Copernicus's Heliograph at Olsztyn -- the 500th Anniversary of a Scientific Milestone

Exactly 500 years ago, Nicolaus Copernicus drew a lattice of lines on a panel above the doorway to his rooms at Olsztyn Castle, then in the Bishopric of Warmia. Although its design has long been regarded as some kind of reflecting vertical sundial, the exact astronomical designation of the lines and related measuring techniques remained unknown. Surprisingly, Copernicus did not refer to his new observational methods in his principal work, \textit{De Revolutionibus}. A data analysis of a 3D model of the panel has, at last, solved the mystery: Copernicus created a new type of measuring device -- a heliograph with a non-local reference meridian -- to precisely measure ecliptic longitudes of the Sun around the time of the equinoxes. The data, 3D model and modeling results of our analysis are open access and available in the form of digital (Jupyter) notebooks

Minimal Assumption Derivation of a Bell-type Inequality

John Bell showed that a big class of local hidden-variable models stands in conflict with quantum mechanics and experiment. Recently, there were suggestions that empirically adequate hidden-variable models might exist which presuppose a weaker notion of local causality. We will show that a Bell-type inequality can be derived also from these weaker assumptions. IntroductionThe EPR-Bohm experimentLocal causalityBell's inequality from separate common causes 4.1 A weak screening-off principle4.2 Perfect correlation and ‘determinism'4.3 A minimal theory for spins4.4 No conspiracyDiscussio

Die unvollendete Sonnenuhr von der Agora der Italiker auf Delos

Only one case of an unfinished ancient sundial can be found in the scientific literature. Found on the Greek island of Delos, it was first reported in 1938, although the sundial was then later considered lost. In our campaign of October 2012, we rediscovered the sundial. Using new and elaborate techniques, we created a 3D model of the sundial, which has enabled us to answer questions concerning its construction principles and the manufacturing processes used. Our first evaluation has revealed that, initially, its creators had intended to construct a cut conical sundial. Its discovery next to a workshop suggests that the sundial was left there in its unfinished state on the destruction of the island’s main town

Die Entasis der Säulen des Pantheon

The diameter of classical columns slightly decreases with height. Vitruvius calls it “entasis” and cites aesthetic reasons for its use already in Greek architecture. However, the exact geometrical shape of the entasis remained unexplained. It was subject to wide speculation even in later times. The large columns at the Porticus of the Pantheon in Rome are made with an entasis. This article describes the exact measurements of their proportion and a method to determine the geometry of the entasis. The Bern Digital Pantheon Model is used as the data source

Hilfeplanung im Jugendamt Landkreis Hildesheim. Eine Arbeitsbroschüre für die Mitarbeiter_innen des Jugendamts-Erziehungshilfe im Landkreis Hildesheim

In der Zeit von Juli 2015 bis September 2017 fand in Zusammenarbeit des Jugendamts-Erziehungshilfe des Landkreises Hildesheim und der Universität Hildesheim das Projekt „Hilfeplanung in den Hilfen zur Erziehung“ statt. Das Projekt hatte zum Ziel, gemeinsame Standards in den einzelnen Arbeitsschritten der Hilfeplanung festzulegen. Die folgende Broschüre stellt die zentralen Diskussionen und Ergebnisse des Projekts dar und gibt somit einen Überblick über die im Projekt erarbeiteten und die für das Jugendamt-Erziehungshilfe konstitutiven Standards im Rahmen des Hilfeplanungsprozesses

Longitude

This study traces the development of the concept of geographical longitude: from the ear- liest known Mesopotamian evidence of geographical concepts through its incorporation into mathematical astronomy and to its transmission to ancient Greek philosophy and scholarship. We show that there is a tight connection between the observation of lunar eclipses and the development of a quantitative representation of terrestrial longitudes. It was not until Ptolemy that geographical longitude was systematically quantified through angular differences. It is demonstrated that the ancient scholars failed in their attempts to determine geographical longitude by astronomical means, and that even certain Syriac texts which specify how to determine longitude using a planispheric astrolabe were unable to resolve this scientific challenge

Causation, Measurement Relevance and No-conspiracy in EPR

In this paper I assess the adequacy of no-conspiracy conditions employed in the usual derivations of the Bell inequality in the context of EPR correlations. First, I look at the EPR correlations from a purely phenomenological point of view and claim that common cause explanations of these cannot be ruled out. I argue that an appropriate common cause explanation requires that no-conspiracy conditions are re-interpreted as mere common cause-measurement independence conditions. In the right circumstances then, violations of measurement independence need not entail any kind of conspiracy (nor backwards in time causation). To the contrary, if measurement operations in the EPR context are taken to be causally relevant in a specific way to the experiment outcomes, their explicit causal role provides the grounds for a common cause explanation of the corresponding correlations.Comment: 20 pages, 1 figur

Machine learning for the history of ideas

The information technological progress that has been achieved over the last decades has also given the humanities the opportunity to expand their methodological toolbox. This paper explores how recent advancements in natural language processing may be used for research in the history of ideas so as to overcome traditional scholarship's inevitably selective approach to historical sources. By employing two machine learning techniques whose potential for the analysis of conceptual continuities and innovations has never been considered before, we aim to determine the extent to which they can enhance conventional research methods. It will amount to a critical evaluation of how the advantages of computational in-breadth analysis could be combined with the merits of traditional in-depth analysis in a philosophically fruitful way. After a brief technical description, the approach will be applied to an example: the conceptual (dis)continuity between medieval and early modern philosophy. All the challenges encountered during development and application will be carefully evaluated. We will then be able to assess whether these tools and techniques present promising extensions to the methodological toolbox of traditional scholarship, or whether they do not yet have the potential for a task as complex as the analysis of philosophical literature. The present investigation can thus be seen as an experiment on how far one can go with current machine-learning techniques in this area of research. In doing so, it provides important insights and guidance for future advances in the field.Peer Reviewe