Time troubles: clocks and practices of precision in early eighteenth-century observatories.

In 1736/37, Joseph-Nicolas Delisle and Jean Jacques Dortous de Mairan communicated about the clocks that would enable the astronomers of the Saint Petersburg observatory to make highly exact observations. Delisle, who was in charge of the Saint Petersburg observatory, demanded old-fashioned clocks in the manner of Huygens. Mairan, well-versed in astronomy himself, recommended equation clocks. The article uses these seemingly inappropriate preferences to discuss eighteenth-century notions of accuracy and precision in clocks. It analyses the multiple factors that influenced expectations regarding the performance of timekeeping instruments, and draws attention to handling and monitoring practices. The latter reflected the individual user's purposes and experience, but also affected the clocks' going. Furthermore, the article presents the result of a statistical analysis, which serves to evaluate the historical performance of the Saint Petersburg observatory clocks and provides a foil against which Delisle's judgement of them is examined.

Directions of precision: George Graham's instructions for his pendulum astronomical clocks.

In the 1720s two Jesuit astronomers working at the court of King João V of Portugal, in Lisbon, received several instruments produced by the best makers in London, Paris and Rome. With the crucial help of the Portuguese diplomatic network contacts with academies, savants and instrument makers were established, seeking technical advice and the best astronomical instruments available at the time. It was in this context that in April 1726 a set of Latin instructions accompanying pendulum clocks made by George Graham were dispatched from London to Lisbon. These unpublished instructions are now preserved in the papers of Giovanni Battista Carbone, one of these Jesuit astronomers, offering a significant window into the procedures and technical details involved in the setting, operation and transport of Graham's astronomical clocks. In this paper, I will not only discuss this important document in the framework of Graham's contributions to astronomy and horology, but also in the perspective of the search for accuracy.

Searching for precision: Lorenz Eichstadt's Tabulae harmonicae coelestium motuum (Stetin 1644) and astronomical prediction after Kepler.

In the century between the creation of the first large, European astronomical observatory by Tycho Brahe in the 1580s and the national observatories of France and England in the 1660-1670s, astronomers constructed ever more sets of tables, derived from various geometrical and physical models, to compute planetary positions. But how were these tables to be evaluated? What level of precision or accuracy should be expected from mathematical astronomy? In 1644, the Stetin astronomer and calendar-maker Lorenz Eichstadt published a new set of tables, mostly cobbled together from earlier tables, which include a running commentary on how his tables might be expected to match 'observed' planetary positions. His earlier works also often display a rhetoric of 'exactitude' and 'error'. Eichstadt thus offers a case study of explicit discussions of 'precision' in mid-seventeenth astronomy. Although some tables could generate positions to arcseconds, Eichstadt argued that a regime of five arcminutes should be enough for most table users who were, presumably, computing horoscopes.

The mule on the Mount Wilson trail: George Ellery Hale, American scientific cosmology, and cosmologies of American science.

This article explores the relation between two different modes of cosmology: the social and the scientific. Over the twentieth century, scientific understandings of the dimensions and operations of the physical universe changed dramatically, significantly prompted by astronomical and astrophysical research undertaken at the Mount Wilson Observatory in Pasadena, California. Could those understandings be readily translated into social theory? Studies across a range of disciplines have intimated that the scientific cosmos might be less essential to the worlds of meaning and belonging that people and communities compose around themselves than more local and relational models of an ordered whole. The article applies that proposition to the Mount Wilson Observatory itself, arguing that the observatory's founder, George Ellery Hale, and his acolytes were deeply invested in practices of terrestrial place-making, the politics of belonging, and the cadences of civilizational time as applied to their city and its region. Moreover, they struggled to construct a philosophy integrating the cosmos they were seeking to fix at home with the contortions and careering trajectories of the universal whole.

'Si te omnimoda delectat precisio': early astronomical instruments with scales and the multiple meanings of precision in the sixteenth century.

This paper explores the various meanings of precision during the early modern period in Europe. In contrast with existing literature focused on assessing the precision of early instruments, this study delves into the intended significance of the term 'precision' as understood by historical figures such as J. Stöffler, P. Nunes or F. Mordente. By analysing a selection of instruments equipped with scales, both in their physical form and as they are described in instrument texts, several facets of precision emerge. Some findings demonstrate that the precision of scales can be enhanced through corrections obtained from tables. In other cases, visual estimation is substituted with a method for obtaining values of multiple sexagesimal places. Furthermore, certain instruments designed to represent theoretical concepts achieve greater precision by incorporating the most intricate details of these notions. This investigation into lesser-known meanings of precision underscores the need of comprehensively exploring the concepts, the practices and the terminology surrounding precision that were in use over the fifteenth and sixteenth centuries.

"All manner of gymnastic evolutions" for science: Dorothea Klumpke (1861-1942) and a life in astronomical research.

In this article, the extraordinary life of the astronomer Dorothea Klumpke (1861-1942) is described in detail for the first time, focussing on the four phases of her career, in which she researched various astronomical questions both as an amateur and as an employee of an observatory and as one half of a couple in science. For this reason, Klumpke's biography provides insights into the cornucopia of research approaches in astronomy at the time, in which professional and amateur astronomers explored the heavens in observatories, on field trips to exotic countries, in their own backyards, or aboard hot air balloons, using telescopes, gazing through the lenses of cameras and spectroscopes, or based on mathematical reasoning. By comparing her life to biographies of other contemporary women, including Klumpke's sisters, among them the famous neurologist Augusta Klumpke-Déjerine, the criteria that women had to fulfill in order to pursue an academic career in the long nineteenth century will be discussed at the same time. In this, particular attention will be paid to factors over which women themselves had no influence, also to show that before the middle of the twentieth century, many stars had to align in order to have such an unusual career as Dorothea Klumpke.

Machine learning-based spatial data development for optimizing astronomical observatory sites in Indonesia.

Astronomical observatory construction plays an essential role in astronomy research, education, and tourism development worldwide. This study develops siting distribution scenarios for astronomical observatory locations in Indonesia using a suitability analysis by integrating the physical and atmospheric observatory suitability indexes, machine learning models, and long-term climate models. Subsequently, potential sites are equalized based on longitude and latitude zonal divisions considering air pollution disturbance risks. The study novelty comes from the integrated model development of physical and socio-economic factors, dynamic spatiotemporal analysis of atmospheric factors, and the consideration of equitable low air-pollution-disturbance-risk distribution in optimal country-level observatory construction scenarios. Generally, Indonesia comprises high suitability index and low multi-source air pollution risk areas, although some area has high astronomical suitability and high-medium air pollution risk. Most of Java, the east coast of Sumatra, and the west and south coasts of Kalimantan demonstrate "low astronomical suitability-high air pollution risk." A total of eighteen locations are recommended for new observatories, of which five, one, three, four, two, and three are on Sumatra, Java, Kalimantan, Nusa Tenggara, Sulawesi, and Papua, respectively. This study provides a comprehensive approach to determine the optimal observatory construction site to optimize the potential of astronomical activities.

The increasing effects of light pollution on professional and amateur astronomy.

The starry sky has been a source of inspiration throughout human history. Astronomy has been a common element in all cultures and civilizations, being used to establish calendars, navigate and discover new lands, and drive numerous scientific and technical breakthroughs. This Review discusses how it is becoming increasingly difficult for professional and amateur astronomers to observe the night sky because of light pollution. Artificial light at night, radio interference, and the deployment of satellite constellations are all rapidly increasing and are having adverse impacts on astronomical observations, limiting scientific discoveries, cultural connections to the night sky, and opportunities presented by astrotourism. Potential mitigation strategies to preserve the night sky are discussed.

Representing noise: stacked plots and the contrasting diplomatic ambitions of radio astronomy and post-punk.

Sketched in 1979 by graphic designer Peter Saville, the record sleeve of Joy Division's Unknown Pleasures seemingly popularized one of the most celebrated radio-astronomical images: the 'stacked plot' of radio signals from a pulsar. However, the sleeve's designer did not have this promotion in mind. Instead, he deliberately muddled the message it originally conveyed in a typical post-punk act of artistic sabotage. In reconstructing the historical events associated with this subversive effort, this essay explores how, after its adoption as an imaging device utilized in radio astronomy, the stacked plot gave representation to the diplomacy agendas of two distinct groups. The post-punk reworking of the stacked plot exemplified the ambition of this artistic movement to attack the images associated with social conventions and norms by amplifying their 'semantic noise', and, in so doing, seeking to negotiate a social space for those sharing these subversive goals. Conversely, radio astronomers used the stacked plot to display the presence of interfering radio transmitters in the frequencies exclusively allocated to astronomical research, thus advocating the removal of this electronic noise in the context of international telecommunication negotiations. The article thus shows how the representation of different types of noise through similar images shaped contrasting ambitions in the separate domains of science diplomacy and everyday diplomacy.