33 research outputs found
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
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
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
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
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