7 research outputs found
Supporting Pre-Service Primary School Teachers with Hands-on-Science
The education that primary school students receive shapes their relationship with science. Elementary school teachers report they have low confidence and enthusiasm about teaching science. The Hands-on-Science Program at UT Austin was created to serve the unique needs of Applied Learning and Development majors. HoS consists of four required content courses: Physics, Chemistry & Geology, Biology, and Astronomy & Earth Climate. HoS classes differ from traditional science courses in two ways: (1) method of instruction, and (2) content. Our students attain higher learning gains and display improved attitudes towards learning science, compared to students who take traditional science classes
Relaxation Phenomena in a System of Two Harmonic Oscillators
We study the process by which quantum correlations are created when an
interaction Hamiltonian is repeatedly applied to a system of two harmonic
oscillators for some characteristic time interval. We show that, for the case
where the oscillator frequencies are equal, the initial Maxwell-Boltzmann
distributions of the uncoupled parts evolve to a new equilibrium
Maxwell-Boltzmann distribution through a series of transient Maxwell-Boltzmann
distributions. Further, we discuss why the equilibrium reached when the two
oscillator frequencies are unequal, is not a thermal one. All the calculations
are exact and the results are obtained through an iterative process, without
using perturbation theory.Comment: 22 pages, 6 Figures, Added contents, to appear in PR
Recommended from our members
Relaxation in harmonic oscillator systems and wave propagation in negative index materials
textThis dissertation is divided up into two parts, each examining a distinct
theme. The rst part of our work concerns itself with open quantum systems and
the relaxation phenomena arising from the repeated application of an interaction
Hamiltonian on systems composed of quantum harmonic oscillators. For the second
part of our work, we shift gears and investigate the wave propagation in left-handed
media, or materials with simultaneously negative electric permeability and magnetic
permeability . Each of these two parts is complete within its own context.
In the rst part of this dissertation, we introduce a relaxation-generating
model which we use to study the process by which quantum correlations are created when an interaction Hamiltonian is repeatedly applied to bipartite harmonic oscillator
systems for some characteristic time interval . The two important time scales
which enter our results are discussed in detail. We show that the relaxation time
obtained by the application of this repeated interaction scheme is proportional to
both the strength of interaction and to the characteristic time interval . Through
discussing the implications of our model, we show that, for the case where the oscillator
frequencies are equal, the initial Maxwell-Boltzmann distributions of the
uncoupled parts evolve to a new Maxwell-Boltzmann distribution through a series
of transient Maxwell-Boltzmann distributions, or quasi-stationary, non-equilibrium
states. We further analyze the case in which the two oscillator frequencies are unequal
and show how the application of the same model leads to a non-thermal steady
state. The calculations are exact and the results are obtained through an iterative
process, without using perturbation theory.
In the second part of this dissertation, we examine the response of a plane
wave incident on a
at surface of a left-handed material, a medium characterized
by simultaneously negative electric permittivity and magnetic permeability . We
do this by solving Maxwell's equations explicitly. In the literature up to date,
it has been assumed that negative refractive materials are necessarily frequency
dispersive. We propose an alternative to this assumption by suggesting that the
requirement of positive energy density can be relaxed, and discuss the implications
of such a proposal. More speci cally, we show that once negative energy solutions
are accepted, the requirement for frequency dispersion is no longer needed. We
further argue that, for the purposes of discussing left-handed materials, the use of
group velocity as the physically signi cant quantity is misleading, and suggest that
any discussion involving it should be carefully reconsidered.Physic
Hands-on-Science: Using Education Research to Construct Learner-Centered Classes
Research into the process of learning, and learning astronomy, can be informative for the development of a course. Students are better able to incorporate and make sense of new ideas when they are aware of their own prior knowledge (Resnick et al. 1989; Confrey 1990), have the opportunity to develop explanations from their own experience in their own words (McDermott 1991; Prather et al. 2004), and benefit from peer instruction (Mazur 1997; Green 2003). Students in astronomy courses often have
difficulty understanding many different concepts as a result of difficulties with spatial reasoning and a sense of scale. The Hands-on-Science program at UT Austin incorporates these research-based results into four guided-inquiry, integrated science courses (50 students each). They are aimed at pre-service K–5 teachers but are open to other majors as well. We find that Hands-on-Science students not only attain more favorable changes in attitude towards science, but they also outperform students in traditional lecture courses in content gains.
Workshop Outcomes: Participants experienced a research-based, guided-inquiry lesson about the motion of objects in the sky and discussed the research methodology for assessing students in such a course