70 research outputs found

    London's weather and the everyday: two centuries of newspaper reports

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    This study surveys 200 years of London’s weather and its public reporting in newspapers to reveal some of the recurring modes of reporting and linguistic styles that are used to describe and make sense of the human experience of weather. These modes include: the cultural anxieties prompted by ‘unusual weather’; the visual dramas of ‘great storms’; the weather as culpable; and bench-marking extreme weather. Even as the broader processes and patterns of our climate are changing, at the level of the everyday the human and cultural experience of weather remains remarkably familiar

    In-flight scale/distortion calibration of the Hubble Space Telescope fixed-head star trackers

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    This paper describes an in-flight scale and distortion calibration procedure that has been developed for the Ball Aerospace Systems Division Fixed-Head Star Trackers (FHST's) used on the Hubble Space Telescope (HST). The FHST is a magnetically focused and deflected imaging sensor that is designed to track stars as faint as m(sub v) = 5.7 over an 8 degree by 8 degree field of view. Raw FHST position measurements are accurate to approximately 200 arcseconds, but this can be improved to 10-15 arcseconds by processing the raw measurements through calibration polynomials that correct for flat field, temperature intensity, and magnetic field effects. The coefficients for these polynomials were initially determined using ground test data. On HST the use of three FHST's is an integral part of the preliminary attitude update procedures required before the acquisition of guide stars for science observations. To this end, FHST-based attitude determination having single-axis errors no worse than 22 arcseconds (1 sigma) is required. In early 1991 it became evident that one of the HST FHST's was experiencing a significant change in its optical scale. By mid-1993 the size of this error had grown to a point that, if not corrected, it would correspond to a maximum position error on the order of 100 arcseconds. Subsequent investigations demonstrated that substantial, uncompensated cubic distortion effects had also developed, the maximum contribution to position errors from the cubic terms being on the order of 30 arcseconds. To ensure accurate FHST-based attitude updates, procedures have been developed to redetermine the FHST scale and distortion calibration coefficients based on in-flight data gathered during normal HST operations. These scale and distortion calibrations have proven very effective operationally, and procedures are in place to monitor FHST calibration changes on a continuing basis

    Habit, Memory, and the Persistence of Socialist-Era Street Names in Postsocialist Bucharest, Romania

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    The critical study of toponymy has paid considerable attention to the renaming of urban places following revolutionary political change. Such renaming is intended to institutionalize a new political agenda through shaping the meanings in everyday practices and landscapes. Renaming, however, might not always be successful, and this article examines this issue with reference to a market in Bucharest, Romania. Originally named Piaţa Moghioroş during the socialist era to commemorate a leading Communist Party activist, the market was renamed in the postsocialist period. Yet, more than two decades on, the original name remains in widespread everyday use. Using a mixed-method approach, we seek to advance the critical toponymies literature by exploring the persistence of the socialist-era name within everyday practice. Although many authors have highlighted the issue of popular resistance to an unpopular renaming, we find little evidence of conscious resistance, and instead we explore the importance of habit within everyday practices as an explanation, drawing on an understanding of habit derived from sociocognitive psychology. This perspective proposes that habits are stable and hard to break if the broader context in which they are situated is stable. We suggest that this explanation, rather than popular contestation, has more to offer in understanding the persistence of the toponym Piaţa Moghioroş. We thus highlight the importance of considering how the “users” of place names react to the changes of such names and create their own meanings in relation to them in ways unintended by elites

    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure
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