Macroscopic quantum resonators (MAQRO)

Quantum physics challenges our understanding of the nature of physical reality and of space-time and suggests the necessity of radical revisions of their underlying concepts. Experimental tests of quantum phenomena involving massive macroscopic objects would provide novel insights into these fundamental questions. Making use of the unique environment provided by space, MAQRO aims at investigating this largely unexplored realm of macroscopic quantum physics. MAQRO has originally been proposed as a medium-sized fundamental-science space mission for the 2010 call of Cosmic Vision. MAQRO unites two experiments: DECIDE (DECoherence In Double-Slit Experiments) and CASE (Comparative Acceleration Sensing Experiment). The main scientific objective of MAQRO, which is addressed by the experiment DECIDE, is to test the predictions of quantum theory for quantum superpositions of macroscopic objects containing more than 10e8 atoms. Under these conditions, deviations due to various suggested alternative models to quantum theory would become visible. These models have been suggested to harmonize the paradoxical quantum phenomena both with the classical macroscopic world and with our notion of Minkowski space-time. The second scientific objective of MAQRO, which is addressed by the experiment CASE, is to demonstrate the performance of a novel type of inertial sensor based on optically trapped microspheres. CASE is a technology demonstrator that shows how the modular design of DECIDE allows to easily incorporate it with other missions that have compatible requirements in terms of spacecraft and orbit. CASE can, at the same time, serve as a test bench for the weak equivalence principle, i.e., the universality of free fall with test-masses differing in their mass by 7 orders of magnitude.Comment: Proposal for a medium-sized space mission, 28 pages, 9 figures - in v2, we corrected some minor mistakes and replaced fig. 9 with a higher-resolution version; Experimental Astronomy, March 2012, Online, Open Acces

Investigating professional engineer’s professional learning: a practice theory perspective

With the increasing challenges facing professional engineers working in more complex, global and inter-disciplinary contexts, different approaches to understanding how engineers practice and learn are necessary. This paper draws on recent research in the social sciences from the field of workplace learning, to suggest that a practice theory perspective on engineers’ professional learning is fruitful. It shifts the focus from the attributes of the individual learner (knowledge, skills and attitudes) to the attributes of the practice (interactions, materiality, opportunities, challenges). Learning is thus more than the technical acquisition and transfer of knowledge, but a complex bundle of activities that is social, material, embodied and emerging. The paper is illustrated with examples from a research study of the learning of experienced engineers in the construction industry to demonstrate common practices—site walks and design review meetings—in which learning takes place