Liesbeth de Wreede
Snellius's exactification of measurements
Willebrord Snellius (1580—1626), professor of mathematics at Leiden University in the Dutch Republic, is one of the most well-known scientists of the Dutch `Golden Age'. Until now, his fame was mainly based on isolated contributions to the mathematical sciences, such as his invention of the optical Law of Refraction, his development of the method of triangulation and his formula for the area of a cyclic quadrilateral. In my thesis, I argue that his position in his own time has to be studied in order to assess his historical significance. His mathematical oeuvre must be considered as a whole, the fruit of a programme to elevate the mathematical sciences to the level of (humanist) scholarship. An important aspect of this programme is Snellius's concern with exactness, which can be understood both as the demarcation of proper concepts in mathematics and as the degree of precision of measured values. In my talk, I will discuss some examples from mixed mathematics to substantiate my claims.
Sébastien Maronne
Descartes' ovals in Excerpta Mathematica
and the method for normals
As far as I know, we find the first and only one occurence, before La Géométrie (1637), of Descartes' method for normals in a sequence of texts of the Excerpta Mathematica dealing with ovals and dated by Tannery before 1630.
We can think that the context of the method for normals could has been given, at least partly, by dioptrics questions, as we will try to show in this study where we will examine precisely some of these fragments about ovals and the texts of La Géométrie which followed. We suggest on the other hand a reconstruction of the solution which could have been given by Descartes to the inverse normals problem which leads to ovals, yet founded on the method of normals which appears in La Géométrie.
Marc van der Poel
Latin as a vehicle for scientific discourse in the 17th and 18th centuries
In my paper I will first present some historical facts to explain why Latin was still commonly used in scholarly discourse during the 17th and 18th centuries. Secondly, I will briefly discuss the style of a few Latin texts written by Willebord Snellius and Tobias Mayer. In accordance with the theme of the symposium, I will attempt to formulate a few thoughts on the question of whether Latin was a suitable, i.e. sufficiently 'exact', language for the expression of scientific ideas in the 17th and 18th centuries.
Rob van Gent
Measuring the Stars for a New Sky
Up to the end of the 16th century all Western star atlases and celestial globes depended almost exclusively on the star catalogue embedded in Ptolemy's Almagest for the portrayal of the heavens. Within a short span of only a few years centred around 1600 several new star catalogues became available mapping not only the northern hemisphere in greater precision but also covering for the first time the entire southern hemisphere. In my paper I will discuss the genesis of these new star catalogues and compare their internal accuracy and completeness.
By the scientific revolution modern physics and mathematics were borne. At the same time the phenomenon of vulgarization and popularization of the new natural philosophy marked the scientific culture of the european republic of letters.
During the last three decades a lot of research was done to understand this phenomenon better. But the role of mathematics within this popular scientific culture was not studied in detail yet. Considering the importance of mathematics for the modern natural sciences, questions of their role within the popular scientific culture and their significance for the interested laymen come up.
In my lecture I will address some aspects of these questions. The focus of my discussion will lay on the 18th century. In this era Noël Regnault (1683—1762) wrote in Les entretiens physiques d'Ariste et d'Eudoxe ou la physique nouvelle en dialogues (1729) that mathematics make physics inaccessible for beginners and tried to avoid them; in contrast the writer Isabelle de Charrière (1740—1805), excluded from the scientific institutions, studied conic sections for the better understanding of Newtons physics.
Steven Wepster
On Longitude and Lunars: the other half of the story
The inability of mariners to establish their geographical longitude was felt as a pressing problem from early in the sixteenth century onwards. In 1714, British Parliament offered a prize for a `practicable and useful' solution to the problem. 51 years later they recognised that two methods had been submitted to them that were worthy of a prize. One method relied on a timekeeper (clock) that kept accurate time at sea, such as John Harrison had constructed recently. The other method, that of lunar distances, needed accurate predictions of the motion of the moon, and these were provided by Tobias Mayer's lunar tables.
The history of the chronometer method has attracted much more attention than that of the lunar distance method, although the latter was virtually the only `practicable and useful' method until the middle of the 19th century, when timekeepers could be produced for affordable prices. My talk will focus on the history, the impact, and the difficulties of the lunar distance method.