Frozen time in hyperbolic spacetime motion

According to the Lorentz transformation and clearly seen from the Minkowski diagram, hyperbolic spacetime motion of a test object relative to a stationary reference frame can be performed in a specific way such that time becomes frozen in the moving frame of the test object. In that case, time can be arranged to become frozen even at moderate relativistic velocities, in contrast to the minute traditional relativistic time dilation at such velocities. An appendix gives a simple illustration in Minkowski form of how time in a frame in hyperbolic motion can become frozen to a complete standstill relative to a stationary frame. (Published in Phys. Scr. 84 (2011) 035004) In addition to the paper, the arXiv file also contains a discussion of Frequently Asked Questions from readers. Further questions not adequately dealt with in the existing FAQ are welcome.Comment: Paper (5 pages, 5 figures) plus FAQ (12 pages, 9 figures), FAQ #2a revised and extende

Demographic development in North and South - global trends and challenges for education

After looking at today\u27s demographic situation, this paper will attempt to demonstrate the need for lifelong learning. It will briefly review the current world situation in terms of ageing, health, poverty and hunger, urbanisation and migration. It will then show that lifelong learning, in particular when conceived as an overarching sector-wide approach, can enable individuals to meet the challenges in their private lives and in social and work environments in today\u27s fast-changing world. The importance of literacy and adult learning and education - as the foundation and major component of lifelong learning - will be underlined. (DIPF/Orig.)In diesem Artikel wird versucht die Notwendigkeit des lebenslangen Lernens aufzuzeigen, indem die heutige demographische Situation betrachtet wird. Es wird kurz die derzeitige weltweite Lage im Bezug auf Alterung, Gesundheit, Armut und Hunger, Urbanisierung und Migration dargestellt. Es wird gezeigt, dass lebenslanges Lernen eine allumfassende Methode ist, die Personen dazu befähigen kann, in einer sich schnell wandelnden Welt zu leben und zu arbeiten. Die Bedeutung der Alphabetisierung und Erwachsenenbildung - als Grundlage des lebenslangen Lernens - und der Bedarf der Entwicklung von Schlüsselkompetenzen werden betont. Es wird für eine dringend notwendige Anerkennung und Bestätigung der formellen und informellen Bildung plädiert. (DIPF/Orig.

Lorentz-covariant quantum transport and the origin of dark energy

A possible explanation for the enigma of dark energy, responsible for about 76 % of the mass-energy of the universe, is obtained by requiring only that the rigorous continuity equation (the Boltzmann transport equation) for quanta propagating through space should have the form of a Lorentz-covariant and dispersion-free wave equation. This requirement implies (i) properties of space-time which an observer would describe as uniform expansion in agreement with Hubble's law, and (ii) that the quantum transport behaves like in a multiplicative medium with multiplication factor = 2. This inherent, essentially explosive multiplicity of vacuum, thus caused by the requirement of Lorentz-covariance, is suggested as a potential origin of dark energy. In addition, it is shown (iii) that this requirement of Lorentz-covariant quantum transport leads to an apparent accelerated expansion of the universe. In addition to the updated manuscript for Phys. Scr., the arXiv file also contains a discussion of about a dozen Frequently Asked Questions from readers. Further questions not adequately dealt with in the existing FAQ are welcome.Comment: Paper (8 pages, 9 figures) plus Frequently Asked Questions (5 pages

Factors for success in Swedish biogas

The energy sector of modern time is currently faced with several challenges. These are both production oriented and environmental oriented in nature. The energy of the future is intended to support an increasing demand while at the same time reduce its environmental affection. This stresses a development towards production methods of renewable energy. Among the existing methods, biogas is presented as an attractive alternative. Further, biogas is also perceived as an attractive business concept within the agricultural sector, since this sector contains a good supply of substrate that can be used in the biogas process. As an effect, biogas would enable renewable energy production in combination with biological waste treatment and thus there are several environmental benefits with using this method. The potential for producing biogas in Sweden today, is relatively unexploited. Studies shows that there still is a large potential for producing biogas in Sweden, where a large share is represented by agricultural products. This study aims at identifying factors that are important for a further development in agricultural based biogas production. The study have been based on interviews with 31 agricultural biogas producers, where the findings has been analyzed using resource based view and Diffusion theory. The study has shown that agricultural biogas production in Sweden needs to develop in order to become competitive. To enable such a development, factors such as support from external parties and investments in technological development is viewed as important.Energisektorn är i dagsläget en sektor som innehåller flera problem. Dels finns det miljömässiga som produktionsmässiga problem. Framtidens energi ska dels kunna bistå en ökande population med energi samtidigt som den ska minska sin miljöpåverkan. Detta kommer att kräva nya metoder för att producera energi. Biogas presenteras som ett attraktivt alternativ för att producera förnyelsebar energi. Vidare är biogas ett intressant affärskoncept inom jordbrukssektorn, då det finns god tillgång till substrat som kan användas i biogas processen. Effekten av biogas skulle innebära produktion av förnyelsebar energi kombinerat med biologisk avfallshantering. Således finns det flera miljömässiga effekter med biogas produktion. Potentialen för att producera biogas är i dagsläget i relativt liten i Sverige. Studier visar att det finns stor potential att utöka produktionen av biogas, där en stor andel beräknas komma från jordbruks produkter. Denna studie syftar till att identifiera framgångs faktorer för den Svenska jordbruksbaserade biogas produktionen, för att utforska möjligheterna till en fortsatt utveckling. Studien baseras på intervjuer från 31 jordbruksbaserade biogas producenter där insamlad data har analyserats med resursbaserad teori och spridnings teori. Studien visar att jordbruksbaserad biogas produktion är i behov av utveckling för att bli konkurrenskraftigt. För att möjligöra en sådan utveckling, pekas faktorer såsom inverkan från externa parter samt vidare satsningar i teknik ut som viktiga

Logarithmic good reduction, monodromy and the rational volume

Let $R$ be a strictly local ring complete for a discrete valuation, with fraction field $K$ and residue field of characteristic $p > 0$. Let $X$ be a smooth, proper variety over $K$. Nicaise conjectured that the rational volume of $X$ is equal to the trace of the tame monodromy operator on $\ell$-adic cohomology if $X$ is cohomologically tame. He proved this equality if $X$ is a curve. We study his conjecture from the point of view of logarithmic geometry, and prove it for a class of varieties in any dimension: those having logarithmic good reduction.Comment: final version, to appear in Algebra & Number Theor