On Logical Depth and the Running Time of Shortest Programs

The logical depth with significance $b$ of a finite binary string $x$ is the shortest running time of a binary program for $x$ that can be compressed by at most $b$ bits. There is another definition of logical depth. We give two theorems about the quantitative relation between these versions: the first theorem concerns a variation of a known fact with a new proof, the second theorem and its proof are new. We select the above version of logical depth and show the following. There is an infinite sequence of strings of increasing length such that for each $j$ there is a $b$ such that the logical depth of the $j$th string as a function of $j$ is incomputable (it rises faster than any computable function) but with $b$ replaced by $b+1$ the resuling function is computable. Hence the maximal gap between the logical depths resulting from incrementing appropriate $b$'s by 1 rises faster than any computable function. All functions mentioned are upper bounded by the Busy Beaver function. Since for every string its logical depth is nonincreasing in $b$, the minimal computation time of the shortest programs for the sequence of strings as a function of $j$ rises faster than any computable function but not so fast as the Busy Beaver function.Comment: 12 pages LaTex (this supercedes arXiv:1301.4451

Post-colonial legacies in Seville: traces of the Ibero-American Exhibition, 1929

The Ibero-American Exhibition (IAE), celebrated in Seville in 1929, has endured and survived a number of periods which have affected not only its use, but also its meaning. The aim of this paper is to evaluate the context in which the IAE was designed, highlighting connections with broader international understandings: first, regarding the creation of new identities during the Spanish post-colonial period (in both Latin America and Spain); second, the organisation of international exhibitions, which aimed at showcasing advances (technological and colonial), as well as the construction of colonial identities. These two conditions have a clear impact in the construction and delivery of the IAE project, which can be traced on the legacy that the Ibero-American Exhibition has had in Seville, especially through its pavilions, built as permanent structures. The built environment in Seville will serve to evaluate how it was used in the past, in the present, and how it could become a future environment for a further understanding of the relationships between Spain and its former colonies in Latin America

Experiencing memory museums in Berlin. The Otto Weidt Workshop for the Blind Museum and the Jewish Museum Berlin

This article explores memory studies from the audience’s perspective, focusing on the perception of Holocaust narratives in two museums in Berlin. This research builds on and contributes to a number of emerging issues in memory studies, tourism perception and museum design: the debate on experiential authenticity, Dark Tourism, and the analysis of memory studies from the perspective of the user. The main data facilitating the analysis is based on responses shared on TripAdvisor; the case studies being the Otto Weidt Workshop for the Blind Museum and the Jewish Museum Berlin. The analysis of these museums, focusing on their narratives, design features and comments from visitors, will highlight a potential shift from the traditional object-focused museum, to a phenomenological subject focused one. It will be argued, then, that the understanding and consumption of authenticity encompasses a very flexible definition, not only based on the nature of the objects exhibited, but on the production of authentic experiences