A leap of faith: Abbott, Bellamy, Morris, Wells and the fin-de-siècle route to utopia

In the great surge of utopian writing that was produced during the fin de siècle, Edward Bellamy, William Morris and H. G. Wells among others imagined utopias that were global in scale and located in the future. They made a radical shift in utopian thinking by drawing a historical trajectory between their own time and that of utopia. A contemporaneous text that might seem to have little in common with these “historical utopias” is E. A. Abbott’s Flatland: A Romance of Many Dimensions (1884). This article shows how closely its ideas can bring into focus those of the specifically utopian texts being written alongside it. Flatland breaks the conventions of utopian narrative by removing the reader from the narrative plane and situating us instead in the “impossible” third dimension. The “leap of faith” necessary for scientific or religious revelation is simultaneously invoked as the route to utopia

Shape-from-Template dans Flatland

International audienceLe Shape-from-template (SfT) consiste en la reconstruction d'un objet déformable observé sur une image grâce à sa forme de référence. Le 2DSfT est le cas usuel du SfT où la forme de référence est une surface plongée dans un espace 3D et l'image une projection 2D. Nous présentons le 1DSfT, un nouveau cas du SfT où la forme de référence est une courbe plongée dans un espace 2D et l'image une projection 1D. Nous nous concentrons sur les déformations isométriques, pour lesquelles le 2DSfT est un problème bien posé. À travers une étude théorique du 1DSfT avec projection perspective, nous montrons que ce cas est lié au 2DSfT, mais qu'il possède des propriétés différentes : (i) le 1DSfT ne possède pas de solution à la fois exacte et locale et (ii) le 1DSfT ne possède pas de solution unique, mais un nombre fini d'au moins deux solutions. Ensuite, nous proposons deux méthodes d'initialisation convexes: une solution locale et analytique basée sur la linéarité infinitésimale et une solution globale basée sur l'inextensibilité. Nous montrons comment le raffinement non-convexe peut être implémenté et comment l'isométrie peut être contrainte avec une nouvelle paramétrisation basée sur l'angle. Enfin, notre méthode est testée sur des données simulées et réelles

Four-dimensional geometry applied to video game design

This project aimed to develop and evaluate "Realm Paradox," a video game designed to introduce the concept of the 4th dimension to a broad audience. The game had educational components and went through a rigorous playtesting procedure to see how well it will help players better grasp the fourth dimension. Through the analysis of playtest data and participant feedback, it was determined that the game successfully improved players' comprehension of the 4th dimension. Overall, "Realm Paradox" demonstrated its potential as an engaging and educational tool for exploring higher dimensional concepts

Recasting the Discarded Image: C. S. Lewis on the Modern Side

Excerpt: It is then something of a simplification to see Lewis as a “dinosaur” out of step with his own time. As a modern apologist he managed to retain the framework of the multi-level medieval model, but only with the assistance of credible modern sources that challenge the hegemony of the one-story “developmental” model of evolutionary naturalism. The threetier hierarchy – material, organic, spiritual – that arose out of the turnof- the-century revolt against positivism provided a means of exposing the reductive tendencies of the naturalistic orientation and affirming a traditional conception of the Supernatural that transcends natural order. The idea of higher dimensional space not only offered a way to illustrate this three-tier hierarchy but also to imagine an even more variegated hierarchy of “Natures piled upon Natures.” It also opened the door to the vision of alternative time-tracks and parallel worlds, a multiverse that expands the frontiers of the cosmic order beyond anything conceived by our premodern forebears

Cubic membranes: a legend beyond the Flatland* of cell membrane organization

Cubic membranes represent highly curved, three-dimensional nanoperiodic structures that correspond to mathematically well defined triply periodic minimal surfaces. Although they have been observed in numerous cell types and under different conditions, particularly in stressed, diseased, or virally infected cells, knowledge about the formation and function of nonlamellar, cubic structures in biological systems is scarce, and research so far is restricted to the descriptive level. We show that the “organized smooth endoplasmic reticulum” (OSER; Snapp, E.L., R.S. Hegde, M. Francolini, F. Lombardo, S. Colombo, E. Pedrazzini, N. Borgese, and J. Lippincott-Schwartz. 2003. J. Cell Biol. 163:257–269), which is formed in response to elevated levels of specific membrane-resident proteins, is actually the two-dimensional representation of two subtypes of cubic membrane morphology. Controlled OSER induction may thus provide, for the first time, a valuable tool to study cubic membrane formation and function at the molecular level

Fuel Efficient Computation in Passive Self-Assembly

In this paper we show that passive self-assembly in the context of the tile self-assembly model is capable of performing fuel efficient, universal computation. The tile self-assembly model is a premiere model of self-assembly in which particles are modeled by four-sided squares with glue types assigned to each tile edge. The assembly process is driven by positive and negative force interactions between glue types, allowing for tile assemblies floating in the plane to combine and break apart over time. We refer to this type of assembly model as passive in that the constituent parts remain unchanged throughout the assembly process regardless of their interactions. A computationally universal system is said to be fuel efficient if the number of tiles used up per computation step is bounded by a constant. Work within this model has shown how fuel guzzling tile systems can perform universal computation with only positive strength glue interactions. Recent work has introduced space-efficient, fuel-guzzling universal computation with the addition of negative glue interactions and the use of a powerful non-diagonal class of glue interactions. Other recent work has shown how to achieve fuel efficient computation within active tile self-assembly. In this paper we utilize negative interactions in the tile self-assembly model to achieve the first computationally universal passive tile self-assembly system that is both space and fuel-efficient. In addition, we achieve this result using a limited diagonal class of glue interactions

Size-Dependent Tile Self-Assembly: Constant-Height Rectangles and Stability

We introduce a new model of algorithmic tile self-assembly called size-dependent assembly. In previous models, supertiles are stable when the total strength of the bonds between any two halves exceeds some constant temperature. In this model, this constant temperature requirement is replaced by an nondecreasing temperature function $\tau : \mathbb{N} \rightarrow \mathbb{N}$ that depends on the size of the smaller of the two halves. This generalization allows supertiles to become unstable and break apart, and captures the increased forces that large structures may place on the bonds holding them together. We demonstrate the power of this model in two ways. First, we give fixed tile sets that assemble constant-height rectangles and squares of arbitrary input size given an appropriate temperature function. Second, we prove that deciding whether a supertile is stable is coNP-complete. Both results contrast with known results for fixed temperature.Comment: In proceedings of ISAAC 201