Wolfgang Liebert

Proper choice of the time delay for the analysis of chaotic time series

It is shown that the first minimum of the logarithm of the generalized correlation integral C1(τ) provides an easily evaluable criterion for the proper choice of the time delay τ that is needed to reconstruct the trajectory in phase space from chaotic scalar time series data.

Optimal embeddings of chaotic attractors from topological considerations

Guided by topological considerations, a new method is introduced to obtain optimal delay coordinates for data from chaotic dynamic systems. By determining simultaneously the minimal necessary embedding dimension as well as the proper delay time we achieve optimal reconstructions of attractors. This can be demonstrated, e.g., by reliable dimension estimations from limited data series.

Collingridge’s dilemma and technoscience

Collingridge’s dilemma is one of the most well-established paradigms presenting a challenge to Technology Assessment (TA). This paper aims to reconstruct the dilemma from an analytic perspective and explicates three assumptions underlying the dilemma: the temporal, knowledge and power/actor assumptions. In the light of the recent transformation of the science, technology and innovation system—in the age of “technoscience”—these underlying assumptions are called into question. The same result is obtained from a normative angle by Collingridge himself; he criticises the dilemma and advances concepts on how to keep a technology controllable. This paper stresses the relevance of the dilemma and of Collingridge’s own ideas on how to deal with the dilemma. Today, a positive interpretation of technoscience for effective TA is possible.ZusammenfassungAusgangspunkt ist das so genannte Collingridge Dilemma, das TA vielfach herausgefordert hat und noch immer herausfordert. Das Dilemma wird analytisch rekonstruiert. Wir führen drei zugrunde liegende Annahmen aus: eine zeitliche, eine wissensbezogene und eine akteurs- und einfluss-orientierte. Wird der derzeitige Wandel des Wissenschafts-, Technik- und Innovationssystems—im Zeitalter von Technoscience—mit betrachtet, dann zeigt sich, dass die zugrunde liegenden Annahmen nicht mehr gut begründbar sind. Das vorliegende Papier zeigt, dass dennoch die Überlegungen Collingridges, wie mit dem Dilemma umgegangen werden kann, für heutige TA-Debatten relevant bleiben und dass eine positive Interpretation von Technoscience für die Möglichkeit von effektiver TA gegeben ist.RésuméLe dilemme de Collingridge porte sur l’un des paradigmes les plus établis et qui pose de réels défis à l’évaluation des choix technologiques (TA). Ce document vise à reconstruire le dilemme de manière analytique et à expliquer trois suppositions sous-jacentes: une temporelle, une basée sur la connaissance et enfin une basée sur l’acteur et le pouvoir. A la lumière des récentes transformations du système de la science, de la technologie et de l’innovation—à l’âge de la technoscience—ces suppositions sous-jacentes sont remises en question. Collingridge lui-même est arrivé à ce résultat sous un angle normatif; il a critiqué le dilemme et propose des concepts sur la manière de garder la technologie contrôlable. Ce document souligne l’importance du dilemme et des propres idées de Collingridge sur la manière de traiter ce dilemme. Une interprétation positive de la technoscience pour une TA efficace est possible aujourd’hui.

Preparing to Understand and Use Science in the Real World: Interdisciplinary Study Concentrations at the Technical University of Darmstadt

In order to raise awareness of the ambiguous nature of scientific-technological progress, and of the challenging problems it raises, problems which are not easily addressed by courses in a single discipline and cannot be projected onto disciplinary curricula, Technical University of Darmstadt has established three interdisciplinary study concentrations: “Technology and International Development”, “Environmental Sciences”, and “Sustainable Shaping of Technology and Science”. These three programmes seek to overcome the limitations of strictly disciplinary research and teaching by developing an integrated, problem-oriented approach. For example, one course considers fundamental nuclear dilemmas and uses role-playing techniques to address a controversy in the area of nuclear security. At the same time, incorporating interdisciplinary teaching into a university that is organized around mono- or multi-disciplinary faculties also poses a number of challenges. Recognition in disciplinary curricula, and appropriate organizational support and funding are examples of those challenges. It is expected that science and engineering students, empowered by such interdisciplinary study programmes, will be better prepared to act responsibly with regard to scientific and technological challenges.

Competition and conflicts on resource use

Preamble.- Part I: Role of Resources for International Conflict Constellations.- Part II: Conflicts on Fossil and Nuclear Energy Supply.- Part III: Perspectives of Strategic Material Resources Management.- Part IV: Sustainable Solutions for Resource Consumption.- Part V: Water Conflict Prevention by Water Resource Management.- Part VI: Resource Aspects in Renewable Energy Technologies.

The German plutonium balance, 1968–1999

Dr. Martin Kalinowski works in the International Data Center of the Provisional Technical Secretariat of the Preparatory Commission for the Comprehensive Test Ban Treaty Organization (CTBTO), Vienna, Austria. He is the editor of Global Elimination of Nuclear Weapons (Baden-Baden: Nomos Verlag, 2000). Dr. Wolfgang Liebert and Dr. Silke Aumann work in the Interdisciplinary Working Group on Science, Technology, and Security (IANUS) at Darmstadt University of Technology, Darmstadt, Germany.

Nuclear Fusion Power for Weapons Purposes

Fusion reactors have the potential to be used for military purposes. This article provides quantitative estimates about weapon-relevant materials produced in future commercial fusion reactors and discusses how suitable such materials are for use in nuclear weapons. Whether states will consider such use in the future will depend on specific regulatory, political, economic, and technical boundary conditions. Based on expert interviews and the political science literature, we identify three of these conditions that could determine whether fusion power will have a military dimension in the second half of this century: first, the technological trajectory of global energy policies; second, the management of a peaceful power transition between rising and declining powers; and third, the overall acceptance of the nuclear normative order. Finally, the article discusses a few regulatory options that could be implemented by the time fusion reactors reach technological maturity and become commercially available; such research on fusion reactor safeguards should start as early as possible and accompany the current research on experimental fusion reactors.

Nuclear Fuel Chain: Uranium Resources and Associated Risks

Already in the 1950s King Hubbert pointed out the limited availability of fossil and uranium resources for energy usage. Many agree that reserves of oil will become scarce within this century and that to meet the world’s increasing demand for energy while simultaneously mitigating climate change, carbon intensive fossil fuels must be replaced by decarbonized energy sources. Thus, at least theoretically, nuclear energy could play a relevant role in the future energy system. However, uranium still is the main source material for all nuclear programmes world-wide and one should carefully examine its future availability before investing in a nuclear renaissance. Furthermore, uranium enrichment, a technology necessary to fuel today’s nuclear reactors, can be used to produce highly enriched uranium for nuclear weapons. This sensitive technology is already a cause of conflict in the international arena due to the fear that additional states get access to the bomb (nuclear proliferation).

Entwicklung und Einsatz der Atombombe

»What has been done is the greatest achievement of organized science in history«. Diese Aussage mit Bezug auf die Entwicklung der Atomwaffe findet sich in der Erklarung des US-Prasidenten Harry Truman (Cantelon et al. 1991, 66), die am 6. August 1945, kurz nach Abwurf der ersten Bombe auf Hiroshima, veroffentlicht wurde. Der wissenschaftlich-technische Erfolg bislang beispielloser, planvoller Forschung ist aber zu kontrastieren mit den politischen Folgen und der ethischen Problematik der Entwicklung und des Einsatzes der Atombombe. Mit der Bombe wurde die Debatte uber die Verantwortung der Wissenschaft eroffnet. Diese erste grose Debatte wird bis heute fortgefuhrt und fokussiert bereits wie in einem Brennglas den modernen technikethischen Diskurs.

Dual-use-Forschung und -Technologie

In den letzten Jahren kann man immer wieder in offentlichen Medien uber die Dual-use-Problematik lesen. Dann geht es zumeist um die Notwendigkeit von Exportkontrollmasnahmen fur nukleare, chemische, biologische oder Raketen ermoglichende Technologien oder deren Komponenten, die fur die Herstellung von Massenvernichtungswaffen geeignet sind. In Bezug auf biotechnologische Forschung besteht Sorge, dass der wissenschaftliche Fortschritt, dessen grundlegende oder anwendungsbezogene Erkenntnisse fur neue medizinische Therapien oder pharmazeutische Produkte genutzt werden sollen, ebenfalls — ob nun unbeabsichtigt oder gezielt — auch zu neuartigen oder in ihrer Wirkung verbesserten Biotoxinen fuhren konnen, die in Waffen Anwendung finden konnten. Stets wird dabei Dual-use gemunzt auf Forschungsanstrengungen und Technologien, fur die eigentlich zivile Anwendungen vorgesehen waren, die aber auch fur militarische Zwecke genutzt werden konnen (NRC 2003, 14). Militarisch relevante Technologien konnen ›in die falschen Hande‹ gelangen, daher musse ihr ›Missbrauch‹ insbesondere durch strikte Exportkontrollen so weit wie moglich vermieden werden.