Teaching Physics Using Virtual Reality

We present an investigation of game-like simulations for physics teaching. We report on the effectiveness of the interactive simulation "Real Time Relativity" for learning special relativity. We argue that the simulation not only enhances traditional learning, but also enables new types of learning that challenge the traditional curriculum. The lessons drawn from this work are being applied to the development of a simulation for enhancing the learning of quantum mechanics

A progress report on using bolometers cooled by adiabatic demagnetization refrigeration

For sensitive detection of astronomical continuum radiation in the 200 micron to 3 mm wavelength range, bolometers are presently the detectors of choice. In order to approach the limits imposed by photon noise in a cryogenically cooled telescope in space, bolometers must be operated at temperatures near 0.1 K. Researchers report progress in building and using bolometers that operate at these temperatures. The most sensitive bolometer had an estimated noise equivalent power (NEP) of 7 x 10(exp 017) W Hz(exp -1/2). Researchers also briefly discuss the durability of paramagnetic salts used to cool the bolometers

Calibration of the LIGO displacement actuators via laser frequency modulation

We present a frequency modulation technique for calibration of the displacement actuators of the LIGO 4-km-long interferometric gravitational-wave detectors. With the interferometer locked in a single-arm configuration, we modulate the frequency of the laser light, creating an effective length variation that we calibrate by measuring the amplitude of the frequency modulation. By simultaneously driving the voice coil actuators that control the length of the arm cavity, we calibrate the voice coil actuation coefficient with an estimated 1-sigma uncertainty of less than one percent. This technique enables a force-free, single-step actuator calibration using a displacement fiducial that is fundamentally different from those employed in other calibration methods.Comment: 10 pages, 5 figures, submitted to Classical and Quantum Gravit

The Great Recession, Austerity and Inequality: Evidence from Ireland. ESRI WP499. April 2015

The advent of the Great Recession and the widespread adoption of fiscal austerity policies have heightened concern about inequality and its effects. We examine how the distribution of income in Ireland has evolved over the years 2008 to 2013, using data from the CSO’s Survey on Income and Living Conditions. Snapshots of the income distribution show that the greatest falls in income were for the bottom decile (poorest 10 per cent). Longitudinal analysis shows that these sharp falls were not due to decreasing income for those remaining in the bottom decile, but to falling income among those with somewhat higher incomes. Most of those falling into the bottom decile came from the bottom one third of the income distribution

BUDGET PERSPECTIVES 2016, PAPER 1. Exploring Tax and Welfare Options. June 2015

Budgetary policies on income-related taxes and welfare must find a balance between providing income support to those in need and maintaining a financial incentive to work which supports high employment. This paper focuses principally on the “cash” or “first round” impact of tax and welfare policy changes across the income distribution. Incentive issues are considered in Section 5 of this paper, and in a companion paper to this conference (Savage et al., 2015)

Two scenarios for avalanche dynamics in inclined granular layers

We report experimental measurements of avalanche behavior of thin granular layers on an inclined plane for low volume flow rate. The dynamical properties of avalanches were quantitatively and qualitatively different for smooth glass beads compared to irregular granular materials such as sand. Two scenarios for granular avalanches on an incline are identified and a theoretical explanation for these different scenarios is developed based on a depth-averaged approach that takes into account the differing rheologies of the granular materials.Comment: 4 pages, 4 figures, accepted to Phys. Rev. Let