296 research outputs found
Finding the Needles in the Haystacks: High-Fidelity Models of the Modern and Archean Solar System for Simulating Exoplanet Observations
We present two state-of-the-art models of the solar system, one corresponding
to the present day and one to the Archean Eon 3.5 billion years ago. Each model
contains spatial and spectral information for the star, the planets, and the
interplanetary dust, extending to 50 AU from the sun and covering the
wavelength range 0.3 to 2.5 micron. In addition, we created a spectral image
cube representative of the astronomical backgrounds that will be seen behind
deep observations of extrasolar planetary systems, including galaxies and Milky
Way stars. These models are intended as inputs to high-fidelity simulations of
direct observations of exoplanetary systems using telescopes equipped with
high-contrast capability. They will help improve the realism of observation and
instrument parameters that are required inputs to statistical observatory yield
calculations, as well as guide development of post-processing algorithms for
telescopes capable of directly imaging Earth-like planets.Comment: Accepted for publication in PAS
Papier-mach(in)e: Thinking with âstickyâ paper in the cloud
There is nothing less about paper and its use when it comes to academic study as we experience increasingly converging media spaces and functionalities of online applications within the screens of our laptops, mobile phones and tablet devices. The paper persists, and the paperless office, classroom and pedagogy become nothing but pure rhetoric. Hence, it is most pertinent to focus on paper and its âstickinessâ in maintaining educational structures and practices. Usually hidden from view or neglected in educational technology studies is a consideration on how we think and interact not only with our mind but also with our heads and limbs. This paper will argue that paper has a composite place or bearing, a kind of stickiness to our technologised bodies, digital mobilities and hybrid practices in what I have coined here as papier-mach(in)e. This claim will be supported by evidence that demonstrates how we simply think both practically and pathically and that our mobilities in media and physical spaces are in one form or another meshed with paper. In fact, a drive towards a paperless classroom or pedagogy is without much foundation when it comes to mobilising a sustainable agenda for technology-enhanced learning
Recommended from our members
Metal-ligand ``multiple`` bonding: Revelations in the electronic structure of complexes of high-valent f-elements
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project has been to extend the understanding of the nature of interactions between f-metals and first row elements (important both in natural systems and in ceramics), as well as providing important new information regarding basic differences in the chemical nature of d- and f-metals. By developing preparative routes to novel classes of early actinide and lanthanide complexes in which metal-ligand bonding is formally unsaturated, this project has provided the means to study orbital interactions and charge distribution in these species by physical, chemical, and theoretical means. Evaluation of the physical and chemical characteristics of these species is providing dramatic evidence for the involvement of valence metal orbitals [nf and (n+1)d] in bonding, and is yielding new insights into the factors influencing stability of related species
Preparation and Reactions of Base-Free Bis(1, 2, 4-tri-tert-butylcyclopentadienyl)uranium Methylimide, Cp2UdNMe, and Related Compounds
Introducing the âanalogs for Venusâ geologically recent surfacesâ initiative: an opportunity for identifying and analyzing recently active volcano-tectonic areas of Venus trough a comparative study with terrestrial analogs
Several missions to Venus have been recently selected for launch [1â6], opening a new era for the exploration of the planet. One of the key questions that the future missions need to address is whether Venus is presently volcanically active [7â15]. Studying areas of active volcanism and tectonism on Venus is crucial to reveal clues about the geologic past of the planet, as well as provide information about the volatile content of its interior and the formation of its dense atmosphere. The âAnalogsfor VENusâ GEologically Recent Surfacesâ (AVENGERS) initiative aims to build a comprehensive database of terrestrial analog sites for the comparative study of recent and possibly on- going volcanic activity on Venus. Besides its scientific relevance, the AVENG- ERS initiative also acts as a bridge for international scientific collaboration, including the leadership and/or team members from the currently selected missions to Venus
Mount Etna as a terrestrial laboratory to investigate recent volcanic activity on Venus by future missions:A comparison with Idunn Mons, Venus
The recently selected missions to Venus have opened a new era for the exploration of this planet. These missions will provide information about the chemistry of the atmosphere, the geomorphology, local-to-regional surface composition, and the rheology of the interior. One key scientific question to be addressed by these future missions is whether Venus remains volcanically active, and if so, how its volcanism is currently evolving. Hence, it is fundamental to analyze appropriate terrestrial analog sites for the study of possibly active volcanism on Venus. To this regard, we propose Mount Etna - one of the most active and monitored volcanoes on Earth - as a suitable terrestrial laboratory for remote and in-situ investigations to be performed by future missions to Venus. Being characterized by both effusive and explosive volcanic products, Mount Etna offers the opportunity to analyze multiple eruptive styles, both monitoring active volcanism and identifying the possible occurrence of pyroclastic activity on Venus. We directly compare Mount Etna with Idunn Mons, one of the most promising potentially active volcanoes of Venus. Despite the two structures show a different topography, they also show some interesting points of comparison, and in particular: a) comparable morpho-structural setting, since both volcanoes interact with a rift zone, and b) morphologically similar volcanic fields around both Mount Etna and Idunn Mons. Given its ease of access, we also propose Mount Etna as an analog site for laboratory spectroscopic studies to identify the signatures of unaltered volcanic deposits on Venus
Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment
Here we review how environmental context can be used to interpret whether O2
is a biosignature in extrasolar planetary observations. This paper builds on
the overview of current biosignature research discussed in Schwieterman et al.
(2017), and provides an in-depth, interdisciplinary example of biosignature
identification and observation that serves as a basis for the development of
the general framework for biosignature assessment described in Catling et al.,
(2017). O2 is a potentially strong biosignature that was originally thought to
be an unambiguous indicator for life at high-abundance. We describe the
coevolution of life with the early Earth's environment, and how the interplay
of sources and sinks in the planetary environment may have resulted in
suppression of O2 release into the atmosphere for several billion years, a
false negative for biologically generated O2. False positives may also be
possible, with recent research showing potential mechanisms in exoplanet
environments that may generate relatively high abundances of atmospheric O2
without a biosphere being present. These studies suggest that planetary
characteristics that may enhance false negatives should be considered when
selecting targets for biosignature searches. Similarly our ability to interpret
O2 observed in an exoplanetary atmosphere is also crucially dependent on
environmental context to rule out false positive mechanisms. We describe future
photometric, spectroscopic and time-dependent observations of O2 and the
planetary environment that could increase our confidence that any observed O2
is a biosignature, and help discriminate it from potential false positives. By
observing and understanding O2 in its planetary context we can increase our
confidence in the remote detection of life, and provide a model for
biosignature development for other proposed biosignatures.Comment: 55 pages. The paper is the second in a series of 5 review manuscripts
of the NExSS Exoplanet Biosignatures Workshop. Community commenting is
solicited at https://nexss.info/groups/ebww
Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses
The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined
- âŠ