Top Research Papers on Space

This work provides the first unambiguous evidence for a hippocampal representation of a conceptual space compared with a general feature-based space, by showing that the hippocampal distance signal selectively reflects the mapping of specifically conceptually relevant rather than of all feature dimensions.

This open access book provides a comprehensive view on data ecosystems and platform economics from methodical and technological foundations up to reports from practical implementations and applications in various industries.\nTo this end, the book is structured in four parts: Part I “Foundations and Contexts” provides a general overview about building, running, and governing data spaces and an introduction to the IDS and GAIA-X projects. Part II “Data Space Technologies” subsequently details various implementation aspects of IDS and GAIA-X, including eg data usage control, the usage of blockch...

Advances in quantum technologies are giving rise to a revolution in the way fundamental physics questions are explored at the empirical level. At the same time, they are the seeds for future disruptive technological applications of quantum physics. Remarkably, a space-based environment may open many new avenues for exploring and employing quantum physics and technologies. Recently, space missions employing quantum technologies for fundamental or applied studies have been proposed and implemented with stunning results. The combination of quantum physics and its space application is the focus of...

Developer productivity is about more than an individual's activity levels or the efficiency of the engineering systems relied on to ship software, and it cannot be measured by a single metric or dimension. The SPACE framework captures different dimensions of productivity, and here we demonstrate how this framework can be used to understand productivity in practice and why using it will help teams better understand developer productivity and create better measures to inform their work and teams.

The shell bound by the Karman line at a height of ~80–100 km above the Earth’s surface and geosynchronous orbit at ~36,000 km is defined as the orbital space surrounding the Earth. It is within this region, and especially in low Earth orbit, where environmental issues are becoming urgent because of the rapid growth of the anthropogenic space object population, including satellite ‘mega-constellations’. In this Perspective, we summarize the case for considering the orbital space around the Earth as an additional ecosystem, subject to the same care and concerns, and the same broad regulations as...

Abstract The article investigates the control of the platform labour process by means of the digital production of space and how workers resist it. The segment of German platform‐mediated food delivery is examined via qualitative interviews and auto‐ethnography. It is shown how the platforms create different spaces to efficiently coordinate and control mobile delivery gig work. Steered by geolocalisation and geofencing, the couriers operate autonomously in spatial corridors defined by the platforms. The agency of the riders is thus limited, but they are occasionally able to undermine the platf...

Urban green spaces (UGS) offer a wide range of ecosystem services to city dwellers, contributing to their health and well-being. The resources of formally designated UGS, such as parks and forests, are frequently underprovided, however. This results in unequal access to UGS, which has become an environmental justice issue. We investigated the potential of informal green spaces (IGS) to complement existing formal UGS to reduce distributional inequity in UGS availability. We focused on the most vulnerable groups of citizens, children and elderly residents, for whom the availability of UGS plays ...

Abstract The Galilean moons play major roles in the giant magnetosphere of Jupiter. At the same time, the magnetospheric particles and fields affect the moons. The impact of magnetospheric ions on the moons' atmospheres supplies clouds of escaping neutral atoms that populate a substantial fraction of their orbits. At the same time, ionization of atoms in the neutral cloud is the primary source of magnetospheric plasma. The stability of this feedback loop depends on the plasma/moon‐atmosphere interaction. The purpose of this review is to describe the physical processes that shape the space envi...

A bstract The covariant phase space method of Iyer, Lee, Wald, and Zoupas gives an elegant way to understand the Hamiltonian dynamics of Lagrangian field theories without breaking covariance. The original literature however does not systematically treat total derivatives and boundary terms, which has led to some confusion about how exactly to apply the formalism in the presence of boundaries. In particular the original construction of the canonical Hamiltonian relies on the assumed existence of a certain boundary quantity “ B ”, whose physical interpretation has not been clear. We here give an...

Space-time wave packets (STWPs) constitute a broad class of pulsed optical fields that are rigidly transported in linear media without diffraction or dispersion, and are therefore propagation-invariant in the absence of optical nonlinearities or waveguiding structures. Such wave packets exhibit unique characteristics, such as controllable group velocities in free space and exotic refractive phenomena. At the root of these behaviors is a fundamental feature underpinning STWPs: their spectra are not separable with respect to the spatial and temporal degrees of freedom. Indeed, the spatiotemporal...

The past decade has experienced an increase in the number of studies on organizational space or where work occurs. A number of these studies challenge traditional views of organizational space as a fixed, physical workspace because researchers fail to account for the spatial dynamics that they observe. New technologies, shifting employee-employer relations, and burgeoning expectations of the contemporary workforce blur boundaries between home and work, connect people and things that historically could not be linked, and extend workspaces to nearly everywhere, not just office buildings. Researc...

There is an urgent demand to introduce a concept, that is, confined space, which is capable of precisely monitoring the process of elec-tron/charge transfer by a designable and controllable sensing interface whose size is comparable with that of single entities.

The Micius satellite, launched from China in August 2016, is the first and only satellite dedicated entirely to quantum experiments. The ultralow loss transmission of photons on most of the path between ground and space enables quantum communication capabilities that are still far from being realized. This review details the commissioning of Micius as a full quantum communications system, and describes the achievement of global-scale quantum key distribution, entanglement distribution, and other fundamental studies, with this unique space-based system.

A bstract We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica c...

The covariant phase space method of Iyer, Lee, Wald, and Zoupas gives an elegant way to understand the Hamiltonian dynamics of Lagrangian field theories without breaking covariance. The original literature however does not systematically treat total derivatives and boundary terms, which has led to some confusion about how exactly to apply the formalism in the presence of boundaries. In particular the original construction of the canonical Hamiltonian relies on the assumed existence of a certain boundary quantity “B”, whose physical interpretation has not been clear. We here give an algorithmic...

We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica copies of t...

The key technologies of ISA are analyzed from three aspects: assembly structure design, robot technologies and integrated management technologies, which show that ISA will play a vital role in human space exploration in the future.

This review provides an overview of some algorithmic approaches to defining and exploring chemical spaces that have the potential to operationalize the process of molecular discovery and emphasizes the potential roles of machine learning and the consideration of synthetic feasibility, which is a prerequisite to ‘closing the loop’.

Five classes of synthetic light-switchable compounds are discussed—diarylethenes, anthracenes, azobenzenes, spiropyrans, and donor–acceptor Stenhouse adducts—comparing their behaviors under confinement and in solution, and it is found that photoswitches requiring less conformational freedom for switching are, as expected, more straightforward to isomerize reversibly under confinement.

People feel lonely when their social needs are not met by the quantity and quality of their social relationships. Most research has focused on individual-level predictors of loneliness. However, macro-level factors related to historical time and geographic space might influence loneliness through their effects on individual-level predictors. In this Review, we summarize empirical findings on differences in the prevalence of loneliness across historical time and geographical space and discuss four groups of macro-level factors that might account for these differences: values and norms, family a...