journal Applied Optics. Grosseteste’s treatise De iride [On Rainbows], which may be familiar to long-term followers of the Ordered Universe project, explores theoretical optics, colour theory, and meteorology to give one of the most comprehensive pre-renaissance scientific writings on the rainbow. With this most recent article, we explore his pioneering model of rainbow formation – the first to use refraction (and not just reflection) in medieval Europe. Through an interdisciplinary combination of historical review, geometric optics, and both practical and simulated experiment, we give a thorough overview of the historical significance of the De iride, and look at what lessons we can learn from it today.
This fruitful exploration has not been done before. Although Grosseteste provides a detailed description of what he believes are the geometric underpinnings of a rainbow, he has previously been disregarded in this area. David Lindberg even went so far as to say that ‘his theory of the rainbow could not account for even the most basic phenomena and has remained largely unintelligible to the modern day.’ Well, we thought there might have been more to Grosseteste’s thought than that, being familiar with his mathematical mind and keen curiosity about the natural world. As a research team with a diverse expertise, we together arrived at an interpretation of Grosseteste’s optical mechanism that was intelligible, elegant and, most excitingly, perfectly testable. To our surprise, the caustics – patterns of gathered light – produced by a transparent cone are just as Grosseteste describes.
Remarkably, we have already been contacted by researchers investigating atmospheric optics, who have found some striking correspondences between their own work and our interpretation of Grosseteste’s De iride. Markus and Sarah Selmke’s recent paper, “Artificial circumzenithal and circumhorizontal arcs” published in American Journal of Physics, explores to great depths the kinds of refractive optical interactions between transparent cones, as modelled by glassware filled with water, and incident light. The authors have shown that Parry arcs, a type of halo, are analogous to the caustics produced by shining light through a wine glass of water. Although not as frequently observed as rainbows, Parry arcs are similarly beautiful displays of dispersive colour seen in the heavens, providing certain atmospheric conditions are met. The paper features a combination of practical and mathematical experimentation, similar to our own approach in the Applied Optics paper, and states that “light entering through the top air-water interface and leaving through the lateral cone surface results in an analogy to Parry’s halo”. This is identical to Grosseteste’s geometric scheme, as we interpreted it. Although, to his detractors, his likening of a rainbow to that of light going through a transparent cone might sound crude, or even ridiculous, it appears this simple model does indeed capture the optical principles behind a dispersive atmospheric phenomenon.
Grosseteste was wrong about rainbows. Not long after him, rainbows were correctly understood to be produced by light interacting with near-spherical raindrops, by both Kamal al-Din al-Farisi and Theodoric of Freiburg in the fourteenth century. But Grosseteste was not wrong about the optical qualities of transparent cones, and although the optical scene he describes in De iride does not relate to rainbows, it is analogous to another kind of dispersive optical event seen in the heavens.
Of course, it would be incorrect to claim that Grosseteste had solved the mystery of Parry’s arc back in the thirteenth century. He had probably never seen or heard of one, as they are rare outside the Arctic circles, and it wasn’t until 1820 that William Parry observed and drew one. Was this mere coincidence, could Grosseteste have happened upon an atmospheric optical mechanism by chance? Perhaps. But it is worth bearing in mind that his theory was likely grounded in observation, and formulated to be as parsimonious as possible. I think that rather than chance, it is instead even clearer we are reading the work of someone with a scientific mind, curiosity about nature, and a belief in a profoundly ordered universe.
Cate Watkinson talks through her ideas for the National Glass Centre, University of Sunderland’s, upcoming exhibition on Grosseteste, light and colour, in the autumn. This is the second film made by Claire Todd, exploring aspects of how the pieces and the exhibition come together. Colour, Light and the magic of glass….
We are very grateful for the support of the Durham University Institute of Advanced Study in making these films possible.
The Ordered Universe project is pleased to announce its latest publication, for the Applied Optics journal, Vol. 56 (2017), G197-G204, and fully open access. The experiments and writing of the paper were led and marshalled by expertly Joshua Harvey (Mellon Foundation funded graduate student at Oxford University, Dept of Engineering Science and Pembroke college), with assistance from other members of the team, from the sciences and humanities. The paper focuses on the middle part of Grosseteste’s treatise On the Rainbow (De iride) and the shape that the rainbow forms in the sky. This precedes discussion of the colours of the rainbow, covered in other Ordered Universe papers. The current paper offers an historical context for the treatise before moving to the main discussion, testing Grosseteste’s optical thought with physical experiment and physics-based simulation. The results are available below, and show, again, the benefits of collaborative working to unlock problems posed by thinkers of the past.
The first in a short series of films by Claire Todd chronicling the development of the National Glass Centre exhibition drawing on Ordered Universe research and the scientific works of Robert Grosseteste. Here Colin Rennie talks about his rainbow sculpture.
We are very grateful to Durham’s Institute of Advanced Study for providing resource to enable the making of these films.
Another memorable day at the National Glass Centre. Giles, Brian and Alex Carr, together with David Lowther (Leverhulme Early Career Fellow at Durham, working on the history of zoology in the modern period, especially of collections and birds), went over to Sunderland to see the preparations for the Grosseteste-inspired exhibition opening in October. We also went to complete the filming for the documentary element of Through a Glass Darkly with Alan Fentiman. We had a fantastic time – Colin Rennie made one of his rainbow strands for us. As you’ll see from the clip below, this was quite extraordinary, culminating in molten glass being stretched and spun, changing colour as it cooled.
Colin Rennie making a rainbow national glass centre Sunderland https://t.co/wq07WMF8jV
— Giles Gasper (@GilesGasper) June 29, 2017
The final products of rainbow sculpture, some 20 or so, will be mounted in an steel frame, each strand moving seamlessly from one colour to another.
Cate Watkinson took us through her installations, with models of the larger pieces of glass in sequences. We experimented with torchlight and one of the circular moulds of blue glass, creating internal and external shadows, reflection and patterns at the edge of diaphanous media (as Grosseteste might have observed). Cate is working too on embedding Grosseteste’s treatise De colore (or parts of it) into glass, as well as the larger colour pieces and the movement from black to white.
The exhibition opens on 20th October – we’ll have more updates on progress and activities around the exhibition. For now, we can safely reveal that it will be amazing.