5-choosability of graphs with crossings far apart

We give a new proof of the fact that every planar graph is 5-choosable, and use it to show that every graph drawn in the plane so that the distance between every pair of crossings is at least 15 is 5-choosable. At the same time we may allow some vertices to have lists of size four only, as long as they are far apart and far from the crossings.Comment: 55 pages, 11 figures; minor revision according to the referee suggestion

Scientific Instruments and Epistemology Engines

This article outlines the gradually changing attitude towards instruments and materials in the philosophy and historiography of science and confronts contemporary revaluations of the material culture of science with Hans-Jörg Rhein- berger's concept of an experimental system and Don Ihde's notion of an epistemology engine

Philosophical Toys Today

The article introduces a thematic issue of the journal Theory of Science that attempts to revive the category of "philosophi- cal toys" - objects and instruments designed for experimental scientific research that simultaneously played crucial role in the creation of the modern visual culture. It claims that to fully understand their nature and the kind of experience philosophical toys induce, it is necessary to situate their origins in eighteenth-century experimental science and aesthetics and proposes to approach them as perceptual and cognitive extensions