Aesthetic of the Sub-Atomic: C T R Wilson [2015]

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Exploring the Aesthetic of C. T. R. Wilson’s Work

[This is a slightly edited version of a presentation given on 4 July 2015, at Highland Institute for Contemporary Art, Dalcrombie, near Inverness, at the exhibition: Wilson Chamber Images: The Aesthetic of the Sub-Atomic.—murdo-macdonald.html  ]




I am not a scientist. If I would describe myself as anything I am a visual thinker. I had no real sense of mathematics until I saw a visual proof of Pythagoras. Now, having studied the practices of painting and the theories of psychology, I find myself an art historian. I’m not particularly interested in aesthetics from a philosophical point of view. But ‘aesthetic’ is an interesting word, isn’t it? It’s interesting because it implies feeling.

So: what, for me, is the feeling of works by C. T. R. Wilson, and how might one approach that question of feeling, of the aesthetic?

I have tried to answer that question for myself by presenting in this exhibition both enlargements from photographs by Wilson and photographic responses to those prints, sampled by myself.

I have been thinking about these issues for a while. Most of my life, in fact. In 1986 in my PhD thesis, I wrote about what I called the inappropriate separation of science and the aesthetic, and I want to revisit some of that thinking here.

Consider a typical image by Leonardo da Vinci. While aesthetically good notions like balance and symmetry tell one a great deal about what constitutes good art they tell one equally what constitutes good science. You can respond to a drawing by Leonardo by losing yourself in it as a work of art or using it as a tool of analysis for your scientific thinking, but it is a wonderful work of drawing either way. It has an aesthetic effect on us, whether we see it for its precise scientific observation and visual hypotheses, or for the ambiguity that characterises it as a work of art.

Similarly a great equation such as Einstein’s E=MC2, is no less aesthetically pleasing than a painting by Mondrian or Claude. They all depend on elegance, balance and coherence. Indeed when I was studying for my PhD I found William J. Kaufmann’s illuminating introductory book, Relativity and Cosmology, in which he considered Einstein’s work to have aesthetic ‘validity’ over its competitors.

Kaufmann writes: “It should, however, be pointed out that, mathematically, Einstein’s theory is extremely simple and beautiful. The competing theories are not. If beauty and simplicity are in some way a measure of validity, we may continue with confidence in assuming Einstein was right.”

So beauty and simplicity, feelings of elegance if you like, or, as we might say, aesthetic ideas, are for Kaufmann at the heart of scientific judgment. No surprise there, but it begins to shift the colloquial use of the word ‘aesthetic’ away from the sole province of art.

A stimulating discussion of the importance of such beauty in science, specifically with reference to Einstein’s general relativity, can be found in writing by Paul Dirac entitled ‘The test of Einstein’. Dirac goes even further than Kaufmann, holding that the primary test of a scientific theory is its beauty, a point he also made strongly with reference to Schrodinger’s wave equations. He says of Einstein: “He was guided only by the requirement that his theory should have the beauty and the elegance which one would expect to be provided by any fundamental description of nature. He was working entirely from these ideas of what nature ought to be like and not from the requirement to account for certain experimental results.” and later: “… one has an overpowering belief that its foundations must be correct quite independent of its agreement with observation.”

It is, however, unfortunately true that culturally we are not encouraged to appreciate the beauty of science, or rather that beauty is somehow hived off into the province of art not of science. But that is a function of our contemporary cultural reality, not of beauty. So my point is one that I find very obvious, namely that aesthetic criteria unite art and science rather than uniquely specifying art.

That is about as far as I got in my PhD in 1986, but I have been exploring the aesthetic unity of art and science ever since. The work of C. T. R. Wilson has been central to that exploration for as long as I can remember, but I do not remember exactly when Wilson began to figure for me as a name. By the end of the 1970s I had become aware of the bubble chamber photographs used by Fritjof Capra in The Tao of Physics, and also those used by C. H. Waddington in Behind Appearance, in which Waddington explored modern science through modern art and vice versa.

Capra’s analogies between the new physics and spiritual metaphors for cosmic energy such as the Dance of Shiva, are still of current interest. Indeed it is because of Capra’s influence that a statue of the Dance of Shiva was erected at CERN in 2008.

But I eventually realised that the primary sensor for particle physics for the first half of the twentieth century, the absolutely crucial period in the development of the discipline, was not the bubble chamber at all, but its predecessor, the cloud chamber, and that the cloud chamber had been developed by a Scot called C. T. R. Wilson. Wilson seemed to be a remarkably forgotten figure considering his importance. Part of that forgetting of Wilson seemed to be bound up with the fact that very few cloud chamber images were easily available, in contrast to numerous bubble chamber images and, more recently, images from computerised sensors at CERN.

One can find a typical example of such ‘missing’ cloud chamber images in an interesting book by John Barrow entitled Cosmic Imagery: Key Images in the History of Science. It is ironic that Wilson’s importance is acknowledged in the text and Barrow’s chapter title, ‘Writing on Air,’ obviously refers to Wilson’s cloud chamber work, but in spite of that the image that illustrates the ideas is a bubble chamber image, not a cloud chamber image. It is not as if Barrow is not taking Wilson seriously. Indeed he writes that “These observations gave us the first concrete look at the smallest particles of matter …. The cloud chamber led to many dramatic discoveries …”

Barrow goes on to quote from a memoir of Wilson by another notable physicist, P. M. S. Blackett. Blackett received a Nobel Prize for his work with the cloud chamber in 1948, twenty-one years after Wilson’s Nobel Prize. As quoted by Barrow, what Blackett wrote after Wilson’s death was this: “Of all the scientists of this age, he was perhaps the most gentle and serene, and the most indifferent to prestige and honour. His absorption in his work arose from his intense love of the natural world and from his delight in its beauties.”

It was only in 1952 that the bubble chamber was invented. That period of over forty years between Wilson’s first successful cloud chamber photographs in 1911 and the invention of the bubble chamber, simply emphasises the significance of the cloud chamber during the critical period of development of twentieth century physics. That makes the popular emphasis on bubble chamber images even stranger. So what’s going on here? Well, the answer I would suggest is the obvious one, namely that Capra’s Tao of Physics was so successful that people tend to look no further than the imagery that he used.

The reason that Capra used bubble chamber imagery was he was writing in the 1970s, and there was a lot of excellent bubble chamber imagery available at the point. Capra wasn’t trying to write a history of science, he was popularising ideas, and very effectively. I can’t complain about that, because Capra helped to introduce me to the whole topic, and that eventually led me to Wilson. What is interesting now is that while, if I understand it rightly, bubble chamber research has been superseded, there is still cloud chamber research continuing, not least at CERN.

Thanks to an introduction from Alan Watson, Professor of Physics at Leeds University, I made contact recently with the leader of the cloud chamber project at CERN, Jasper Kirkby. If I understand it rightly, one of the purposes of the CERN project is to discover if cosmic rays can actually be a causal factor in the formation of clouds in Earth’s atmosphere. Fascinating stuff. I thought Jasper Kirkby might be interested in the Wilson material that underpins this exhibition at HICA, and indeed he was. He sent a thoughtful response, which I want to quote from here because it gives a very clear picture of the regard in which Wilson is held:

“Wilson was a brilliant experimentalist. I am hugely impressed by the technical quality of his cloud chamber photographs. I doubt whether we could improve on them, even today. Yet he did all this with the laboratory glassware and materials (gelatin…) of 100 years ago. His cloud chambers look deceptively simple (I had a good look at them at the Cavendish a few years ago) but – like Harrison’s clocks – they were built by a virtuoso and were far ahead of their time.”

He concludes:

“I think CTR Wilson would have been pleased to know that his cloud chamber concept is now the basis of the world’s leading experiment studying aerosol particles (cloud seeds) and clouds in the laboratory – exactly as he had envisaged when he originated his cloud chamber ideas at the Ben Nevis Observatory.”

So I do not want to give the impression that there is little appreciation of Wilson in the physics community, far from it. He just seems to have dropped out of public sight. This obscuring of Wilson from public gaze is the more ironic because the major history written about the experimental side of twentieth century particle physics devotes more space to Wilson than to almost anybody else. That history, Peter Galison’s Image and Logic: A Material Culture of Microphysics, published in 1997, extends to almost one thousand pages. Wilson has almost a full column of the index devoted to him and consideration of Wilson’s apparatus is at the heart of Galison’s text.

But a little more about Wilson himself now. C. T. R. Wilson was born in 1869 at a farm in the Pentland Hills near Edinburgh. He is commemorated nearby in a plaque erected by the Institute of Physics and the Royal Meteorological Society. He did his important work at the Cavendish Laboratory in Cambridge (with crucial inspiration from a period studying at the observatory at the top of Ben Nevis) and retired to Edinburgh, where his friend Max Born was professor. In due course he moved to Carlops where he died in 1959.

He was awarded the Nobel Prize in Physics for 1927 and that same year one finds him along with Einstein and Marie Curie in the front row of a photograph taken at the Solvay Conference. Max Born and Niels Bohr are just behind him. Most of the others you would expect are there: Dirac, Planck, Heisenberg, etc. It is one of the most important group photographs in the history of science.

Reflecting on my own interest in Wilson. Over the years I have often found myself teaching students about art and science, and about visual thinking as the great link between them – Leonardo, Patrick Geddes, D’Arcy Thompson, Waddington, etc. But I would always try to put in a cloud chamber photograph or two by Wilson or by one of the scientists he enabled, not least because of the remarkable way his images, for example those from 1912, seemed to prefigure the experimental painting techniques of fifty years later. I would not want to push simplistic analogies, but in the wider history of visual thinking such echoes between disciplines across time are at least interesting. But that, and sticking the odd cloud chamber image to my office door was all I ever got around to doing with respect to Wilson. That changed in about 2006, when I mentioned my interest to the physicist Mervyn Rose, a colleague at the University of Dundee. Mervyn Rose shared my interest in Wilson and in due course he made included me in an email group, which was trying to get more recognition for Wilson by getting his face on a stamp or a bank note.

A turning point came at the end of 2012 when the Royal Society of Edinburgh decided to mark the centenary of Wilson’s epoch-making 1912 paper with a one-day conference. I was able to meet people who had only been names to me on the email circulation list. One such was Alan Watson, whose presentation re-emphasised for me not only Wilson’s scientific value but also his aesthetic achievement. I would like to acknowledge my debt to all the speakers that day, not least Malcolm Longair of the Cavendish Laboratory.

By this time I could see an art/science project taking form around Wilson’s key early images. My initial thought was to find a set of good prints of them. At that time one could only access them easily through the fairly greyish halftones typical of scientific publications circa 1912. Even in that form they are beautiful, but I wanted to raise the visual level on which they could be appreciated. I thought that would be straightforward enough, so with the help of Joanna McManus, the image librarian at the Royal Society in London I inspected the original paper in the proceedings and began to study associated material. That associated material included a wonderful selection of Wilson’s images made by Philip Dee, Wilson’s student. Dee became Professor of Physics at Glasgow, and was, like Wilson a Fellow of the Royal Society. But I could find no full set of prints or negatives corresponding to the 1912 paper.

However two other things were happening by then. Alan Watson (himself a Fellow of the Royal Society) and I were in contact and supporting each other in our various efforts, not least with respect to attempting to get Wilson represented in the Scottish National Portrait Gallery and having his images given more prominence in the display at the Royal Museum of Scotland. Those efforts continue and are beginning to bear fruit.

In addition I had been in touch with another of the speakers at Royal Society of Edinburgh conference, Andrew Wilson, C. T. R. Wilson’s grandson. Andrew told me that he had a box of material, which I was welcome to have a look at. That was an intriguing offer. Thanks to the support of the Royal Society of Edinburgh I was able to cover travel costs to pursue things further. My expectation was that I would also visit the Cavendish Laboratory at Cambridge, where Wilson was professor. In fact I never got there, although I no doubt will in due course. The reason I didn’t get there is the basis of the exhibition at HICA, namely the material that Andrew Wilson had in his possession. In summer 2014 Andrew showed me a few boxes on glass plates, which looked intriguing, and then he just suggested I took them away to examine at my leisure. I was only too pleased to do so. His only stipulation was that I should try and find a good collection to which he could present the work. I did so, and it has now been accessioned by the Royal Scottish Academy.

When I began to examine the collection it was utterly fascinating. There were about sixty items, a mixture of glass plate negatives, positive lanternslides and a few prints. The first things I noticed were two lanternslides illustrating the two images from Wilson’s 1911 paper. These are among the most important images in the history of science. They record the very first records of the tracks of sub-atomic particles. And I was holding Wilson’s own lantern slides in my hands.

In due course they were digitized for me by my colleague Gair Dunlop, and printed at the Visual Research Centre of the University of Dundee by Paul Harrison. They are a key feature of the installation at HICA, both in themselves shown at various scales, as the basis of a number of my own photographic responses to Wilson’s work.

I realized that Andrew Wilson’s collection of his grandfather’s material was an important collection by any standard. Some elements of it are unique, for example a glass plate negative which is clearly the basis of one of the key images in Wilson’s 1912 paper for the transactions of the Royal Society. It was the negative that provided the stunningly beautiful positive image on the HICA exhibition invitation card. However just as important as such unique material was material that gives insight into Wilson’s lectures and communication with colleagues, in the form of positive lantern slides of key images, such as the two images from the 1911 Royal Society paper that I’ve noted.

My intention is that the collection in its new home in the Royal Scottish Academy will act (i) as a catalyst to draw attention to the significance of Wilson from the point of view of artists as well as from a scientific point of view; (ii) to help us all to recognize Wilson’s role as a pioneering photographer of importance as part of the history of photography, as well as a pioneering scientist; and (iii) I would like this gift from Andrew Wilson to act as focus to encourage study of other Scottish collections of Wilson’s work (and indeed collections elsewhere), for example those of Glasgow, Aberdeen and Heriot Watt universities.

In conclusion I want to explore Wilson’s aesthetic through his own words. When he was awarded his Nobel Prize in 1927, he began his speech as follows:

“In September 1894 I spent a few weeks in the Observatory which then existed on the summit of Ben Nevis, the highest of the Scottish hills. The wonderful optical phenomena shown when the sun shone on the clouds surrounding the hill-top, and especially the coloured rings surrounding the sun (coronas) or surrounding the shadow cast by the hill-top or observer on mist or cloud (glories), greatly excited my interest and made me wish to imitate them in the laboratory.”

And that attempt to imitate those conditions in the laboratory laid the basis for Wilson’s cloud chamber. But as Wilson himself says: “my experimental work on condensation phenomena was not resumed for many years’ until ‘towards 1910 I began to make experiments with a view to increasing the usefulness of the condensation method.”

And later: “Much time was spent in making tests of the most suitable form of expansion apparatus and in finding an efficient means of instantaneous illumination of the cloud particles for the purpose of photographing them. In the spring of 1911 tests were still incomplete, but it occurred to me one day to try whether some indication of the tracks might not be made visible with the rough apparatus already constructed. The first test was made with X-rays, with little expectation of success, and in making an expansion of the proper magnitude for condensation on the ions while the air was exposed to the rays I was delighted to see the cloud chamber filled with little wisps and threads of clouds – the tracks of the electrons ejected by the action of the rays.”

“The radium-tipped metal tongue of a spintharoscope was then placed inside the cloud chamber and the very beautiful sight of the clouds condensed along the tracks of the Alpha-particles was seen for the first time. The long thread-like tracks of fast Beta particles were also seen when a suitable source was brought near the cloud chamber.”

“Some rough photographs were obtained and were included in a short communication to the Royal Society made in April 1911.”

I repeat: “Some rough photographs were obtained.” That’s a bit like Galileo saying that he had obtained some rough drawings of the moons of Jupiter looking though his telescope in Padua in 1610. As I have already noted these two ‘rough photographs’ that Wilson published in the Proceedings of the Royal Society in 1911 are among the most important images in the history of science. They are the very first visualizing of Alpha and Beta particles. And Wilson’s pleasure in the visual is evident: listen to what he says of the first photograph: “I was delighted to see the cloud chamber filled with little wisps and threads of clouds – the tracks of the electrons ejected by the action of the rays.” And of the second: “the very beautiful sight of the clouds condensed along the tracks of the Alpha-particles was seen for the first time.”

So however rough they were by Wilson’s later standards, as he makes clear these images were to his mind also very beautiful. Words like ‘beauty’ and ‘delight’ – aesthetic words – characterize Wilson’s approach to nature, to science and to his own images.

My aim both in the exhibition at HICA and in this brief reflection that accompanies it has been to give some insight into that beauty and delight.