Constructing Futures: Outlining a Transhumanist Vision of the Future and the Challenge to Christian Theology of its Proposed Uses of New and Future Developments in Technology

Transhumanists arc committed to re-evaluating the entire human condition and offering proposalsfor transcending mortality, principally by augmenting the human body with mechanical components or by transferring the human mind into intelligent hyper-computers. In this essay, the author\'s methodology is to critique the culture oftranshumanism, arguing, with Barbour, that all technology is tool whose use is determined by the cultural and socialframeworks within which it is utilized. Transhumanism is characterized as morally ambiguous, extremely individualistic, fixated upon health, vitality, and power, ideological, reductionist, and self-deluded. Its proposed use of technology is, thus, highly suspect and deserves a robust theological response

Pion and Nucleon Structure Functions near x = 1

In a colored-quark and vector-gluon model of hadrons we show that a quark carrying nearly all the momentum of a nucleon (x≈1) must have the same helicity as the nucleon; consequently νW^2_n/νW^p_2→(3/7) as x→1, not (2/3) as might naively have been expected. Furthermore as x→1, νW^(π)_2∼(1-x)^2 and (σ_(L)/σ_(T))π∼μ^(2)Q^(-2)(1-x)^(-2)+O(g^2); the resulting angular dependence for e^(+)e^(-)→h^(±)+ X is consistent with present data and has a distinctive form which can be easily tested when better data are available

The small-slope approximation for layered, fluid seafloors

The article of record as published may be found at http://dx.doi.org/10.1121/10.0000470The small-slope approximation (SSA) for rough-interface scattering is most commonly applied to the upper bound ary of either impenetrable media or uniform half-space media, but has been recently developed for layered media in the acoustic and electromagnetic cases. The present work gives an overview of three forms of the SSA for layered media. The first has been previously presented in the acoustics literature. The second is from the electromagnetics literature and in the present work is converted to the fluid-sediment problem. A missing proof is supplied of a key consistency condition demanded of the small-slope ansatz. As is usual, these small-slope results are expressed in k-space. A third SSA for layered seafloors follows from conversion of the usual half-space formulation from k-space to coordinate space. This form turns out to be useful for reverberation simulations. The three different approaches are compared with respect to scattering strength and the coherent reflection coefficient, but an assessment of their relative merits will require comparison with exact calculations.U.S. Office of Naval Researc

The relative effect of particles and turbulence on acoustic scattering from deep sea hydrothermal vent plumes revisited

Author Posting. © Acoustical Society of America, 2017. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 141 (2017): 1446–1458, doi:10.1121/1.4974828.The relative importance of suspended particles and turbulence as backscattering mechanisms within a hydrothermal plume located on the Endeavour Segment of the Juan de Fuca Ridge is determined by comparing acoustic backscatter measured by the Cabled Observatory Vent Imaging Sonar (COVIS) with model calculations based on in situ samples of particles suspended within the plume. Analysis of plume samples yields estimates of the mass concentration and size distribution of particles, which are used to quantify their contribution to acoustic backscatter. The result shows negligible effects of plume particles on acoustic backscatter within the initial 10-m rise of the plume. This suggests turbulence-induced temperature fluctuations are the dominant backscattering mechanism within lower levels of the plume. Furthermore, inversion of the observed acoustic backscatter for the standard deviation of temperature within the plume yields a reasonable match with the in situ temperature measurements made by a conductivity-temperature-depth instrument. This finding shows that turbulence-induced temperature fluctuations are the dominant backscattering mechanism and demonstrates the potential of using acoustic backscatter as a remote-sensing tool to measure the temperature variability within a hydrothermal plume.We thank the National Science Foundation for support (NSF Award Nos. OCE-0824612 and OCE-1234163 to APL-UW; NSF Award Nos. OCE-0825088 and OCE-1234141 to Rutgers)

High-frequency bistatic scattering by sub-bottom gas bubbles

Author Posting. © Acoustical Society of America, 1997. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 102 (1997): 806-814, doi:10.1121/1.419906.A previous study of high-frequency acoustic backscattering data collected at Eckernfoerde Bay, Germany revealed that scattering is mainly due to methane gas bubbles buried about a meter beneath the seafloor [Tang et al., J. Acoust. Soc. Am. 96, 2930–2936 (1994)]. A backscattering model was developed [Tang, Geo-Marine Lett. 16, 161–169 (1996)] where the gas bubbles were approximated by oblate spheroids. In this paper, a bistatic scattering model is proposed as an extension of the previously developed backscattering model. In this model, gas bubbles are again assumed to be oblate spheroids with varying aspect ratios and a single-scattering approximation is used. The model is compared to bistatic data acquired in Eckernfoerde Bay, Germany. In particular, the azimuthal dependence of the bistatic scattering strength predicted by the model is tested against experimental data and it is found that both the model and the bistatic scattering strength data exhibit a mild azimuthal dependence. Best agreement between model and data requires a 35% reduction in areal bubble density relative to that used in the backscattering model/data comparison. Possible reasons for this are discussed including multiple scattering effects.This work is supported by the Coastal Benthic Boundary Layer Special Research Program, Office of Navel Research Grant No. N00014-95-1-G904

Pion form factor

We give the normalized leading asymptotic Q2 dependence of the pion form factor in quantum chromodynamics: Fπ(Q2)→Q2→±∞-2fπ2/bQ2ln|Q2|, where fπ is the pion decay constant and b=(11-2/3Nf)/16π2. Up to non-leading-logarithmic corrections, this is equivalent to Fπ(Q2)→Q2→±∞8παs(Q2)fπ2/(-Q2). These results are obtained by solving the light-cone pion Bethe-Salpeter equation in quantum chromodynamics to leading-logarithmic accuracy

Effects of macrofauna on acoustic backscatter from the seabed: Field manipulations in West Sound, Orcas Island, Washington, U.S.A.

Previous observations with a bottom-mounted, radially scanning sonar (BAMS) at 40 kHz suggested that macrofaunal activities influence low-angle, acoustic backscatter from seafloor sediments. In order to test that possibility experimentally, we measured and modeled time series of backscatter strength at both 40 and 300 kHz prior to manipulation and then introduced several macrofaunal species at known abundances to randomly selected locations within the ensonified area. We worked in West Sound, Orcas Island, Washington, at a water depth of 20.4 m and for the more frequently recorded 40-kHz series extracted effects by the time-series method known as intervention analysis, wherein the intervention was the experimental alteration. We observed increased backscatter from patches of the small protobranch bivalve Acila castrensis, and of the cockle Clinocardium nuttali, from bait used as chum for fishes and crabs, and from tethered crabs (Cancer magister); other treatments showed no significant change. All of the effective treatments involved increased backscatter at 300 kHz from animals that have obvious hard parts or air bladders. Power calculations for intervention analysis and geoacoustic modeling suggest that failure of other treatments to show significant effects on backscatter strength stems from the small size of the organisms and structures used relative to the 40-kHz wavelength (3.7 cm) and to low sound-speed contrasts between surficial sediments at this site and overlying water (at both frequencies), producing low backscatter levels from both volume heterogeneity and surface microtopography. This experiment demonstrates, however, that low-angle acoustic backscatter can be used to observe at least some populations of benthic animals over a large area (ca. 8000 m2) and that intervention analysis can be a useful tool where logistics permit repeated observation but few or no spatial replicates—frequently the case in ecological manipulations