Demonstration of temporal cloaking

Recent research has uncovered a remarkable ability to manipulate and control electromagnetic fields to produce effects such as perfect imaging and spatial cloaking. To achieve spatial cloaking, the index of refraction is manipulated to flow light from a probe around an object in such a way that a 'hole' in space is created, and the object remains hidden. Alternatively, it may be desirable to cloak the occurrence of an event over a finite time period, and the idea of temporal cloaking has been proposed in which the dispersion of the material is manipulated in time, producing a 'time hole' in the probe beam to hide the occurrence of the event from the observer. This approach is based on accelerating the front part of a probe light beam and slowing down its rear part to create a well controlled temporal gap--inside which an event occurs--such that the probe beam is not modified in any way by the event. The probe beam is then restored to its original form by the reverse manipulation of the dispersion. Here we present an experimental demonstration of temporal cloaking in an optical fibre-based system by applying concepts from the space-time duality between diffraction and dispersive broadening. We characterize the performance of our temporal cloak by detecting the spectral modification of a probe beam due to an optical interaction and show that the amplitude of the event (at the picosecond timescale) is reduced by more than an order of magnitude when the cloak is turned on. These results are a significant step towards the development of full spatio-temporal cloaking.     

Why the ultimate argument for scientific realism ultimately fails

In this paper, I argue that the ultimate argument for Scientific Realism, also known as the No-Miracles Argument (NMA), ultimately fails as an abductive defence of Epistemic Scientific Realism (ESR), where (ESR) is the thesis that successful theories of mature sciences are approximately true. The NMA is supposed to be an Inference to the Best Explanation (IBE) that purports to explain the success of science. However, the explanation offered as the best explanation for success, namely (ESR), fails to yield independently testable predictions that alternative explanations for success do not yield. If this is correct, then there seems to be no good reason to prefer (ESR) over alternative explanations for success.     

Aggressive,omnivorous, invasive: the Erythraean moon crab Matuta victor (Fabricius, 1781) (Crustacea: Decapoda: Matutidae) in the eastern Mediterranean sea

Since its first sighting in 2012 in Haifa Bay, Israel, the population of the Indo-Pacific moon crab, Matuta victor, has increased greatly along the Israeli littoral and spread to Lebanon and the Mediterranean coast of Turkey. To examine possible interactions with the Levantine nearshore psammophilic community, the crab’s feeding behaviour was observed in situ and the foregut contents of 69 specimens collected in December 2015 and June 2016 were analysed. Its omnivorous diet was confirmed and previously unknown intraspecific competitive feeding behaviour is reported. The agonistic behaviour may denote behavioural flexibility that enables the crabs to colonize and persist in a depauperate novel habitat. Site-specific disturbance regimen related to human activities seems to have had a critical role in driving the rapid population increase.     

Engineering Systems Thinking: A Multifunctional Definition

This paper asks what engineering systems thinking is and seeks to determine what distinguishes it from systems thinking. The purpose of the study was to identify the characteristics of engineers who are able to think in the manner we call engineering systems thinking. The study seeks to define the term engineering systems thinking on a theoretical level and then to move from the theoretical level to the operational level. A thorough understanding of engineering systems thinking on both the theoretical and operational levels will prove useful in the design of curricula to improve and develop thinking of this sort. Our study was based on 28 interviews, 14 lectures, and 2 observation sites. This paper treats only the material that pertains directly to engineering systems thinking.