888 research outputs found
Bell's Theorem and Locally-Mediated Reformulations of Quantum Mechanics
Bell's Theorem rules out many potential reformulations of quantum mechanics,
but within a generalized framework, it does not exclude all "locally-mediated"
models. Such models describe the correlations between entangled particles as
mediated by intermediate parameters which track the particle world-lines and
respect Lorentz covariance. These locally-mediated models require the
relaxation of an arrow-of-time assumption which is typically taken for granted.
Specifically, some of the mediating parameters in these models must
functionally depend on measurement settings in their future, i.e., on input
parameters associated with later times. This option (often called
"retrocausal") has been repeatedly pointed out in the literature, but the
exploration of explicit locally-mediated toy-models capable of describing
specific entanglement phenomena has begun only in the past decade. A brief
survey of such models is included here. These models provide a continuous and
consistent description of events associated with spacetime locations, with
aspects that are solved "all-at-once" rather than unfolding from the past to
the future. The tension between quantum mechanics and relativity which is
usually associated with Bell's Theorem does not occur here. Unlike conventional
quantum models, the number of parameters needed to specify the state of a
system does not grow exponentially with the number of entangled particles. The
promise of generalizing such models to account for all quantum phenomena is
identified as a grand challenge.Comment: 61 pages, 2 figures; accepted for publication by Rev. Mod. Phy
A Future-Input Dependent model for Greenberger-Horne-Zeilinger correlations
It is widely appreciated, due to Bell's theorem, that quantum phenomena are
inconsistent with local-realist models. In this context, locality refers to
local causality, and there is thus an open possibility for reproducing the
quantum predictions with models which internally violate the causal arrow of
time, while otherwise adhering to the relevant locality condition. So far, this
possibility has been demonstrated only at a toy-model level, and only for
systems involving one or two spins (or photons). The present work extends one
of these models to quantum correlations between three or more spins which are
entangled in the Greenberger-Horne-Zeilinger state.Comment: 8 Pages, 2 figure
Language Awareness of Teacher Trainees
Knowledge of language is the basis of every teacher’s daily work. After completing their training, teacher trainees will utilize their knowledge of language as both the basis and the setting for their future educational decisions regarding reading, writing, and language communication. Insights into the importance of language in teaching indicate that teaching language knowledge should occupy a prominent position in teacher-training programs. Accordingly, courses in applied linguistics have been added to courses on academic writing and constitute an essential part of teacher-training programs throughout the world. However, despite the acknowledged importance of language classes in teacher training, there is little systematic research into the changes that occur in teacher trainees’ language knowledge following completion of these courses in applied linguistics. This study investigates the change in teachers’ phonological and morphological awareness in Hebrew following their participation in a course entitled "Language Sound and Form". In a test conducted at the beginning and end of each year, teacher trainees were asked to choose the correct morpho-phonemic structure out of two or three options. The words were inserted into sentences consisting of pseudo-words and real words. Significant improvements were found between students’ skills at the beginning of the academic year and its end, indicating that participation in the course apparently helped augment teacher trainees’ linguistic knowledge. Furthermore, this improvement was shown to enable the application of this knowledge to new forms. These findings form the basis of a discussion about the importance of linguistic knowledge in teachers’ training
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