Domesticating Light: Standards and Artisanal Knowledge in Early Astrophysics

Astrophysics was born in the nineteenth century as a “New Astronomy” (in the words of Samuel Langley, 1884), a knowledge built primarily by amateurs who explored deep space by studying the Sun, stars and nebulae. They were credible enough to interest physicists who did research on the properties of radiation and hence came to constitute a solid and recognised discipline. The aim of this research is to study the contribution of artisanal knowledge in the construction of this new discipline at two distinct moments. The first, when artisans worked to find a standard to normalise the manufacture of the glass with which the lenses of refracting telescopes were manufactured. The most recognised of these artisans was Fraunhöfer. The second moment occurred when the experience of artisan knowledge enabled the manufacture of instruments that improved the traditional classification of the magnitude of the stars. The search for standards led to an alliance between artisans and scientists during the same period in which spectroscopy was carried out. In this case, a unit of luminous intensity was sought that could serve as a standard to classify the stars by their luminosity. Industries, university laboratories and astronomers interested in solar astronomy (such as Karl F. Zöllner), collaborated with the artisan manufacturers of measuring devices, and gave rise to a paradigmatic case of science and industry transfer.