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    Distributional Energy-Momentum Densities of Schwarzschild Space-Time

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    For Schwarzschild space-time, distributional expressions of energy-momentum densities and of scalar concomitants of the curvature tensors are examined for a class of coordinate systems which includes those of the Schwarzschild and of Kerr-Schild types as special cases. The energy-momentum density T~μν(x)\tilde T_\mu^{\nu}(x) of the gravitational source and the gravitational energy-momentum pseudo-tensor density t~μν\tilde t_\mu^{\nu} have the expressions T~μν(x)=Mc2δμ0δ0νδ(3)x)\tilde T_\mu^{\nu}(x) =-Mc^2\delta_\mu^0\delta_0^{\nu} \delta^{(3)}x) and t~μν=0\tilde t_\mu^{\nu}=0, respectively. In expressions of the curvature squares for this class of coordinate systems, there are terms like δ(3)(x)/r3\delta^{(3)}(x)/r^3 and [\delta^{(3)}(x)}]^2, as well as other terms, which are singular at x=0x=0. It is pointed out that the well-known expression Rρσμν()Rρσμν()R^{\rho\sigma\mu\nu}({}) R_{\rho\sigma\mu\nu}({}) =48G2M2/c4r6=48G^{2}M^{2}/c^{4}r^{6} is not correct, if we define 1/r6=limϵ01/(r2+ϵ2)31/r^6 = \lim_{\epsilon\to 0}1/(r^2+\epsilon^2)^3.}Comment: 21 pages, LaTeX, uses amssymb.sty. To appear in Prog. Theor. Phys. 98 (1997

    An Isotopic analysis of the hydrology and riparian vegetation water sources on Bishop Creek

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    Five power generation plants along an eleven kilometer stretch divert Bishop Creek water for hydro-electric power. Stream diversion may be adversely affecting the riparian vegetation. Stable isotopic analysis is employed to determine surface water/ground-water interactions along the creek. surface water originates primarily from three headwater lakes. Discharge into Bishop Creek below the headwaters is primarily derived from ground water. The average δD and δ18O values are significantly different for surface water and ground water that an isotopic analysis can delineate between these two components of flow. Therefore isotopic shifts along the creek can determine gaining reaches. In addition, by knowing the isotopic signatures of various waters in the watershed, it may be possible to examine tree waters to determine their water source(s)

    The Final Count Down: A Review of Three Decades of Flight Controller Training Methods for Space Shuttle Mission Operations

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    Operations of human spaceflight systems is extremely complex; therefore, the training and certification of operations personnel is a critical piece of ensuring mission success. Mission Control Center (MCC-H), at the Lyndon B. Johnson Space Center in Houston, Texas, manages mission operations for the Space Shuttle Program, including the training and certification of the astronauts and flight control teams. An overview of a flight control team s makeup and responsibilities during a flight, and details on how those teams are trained and certified, reveals that while the training methodology for developing flight controllers has evolved significantly over the last thirty years the core goals and competencies have remained the same. In addition, the facilities and tools used in the control center have evolved. Changes in methodology and tools have been driven by many factors, including lessons learned, technology, shuttle accidents, shifts in risk posture, and generational differences. Flight controllers share their experiences in training and operating the space shuttle. The primary training method throughout the program has been mission simulations of the orbit, ascent, and entry phases, to truly train like you fly. A review of lessons learned from flight controller training suggests how they could be applied to future human spaceflight endeavors, including missions to the moon or to Mars. The lessons learned from operating the space shuttle for over thirty years will help the space industry build the next human transport space vehicle

    Interpreting Craig for new audiences

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    Kate Bailey, Curator of Space and Light: Edward Gordon Craig, will introduce the exhibition and discuss the interpretation of the subject, the creative process and the engagement of new and international audiences with Craig's work. Scriptwriter Jane Collins will provide insight into the development and production of the audio script for the exhibition

    Second thoughts are best: Edward Gordon Craig and an education through theatre design

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    Craig’s vision of theatre making was one of ongoing reinvention; to turn over what had been and to look for new ‘truths'. It required a mastery of the multiple domains of theatre practice: the visual, the performative and the technical as well as an acute engagement with the intangible, the poetic and perhaps the spiritual. This paper will focus on the UK; to provide a sense of the emergence and development of theatre design as a site of study and to place Craig’s vision of the ‘theatre athlete’ in the context of contemporary theatre design education. Perhaps a hundred years on from ‘On The Art of the Theatre’, this is a good time for ‘second thoughts’; to review and evaluate Craig’s legacy and influence and to consider what advice he might have for us in contemplating the next hundred
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