Two Examples of Circular Motion for Introductory Courses in Relativity

The circular twin paradox and Thomas Precession are presented in a way that makes both accessible to students in introductory relativity courses. Both are discussed by examining what happens during travel around a polygon and then in the limit as the polygon tends to a circle. Since relativistic predictions based on these examples can be verified in experiments with macroscopic objects such as atomic clocks and the gyroscopes on Gravity Probe B, they are particularly convincing to introductory students.Comment: Accepted by the American Journal of Physics This version includes revision

Report of the Terrestrial Bodies Science Working Group. Volume 4: The moon

A rationale for furture exploration of the moon is given. Topics discussed include the objectives of the lunar polar orbiter mission, the mission profile, and general characteristics of the spacraft to be used

The stellar dynamics and mass of NGC 1316 using the radial velocities of planetary nebulae

We present a study of the kinematics of the outer regions of the early-type galaxy NGC 1316, based on radial velocity measurements of 43 planetary nebulae as well as deep integrated-light absorption line spectra. The smoothed velocity field of NGC 1316 indicates fast rotation at a distance of 16 kpc, possibly associated with an elongated feature orthogonal to the inner dust lanes. The mean square stellar velocity is approximately independent of radius, and the estimated total mass of the system is 2.6 x 10^11 M_sun within a radius of 16 kpc, implying an integrated mass-to-light ratio of M/L_B = 8.Comment: 39 pages, 14 figures, in press on The Astrophysical Journal n. 50

Оценка эффективности катионита КУ-2-8 при извлечении ионов меди из воды в присутствии ионов жесткости

Наведено результати досліджень з визначення ефективності катіоніту КУ-2-8 під час вилучення йонів міді з води в присутності йонів жорсткості за низьких концентрацій йонів міді. Показано, що в статичних умовах при концентрації міді від 1 до 30 мг/дм3 вилучення міді проходить неефективно як з дистильованої, так і з водопровідної води незалежно від форми йоніту. Даний показник знижується під час збільшення об’єму розчину при фіксованому об’ємі йоніту. Суттєвого підвищення ефективності вилучення йонів міді на даному катіоніті досягнуто в динамічних умовах при використанні йоніту в кислій та сольовій формі і наявності в розчині йонів жорсткості. Встановлено, що ефективність десорбції йонів міді розчинами хлоридної кислоти в статичних умовах була низькою. В динамічних умовах досягнуто практично повного вилучення йонів міді розчинами хлоридної кислоти.The results of studies to determine the effectiveness of KU-2-8 cation extracting copper ions from water hardness ions in the presence of low concentrations of copper ions. It is shown that at concentration of copper from 1 to 30 mg/dm3 extraction of copper takes place in static conditions inefficiently both from distilled and from tap water irrespective of an ionite form. This indicator decreases at increase in volume of solution at the fixed ionite volume. Significant efficiency removal of copper ions in this cation achieved in dynamic conditions using resin in acid and salt form in the presence of ions in solution stiffness. It was established that the efficiency of desorption of copper ions hydrochloric acid solutions in static conditions was low. In dynamic conditions reached almost complete desorption of copper ions by solutions of hydrochloric acid.Приведены результаты исследований по определению эффективности катионита КУ-2-8 при извлечении ионов меди из воды в присутствии ионов жесткости при низких концентрациях ионов меди. Показано, что в статических условиях при концентрации меди от 1 до 30 мг/дм3 извлечение меди проходит неэффективно как из дистиллированной, так и из водопроводной воды независимо от формы ионита. Данный показатель снижается при увеличении объема раствора при фиксированном объеме ионита. Существенного повышения эффективности извлечения ионов меди на данном катионите достигнуто в динамических условиях при использовании ионита в кислой и солевой форме при наличии в растворе ионов жесткости. Установлено, что эффективность десорбции ионов меди растворами соляной кислоты в статических условиях была низкой. В динамических условиях достигнуто практически полной десорбции ионов меди растворами соляной кислоты

Absolute Present, Zen and Schrödinger’s One Mind

Erwin Schrödinger holds a prominent place in the history of science primarily due to his crucial role in the development of quantum physics. What is perhaps lesser known are his insights into subject-object duality, consciousness and mind. He documented himself that these were influenced by the Upanishads, a collection of ancient Hindu spiritual texts. Central to his thoughts in this area is that Mind is only One and there is no separation between subject and object. This chapter aims to bridge Schrödinger’s view on One Mind with the teachings of Dōgen, a twelfth century Zen master. This bridge is formed by addressing the question of how time relates to One Mind, and subject-object duality. Schrödinger describes the experience of One Mind to be like a timeless now, whereas subject-object duality involves a linear continuum of time. We show how these differing positions are unified in the notion of ‘absolute present’, which was put forward in the philosophy of Nishida Kitarō (1871–1945). In addition, we argue that it is in this notion of absolute present that the views of Schrödinger, Dōgen and Nishida meet

Quantified HI Morphology I: Multi-Wavelengths Analysis of the THINGS Galaxies

Galaxy evolution is driven to a large extent by interactions and mergers with other galaxies and the gas in galaxies is extremely sensitive to the interactions. One method to measure such interactions uses the quantified morphology of galaxy images. Well-established parameters are Concentration, Asymmetry, Smoothness, Gini, and M20 of a galaxy image. Thus far, the application of this technique has mostly been restricted to restframe ultra-violet and optical images. However, with the new radio observatories being commissioned (MeerKAT, ASKAP, EVLA, WSRT/APERTIF, and ultimately SKA), a new window on the neutral atomic hydrogen gas (HI) morphology of a large numbers of galaxies will open up. The quantified morphology of gas disks of spirals can be an alternative indicator of the level and frequency of interaction. The HI in galaxies is typically spatially more extended and more sensitive to low-mass or weak interactions. In this paper, we explore six morphological parameters calculated over the extent of the stellar (optical) disk and the extent of the gas disk for a range of wavelengths spanning UV, Optical, Near- and Far-Infrared and 21 cm (HI) of 28 galaxies from The HI Nearby Galaxy Survey (THINGS). Though the THINGS sample is small and contains only a single ongoing interaction, it spans both non-interacting and post-interacting galaxies with a wealth of multi-wavelength data. We find that the choice of area for the computation of the morphological parameters is less of an issue than the wavelength at which they are measured. The signal of interaction is as good in the HI as in any of the other wavelengths in which morphology has been used to trace the interaction rate to date, mostly star-formation dominated ones (near- and far-ultraviolet). The Asymmetry and M20 parameters are the ones which show the most promise as tracers of interaction in 21 cm line observations.Comment: 16 pages, 11 figure, table 1, accepted by MNRAS, appendix not include

Gravitational Lensing by Dark Matter Caustics

Dark matter caustics have specific density profiles and, therefore, precisely calculable gravitational lensing properties. We present a formalism which simplifies the relevant calculations, and apply it to four specific cases. In the first three, the line of sight is tangent to a smooth caustic surface. The curvature of the surface at the tangent point is positive, negative or zero. In the fourth case the line of sight passes near a cusp. For each we derive the map between the image and source planes. In some cases, a point source has multiple images and experiences infinite magnification when the images merge. Unfortunately, for the dark matter caustics expected in realistic galactic halo models, the angular resolution required to resolve the multiple images is not presently achievable. A more promising approach aims to observe the distortions caused by dark matter caustics in the images of extended sources such as radio jets.Comment: 36 pages, 11 figure

Variability of atmospheric dimethylsulphide over the southern Indian Ocean due to changes in ultraviolet radiation

Dimethylsulphide (DMS) is a climatically important component of global biogeochemical cycles, through its role in the sulphur cycle. Changes in ultraviolet radiation (UV) exhibit both positive and negative forcings on the dynamics of production and turnover of DMS and its precursor dimethylsulphoniopropionate (DMSP). In this study we investigate the net forcing of UV on atmospheric DMS. The work is based on a 10-year record of observed DMS at Amsterdam Island in the southern Indian Ocean, and satellite-based retrievals of surface UV and photosynthetically active radiation (PAR). The results show an inverse relationship between UV radiation and atmospheric DMS associated with extreme changes (defined as the greatest 5%) in daily UV, independent of changes in wind speed, sea surface temperature, and PAR

The ethics of uncertainty for data subjects

Modern health data practices come with many practical uncertainties. In this paper, I argue that data subjects’ trust in the institutions and organizations that control their data, and their ability to know their own moral obligations in relation to their data, are undermined by significant uncertainties regarding the what, how, and who of mass data collection and analysis. I conclude by considering how proposals for managing situations of high uncertainty might be applied to this problem. These emphasize increasing organizational flexibility, knowledge, and capacity, and reducing hazard