3,629 research outputs found

    Simulating What?

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    Any attempt to simulate science has first to say what science is. This involves asking three questions: 1) The Scope Question: What bit of science is the target? It is immensely confusing (as the history of these debates shows), if one simulates some little aspect of science, as in the case of BACON, and then claims that one has built a machine that can 'do science'. 2) The Micro-World Question: Is the criterion of success the reproduction of human science – with all the same findings turning up – or the simulation of something that is believed to be a scientific process with results that pertain only to the world of the simulation which do not correspond to the outcome of human science as we know it? If the latter it will be important to be sure that one is not merely developing a 'micro-world' – a world so tidied up for the purposes of simulation that it does not bear on human science. 3) The Chess Question: Even if the idea to reach the same results as has been reached by human science, does it have to be by 'the same' means in order to count as a simulation of human science? I call it the 'chess question' because Deep Blue does not play in the same way as human grand masters but is still better at winning.Science, Language, Demarcation, Micro-World, BACON, Chess

    Emission Line Galaxies in the STIS Parallel Survey II: Star Formation Density

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    We present the luminosity function of [OII]-emitting galaxies at a median redshift of z=0.9, as measured in the deep spectroscopic data in the STIS Parallel Survey (SPS). The luminosity function shows strong evolution from the local value, as expected. By using random lines of sight, the SPS measurement complements previous deep single field studies. We calculate the density of inferred star formation at this redshift by converting from [OII] to H-alpha line flux as a function of absolute magnitude and find rho_dot=0.043 +/- 0.014 Msun/yr/Mpc^3 at a median redshift z~0.9 within the range 0.46<z<1.415 (H_0 = 70 km/s/Mpc, Omega_M=0.3, Omega_Lambda=0.7. This density is consistent with a (1+z)^4 evolution in global star formation since z~1. To reconcile the density with similar measurements made by surveys targeting H-alpha may require substantial extinction correction.Comment: 16 preprint pages including 5 figures; accepted for publication in Ap

    Demarcating Fringe Science for Policy

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    Here we try to characterize the fringe of science as opposed to the mainstream. We want to do this in order to provide some theory of the difference that can be used by policy-makers and other decision-makers but without violating the principles of what has been called ‘Wave Two of Science Studies’. Therefore our demarcation criteria rest on differences in the forms of life of the two activities rather than questions of rationality or rightness; we try to show the ways in which the fringe differs from the mainstream in terms of the way they think about and practice the institution of science. Along the way we provide descriptions of fringe institutions and sciences and their outlets. We concentrate mostly on physics

    Keeping the collectivity in mind?

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    The key question in this three way debate is the role of the collectivity and of agency. Collins and Shrager debate whether cognitive psychology has, like the sociology of knowledge, always taken the mind to extend beyond the individual. They agree that irrespective of the history, socialization is key to understanding the mind and that this is compatible with Clark’s position; the novelty in Clark’s “extended mind” position appears to be the role of the material rather than the role of other minds. Collins and Clark debate the relationship between self, agency, and the human collectivity. Collins argues that the Clark’s extended mind fails to stress the asymmetry of the relationship between the self and its material “scaffolding.” Clark accepts that there is asymmetry but that an asymmetrical ensemble is sufficient to explain the self. Collins says that we know too little about the material world to pursue such a model to the exclusion of other approaches including that both the collectivity and language have agency. The collectivity must be kept in mind! (Though what follows is a robust exchange of views it is also a cooperative effort, authors communicating “backstage” with each other to try to make the disagreements as clear and to the point as possible.

    Detection and Estimation Theory

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    Contains research objectives and reports on two research projects.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E)U. S. Navy Purchasing Office Contract N00140-67-C-021

    Detection and Estimation Theory

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    Contains reports on theses completed and four research projects.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E

    Measuring Parton Densities in the Pomeron

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    We present a program to measure the parton densities in the pomeron using diffractive deep inelastic scattering and diffractive photoproduction, and to test the resulting parton densities by applying them to other processes such as the diffractive production of jets in hadron-hadron collisions. Since QCD factorization has been predicted NOT to apply to hard diffractive scattering, this program of fitting and using parton densities might be expected to fail. Its success or failure will provide useful information on the space-time structure of the pomeron.Comment: Contains revisions based on Phys. Rev. D referee comments. RevTeX version 3, epsf, 31 pages. Uuencoded compressed postscript figures appended. Uncompressed postscript files available at ftp://ftp.phys.psu.edu/pub/preprint/psuth136

    Emission Line Galaxies in the STIS Parallel Survey I: Observations and Data Analysis

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    In the first three years of operation STIS obtained slitless spectra of approximately 2500 fields in parallel to prime HST observations as part of the STIS Parallel Survey (SPS). The archive contains almost 300 fields at high galactic latitude (|b|>30) with spectroscopic exposure times greater than 3000 seconds. This sample contains 220 fields (excluding special regions and requiring a consistent grating angle) observed between 6 June 1997 and 21 September 2000, with a total survey area of about 160 square arcminutes. At this depth, the SPS detects an average of one emission line galaxy per three fields. We present the analysis of these data, and the identification of 131 low to intermediate redshift galaxies detected by optical emission lines. The sample contains 78 objects with emission lines that we infer to be redshifted [OII]3727 emission at 0.43<z<1.7. The comoving number density of these objects is comparable to that of H-alpha emitting galaxies in the NICMOS parallel observations. One quasar and three probable Seyfert galaxies are detected. Many of the emission-line objects show morphologies suggestive of mergers or interactions. The reduced data are available upon request from the authors.Comment: 58 preprint pages, including 26 figures; accepted for publication in ApJ
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