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| Accesso online: | https://www.research.unipd.it/handle/11577/3425389 |
| Autore principale: | Roberti, Valentina.
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| Titolo: | Maxwell and Helmholtz and the birth of the theory of colour / Valentina Roberti. |
| Note: | Tesi di dottorato in Fisica, XXXI ciclo, Università degli studi di Padova, 2018 Tutor: Giulio Peruzzi |
| Abstract: | The present research study offers an overall picture of Maxwell and Helmholtz's fundamental contributions to the science of colour, which constitute the basis of modern colorimetry, colour photography and colour metrics. The first main part of the dissertation, which embraces chapter 2 and chapter 3, is dedicated to a chronological account of their pivotal achievements on the subject, giving special focus on how they interpreted and elaborated over the course of the years Newton and Young's theories of colour, which represent a fundamental starting point for both Maxwell and Helmholtz's research in the field. Among their key contributions reported in the present work, it is worth mentioning that the two scientists clarified, for the first time and independently from one another, the distinction between additive and subtractive colour mixing, eliminating definitively Newton's confusion between optical and pigment mixture of colours (confusion still existing in Young's famous works and up to the solution provided by Forbes, Maxwell and Helmholtz). Moreover, they adopted Newton's analogy of the centre of gravity to predict the outcome of optical mixture of light and eliminated the arbitrary choice of the number of primary colours. Among Maxwell and Helmholtz's crucial experiments, deeply described and analysed in the text and from which they could obtain their colour diagrams (an equilateral triangle for Maxwell and a truncated hyperbola for Helmholtz), it is worth to cite the V-shaped slit experiment performed by Helmholtz, the famous Maxwell's colour top, Helmholtz's colour mixing experiment to detect directly pairs of complementary colours and Maxwell's colour box. From an analysis of the obtained colour diagram, Helmholtz expressed pivotal considerations on the geometry of colour space: colour space could not be uniform, i.e. equal distances did not correspond to equal perceptual difference. Helmholtz's reflections introduce the second main part of the dissertation, composed of chapters 4 and 5, dedicated to the work undertaken by Helmholtz on the geometry of colour space, which he interpreted, such as Riemann before him, as non-Euclidian. This second part begins with a deep analysis of the studies on colour and colour perception carried out by Helmholtz's collaborators König, Dieterici and Brodhun, working in his laboratory in Berlin. Their crucial results constitute Helmholtz's starting point for the definition of his line element in colour space, which he elaborated following ideas borrowed from the new-born field of psychophysics. He extended the one-dimensional Weber-Fechner law of psychophysics to a complex of three dimensions, such as the colour space for subjects with normal colour vision. Helmholtz's mathematical treatment and related considerations are contained in three papers, published between 1891 and 1892, of which a partial English translation, with related analysis, is provided. To conclude, in chapter 6 a short overview of the development of colorimetry, after Maxwell and Helmholtz's works, can be found [...] |
| Altri autori: | Peruzzi, Giulio, 1960-
Università degli studi (Padova). |
| Collezione tematica: | Tesi di dottorato di interesse storico-scientifico (Italia).
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| 000001083121 |
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