633 research outputs found
The force of gravity in Schwarzschild and Gullstrand-Painlev\'e coordinates
We derive the exact equations of motion (in Newtonian, F=ma, form) for test
masses in Schwarzschild and Gullstrand-Painlev\'e coordinates. These equations
of motion are simpler than the usual geodesic equations obtained from
Christoffel tensors in that the affine parameter is eliminated. The various
terms can be compared against tests of gravity. In force form, gravity can be
interpreted as resulting from a flux of superluminal particles (gravitons). We
show that the first order relativistic correction to Newton's gravity results
from a two graviton interaction.Comment: 6 pages, Honorable mention in 2009 Gravity Essay Competition,
submitted IJMPD, added reference
The Americans with Disabilities Act: What it Means to Small Business Owners
Small Business owners with as few as 15 employees came under the provisions  of the Americans With Disabilities Act on July 26, 1994. A small business not affected in the employment  area  may  need  to  provide  the  disabled  customer  access  to  the  business. Successful small business strategies for the future should  systematically  incorporate not only the philosophy of accommodation for the disabled , but realistic attention to details of compliance and competitiveness. This paper reviews terms and conditions that will aid the business compliance owner in planning  for  compliance  with the ADA.  Additional  sources of  help are also provided
Thomas Coram: the life and times of a research unit at the Institute of Education (London)
For nearly 50 years, the Thomas Coram Research Unit (TCRU) has been integral to the IOE (Institute of Education), UCLâs Faculty of Education and Society (University College London, UK). This article is written from the perspectives of four researchers who have served in the TCRUâs formative years and over its lifetime. It chronicles the TCRUâs history and meaning, situating these reflections within the wider and much changed context of academia, politics and society. It begins with an overview of the TCRUâs origins as a dedicated government-funded research unit in 1973, the rationale and aims of its founder and first director, Jack Tizard, and the TCRUâs subsequent evolution, and its work in the fields of childhood, families and childrenâs services. This is followed by a consideration of some important features of the TCRU, which have created its distinct identity, for example multidisciplinarity, working with mixed methods, international collaborations, a convivial and collegiate environment and a continuing capacity to generate new ideas and directions for research. The article also reflects on some of the challenges faced by the TCRU and how it has responded to them. The article concludes by considering whether there is still a place today for a dedicated, university-based social research unit with a long-term and strategic orientation
Taxation of farms in Missouri
Publication authorized September 18, 1926.Digitized 2007 AES.Includes bibliographical references
Generational research: between historical and sociological imaginations
This paper reflects on Julia Brannenâs contribution to the development of theory and methods for intergenerational research. The discussion is contextualised within a contemporary âturn to timeâ within sociology, involving tensions and synergies between sociological and historical imagination. These questions are informed by a juxtaposition of Brannenâs four-generation study of family change and social historian Angela Davisâs exploration women and the family in England between 1945 and 2000. These two studies give rise to complementary findings, yet have distinctive orientations towards the status and treatment of sources, the role of geography in research design and limits of generalisatio
Scientific mindfulness: a foundation for future themes in international business
We conceptualize new ways to qualify what themes should dominate the future IB
research agenda by examining three questions: Whom should we ask? What should we ask and which selection criteria should we apply? What are the contextual forces? We propose scientific mindfulness as the way forward for generating themes in IB research
On the Application of a Monolithic Array for Detecting Intensity-Correlated Photons Emitted by Different Source Types
It is not widely appreciated that many subtleties are involved in the
accurate measurement of intensity-correlated photons; even for the original
experiments of Hanbury Brown and Twiss (HBT). Using a monolithic 4x4 array of
single-photon avalanche diodes (SPADs), together with an off-chip algorithm for
processing streaming data, we investigate the difficulties of measuring
second-order photon correlations g2 in a wide variety of light fields that
exhibit dramatically different correlation statistics: a multimode He-Ne laser,
an incoherent intensity-modulated lamp-light source and a thermal light source.
Our off-chip algorithm treats multiple photon-arrivals at pixel-array pairs, in
any observation interval, with photon fluxes limited by detector saturation, in
such a way that a correctly normalized g2 function is guaranteed. The impact of
detector background correlations between SPAD pixels and afterpulsing effects
on second-order coherence measurements is discussed. These results demonstrate
that our monolithic SPAD array enables access to effects that are otherwise
impossible to measure with stand-alone detectors.Comment: 17 pages, 6 figure
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