Introduction to light forces, atom cooling, and atom trapping

This paper introduces and reviews light forces, atom cooling and atom trapping. The emphasis is on the physics of the basic processes. In discussing conservative forces the semi-classical dressed states are used rather than the usual quantized field dressed states.Comment: 12 pages, Latex, 7 Postscript figure

Understanding European Union international message telephone services demand

This study provides a contemporary understanding of demand relations in European Union (EU) international message telephone service (IMTS) markets prior to full liberalization at January 1 1998. Point-to-point demand equations that relate IMTS demand to prices, income, population and distance are estimated on bilateral market data for ten EU countries from 1990 to 1995. Model estimates suggest price elasticities of outgoing and incoming demand between 20.175 and 20.456, and 20.215 and 20.674, respectively. These elasticity estimates provide an empirical base from which to calculate welfare gains from the full deregulation of EU IMTS markets after 1998.Elasticity; European Union; International telephone demand

Atom-laser dynamics

An ideal atom laser would produce an atomic beam with highly stable flux and energy. In practice, the stability is likely to be limited by technical noise and nonlinear dynamical effects. We investigate the dynamics of an atom laser using a comprehensive one-dimensional, mean-field numerical model. We fully model the output beam and experimentally important physics such as three-body recombination. We find that at highpump rates, the latter plays a role in suppressing the high-frequency dynamics, which would otherwise limit the stability of the output beam

Stability of continuously pumped atom lasers

A multimode model of a continuously pumped atom laser is shown to be unstable below a critical value of the scattering length. Above the critical scattering length, the atom laser reaches a steady state, the stability of which increases with pumping. Below this limit the laser does not reach a steady state. This instability results from the competition between gain and loss for the excited states of the lasing mode. It will determine a fundamental limit for the linewidth of an atom laser beam

Student experiences of virtual reality - a case study in learning special relativity

We present a study of student learning through the use of virtual reality. A software package is used to introduce concepts of special relativity to students in a game-like environment where users experience the effects of travelling at near light speeds. From this new perspective, space and time are significantly different to that experienced in everyday life. The study explores how students have worked with this environment and how these students have used this experience in their study of special relativity. A mixed method approach has been taken to evaluate the outcomes of separate implementations of the package at two universities. Students found the simulation to be a positive learning experience and described the subject area as being less abstract after its use. Also, students were more capable of correctly answering concept questions relating to special relativity, and a small but measurable improvement was observed in the final exam

Through Einsteins Eyes

We have developed a relativistically accurate computer graphics code, and have used it to produce photo-realistic images and videos of scenes where special relativistic effects dominate, either in astrophysical contexts or in imaginary worlds where the speed of light is only a few metres per second

Developing a virtual physics world

In this article, the successful implementation of a development cycle for a physics teaching package based on game-like virtual reality software is reported. The cycle involved several iterations of evaluating students' use of the package followed by instructional and software development. The evaluation used a variety of techniques, including ethnographic observation, surveys, student focus groups and conventional assessment. The teaching package included a laboratory manual, instructional support materials and the Real Time Relativity software that simulates a world obeying special relativistic physics. Although the iterative development cycle was time consuming and costly, it gave rise to substantial improvements in the software user interface and in the students' learning experience

Mastery learning in a large first year physics class

In 2009 we tried an experiment in our large core first year physics course: we introduced mastery learning. The basic idea behind mastery learning is that any student can learn anything well, but that it takes some students much longer than others. We should therefore let students proceed through a course at different speeds, while insisting that they totally master each section of the course before moving on. The students have to get over 80% in each homework assignment before they are allowed to take the next one. They are, however, allowed to take different versions of each assignment multiple times until they reach this threshold. At the end, the weaker students would have covered less content than the strong ones, but they should have fully understood whatever they did. In the laboratory component, the students were assessed in each experiment against a set of lab mastery goals. The students could pass the lab component only if they have mastered each of these goals at least once. Did it work? Logistically it worked very well, somewhat to our surprise. There were a number of striking unexpected benefits: students did more work, complained less about the workload, asked for help more often, and showed an improved ability to solve questions first time around. Gains in student conceptual understanding were much improved, but this may be due to other innovations introduced in the course. Examination performance, however, did not improve, even on the most basic material. Students could do the problems when given unlimited time and assistance from peers, but not in exam conditions