Schrödinger is perhaps better known for proposing in 1935 the thought experiment involving a cat in a sealed box with an atomic particle. The particle was about to liberate itself at some point in time and thereby release a death-dealing dose to the cat – by opening the box to determine the cat's fate would be interference and therefore nullify the experiment. As one of the team credited with proposing the theory of quantum mechanics a decade earlier, the thought experiment riffed on the flighty nature of early research in particle physics; however, Schrödinger's broader interdisciplinary research engaged mainly with several fields of observable physics, also with psychology and perception and including the area of color theory, the subject of this volume. In the early 1920s a series of papers were published in Germany detailing his earlier researches and nearly 100 years later, Dr Niall has brought all the papers in translated form together for the first time. (In acknowledging the vicissitudes of translation, two of the eight chapters are reprinted in the original).

The translator's introductory essay jumps right into the issues assuming a level of knowledge in the reader with physics research and its methodologies, commencing with Newton's light experiments through to Fechner's Law and Helmholtz's work with geometric axioms. Schrödinger was in a scientific tradition that sets out to explain color and the relationships between different colors, in some form of mathematical structure. We are very used to color wheels and other geometric pictures of color relationships, and it is not misplaced to see this work from the perspective of geometry.

An example of a key question that might be answered from an effective color model put in lay terms is, Are these two colors of the same brightness? This is surely an issue that exercises many visual artists. It relates closely to one of the problems that Schrödinger worked on, the formal meaning of brightness. We see in these papers he does this in the light of a clear understanding that, for some researchers, the very notion of defining ‘equal brightness’ is altogether impossible. However, he shows that, using his model, empirical studies can be defined that can answer the question; (studies that he seems to have left to others). That oversimplifies it, but the point is that he worked towards a solution and, perhaps most significantly, was very open about the possible outcome.

Whilst Schrödinger’s mathematics is formal and precise and does not bring color to life in an imaginative sense, it is the kind of thing we need if we are to deal with color computationally. Interestingly, in the digital arts we see many examples of color still being selected ‘by eye’, in the traditional sense, or being used as markers of difference and so essentially selected arbitrarily. The computational, systems, analysis and generation of color and color relationships in digital art are less common, although some artists (including one of the reviewers) certainly do this. To them, this formal modeling of color is vital and the problems that are associated with it very real. To use such models in digital art is it useful to have discrete mathematical descriptions, rather than the continuous mathematical formulations seen in these 1920s papers, but that is a relatively small matter to overcome.

A fundamental issue is one that Schrödinger takes very seriously. It is the relationship between color differences according to formal physical models and according to human perception. The scientific view is that perception is distorted and limited in various ways that offer a challenge to finding a reliable mapping between the two, something that we read about in these papers. An artist might turn that issue on its head. Color is something we perceive, and the physical models that so far scientists have developed, based admittedly on the physics of light etc., are struggling to describe it accurately. Either way round it remains a problem. The papers in this book show that Schrödinger was an important figure in history of attempts to solve it. Indeed, we read interesting investigations into the properties of human vision in which he seeks to understand the physical basis for our perception of color and even postulates developments in human evolution that could explain certain characteristics of that perception.

Particularly impressive in all of Schrödinger’s writings presented here is the frank tentative and open approach that he takes. For example, saying “it seems to me that a complete explanation of the subjective color of starlight is provided by” He is often careful in what he claims whilst providing very tightly woven arguments.

For all the positive things that we can remark on in relation to the papers translated here, it is not possible to be so praising of the book itself. The subtitle is Translated with Modern Commentary, but although it is true that the papers are translated, the commentary is fairly brief. Although it is clearly written and does not include mathematics directly, it does assume a certain level of familiarity with the technicalities of the field. The selected papers are collected together and presented in English translations and that is certainly helpful. However, as indicated above, the work is interesting and valuable to non-experts, such as some artists, who might find the mathematics hard going. For this broader readership, an introduction with more explanation and a lay summary of each paper would have helped. An index is another element that would have been helpful but is missing.