Constraint on intermediate-range gravity from earth-satellite and lunar orbiter measurements, and lunar laser ranging

In the experimental tests of gravity, there have been considerable interests in the possibility of intermediate-range gravity. In this paper, we use the earth-satellite measurement of earth gravity, the lunar orbiter measurement of lunar gravity, and lunar laser ranging measurement to constrain the intermediate-range gravity from lambda=1.2*10^{7}m - 3.8*10^{8}m. The limits for this range are alpha=10^{-8}-5*10^{-8}, which improve previous limits by about one order of magnitude in the range lambda=1.2*10^{7}m-3.8*10^{8}m.Comment: 8 pages, International Journal of Modern Physics D, in press (World Scientific, 2005

The microscopic origin of thermodynamic entropy in isolated systems

A microscopic understanding of the thermodynamic entropy in quantum systems has been a mystery ever since the invention of quantum mechanics. In classical physics, this entropy is believed to be the logarithm of the volume of phase space accessible to an isolated system [1]. There is no quantum mechanical analog to this. Instead, Von Neumann's hypothesis for the entropy [2] is most widely used. However this gives zero for systems with a known wave function, that is a pure state. This is because it measures the lack of information about the system rather than the flow of heat as obtained from thermodynamic experiments. Many arguments attempt to sidestep these issues by considering the system of interest coupled to a large external one, unlike the classical case where Boltzmann's approach for isolated systems is far more satisfactory. With new experimental techniques, probing the quantum nature of thermalization is now possible [3, 4]. Here, using recent advances in our understanding of quantum thermalization [5-10] we show how to obtain the entropy as is measured from thermodynamic experiments, solely from the self-entanglement of the wavefunction, and find strong numerical evidence that the two are in agreement for non-integrable systems. It is striking that this entropy, which is closely related to the concept of heat, and generally thought of as microscopic chaotic motion, can be determined for systems in energy eigenstates which are stationary in time and therefore not chaotic, but instead have a very complex spatial dependence.Comment: Manuscript is 5 pages, 2 figures, plus supplementary materials of 8 pages and 5 figure

Culture and Language: An Action Research Study on the Impact of Integrating Culture into a Chinese Language Immersion Program

Though a framework for foreign language education exists, the lack of guidelines, proper implementation, and benchmarks, along with scarce research on the effects of implementing cultural aspects in immersion classrooms leaves foreign language educators in the dark. An action research study design was utilized in a second grade Chinese immersion program at a language academy, investigating the impacts of the inclusion of culture activities in the classroom. Areas included were cultural exposure, teaching methods, teaching materials, cross cultural education, and challenges. Research data collected included students’ unit test scores, journals, parent surveys, and parent interviews. Time practicing is important, yet the time needed to include cultural activities takes away from preparation for summative assessment. The researcher suggests the use of formative assessments to increase familiarity of summative assessment material. The inclusion of cultural activities can increase student engagement and excitement in learning which can translate into increased expression of learning through journals. The researcher suggests increasing activity difficulty to increase the zone of proximal development and push the growing edge of students to support a curriculum that meets students at their current level of learning but also pushes beyond to improve skills. It is suggested to implement cultural activities over a longer time period in order to further explore the impact of cultural activities on student learning. Overall, the benefits of inclusion of cultural activities into foreign language education classrooms are encouraging, and even small adjustments can positively impact student performance in language immersion programs