3,418 research outputs found
Comets in Australian Aboriginal Astronomy
We present 25 accounts of comets from 40 Australian Aboriginal communities,
citing both supernatural perceptions of comets and historical accounts of
bright comets. Historical and ethnographic descriptions include the Great
Comets of 1843, 1861, 1901, 1910, and 1927. We describe the perceptions of
comets in Aboriginal societies and show that they are typically associated with
fear, death, omens, malevolent spirits, and evil magic, consistent with many
cultures around the world. We also provide a list of words for comets in 16
different Aboriginal languages.Comment: Accepted in the "Journal for Astronomical History & Heritage", 17
Pages, 6 Figures, 1 Tabl
"Bridging the Gap" through Australian Cultural Astronomy
For more than 50,000 years, Indigenous Australians have incorporated
celestial events into their oral traditions and used the motions of celestial
bodies for navigation, time-keeping, food economics, and social structure. In
this paper, we explore the ways in which Aboriginal people made careful
observations of the sky, measurements of celestial bodies, and incorporated
astronomical events into complex oral traditions by searching for written
records of time-keeping using celestial bodies, the use of rising and setting
stars as indicators of special events, recorded observations of variable stars,
the solar cycle, and lunar phases (including ocean tides and eclipses) in oral
tradition, as well as astronomical measurements of the equinox, solstice, and
cardinal points.Comment: Proceedings of IAU Symposium 278, Oxford IX International Symposium
on Archaeoastronomy, International Society for Archaeoastronomy & Astronomy
in Culture (ISAAC), held in Lima, Peru, 5-9 January 2011. 9 pages, 4 images,
1 table (Accepted
Selection principles and pattern formation in fluid mechanics and nonlinear shell theory
Research accomplishments are summarized and publications generated under the contract are listed. The general purpose of the research was to investigate various symmetry breaking problems in fluid mechanics by the use of structure parameters and selection principles. Although all of the nonlinear problems studied involved systems of partial differential equations, many of these problems led to the study of a single nonlinear operator equation of the form F(w, lambda, gamma) = 0, (w is an element of H), (lambda is an element of R1), (gamma is an element of R1). Instead of varying only the load parameter lambda, as is often done in the study of such equations, one of the main ideas used was to vary the structure parameter gamma in such a way that stable solutions were obtained. In this way one determines detailed stability results by making use of the structure of the model equations and the known physical parameters of the problem. The approach was carried out successfully for Benard-type convection problems, Taylor-like problems for short cylinders, rotating Couette-Poiseuille channel flows, and plane Couette flows. The main focus of the research was on wave theory of vortex breakdown in a tube. A number of preliminary results for inviscid axisymmetric flows were obtained
Hubbard Model with Luscher fermions
First applications of the new algorithm simulating dynamical fermions are
reported. The method reproduces previous results obtained with different
techniques.Comment: talk presented at the XII International Symposium LATTICE94,
Bielefeld, Germany, September 1994, to appear in the Proceedings. 3 pages,
LATEX, required Elsevier espcrc2.sty style file is attached at the end of
this LATEX text. Postscript figures included in the latex document with the
epsf facilit
Wurdi Youang: an Australian Aboriginal stone arrangement with possible solar indications
Wurdi Youang is an egg-shaped Aboriginal stone arrangement in Victoria,
Australia. Here we present a new survey of the site, and show that its major
axis is aligned within a few degrees of east-west. We confirm a previous
hypothesis that it contains alignments to the position on the horizon of the
setting sun at the equinox and the solstices, and show that two independent
sets of indicators are aligned in these directions. We show that these
alignments are unlikely to have arisen by chance, and instead the builders of
this stone arrangement appear to have deliberately aligned the site on
astronomically significant positions.Comment: Accepted by Rock Art Researc
Hubbard Model with Luscher fermions - a progress report
Some modifications of the Luscher algorithm, which reduce the autocorelation
time, are proposed and tested.Comment: 3 pages, uuencoded gzipped Postscript, contribution to Lattice 9
Intra-industry trade between The United States and México: 1993-1998
This paper examines changes in intra-industry trade, IIT, in manufactured goods between the US and Mexico over the first five years of the North American Free Trade Agreement. Most industries experienced large increases in, IIT. An examination of various indexes of intra-industry specialization indicates that few industries in either country are candidates for significant adjustment problems. These findings should lessen opposition to greater regional economic integration in the Western Hemisphere
Kinetic tetrazolium microtiter assay
A method for conducting an in vitro cell assay using a tetrazolium indicator is disclosed. The indicator includes a nonionic detergent which solubilizes a tetrazolium reduction product in vitro and has low toxicity for the cells. The incubation of test cells in the presence of zolium bromide and octoxynol (TRITON X-100) permits kinetics of the cell metabolism to be determined
Lunar and planetary studies
This grant supports the core program in planetary astronomy at Caltech. The research includes observations in the IR, sub-mm, mm and cm wavelengths at national and Caltech observatories with a strong emphasis on integrating the observations with spacecraft data and with models of atmospheric structure, dynamics and chemistry. Muhleman's group made extensive observations of Saturn, Uranus and Neptune which are being interpreted in terms of deep atmospheric structures which are obvious in the 2 and 6 cm maps of Saturn and Uranus. The microwave measurements are one of the few sources of information below the 2 bar level. Goldreich is investigating the dynamics of narrow rings with postdoctoral fellow, Pierre-Yves Longaretti. Their work has focused on the role of collisional stresses on the precession of the rings, since the Voyager radio science results imply that the previous model based on the ring's self-gravity is not the entire story. In addition Borderies, Goldreich and Tremaine have completed an investigation of the dynamics of the Encke division in Saturn's A ring
- …
