The Sloan Digital Sky Survey: Technical Summary

The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of the distribution of luminous and non- luminous matter in the Universe: a photometrically and astrometrically calibrated digital imaging survey of pi steradians above about Galactic latitude 30 degrees in five broad optical bands to a depth of g' about 23 magnitudes, and a spectroscopic survey of the approximately one million brightest galaxies and 10^5 brightest quasars found in the photometric object catalog produced by the imaging survey. This paper summarizes the observational parameters and data products of the SDSS, and serves as an introduction to extensive technical on-line documentation.Comment: 9 pages, 7 figures, AAS Latex. To appear in AJ, Sept 200

The James Webb Space Telescope Mission

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 $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ 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

The US Program in Ground-Based Gravitational Wave Science: Contribution from the LIGO Laboratory

Recent gravitational-wave observations from the LIGO and Virgo observatories have brought a sense of great excitement to scientists and citizens the world over. Since September 2015,10 binary black hole coalescences and one binary neutron star coalescence have been observed. They have provided remarkable, revolutionary insight into the "gravitational Universe" and have greatly extended the field of multi-messenger astronomy. At present, Advanced LIGO can see binary black hole coalescences out to redshift 0.6 and binary neutron star coalescences to redshift 0.05. This probes only a very small fraction of the volume of the observable Universe. However, current technologies can be extended to construct "3rd Generation" (3G) gravitational-wave observatories that would extend our reach to the very edge of the observable Universe. The event rates over such a large volume would be in the hundreds of thousands per year (i.e. tens per hour). Such 3G detectors would have a 10-fold improvement in strain sensitivity over the current generation of instruments, yielding signal-to-noise ratios of 1000 for events like those already seen. Several concepts are being studied for which engineering studies and reliable cost estimates will be developed in the next 5 years

Crash and return:"choque", allusion and composite structure in Alejandro González Iñárritu's "Amores perros" (2000)

Composite structure, a feature of Freud’s dreamwork theory, is relevant to understanding cinematic works in which a range of viewpoints and narratives, dense and diverse themes, highly distinguishable productive elements (here, sound and cinematography) coalesce under a powerful ‘binding’ concept. In the case of what I have termed cine de choque, that concept is the car crash and, more specifically, the Spanish word choque, which can be translated as crash, shock or clash. This category of film refers to a number of recent works (from the late 1990s onwards) by Spanish-speaking directors in which car crashes feature strongly both as pivotal plot devices and as linguistic metaphors informing the aesthetics of the films in question. These films include Alejandro Amenábar’s Abre los ojos (1997), Julio Medem’s Los amantes del círculo polar (1998), Alejandro González Iñárritu’s 21 Grams (2003) and Lucrecia Martel’s La mujer sin cabeza (2010). Here, I deal specifically with the relevance of composite structure to the narrative aesthetics of González Iñárritu’s Amores perros (2000), referring also to the theories of Gilles Deleuze on shock and violence, those of Sergei Eisenstein on organic unity and those of Christian Metz on the 'filmic state'. As well as discussing the movement of the film's aesthetic and thematic content from physical to emotional choque, I explore the dimensions of the crash as a plot device, a symbol of the clash between humanity and modernity and, ultimately, the way in which it is significant as much for what it fails to cause (resolution by figures of authority) as for what it triggers in the lives of the characters