Showing papers by "Ulrich Johann published in 2011"
Max Planck Society1, University of Trento2, European Space Agency3, Paris Diderot University4, Autonomous University of Barcelona5, University of Florida6, Spanish National Research Council7, University of Birmingham8, University of Glasgow9, ETH Zurich10, European Space Operations Centre11, Imperial College London12, University of Zurich13, Polytechnic University of Catalonia14, University of Hertfordshire15
TL;DR: The first complete integration and testing of the space-qualified hardware and are the first tests on an optical system level were performed at the Albert Einstein Institute, Hannover, Germany as discussed by the authors.
Abstract: Preparations for the LISA Pathfinder mission have reached an exciting stage. Tests of the engineering model (EM) of the optical metrology system have recently been completed at the Albert Einstein Institute, Hannover, and flight model tests are now underway. Significantly, they represent the first complete integration and testing of the space-qualified hardware and are the first tests on an optical system level. The results and test procedures of these campaigns will be utilized directly in the ground-based flight hardware tests, and subsequently during in-flight operations. In addition, they allow valuable testing of the data analysis methods using the MATLAB-based LTP data analysis toolbox. This paper presents an overview of the results from the EM test campaign that was successfully completed in December 2009.
26 citations
22 May 2011
TL;DR: In this paper, the transition between macroscopic and microscopic objects is discussed, and the question of what brings about the transition from these two distinct realms, and when does it occur?
Abstract: While quantum concepts like superposition and entanglement are frequently being confirmed in the lab, these concepts seem to be in blatant contradiction to our everyday experience. There, objects are always in distinct states that can be verified without disturbing the system under investigation. Is there an essential difference between macroscopic and microscopic objects, and if there is, what brings about the transition between these two distinct realms, and when does it occur? This question lies at the heart of Schrodinger's famous gedankenexperiment, where a cat is brought into a superposition of being dead and alive. According to quantum theory, this is possible in principle as long as the system in question is isolated completely from its environment such that nobody could possibly know whether the system is in one state or the other except by performing a measurement on the system itself. Several theoretical models have been put forward that propose to modify the laws of quantum theory to introduce a collapse of the wavefunction for complex and/or massive objects or objects that are distributed over large distances [1–6]. We call these models macrorealistic.
5 citations