Magnetoelectric Jones Dichroism in Atoms

The authors suggest that atomic experiments measuring the interference between magnetic-dipole and electric-field-induced electric-dipole transition amplitudes provide a valuable system to study magnetoelectric Jones effects.Comment: 3 pages, 2 figure

Quantum correlations in position, momentum, and intermediate bases for a full optical field of view

We report an eight-element, linear-array, single-photon detector that uses multiple fibers of differing lengths coupled to a single detector, the timing information from which reveals the position in which the photon was measured. Using two such arrays and two detectors we measure the correlations of photons produced by parametric downconversion, without recourse to mechanical scanning. Spatial light modulators acting as variable focal length lenses positioned between the downconversion crystal and the arrays allow us to switch between measurement of position, transverse momentum, or intermediate bases. We observe the product of the variances of the conditional probabilities for position and momentum to be more than an order of magnitude below the classical limit, realizing a full-field demonstration of the Einstein-Podolsky-Rosen paradox. Such, multistate measurement technologies allow access to the higher information content of the photon based upon spatial modes

The medieval climate anomaly and Byzantium: a review of the evidence on climatic fluctuations, economic performance and societal change

At the beginning of the Medieval Climate Anomaly, in the ninth and tenth century, the medieval eastern Roman empire, more usually known as Byzantium, was recovering from its early medieval crisis and experiencing favourable climatic conditions for the agricultural and demographic growth. Although in the Balkans and Anatolia such favourable climate conditions were prevalent during the eleventh century, parts of the imperial territories were facing significant challenges as a result of external political/military pressure. The apogee of medieval Byzantine socio-economic development, around AD 1150, coincides with a period of adverse climatic conditions for its economy, so it becomes obvious that the winter dryness and high climate variability at this time did not hinder Byzantine society and economy from achieving that level of expansion. Soon after this peak, towards the end of the twelfth century, the populations of the Byzantine world were experiencing unusual climatic conditions with marked dryness and cooler phases. The weakened Byzantine socio-political system must have contributed to the events leading to the fall of Constantinople in AD 1204 and the sack of the city. The final collapse of the Byzantine political control over western Anatolia took place half century later, thus contemporaneous with the strong cooling effect after a tropical volcanic eruption in AD 1257. We suggest that, regardless of a range of other influential factors, climate change was also an important contributing factor to the socio-economic changes that took place in Byzantium during the Medieval Climate Anomaly. Crucially, therefore, while the relatively sophisticated and complex Byzantine society was certainly influenced by climatic conditions, and while it nevertheless displayed a significant degree of resilience, external pressures as well as tensions within the Byzantine society more broadly contributed to an increasing vulnerability in respect of climate impacts. Our interdisciplinary analysis is based on all available sources of information on the climate and society of Byzantium, that is textual (documentary), archaeological, environmental, climate and climate model-based evidence about the nature and extent of climate variability in the eastern Mediterranean. The key challenge was, therefore, to assess the relative influence to be ascribed to climate variability and change on the one hand, and on the other to the anthropogenic factors in the evolution of Byzantine state and society (such as invasions, changes in international or regional market demand and patterns of production and consumption, etc.). The focus of this interdisciplinar

What stories should historians be telling at the dawn of the Anthropocene?

This chapter discusses the ways in which history can contribute to coping with the current planetary crisis. It argues that historians should engage more in interdisciplinary exchange across the humanities-natural sciences divide. Thus they will be able to create historical narratives fitting for the Anthropocene—both in terms of explaining it and shaping our responses to it, in particular to the acute planetary crisis that marks its advent. At the same time, history should not give up its drive to critically dissect and analyse socio-political, economic, cultural and ecological change, contributing to developing balanced and resilient public policy

Quantum correlations measured with multi-pixel detectors

This thesis investigates the measurement of spatial correlations of photon pairs generated through spontaneous parametric down-conversion with single-photon sensitive multi-pixel detectors. A custom designed and fabricated 8£1 fibre array detector for time to position multiplexing was characterised. This detector was then commissioned in an experiment measuring the spatial correlations of photon pairs in position, momentum and intermediate bases. The fibre array measured eight positions simultaneously with one Single-Photon Avalanche Diode, which led to an eight-fold increase in the data acquisition rate compared to traditional experiments, where a single SPAD was scanned across the detection plane. To capture all of the emitted light, an electron-multiplying CCD (EMCCD) camera was used. The spatial correlations were measured for the first time in momentumand position bases with a single-photon sensitive camera. Additionally, over 2500 spatial states were accessed,which, to date, is the highest number of accessed states, using the transverse positions of correlated photon pairs. The detected photon pairs were tested, if they fulfil the requirements of entanglement. The calculated variance product was 1 order of magnitude and almost three orders of magnitude below the classical limit of separability for the fibre array and the EMCCD camera respectively. Finally the image enhancement of using a correlated light source with a noise rejection algorithm was investigated experimentally and theoretically

Climate history of Byzantium at the crossroads

This chapter is meant as a basic introduction to the field of climate history of Byzantium as of AD 2022. After explaining what climate history is, it discusses the source base and the big questions of the field, as well as it outlooks for the future

The School of Nisibis: an ancient religious community?

For the first modern scholars, the School of Nisibis constituted a primitive form of what they believe to be an early university. For this reason the School became known as a “theological academy” and many people still think that the community at Nisibis should be understood as a school similar to our modern institutions of advanced education, The trouble with this view is its anachronism. It can be very deceptive to reduce past cultural phaenomena to what we know from our own times. The aim of this paper is to place the School of Nisibis in the context of similar ancient institutions and thus properly understand its idea of education and the spiritual formation it offered to its disciples.For the first modern scholars, the School of Nisibis constituted a primitive form of what they believe to be an early university. For this reason the School became known as a “theological academy” and many people still think that the community at Nisibis should be understood as a school similar to our modern institutions of advanced education, The trouble with this view is its anachronism. It can be very deceptive to reduce past cultural phaenomena to what we know from our own times. The aim of this paper is to place the School of Nisibis in the context of similar ancient institutions and thus properly understand its idea of education and the spiritual formation it offered to its disciples

O pewnym podejściu do modelowania przydziału środków do zadań w przedsiębiorstwach komunalnych

In this article the assignment problem of vehicles to tasks in municipal services companies in the context of designating the minimum routes of vehicles was presented. The mathematical model of the assignment problem was developed, and proposed a method for solving the assignment problem in municipal services companies. The method consists of two stages i.e. the stage of designating the minimum route consisting of all tasks and the stage of designating individual routes for each vehicle. In the light of considerations indicating individual routes we designate the tasks to the implementation, which is the equivalent of solving the assignment problem. The genetic algorithm for solving the optimization problem presented in the first stage of the method was proposed. Verification of this algorithm confirmed its effectiveness.  W artykule przedstawiono zagadnienie przydziału pojazdów do zadań w przedsiębiorstwach komunalnych w kontekście wyznaczania minimalnych tras jazdy pojazdów. Opracowano model matematyczny zagadnienia przydziału oraz zaproponowano metodę rozwiązującą zagadnienie przydziału w przedsiębiorstwach komunalnych. Metoda składa się z dwóch etapów, tj. etapu wyznaczającego minimalną trasę składającą się ze wszystkich zadań oraz etapu wyznaczania tras indywidualnych dla poszczególnych pojazdów. W świetle przeprowadzonych rozważań wskazując trasy indywidualne wyznaczymy zadania do realizacji, co jest tożsame z rozwiązaniem problemu przydziału. Zaproponowano algorytm genetyczny do rozwiązania problemu optymalizacyjnego przedstawionegow pierwszym etapie metody. Weryfikacja algorytmu potwierdziła jego skuteczność